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Sample records for phytophthora cinnamomi associada

  1. Mortality of container-grown blueberry plants inoculated with Phytophthora cinnamomi Rands

    Science.gov (United States)

    We conducted four studies to evaluate the effect of Phytophthora cinnamomi isolates and inoculum delivery methods on root rot development and mortality of container-grown blueberry plants. Phytophthora cinnamomi isolates were obtained from the root zone of symptomatic blueberry plants and identifie...

  2. Resistance to Phytophthora cinnamomi among seedlings from backcross families of hybrid american chestnut

    Science.gov (United States)

    Steven N. Jeffers; Inga M. Meadows; Joseph B. James; Paul H. Sisco

    2012-01-01

    American chestnut (Castanea dentata (Marsh.) Borkh.) once was a primary hardwood species in forests of the eastern United States. Sometime during the late 18th century, it is speculated that Phytophthora cinnamomi, which causes Phytophthora root rot (PRR) on many woody plant species, was introduced to the southeast region of...

  3. Effects of Phytophthora cinnamomi isolate, inoculum delivery method, flood, and drought on vigor, disease severity and mortality of blueberry plants

    Science.gov (United States)

    Four studies evaluated the effect of Phytophthora cinnamomi isolates, inoculum delivery methods, and flood and drought conditions on vigor, disease severity scores, and survival of blueberry plants grown in pots in the greenhouse. Phytophthora cinnamomi isolates were obtained from blueberry plants ...

  4. The Effect of Low Oxygen Stress on Phytophthora cinnamomi Infection and Disease of Cork Oak Roots

    Science.gov (United States)

    Karel A. Jacobs; James D. MacDonald; Alison M. Berry; Laurence R. Costello

    1997-01-01

    The incidence and severity of Phytophthora cinnamomi Rands root disease was quantified in cork oak (Quercus suber L.) roots subjected to low oxygen (hypoxia) stress. Seedling root tips were inoculated with mycelial plugs of the fungus and incubated in ≤1, 3-4, or 21 percent oxygen for 5 days. Ninety-four percent of roots...

  5. Management of Phytophthora cinnamomi root rot disease of blueberry with gypsum and compost

    Science.gov (United States)

    Root rot disease of blueberry caused by Phytophthora cinnamomi is becoming more prevalent as a consequence of widespread adoption of drip irrigation. This creates higher moisture content in the root zone more conducive for the pathogen. Options for disease control under organic management are limi...

  6. Dual RNA-sequencing of Eucalyptus nitens during Phytophthora cinnamomi challenge reveals pathogen and host factors influencing compatibility

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    Febe Elizabeth Meyer

    2016-03-01

    Full Text Available Damage caused by Phytophthora cinnamomi Rands remains an important concern on forest tree species. The pathogen causes root and collar rot, stem cankers and dieback of various economically important Eucalyptus spp. In South Africa, susceptible cold tolerant Eucalyptus plantations have been affected by various Phytophthora spp. with P. cinnamomi considered one of the most virulent. The molecular basis of this compatible interaction is poorly understood. In this study, susceptible Eucalyptus nitens plants were stem inoculated with P. cinnamomi and tissue was harvested five days post inoculation. Dual RNA-sequencing, a technique which allows the concurrent detection of both pathogen and host transcripts during infection, was performed. Approximately 1% of the reads mapped to the draft genome of P. cinnamomi while 78% of the reads mapped to the Eucalyptus grandis genome. The highest expressed P. cinnamomi gene in planta was a putative crinkler effector (CRN1. Phylogenetic analysis indicated the high similarity of this P. cinnamomi CRN1 to that of Phytophthora infestans. Some CRN effectors are known to target host nuclei to suppress defense. In the host, over 1400 genes were significantly differentially expressed in comparison to mock inoculated trees, including suites of pathogenesis related (PR genes. In particular, a PR-9 peroxidase gene with a high similarity to a Carica papaya PR-9 ortholog previously shown to be suppressed upon infection by Phytophthora palmivora was down-regulated two-fold. This PR-9 gene may represent a cross-species effector target during P. cinnamomi infection. This study identified pathogenicity factors, potential manipulation targets and attempted host defense mechanisms activated by E. nitens that contributed to the susceptible outcome of the interaction.

  7. Resistance to Phytophthora cinnamomi in the Genus Abies

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    John Frampton; Fikret Isik; Mike Benson; Jaroslav Kobliha; Jan Stjskal

    2012-01-01

    A major limiting factor for the culture of true firs as Christmas trees is their susceptibility to Oomycete species belonging to the genus Phytophthora. In North Carolina alone, the Fraser fir (Abies fraseri [Pursh] Poir.) Christmas tree industry loses 6 to 7 million dollars annually to root rot primarily caused by ...

  8. Influence of electron beam irradiation on growth of Phytophthora cinnamomi and its control in substrates

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    MigdaŁ, Wojciech; Orlikowski, Leszek B.; Ptaszek, Magdalena; Gryczka, Urszula

    2012-08-01

    Very extensive production procedure, especially in plants growing under covering, require methods, which would allow quick elimination or substantial reduction of populations of specific pathogens without affecting the growth and development of the cultivated plants. Among soil-borne pathogens, the Phytophthora species are especially dangerous for horticultural plants. In this study, irradiation with electron beam was applied to control Phytophthora cinnamomi. The influence of irradiation dose on the reduction of in vitro growth and the population density of the pathogen in treated peat and its mixture with composted pine bark (1:1), as well as the health of Chamaecyparis lawsoniana and Lavandula angustifolia plants were evaluated. Application of irradiation at a dose of 1.5 kGy completely inhibited the in vitro development of P. cinnamomi. This irradiation effect was connected with the disintegration of the hyphae and spores of the species. Irradiation of peat and its mixture with composted pine bark with 10 kGy resulted in the inhibition of stem base rot development in Ch. lawsoniana. Symptoms of the disease were not observed when the substrates were treated with 15 kGy. In the case of L. angustifolia, stem root rot was not observed on cuttings transplanted to infected peat irradiated at a dose of 10 kGy. Irradiation of the horticultural substrates did not affect plant growth.

  9. A method to quantify infection and colonization of holm oak (Quercus ilex) roots by Phytophthora cinnamomi.

    Science.gov (United States)

    Ruiz-Gómez, Francisco J; Sánchez-Cuesta, Rafael; Navarro-Cerrillo, Rafael M; Pérez-de-Luque, Alejandro

    2012-01-01

    Phytophthora cinnamomi Rands. is an important root rot pathogen widely distributed in the north hemisphere, with a large host range. Among others diseases, it is known to be a principal factor in the decline of holm oak and cork oak, the most important tree species in the "dehesa" ecosystem of south-western Spain. Previously, the focus of studies on P. cinnamomi and holm oak have been on molecular tools for identification, functional responses of the host, together with other physiological and morphological host variables. However, a microscopic index to describe the degree of infection and colonization in the plant tissues has not yet been developed. A colonization or infection index would be a useful tool for studies that examine differences between individuals subjected to different treatments or to individuals belonging to different breeding accessions, together with their specific responses to the pathogen. This work presents a methodology based on the capture and digital treatment of microscopic images, using simple and accessible software, together with a range of variables that quantify the infection and colonization process.

  10. A method to quantify infection and colonization of holm oak (Quercus ilex roots by Phytophthora cinnamomi

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    Ruiz-Gómez Francisco J

    2012-09-01

    Full Text Available Abstract Phytophthora cinnamomi Rands. is an important root rot pathogen widely distributed in the north hemisphere, with a large host range. Among others diseases, it is known to be a principal factor in the decline of holm oak and cork oak, the most important tree species in the “dehesa” ecosystem of south-western Spain. Previously, the focus of studies on P. cinnamomi and holm oak have been on molecular tools for identification, functional responses of the host, together with other physiological and morphological host variables. However, a microscopic index to describe the degree of infection and colonization in the plant tissues has not yet been developed. A colonization or infection index would be a useful tool for studies that examine differences between individuals subjected to different treatments or to individuals belonging to different breeding accessions, together with their specific responses to the pathogen. This work presents a methodology based on the capture and digital treatment of microscopic images, using simple and accessible software, together with a range of variables that quantify the infection and colonization process.

  11. Transcriptional profiling of Zea mays roots reveals roles for jasmonic acid and terpenoids in resistance against Phytophthora cinnamomi.

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    Allardyce, Jane Alisa; Rookes, James Edward; Hussain, Hashmath Inayath; Cahill, David Miles

    2013-06-01

    Phytophthora cinnamomi is a soil-borne plant pathogen that has caused widespread damage to vulnerable native ecosystems and agriculture systems across the world and shows no sign of abating. Management of the pathogen in the natural environment is difficult and the options are limited. In order to discover more about how resistant plants are able to defend themselves against this generalist pathogen, a microarray study of plant gene expression following root inoculation with P. cinnamomi was undertaken. Zea mays was used as a resistant model plant, and microarray analysis was conducted using the Affymetrix GeneChip Maize Genome Array on root samples collected at 6- and 24-h post-inoculation. Over 300 genes were differentially expressed in inoculated roots compared with controls across the two time points. Following Gene Ontology enrichment analysis and REVIGO visualisation of the up-regulated genes, many were implicated in plant defence responses to biotic stress. Genes that were up-regulated included those involved in phytoalexin biosynthesis and jasmonic acid/ethylene biosynthesis and other defence-related genes including those encoding glutathione S-transferases and serine-protease inhibitors. Of particular interest was the identification of the two most highly up-regulated genes, terpene synthase11 (Tps11) and kaurene synthase2 (An2), which are both involved in production of terpenoid phytoalexins. This is the first study that has investigated gene expression at a global level in roots in response to P. cinnamomi in a model plant species and provides valuable insights into the mechanisms involved in defence.

  12. Identification of avocado (Persea americana) root proteins induced by infection with the oomycete Phytophthora cinnamomi using a proteomic approach.

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    Acosta-Muñiz, Carlos H; Escobar-Tovar, Lina; Valdes-Rodríguez, Silvia; Fernández-Pavia, Silvia; Arias-Saucedo, Luis J; de la Cruz Espindola Barquera, Maria; Gómez Lim, Miguel Á

    2012-01-01

    Avocado root rot, caused by Phytophthora cinnamomi, is the most important disease that limits avocado production. A proteomic approach was employed to identify proteins that are upregulated by infection with P. cinnamomi. Different proteins were shown to be differentially expressed after challenge with the pathogen by two-dimensional (2-D) gel electrophoresis. A densitometric evaluation of protein expression indicated differential regulation during the time-course analyzed. Some proteins induced in response to the infection were identified by standard peptide mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry and sequencing by MALDI LIFT-TOF/TOF tandem mass spectrometry. Of the 400 protein spots detected on 2-D gels, 21 seemed to change in abundance by 3 hours after infection. Sixteen proteins were upregulated, 5 of these were only detected in infected roots and 11 showed an increased abundance. Among the differentially expressed proteins identified are homologs to isoflavone reductase, glutathione S-transferase, several abscisic acid stress-ripening proteins, cinnamyl alcohol dehydrogenase, cinnamoyl-CoA reductase, cysteine synthase and quinone reductase. A 17.3-kDa small heat-shock protein and a glycine-rich RNA-binding protein were identified as downregulated. Our group is the first to report on gene induction in response to oomycete infection in roots from avocado, using proteomic techniques.

  13. Soil properties linked to Phytophthora cinnamomi presence and oak decline in Iberian dehesas

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    Moreno, G.; Vivas, M.; Pérez, A.; Cubera, E.; Madeira, M.; Solla, A.

    2009-04-01

    symptomatic (declined) trees, at surface, 50, 100 and 150 cm depths. Soil texture, redox potential, mineral N, and the presence of Phytophthora cinnamomi were determined. Soil bulk density was measured at the surface, and soil compactness was measured through a digital penetrometer at 0-40 cm depth. In the stream banks, fine-textured soils were significantly more common under declined trees than under healthy ones, while in slopes the contrary trend occurred. Differences were clearly observed at layers located at 100 and 150 cm depth. Soil bulk density was moderate, with mean values of 1.05 and 1.07 g cm-3 (0-5 cm depth), and 1.28 and 1.30 g cm-3 (5-10 cm) for healthy and declined oaks, respectively. Regarding soil resistance to penetration, values under declined oaks were significantly (p=0.012) higher below 20 cm depth, probably due to compaction caused by old cultivation practices. Most of the soil samples analyzed showed a high level of oxidation (superoxic and manoxic), 28% were suboxic and only 0.7% were anoxic, with a possible limitation of root growth. Although not significant, soils trended to be more reduced under declined oaks at stream banks, with a contrary tendency at slopes (Table 1). The presence of P. cinammomi in soil was positively related to oak decline in stream banks (p=0.011), but not in slopes, and associated to more compacted soils (p=0.05). The presence of P. cinammomi in roots was positively correlated with oak decay (p=0.01), being more abundant among 50-100 cm depth in slopes, and among 100-150 cm depth in the stream banks, but in both cases was mostly associated to fine-textured soils. In conclusion, Q. ilex decline was not related with anoxic conditions limiting root growth, but with soil properties leading to restricted water availability for trees in slopes, and with soil conditions favorable for P. cinnamomi root-infections in the stream banks.

  14. Quantitative RT-PCR analysis of differentially expressed genes in Quercus suber in response to Phytophthora cinnamomi infection.

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    Ebadzad, Ghazal; Cravador, Alfredo

    2014-01-01

    cDNA-AFLP methodology was used to gain insight into gene fragments differentially present in the mRNA profiles of Quercus suber roots infected with zoospores of Phytophthora cinnamomi at different post challenge time points. Fifty-three transcript-derived fragments (TDFs) were identified and sequenced. Six candidate genes were selected based on their expression patterns and homology to genes known to play a role in defence. They encode a cinnamyl alcohol dehydrogenase2 (QsCAD2), a protein disulphide isomerase (QsPDI), a CC-NBS-LRR resistance protein (QsRPc), a thaumatin-like protein (QsTLP), a chitinase (QsCHI) and a 1,3-β-glucanase (QsGlu). Evaluation of the expression of these genes by quantitative polymerase chain reaction (qPCR) revealed that transcript levels of QsRPc, QsCHI, QsCAD2 and QsPDI increased during the first 24 h post-inoculation, while those of thaumatin-like protein decreased. No differential expression was observed for 1,3-β-glucanase (QsGlu). Four candidate reference genes, polymerase II (QsRPII), eukaryotic translation initiation factor 5A (QsEIF-5A), β-tubulin (QsTUB) and a medium subunit family protein of clathrin adaptor complexes (QsCACs) were assessed to determine the most stable internal references for qRT-PCR normalization in the Phytophthora-Q. suber pathosystem in root tissues. Those found to be more stable, QsRPII and QsCACs, were used as internal reference in the present work. Knowledge on the Quercus defence mechanisms against biotic stress is scarce. This study provides an insight into the gene profiling of a few important genes of Q. suber in response to P. cinnamomi infection contributing to the knowledge of the molecular interactions involving Quercus and root pathogens that can be useful in the future to understand the mechanisms underlying oak resistance to soil-borne oomycetes.

  15. Rainfall and temperatures changes have confounding impacts on Phytophthora cinnamomi occurrence risk in the southwestern USA under climate change scenarios.

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    Thompson, Sally E; Levin, Simon; Rodriguez-Iturbe, Ignacio

    2014-04-01

    Global change will simultaneously impact many aspects of climate, with the potential to exacerbate the risks posed by plant pathogens to agriculture and the natural environment; yet, most studies that explore climate impacts on plant pathogen ranges consider individual climatic factors separately. In this study, we adopt a stochastic modeling approach to address multiple pathways by which climate can constrain the range of the generalist plant pathogen Phytophthora cinnamomi (Pc): through changing winter soil temperatures affecting pathogen survival; spring soil temperatures and thus pathogen metabolic rates; and changing spring soil moisture conditions and thus pathogen growth rates through host root systems. We apply this model to the southwestern USA for contemporary and plausible future climate scenarios and evaluate the changes in the potential range of Pc. The results indicate that the plausible range of this pathogen in the southwestern USA extends over approximately 200,000 km(2) under contemporary conditions. While warming temperatures as projected by the IPCC A2 and B1 emissions scenarios greatly expand the range over which the pathogen can survive winter, projected reductions in spring rainfall reduce its feasible habitat, leading to spatially complex patterns of changing risk. The study demonstrates that temperature and rainfall changes associated with possible climate futures in the southwestern USA have confounding impacts on the range of Pc, suggesting that projections of future pathogen dynamics and ranges should account for multiple pathways of climate-pathogen interaction.

  16. Dinámica microbial del suelo asociada a diferentes estrategias de manejo de Phytophthora cinnamomi Rands en aguacate

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    Joaquín Guillermo Ramírez Gil

    2013-12-01

    Full Text Available La marchitez del aguacate es la enfermedad más limitante de este cultivo, cuyo agente causal más relevante es el oomycete Phytophthora cinnamomi Rands. Es por esto que se han desarrollado diferentes estrategias para su manejo integrado, pero aún prevalece el uso de productos químicos, como única medida de manejo, generando impactos negativos en el ambiente y la salud. Uno de los efectos perjudiciales que se ocasiona es la alteración de las poblaciones microbianas en el suelo. Este trabajo estuvo encaminado a conocer la dinámica microbiana del suelo, bajo diferentes estrategias de manejo de esta enfermedad, para lo cual se midió su dinamismo mediante unidades formadoras de colonias (UFC, para hongos, bacterias y actinomicetos, a partir de muestras de suelo y rizósfera de la raíz, bajo incubación en condiciones de anaerobiosis y aerobiosis, además se midió la actividad microbiana total, en condiciones de laboratorio, como complemento se cuantificaron microorganismos como: Trichiderma spp, bacterias formadoras de endosporas (BAFE, celulolíticos, proteolíticos, amilolíticos, solubilizadores de fosfato, fijadores asimbióticos de nitrógeno y promotores del crecimiento, como Pseudomonas spp., fluorescentes. Los resultados encontrados en esta investigación, sugieren que el uso individual y combinado de mantillo orgánico, material compostado de estiércol bovino, enmienda mineral y cascarilla de arroz y la propuesta de integración; incrementan significativamente la población y actividad microbiana aerobia, en la cual se identificaron microorganismos antagonistas como, Trichiderma spp., celulolíticos, Pseudomonas spp. fluorescentes y BAFE.

  17. Population genetic structure of Phytophthora cinnamomi associated with avocado in California and the discovery of a potentially recent introduction of a new clonal lineage.

    Science.gov (United States)

    Pagliaccia, D; Pond, E; McKee, B; Douhan, G W

    2013-01-01

    Phytophthora root rot (PRR) of avocado (Persea americana), caused by Phytophthora cinnamomi, is the most serious disease of avocado worldwide. Previous studies have determined that this pathogen exhibits a primarily clonal reproductive mode but no population level studies have been conducted in the avocado-growing regions of California. Therefore, we used amplified fragment length polymorphism based on 22 polymorphic loci and mating type to investigate pathogen diversity from 138 isolates collected in 2009 to 2010 from 15 groves from the Northern and Southern avocado-growing regions. Additional isolates collected from avocado from 1966 to 2007 as well as isolates from other countries and hosts were also used for comparative purposes. Two distinct clades of A2 mating-type isolates from avocado were found based on neighbor joining analysis; one clade contained both newer and older collections from Northern and Southern California, whereas the other clade only contained isolates collected in 2009 and 2010 from Southern California. A third clade was also found that only contained A1 isolates from various hosts. Within the California population, a total of 16 genotypes were found with only one to four genotypes identified from any one location. The results indicate significant population structure in the California avocado P. cinnamomi population, low genotypic diversity consistent with asexual reproduction, potential evidence for the movement of clonal genotypes between the two growing regions, and a potential introduction of a new clonal lineage into Southern California.

  18. Escherichia coli-based expression system for the heterologous expression and purification of the elicitin β-cinnamomin from Phytophthora cinnamomi.

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    Hofzumahaus, Sebastian; Schallmey, Anett

    2013-08-01

    Elicitins are sterol carrier proteins from the Oomycete genera Phytophthora and Phytium and elicit a hypersensitive response in many economically important plants, in some cases causing a systemic acquired resistance. Their recombinant expression in bacteria is complicated by the presence of three disulfide bonds in the elicitin structure. In consequence, elicitins have so far only been produced in soluble form by isolation from native Phytophthora or Phytium strains or by recombinant expression in the yeast Pichia pastoris. Here, for the first time, we report the soluble expression of the elicitin β-cinnamomin from Phytophthora cinnamomi in Escherichia coli by secretion of the protein into the periplasm. β-Cinnamomin yields have been significantly improved after careful selection of the optimum secretion signal sequence. In total, 17.6 mg β-cinnamomin per liter cell culture have been obtained in shake flasks with the secretion signal sequence of the maltose-binding protein MalE from E. coli. Furthermore, by making use of a C-terminal His-tag, β-cinnamomin purification has been significantly simplified with only one step of immobilized metal ion affinity chromatography yielding protein of high purity (>90%). The established protocol has further been successfully applied to the soluble expression of another elicitin.

  19. ALTERNATIVAS MICROBIOLÓGICAS PARA EL MANEJO DE Phytophthora cinnamomi Rands., EN Persea americana Mill. BAJO CONDICIONES DE CASA-MALLA

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    Joaquín G. Ramírez Gil

    2014-01-01

    Full Text Available Para la producción de aguacate en Colombia es necesario establecer alternativas de manejo amigables con el medio ambiente y de bajo costo para el control de la enfermedad conocida como marchitez, cuyo principal agente causal es Phytophthora cinnamomi. El uso de microorganismos del suelo, es una opción viable para mejorar la nutrición y sanidad en Persea americana, buscando ser más competitivos en aras de afrontar los tratados de libre comercio y poder aprovechar el potencial exportador que presenta este frutal. Entendiendo la complejidad del sistema de la microbiota del suelo, consecuencia de su gran diversidad y de las distintas relaciones ecológicas que lo gobiernan, este trabajo estuvo encaminado a evaluar en condiciones de invernadero el efecto de cepas de Trichoderma sp. , Glomus fasciculatum y una cepa de Pseudomonas sp., en el desarrollo de plántulas de P. americana , sin inocular e inoculadas con P. cinnamomi. Los resultados encontrados en este trabajo sugieren que G. fasciculatum y Pseudomonas sp., solos o en combinación, favorecen el desarrollo de plántulas de aguacate, mientras que Trichoderma sp. presentó los mejores resultados en la reducción del progreso de la enfermedad de marchitez en plantas inoculadas con P. cinnamomi . Los microorganismos del suelo presentan un enorme potencial para el desarrollo y protección contra patógenos en P. americana , pero se hace necesario entender todas las relaciones para poder potenciar su uso como biofertilizantes y agentes de biocontrol.

  20. De novo sequencing, assembly, and analysis of the root transcriptome of Persea americana (Mill.) in response to Phytophthora cinnamomi and flooding.

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    Reeksting, Bianca J; Coetzer, Nanette; Mahomed, Waheed; Engelbrecht, Juanita; van den Berg, Noëlani

    2014-01-01

    Avocado is a diploid angiosperm containing 24 chromosomes with a genome estimated to be around 920 Mb. It is an important fruit crop worldwide but is susceptible to a root rot caused by the ubiquitous oomycete Phytophthora cinnamomi. Phytophthora root rot (PRR) causes damage to the feeder roots of trees, causing necrosis. This leads to branch-dieback and eventual tree death, resulting in severe losses in production. Control strategies are limited and at present an integrated approach involving the use of phosphite, tolerant rootstocks, and proper nursery management has shown the best results. Disease progression of PRR is accelerated under high soil moisture or flooding conditions. In addition, avocado is highly susceptible to flooding, with even short periods of flooding causing significant losses. Despite the commercial importance of avocado, limited genomic resources are available. Next generation sequencing has provided the means to generate sequence data at a relatively low cost, making this an attractive option for non-model organisms such as avocado. The aims of this study were to generate sequence data for the avocado root transcriptome and identify stress-related genes. Tissue was isolated from avocado infected with P. cinnamomi, avocado exposed to flooding and avocado exposed to a combination of these two stresses. Three separate sequencing runs were performed on the Roche 454 platform and produced approximately 124 Mb of data. This was assembled into 7685 contigs, with 106 448 sequences remaining as singletons. Genes involved in defence pathways such as the salicylic acid and jasmonic acid pathways as well as genes associated with the response to low oxygen caused by flooding, were identified. This is the most comprehensive study of transcripts derived from root tissue of avocado to date and will provide a useful resource for future studies.

  1. De novo sequencing, assembly, and analysis of the root transcriptome of Persea americana (Mill. in response to Phytophthora cinnamomi and flooding.

    Directory of Open Access Journals (Sweden)

    Bianca J Reeksting

    Full Text Available Avocado is a diploid angiosperm containing 24 chromosomes with a genome estimated to be around 920 Mb. It is an important fruit crop worldwide but is susceptible to a root rot caused by the ubiquitous oomycete Phytophthora cinnamomi. Phytophthora root rot (PRR causes damage to the feeder roots of trees, causing necrosis. This leads to branch-dieback and eventual tree death, resulting in severe losses in production. Control strategies are limited and at present an integrated approach involving the use of phosphite, tolerant rootstocks, and proper nursery management has shown the best results. Disease progression of PRR is accelerated under high soil moisture or flooding conditions. In addition, avocado is highly susceptible to flooding, with even short periods of flooding causing significant losses. Despite the commercial importance of avocado, limited genomic resources are available. Next generation sequencing has provided the means to generate sequence data at a relatively low cost, making this an attractive option for non-model organisms such as avocado. The aims of this study were to generate sequence data for the avocado root transcriptome and identify stress-related genes. Tissue was isolated from avocado infected with P. cinnamomi, avocado exposed to flooding and avocado exposed to a combination of these two stresses. Three separate sequencing runs were performed on the Roche 454 platform and produced approximately 124 Mb of data. This was assembled into 7685 contigs, with 106 448 sequences remaining as singletons. Genes involved in defence pathways such as the salicylic acid and jasmonic acid pathways as well as genes associated with the response to low oxygen caused by flooding, were identified. This is the most comprehensive study of transcripts derived from root tissue of avocado to date and will provide a useful resource for future studies.

  2. Estudio de la asociación entre algunas propiedades físicas y químicas del suelo y el comportamiento de la pudrición radical del aguacate causada por Phytophthora cinnamomi.

    OpenAIRE

    Romero Moya, Lizzete Dayana

    2014-01-01

    Phytophthora cinnamomi Rands es el agente causal de la pudrición radical, muerte descendente o tristeza del aguacate, considerada como la enfermedad mas importante de este cultivo ocasionando pérdidas hasta un 50% de los árboles en etapa de vivero y durante los primeros años de establecimiento del cultivo. El patógeno invade y descompone las raicillas de las plantas interfiriendo con la absorción de agua y nutrientes, lo que resulta en una muerte progresiva de los árboles. La evidencia ...

  3. Espécies de Phytophthora associadas à gomose em pomares de citros no Estado do Paraná, Brasil

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    Marilda Pereira Caixeta

    2013-12-01

    Full Text Available A gomose dos citros é considerada uma doença de grande importância para a citricultura no Brasil e em nível mundial. A etiologia desta doença compreende um complexo de espécies de Phytophthora. Embora importante, pouco se conhece sobre a gomose nas regiões produtoras de citros no Estado do Paraná. Por isso, este trabalho teve como objetivo identificar espécies de Phytophthora associadas à gomose em pomares de citros no Paraná. Nas regiões Norte, Noroeste e Vale do Ribeira foram retiradas amostras de raízes de plantas com sintomas de gomose e também de solo da rizosfera. Em laboratório, empregando pêra cv. D'anjou como isca e meio de cultivo batata-dextrose-ágar, foram obtidos 21 isolados de Phytophthora spp. Todos os isolados infectaram mudas de limão 'Cravo', reproduzindo os sintomas de gomose e também apresentaram crescimento micelial a 8º C e a 36º C, com exceção do isolado PR20 para 36º C . "In vitro", esses isolados foram heterotálicos, sendo 20 compatíveis ao tipo padrão A2 e um compatível ao tipo padrão A1. Vinte isolados formaram esporângios persistentes e papilados, com 25,5 - 62,0 µm de comprimento (C e 27,9 - 49,6 µm de largura (L e a relação C/L foi de 1,38:1. Um isolado (PR20 apresentou esporângios medindo 40,3 - 55,8 µm de comprimento e 27,9 - 37,2 µm de largura, formando esporângios persistentes, papilados ou bipapilados e de formas distorcidas, não formando clamidósporos. A temperatura ótima para crescimento desse isolado foi entre 20 a 28º C, enquanto para os demais foi de 24 a 32º C, tendo estes produção abundante de clamidósporos globosos de diâmetro variando entre 21,7 a 43,4 µm. De acordo com as características morfofisiológicas apresentadas, dos 21 isolados analisados, 20 pertenceram à espécie P. nicotianae e um à espécie P. citrophthora. A análise de sequências de genes da região ITS1-5.8S-ITS2 do rDNA e usando o teste de "Single-Strand Conformation Polymorphism

  4. Fighting phytophthora in blueberries

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  5. Susceptibility of highbush blueberry cultivars to Phytophthora root rot

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  6. Phytophthora root and stem rot – new disease of Ilex aquifolium "Myrtifolia” in Poland

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2014-08-01

    Full Text Available Phytophthora cinnamomi was often isolated from rotted roots and stems of English holly "Myrtifolia" together with Alternaria alternata, Cylindrocarpon destructanss, Fusarium avenaceum and other fungal species. Inoculation of leaf blades and stem parts of 4 species and 12 holly cultivars with P. cinnamomi showed the spread of rot symptoms on the most of them. On Ilex crenata tissues necrosis did not develop or spread slowly. Isolation of P. cinnamomi only from one holly cultivar in surveyed nursery indicate on transmission of the pathogen with imported young plants.

  7. Effects of wild plants essential oils on the growth of Phytophthra cinnamomi and Castanea sativa

    OpenAIRE

    Sousa, Maria João; Martins,Fátima; Belo, Hélio; Choupina, Altino; Martins, Anabela

    2010-01-01

    Wild plant essential oil effects on the growth control of Phytophthora cinnamomi and Castanea sativa M. João Sousa1, Fátima Martins1, Hélio Belo1, Altino Choupina1, 2 and Anabela Martins1 1Instituto Politécnico de Bragança, Escola Superior Agrária, Campus de Santa Apolónia, Apartado 1172, 5301-854 Bragança, Portugal 2CIMO- Centro de Investigação de Montanha, Campus de Santa Apolónia, Apartado 1172, 5301-854 Bragança, Portugal Corresponding author: In regions that...

  8. New record of Phytophthora root and stem rot of Lavandula angustifolia

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  9. Early-screening for resistance to Phytophthora sp.p. in wild cherry clones (Prunus avium L.

    Directory of Open Access Journals (Sweden)

    Guerri S

    2004-01-01

    Full Text Available A new method for early selection of wild cherry clones for resistance to Phytophthora sp. is presented. Four Phytophthora species (P. cinnamomi, P. citrophthora, P. megasperma, P. alni were tested in vitro on four micropropagated cherry (Prunus avium clones, obtaining reliable and reproducible results. Variability in clones susceptibilities and in parasite virulence has been evidenced. Phytophthora citrophthora is confirmed to be a dangerous parasite, due to its capability to produce symptoms rapidly and its fitness to Mediterranean environments. On the contrary P. alni does not seem a dangerous parasite for wild cherry.

  10. Susceptibility of common alder (Alnus glutinosa) seeds and seedlings to Phytophthora alni and other Phytophthora species

    Energy Technology Data Exchange (ETDEWEB)

    Haque, M. M.; Diez, J. J.

    2012-11-01

    Phytophthora alni is a highly destructive host specific pathogen to alders (Alnus spp.) spreading all over Europe. Recently this pathogen has been reported to cause diseases in common alder (Alnus glutinosa) in Spain. Seeds and seedlings of A. glutinosa were tested in vitro for their susceptibility to alder Phytophthora and other Phytophthora species. Isolates of P. alni ssp. alni, P. cinnamomi, P. citrophthora, P. nicotianae and P. palmivora were used in the experiments. Seeds and seedlings were inoculated with a zoospore suspension and uniform mycelial blocks of agar of the Phytophthora species. Susceptibility was calculated in terms of pathogen virulence on seed germination and seedling mortality 42 and 67 days after inoculation respectively. Seed germination and seedling mortality rates varied differently among the isolates used. Results implied that common alder and its seeds and seedlings are at risk to be infected by P. alni. In addition, other Phytophthora species are able to infect this kind of material showing their relative host non-specificity. This is one important finding concerning alder regeneration in infected areas, and the possibility of disease spread on this plant material. (Author) 42 refs.

  11. Phytophthora viruses.

    Science.gov (United States)

    Cai, Guohong; Hillman, Bradley I

    2013-01-01

    Phytophthora sp. is a genus in the oomycetes, which are similar to filamentous fungi in morphology and habitat, but phylogenetically more closely related to brown algae and diatoms and fall in the kingdom Stramenopila. In the past few years, several viruses have been characterized in Phytophthora species, including four viruses from Phytophthora infestans, the late blight pathogen, and an endornavirus from an unnamed Phytophthora species from Douglas fir. Studies on Phytophthora viruses have revealed several interesting systems. Phytophthora infestans RNA virus 1 (PiRV-1) and PiRV-2 are likely the first members of two new virus families; studies on PiRV-3 support the establishment of a new virus genus that is not affiliated with established virus families; PiRV-4 is a member of Narnaviridae, most likely in the genus Narnavirus; and Phytophthora endornavirus 1 (PEV1) was the first nonplant endornavirus at the time of reporting. Viral capsids have not been found in any of the above-mentioned viruses. PiRV-1 demonstrated a unique genome organization that requires further examination, and PiRV-2 may have played a role in late blight resurgence in 1980s-1990s.

  12. Phytophthora community structure analyses in Oregon nurseries inform systems approaches to disease management.

    Science.gov (United States)

    Parke, Jennifer L; Knaus, Brian J; Fieland, Valerie J; Lewis, Carrie; Grünwald, Niklaus J

    2014-10-01

    Nursery plants are important vectors for plant pathogens. Understanding what pathogens occur in nurseries in different production stages can be useful to the development of integrated systems approaches. Four horticultural nurseries in Oregon were sampled every 2 months for 4 years to determine the identity and community structure of Phytophthora spp. associated with different sources and stages in the nursery production cycle. Plants, potting media, used containers, water, greenhouse soil, and container yard substrates were systematically sampled from propagation to the field. From 674 Phytophthora isolates recovered, 28 different species or taxa were identified. The most commonly isolated species from plants were Phytophthora plurivora (33%), P. cinnamomi (26%), P. syringae (19%), and P. citrophthora (11%). From soil and gravel substrates, P. plurivora accounted for 25% of the isolates, with P. taxon Pgchlamydo, P. cryptogea, and P. cinnamomi accounting for 18, 17, and 15%, respectively. Five species (P. plurivora, P. syringae, P. taxon Pgchlamydo, P. gonapodyides, and P. cryptogea) were found in all nurseries. The greatest diversity of taxa occurred in irrigation water reservoirs (20 taxa), with the majority of isolates belonging to internal transcribed spacer clade 6, typically including aquatic opportunists. Nurseries differed in composition of Phytophthora communities across years, seasons, and source within the nursery. These findings suggest likely contamination hazards and target critical control points for management of Phytophthora disease using a systems approach.

  13. Phytophthora lateralis.

    Science.gov (United States)

    E.M. Hansen

    2011-01-01

    Phytophthora lateralis was named by Tucker and Milbrath in 1942. There are no known synonyms. P. lateralis was classified in morphological group V by Stamps et al. (1990); the group includes homothallic species with paragynous antheridia and nonpapillate, proliferating sporangia.

  14. Diversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.

    Science.gov (United States)

    Scanu, Bruno; Linaldeddu, Benedetto T.; Deidda, Antonio; Jung, Thomas

    2015-01-01

    The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world’s vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago. PMID:26649428

  15. Diversity of Phytophthora Species from Declining Mediterranean Maquis Vegetation, including Two New Species, Phytophthora crassamura and P. ornamentata sp. nov.

    Directory of Open Access Journals (Sweden)

    Bruno Scanu

    Full Text Available The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy. Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago.

  16. Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6.

    Science.gov (United States)

    Hansen, Everett M; Reeser, Paul W; Sutton, Wendy

    2012-01-01

    Phytophthora borealis and Phytophthora riparia, identified in recent Phytophthora surveys of forest streams in Oregon, California and Alaska, are described as new species in Phytophthora ITS Clade 6. They are similar in growth form and morphology to P. gonapodyides and are predominantly sterile. They present unique DNA sequences, however, and differ in temperature/growth relations and geographic distribution.

  17. Exposition of cork oak roots to cryptogein reduced the Infection by Phytophtora cinnamomi

    OpenAIRE

    Maia, I.; Medeira, C.; Candeias, I.; A.C. Moreira; Melo, Eduardo P.; Cravador, A.

    2009-01-01

    The oomycete P. cinnamomi has been described as strong contributing factor to the decline of cork oak and holm oak stands occurring in the Iberian Peninsula. There are no eradication methods available against this pathogen.

  18. Phytophthora beyond agriculture.

    Science.gov (United States)

    Hansen, Everett M; Reeser, Paul W; Sutton, Wendy

    2012-01-01

    Little is known about indigenous Phytophthora species in natural ecosystems. Increasing evidence, however, suggests that a diverse, trophically complex Phytophthora community is important in many forests. The number of described species has steadily increased, with a dramatic spike in recent years as new species have been split from old and new species have been discovered through exploration of new habitats. Forest soil, streams, and the upper canopies of trees are now being explored for Phytophthora diversity, and a new appreciation for the ecological amplitude of the genus is emerging. Ten to twenty species are regularly identified in temperate forest surveys. Half or more of this Phytophthora diversity comes from species described since 2000. Taxa in internal transcribed spacer (ITS) Clade 6 are especially numerous in forest streams and may be saprophytic in this habitat. Three ecological assemblages of forest Phytophthora species are hypothesized: aquatic opportunists, foliar pathogens, and soilborne fine-root and canker pathogens. Aggressive invasive species are associated with all three groups.

  19. Beneficial roles of dietary oleum cinnamomi in alleviating intestinal injury.

    Science.gov (United States)

    Wang, Lei; Hou, Yongqing; Yi, Dan; Ding, Binying; Zhao, Di; Wang, Zhongxing; Zhu, Huiling; Liu, Yulan; Gong, Joshua; Assaad, Houssein; Wu, Guoyao

    2015-01-01

    Cinnamon is a traditional herb used for treatment of many human diseases. The most important chemical compounds of the essential oil are cinnamaldehyde and eugenol. Oleum cinnamomi (OCM, cinnamon oil) is increasingly used as a feed additive to animal diets. Beneficial effects of OCM in protecting tissues from inflammation and injury by endogenous and exogenous agents (such as hydrogen peroxide and lipopolysaccharide (LPS)) may result, in part, from its action on regulating amino acid metabolism in cells to favor the synthesis of glutathione (a major low-molecular-weight antioxidant) from cysteine, glycine and glutamate. In support of this notion, results of recent studies indicate that supplementing OCM (50 mg/kg diet) to a corn- and soybean meal-based diet for piglets weaned at 21 days of age enhances intestinal anti-oxidative capacity and reduces the incidence of diarrhea. Additionally, dietary supplementation with OCM ameliorates LPS-induced mucosal barrier dysfunction and mucosal damage in the small intestine. OCM holds great promise for protecting the gut from injury under conditions of inflammation, infections, and oxidative stress.

  20. The genus Phytophthora anno 2012.

    Science.gov (United States)

    Kroon, Laurens P N M; Brouwer, Henk; de Cock, Arthur W A M; Govers, Francine

    2012-04-01

    Plant diseases caused by Phytophthora species will remain an ever increasing threat to agriculture and natural ecosystems. Phytophthora literally means plant destroyer, a name coined in the 19th century by Anton de Bary when he investigated the potato disease that set the stage for the Great Irish Famine. Phytophthora infestans, the causal agent of potato late blight, was the first species in a genus that at present has over 100 recognized members. In the last decade, the number of recognized Phytophthora species has nearly doubled and new species are added almost on a monthly basis. Here we present an overview of the 10 clades that are currently distinguished within the genus Phytophthora with special emphasis on new species that have been described since 1996 when Erwin and Ribeiro published the valuable monograph 'Phytophthora diseases worldwide' (35).

  1. Vroegtijdig Phytophthora opsporen met biosensor

    NARCIS (Netherlands)

    Jansen, R.M.C.

    2003-01-01

    Phytophthora kan vroegtijdig worden opgespoord met biosensoren. Bij de Leerstoelgroep Agrarische Bedrijfstechnologie van Wageningen Universiteit wordt verder gekeken naar praktische toepassingen van deze techniek

  2. Inhibition of Phytophthora parasitica and P. capsici by Silver Nanoparticles Synthesized Using Aqueous Extract of Artemisia absinthium.

    Science.gov (United States)

    Ali, Mohammad; Kim, Bosung; Belfield, Kevin D; Norman, David; Brennan, Mary; Ali, Gul Shad

    2015-09-01

    Application of nanoparticles for controlling plant pathogens is a rapidly emerging area in plant disease management, and nanoparticles synthesis methods that are economical and ecofriendly are extensively investigated. In this project, we investigated the potential of silver nanoparticles (AgNPs) synthesized with aqueous extract of Artemisia absinthium against several Phytophthora spp., which cause many economically important crop diseases. In in vitro dose-response tests conducted in microtiter plates, 10 µg ml⁻¹ of AgNPs inhibited mycelial growth of P. parasitica, P. infestans, P. palmivora, P. cinnamomi, P. tropicalis, P. capsici, and P. katsurae. Detailed in vitro dose-response analyses conducted with P. parasitica and P. capsici revealed that AgNPs synthesized with A. absinthium extract were highly potent (IC50: 2.1 to 8.3 µg ml⁻¹) and efficacious (100%) in inhibiting mycelial growth, zoospore germination, germ tube elongation, and zoospore production. Interestingly, AgNP treatment accelerated encystment of zoospores. Consistent with in vitro results, in planta experiments conducted in a greenhouse revealed that AgNP treatments prevented Phytophthora infection and improved plant survival. Moreover, AgNP in in planta experiments did not produce any adverse effects on plant growth. These investigations provide a simple and economical method for controlling Phytophthora with AgNP without affecting normal plant physiology.

  3. Draft genome sequences of Phytophthora kernoviae and Phytophthora ramorum lineage EU2 from Scotland

    OpenAIRE

    Christine Sambles; Alexandra Schlenzig; Paul O'Neill; Murray Grant; Studholme, David J.

    2015-01-01

    Newly discovered Phytophthora species include invasive pathogens that threaten trees and shrubs. We present draft genome assemblies for three isolates of Phytophthora kernoviae and one isolate of the EU2 lineage of Phytophthora ramorum, collected from outbreak sites in Scotland.

  4. A simple method for extracting DNA from rhododendron plants infected with Phytophthora spp. for use in PCR

    Directory of Open Access Journals (Sweden)

    Trzewik Aleksandra

    2016-01-01

    Full Text Available Among the numerous protocols that describe the extraction of DNA, those relating to the isolation of DNA from infected plants, are rare. This study describes a rapid and reliable method of extracting a high quality and quantity of DNA from rhododendron leaves artificially infected with Phytophthora cactorum, P. cambivora, P. cinnamomi, P. citrophthora, and P. plurivora. The use of the modified Doyle and Doyle protocol (1987 allowed us to obtain high quantity and quality DNA (18.26 μg from 100 mg of the fresh weight of infected leaves at the ratios of A260/280 and A260/230 - 1.83 and 1.72, respectively, suitable for conventional polymerase chain reaction (PCR and real-time PCR amplifications.

  5. Survey for the presence of Phytophthora cinnamomi on reclaimed mined lands in Ohio chosen for restoration of the American chestnut

    Science.gov (United States)

    Shiv Hiremath; Kirsten Lehtoma; Jenise M. Bauman

    2013-01-01

    We have been planting blight resistant American chestnut seedlings on reclaimed coal mined areas in Southeastern Ohio, which was once within the natural range of the American chestnut. Towards the goal of restoring the American chestnut, we are testing suitable sites that can aid survival, growth and establishment of planted seedlings pre-inoculated with...

  6. Miopatias associadas a agregados tubulares

    OpenAIRE

    Mary Souza Carvalho; Lusvarghi,Edgard S.; Ângela Lobo F. Levy; Paulo N. Borsoi Salum; Consuelo J. Rodrigues; José Antonio Levy

    1993-01-01

    Os autores relatam a caso de paciente de 58 anos de idade do sexo masculino, com quadro de características miastênicas tanto clínica como eletromiograficamente, no qual a biópsia muscular com histoquímica e microscopia eletrônica permitiu fazer o diagnostico de miopatia associada a agregados tubulares. É chamada a atenção para o fato de que as alterações anátomo-patológicas encontradas podem estar presentes em um grupo heterogêneo de pacientes com grande variedade de sintomas, não havendo por...

  7. Irrigation affects severity of root rot caused by Phythophthora plurivora and P. cinnamomi on rhododendron

    Science.gov (United States)

    Plant pathogens in the genus Phytophthora cause root rot that decrease product quality and result in plant death and economic losses to the nursery industry. Recently, we found Phytophthora plurivora prevalent on rhododendron in nurseries in the Pacific Northwest, USA, but there is little informatio...

  8. Biocontrol of Rhizoctonia solani AG-2, the causal agent of damping-off by Muscodor cinnamomi CMU-Cib 461.

    Science.gov (United States)

    Suwannarach, Nakarin; Kumla, Jaturong; Bussaban, Boonsom; Lumyong, Saisamorn

    2012-11-01

    Rhizoctonia solani is a damping-off pathogen that causes significant crop loss worldwide. In this study, the potential of Muscodor cinnamomi, a new species of endophytic fungus for controlling R. solani AG-2 damping-off disease of plant seedlings by biological fumigation was investigated. In vitro tests showed that M. cinnamomi volatile compounds inhibited mycelial growth of pathogens. Among nine solid media tested, rye grain was the best grain for inoculum production. An in vivo experiment of four seedlings, bird pepper, bush bean, garden pea and tomato were conducted. The results indicated that treatment with 30 g of M. cinnamomi inoculum was the minimum dose that caused complete control of damping-off symptoms of all seedlings after one month of planting. The R. solani-infested soil showed the lowest percentage of seed germination. In addition, M. cinnamomi did not cause any disease symptoms. From the results it is clear that M. cinnamomi is effective in controlling R. solani AG-2 both in vitro and in vivo.

  9. Miopatias associadas a agregados tubulares

    Directory of Open Access Journals (Sweden)

    Mary Souza Carvalho

    1993-09-01

    Full Text Available Os autores relatam a caso de paciente de 58 anos de idade do sexo masculino, com quadro de características miastênicas tanto clínica como eletromiograficamente, no qual a biópsia muscular com histoquímica e microscopia eletrônica permitiu fazer o diagnostico de miopatia associada a agregados tubulares. É chamada a atenção para o fato de que as alterações anátomo-patológicas encontradas podem estar presentes em um grupo heterogêneo de pacientes com grande variedade de sintomas, não havendo portanto motivo para considerar-se a existência de uma miopatia com agregados tubulares, já que os achados anátomo-patológicos são inespecíficos e não configuram moléstia específica.

  10. Phytophthora sojae: Diversity among and within Populations

    Science.gov (United States)

    Soybean production is increasing around the world and, to no surprise, so are the reports of soybean diseases caused by Phytophthora sojae, including Phytophthora seed, root, and stem rot. Phytophthora sojae is a diploid oomycete, which is homothallic and is limited to primarily one host: the soybe...

  11. Genome sequences of two Phytophthora species responsible for Sudden Oak Death and Soybean Root Rot provide novel insights into their evolutionary origins and mechanisms of pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathi, Sucheta; Aerts, Andrea; Bensasson, Douda; Dehal, Paramvir; Dubchak, Inna; Garbelotto, Matteo; Gijzen, Mark; Huang, Wayne; Ivors, Kelly; Jiang, Rays; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt; McDonald, Hayes; Medina, Monica; Morris, Paul; Putnam, Nik; Rash, Sam; Salamov, Asaf; Smith, Brian; Smith, Joe; Terry, Astrid; Torto, Trudy; Grigoriev, Igor; Rokhsar, Daniel; Boore, Jeffrey

    2005-12-01

    The approximately 60 species of Phytophthora are all destructive pathogens, causing rots of roots, stems, leaves and fruits of a wide range of agriculturally and ornamentally important plants (1). Some species, such as P. cinnamomi, P. parasitica and P. cactorum, each attack hundreds of different plant host species, whereas others are more restricted. Some of the crops where Phytophthora infections cause the greatest financial losses include potato, soybean, tomato, alfalfa, tobacco, peppers, cucurbits, pineapple, strawberry, raspberry and a wide range of perennial tree crops, especially citrus, avocado, almonds, walnuts, apples and cocoa, and they also heavily affect the ornamental, nursery and forestry industries. The economic damage overall to crops in the United States by Phytophthora species is estimated in the tens of billions of dollars, including the costs of control measures, and worldwide it is many times this amount (1). In the northern midwest of the U.S., P. sojae causes $200 million in annual losses to soybean alone, and worldwide causes around $1-2 billion in losses per year. P. infestans infections resulted in the Irish potato famine last century and continues to be a difficult and worsening problem for potato and tomato growers worldwide, with worldwide costs estimated at $5 billion per year.

  12. A high-temperature tolerant species in clade 9 of the genus Phytophthora: P. hydrogena sp. nov.

    Science.gov (United States)

    Yang, Xiao; Gallegly, Mannon E; Hong, Chuanxue

    2014-01-01

    A previously unknown Phytophthora species was isolated from irrigation water in Virginia, USA. This novel species produces abundant noncaducous and nonpapillate sporangia in soil water extract solution. It sometimes produces chlamydospores and hyphal swellings in aged cultures and in Petri's solution. This species has optimum vegetative growth at 30 C and grows well at 35 C. The lowest and highest temperatures for growth are 5 and 40 C. All isolates examined in this study are compatibility type A1 and produce mostly plerotic oospores when paired with an A2 mating-type tester of P. cinnamomi. Sequence analyses of the rDNA internal transcribed spacer (ITS) regions and the mitochondrially encoded cytochrome c oxidase 1 (cox 1) gene placed this species in clade 9 of the genus Phytophthora. These characteristics support the description of this taxon as a new species for which we propose the name P. hydrogena sp. nov. Further phylogenetic and physiological investigations of clade 9 species revealed a high-temperature tolerant cluster including P. hydrogena, P. aquimorbida, P. hydropathica, P. irrigata, P. chrysanthemi, P. insolita, P. polonica and P. parsiana. These species all grow well at 35 C. The monophyly of the species in this heat-tolerant cluster except P. insolita and P. polonica is highly supported by the maximum-likelihood analyses of the ITS and cox 1 sequences.

  13. Draft genome sequences of Phytophthora kernoviae and Phytophthora ramorum lineage EU2 from Scotland

    Directory of Open Access Journals (Sweden)

    Christine Sambles

    2015-12-01

    Full Text Available Newly discovered Phytophthora species include invasive pathogens that threaten trees and shrubs. We present draft genome assemblies for three isolates of Phytophthora kernoviae and one isolate of the EU2 lineage of Phytophthora ramorum, collected from outbreak sites in Scotland.

  14. Phytophthora infestans, een dynamische ziekteverwekker

    NARCIS (Netherlands)

    Govers, F.

    2010-01-01

    Samenvatting van de inaugurele rede van Francine Govers op 11 juni 2009. Dit artikel beschrijft de stand van zaken in het onderzoek aan oömyceten en in het bijzonder aan Phytophthora infestans, de veroorzaker van de aardappelziekte. Er wordt ingegaan op ziektebestrijding en resistentieveredeling, de

  15. Phytophthora genome sequences uncover evolutionary origins and mechanisms of pathogenesis

    NARCIS (Netherlands)

    Tyler, B.M.; Tripathy, S.; Zhang, X.; Dehal, P.; Jiang, R.H.Y.; Aerts, A.; Arredondo, F.D.; Baxter, L.; Bensasson, D.; Beynon, J.L.; Chapman, J.; Damasceno, C.M.B.; Dorrance, A.E.; Dou, D.; Dickerman, A.W.; Dubchak, I.L.; Garbelotto, M.; Gijzen, M.; Gordon, S.G.; Govers, F.; Grunwald, N.J.; Huang, W.; Ivors, K.L.; Jones, R.W.; Kamoun, S.; Krampis, K.; Lamour, K.H.; Lee, M.K.; McDonald, W.H.; Medina, M.; Meijer, H.J.G.; Nordberg, E.K.; Maclean, D.J.; Ospina-Giraldo, M.D.; Morris, P.F.; Phuntumart, V.; Putnam, N.H.; Rash, S.; Rose, J.K.C.; Sakihama, Y.; Salamov, A.A.; Savidor, A.; Scheuring, C.F.; Smith, B.M.; Sobral, B.W.S.; Terry, A.; Torto-Alalibo, T.A.; Win, J.; Xu, Z.; Zhang, H.; Grigoriev, I.V.; Rokhsar, D.S.; Boore, J.L.

    2006-01-01

    Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oömycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora

  16. Analysis of volatile components in herbal pair herba schizonepetae-ramulus cinnamomi

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Analysis of volatile components in herbal pair (HP) herba schizonepetae-ramulus cinnamomi (HS-RC),single herb HS and RC was carried out by gas chromatography-mass spectrometry (GC-MS) data and chemometric resolution method (CRM).The two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound by CRM.In total,47,61 and 51 chemical components in volatile oil of HS,RC,and HP HS-RC were respectively determined qualitatively and quantitatively,accounting for 90.52%,88.37%,and 88.72% total contents of volatile oil of HS,RC,and HP HS-RC,respectively.The number of the volatile components of HP HS-RC is almost the addition of that of two single herbs,but their relative contents are changed.

  17. Screening Phytophthora rubi for fungicide resistance

    Science.gov (United States)

    Preliminary results from the survey for fungicide resistance in Phytophthora were reported at the 2016 Washington Small Fruit Conference. Phytophthora was isolated from diseased plants in 28 red raspberry fields and tested against mefenoxam, the active ingredient of Ridomil. Most isolates were ident...

  18. Targeted gene mutation in Phytophthora spp.

    NARCIS (Netherlands)

    Lamour, K.H.; Finley, L.; Hurtado-Gonzales, O.; Gobena, D.; Tierney, M.; Meijer, H.J.G.

    2006-01-01

    The genus Phytophthora belongs to the oomycetes and is composed of plant pathogens. Currently, there are no strategies to mutate specific genes for members of this genus. Whole genome sequences are available or being prepared for Phytophthora sojae, P. ramorum, P. infestans, and P. capsici and the d

  19. Variation in Phytophthora infestans: sources and implications

    NARCIS (Netherlands)

    Flier, W.G.

    2002-01-01

    Uitgebreide samenvatting van de dissertatie van Wilbert G. Flier over de oömyceet Phytophthora infestans (Monst.) de Bary, de veroorzaker van 'het kwaad' ofwel de aardappelziekte in de teelt van aardappelen en tomaten

  20. Quality assessment of cortex cinnamomi by HPLC chemical fingerprint, principle component analysis and cluster analysis.

    Science.gov (United States)

    Yang, Jie; Chen, Li-Hong; Zhang, Qin; Lai, Mao-Xiang; Wang, Qiang

    2007-06-01

    HPLC fingerprint analysis, principle component analysis (PCA), and cluster analysis were introduced for quality assessment of Cortex cinnamomi (CC). The fingerprint of CC was developed and validated by analyzing 30 samples of CC from different species and geographic locations. Seventeen chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression of the HPLC fingerprints. The correlation coefficients of similarity in chromatograms were higher than 0.95 for the same species while much lower than 0.6 for different species. Besides, two principal components (PCs) have been extracted by PCA. PC1 separated Cinnamomum cassia from other species, capturing 56.75% of variance while PC2 contributed for their further separation, capturing 19.08% variance. The scores of the samples showed that the samples could be clustered reasonably into different groups corresponding to different species and different regions. The scores and loading plots together revealed different chemical properties of each group clearly. The cluster analysis confirmed the results of PCA analysis. Therefore, HPLC fingerprint in combination with chemometric techniques provide a very flexible and reliable method for quality assessment of traditional Chinese medicines.

  1. Pathogenic diversity of Phytophthora sojae and breeding strategies to develop Phytophthora-resistant soybeans

    Science.gov (United States)

    Phytophthora stem and root rot disease, caused by Phytophthora sojae, is one of the most destructive diseases of soybean (Glycine max (L.) Merr.), and has been increasing in several soybean-producing areas around the world. This disease induces serious limitations on soybean production, with yield l...

  2. Mitochondrial genomics in the Genus Phytophthora with a focus on Phytophthora ramorum

    Science.gov (United States)

    Frank N. Martin; Paul Richardson

    2008-01-01

    The mitochondrial genomes of Phytophthora infestans, P. ramorum and P. sojae have been sequenced and comparative genomics has provided an opportunity to examine the processes involved with genome evolution in the genus Phytophthora. This approach can also be useful in assessing intraspecific...

  3. Phytophthora Database: A forensic database supporting the identification and monitoring of Phytophthora

    Science.gov (United States)

    Due to their high virulence and ability to spread rapidly, Phytophthora species represent a serious threat to agricultural production and ecological systems. Many novel Phytophthora species have been reported in recent years, indicative of our limited understanding of the ecology and diversity of Ph...

  4. Phytophthora rotråte i juletrefelt

    DEFF Research Database (Denmark)

    Talgø, Venche; Thomsen, Iben Margrete

    2015-01-01

    Phytophthora rotråte forårsaket av ulike arter av Phytophthora er et stort problem i juletreproduksjonen iUSA. I Norge er det også rapportert om flere tilfeller av skade på grunn av Phytophthora både i juletrær og klippegrønt, men så langt ikke i Danmark. I begge landene er flere arter av...... Phytophthora funnet på treaktige vekster i grøntanlegg. Vi har også sett en urovekkende spredning av Phytophthora til løvtrær i bynære skoger, vassdrag og naturområder det siste tiåret, spesielt i Norge. Både i Norge og Danmark har vi undersøkt vann i eller like ved juletreplantinger og funnet flere...... Phytophthora-arter, så dette er en skadegjører juletredyrkere må være på vakt overfor...

  5. Nefrocalcinose associada ao uso de esteroide anabolizante

    Directory of Open Access Journals (Sweden)

    Weverton Machado Luchi

    2015-03-01

    Full Text Available Os esteroides anabolizantes têm sido usados como arma terapêutica em diversas condições clínicas. Entretanto, o uso abusivo e indiscriminado, associado a outros suplementos nutricionais, tem gerado efeitos adversos graves. Relato do caso: Sexo masculino, 21 anos, admitido com náuseas, astenia, hiporexia, cefaleia e hipertensão arterial. Exames no sangue evidenciaram Cr: 3,9 mg/dl U:100 mg/dl e Cálcio total 14 mg/dl. Ultrassonografia e biópsia renal compatíveis com nefrocalcinose. Houve melhora gradativa da função renal e da calcemia após hidratação vigorosa e furosemida. Entretanto, após 1 ano, persistiram depósitos renais de cálcio e relação córticomedular reduzida ao ultrassom e creatinina estável em 1,4 mg/dl. Casos anteriores evidenciaram necrose tubular aguda e nefrite intersticial com poucos depósitos de cálcio no interstício renal. Nesse caso, encontramos nefrocalcinose acentuada associada à nefroesclerose. O objetivo deste estudo é relatar a ocorrência de injúria renal aguda com nefrocalcinose associada ao uso de esteroide anabolizante e oferecer uma revisão do assunto.

  6. Identification of cell wall-associated proteins from Phytophthora ramorum

    NARCIS (Netherlands)

    Meijer, H.J.G.; Vondervoort, van de P.J.I.; Yin, Q.Y.; Koster, de C.G.; Klis, F.M.; Govers, F.; Groot, de P.W.J.

    2006-01-01

    The oomycete genus Phytophthora comprises a large group of fungal-like plant pathogens. Two Phytophthora genomes recently have been sequenced; one of them is the genome of Phytophthora ramorum, the causal agent of sudden oak death. During plant infection, extracellular proteins, either soluble secre

  7. Identification of cell wall-associated proteins from Phytophthora ramorum

    NARCIS (Netherlands)

    Meijer, H.J.G.; Vondervoort, van de P.J.I.; Yin, Q.Y.; Koster, de C.G.; Klis, F.M.; Govers, F.; Groot, de P.W.J.

    2006-01-01

    The oomycete genus Phytophthora comprises a large group of fungal-like plant pathogens. Two Phytophthora genomes recently have been sequenced; one of them is the genome of Phytophthora ramorum, the causal agent of sudden oak death. During plant infection, extracellular proteins, either soluble

  8. Quality assessment of Cinnamomi Ramulus by the simultaneous analysis of multiple active components using high-performance thin-layer chromatography and high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Xiaoxue; He, Jiao; Xu, Huarong; Bi, Kaishun; Li, Qing

    2014-09-01

    A novel and improved method for the quality assessment of Cinnamomi Ramulus was developed and completely validated. The method was established using fingerprint technology and simultaneous quantitative determination of six main marker compounds including coumarin, cinnamic alcohol, cinnamic acid, 2-methoxy cinnamic acid, cinnamaldehyde, and 2-methoxy cinnamaldehyde in the herbal medicine for the first time. A newly developed high-performance thin-layer chromatography method, which achieved simultaneous definition of five marker components by comparing the colors and retardation factor values of the bands in high-performance thin-layer chromatography, was first used for the authentication of Cinnamomi Ramulus. The fingerprints of 26 batches of herbal samples from different regions of China showed very similar chromatographic patterns that were evaluated by similarity analysis and hierarchical clustering analysis. In addition, six marker compounds were simultaneously determined using single standard to determine multiple components by the relative response factors. Compared with the external standard method, the new quantitative method was validated to determine multiple compounds in 26 batches of Cinnamomi Ramulus samples. All results demonstrated that the simple and rapid method could be effectively utilized for the quality control of Cinnamomi Ramulus. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Diagnostics of Tree Diseases Caused by Phytophthora austrocedri Species.

    Science.gov (United States)

    Mulholland, Vincent; Elliot, Matthew; Green, Sarah

    2015-01-01

    We present methods for the detection and quantification of four Phytophthora species which are pathogenic on trees; Phytophthora ramorum, Phytophthora kernoviae, Phytophthora lateralis, and Phytophthora austrocedri. Nucleic acid extraction methods are presented for phloem tissue from trees, soil, and pure cultures on agar plates. Real-time PCR methods are presented and include primer and probe sets for each species, general advice on real-time PCR setup and data analysis. A method for sequence-based identification, useful for pure cultures, is also included.

  10. Ataxia heredo-degenerativa associada a hipoacusia

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1964-06-01

    Full Text Available São estudados três irmãos, respectivamente com 16, 8 e 6 anos de idade, todos do sexo masculino, com ataxia heredo-degenerativa associada, em dois dêles, a hipoacusia. Nos antecedentes há referência a moléstia semelhante em um avô e um tio-avô. É discutido o diagnóstico diferencial com a moléstia de Pièrre Marie, a doença de Charcot-Marie-Tooth, a síndrome de Refsum e a neurite intersticial hipertrófica, sendo acentuada a semelhança dos casos estudados com a moléstia de Friedreich. São feitos comentários à associação da doença de Friedreich com distúrbios da audição.

  11. Hepatotoxicidade associada ao uso de esteroides anabolizantes

    Directory of Open Access Journals (Sweden)

    Mónica Brinquinho

    2017-06-01

    Full Text Available O consumo de esteroides androgénicos anabolizantes tem vindo a aumentar no meio desportivo amador, sendo de fácil acesso apesar de se tratarem de substâncias proibidas. Estão descritos múltiplos efeitos laterais, sendo a hepatotoxicidade uma das mais reportadas. Apresentam-se dois casos clínicos representativos da lesão hepática associada ao consumo de esteroides anabolizantes. Ambos evidenciaram morbilidade significativa, embora nenhum deles tenha evoluído para falência hepática. Os autores pretendem chamar a atenção para o consumo destes fármacos, particularmente frequente em indivíduos jovens, praticantes de desporto amador.

  12. 75 FR 44936 - Notice of Request for Extension of Approval of an Information Collection; Phytophthora Ramorum...

    Science.gov (United States)

    2010-07-30

    ...; Phytophthora Ramorum; Quarantine and Regulations AGENCY: Animal and Plant Health Inspection Service, USDA... regulations for the interstate movement of regulated articles to prevent the spread of Phytophthora ramorum... of Phytophthora ramorum, contact Mr. Prakash Hebbar, Program Manager, Emergency and Domestic...

  13. Biological control of Phytophthora root rot of avocato with microorganisms grown in organic mulches Controle biológico da podridão radicular de Phytophthora no abacateiro utilizando substratos orgânicos colonizados

    Directory of Open Access Journals (Sweden)

    Jefferson L. da S. Costa

    2000-10-01

    Full Text Available Organic mulches colonized with microbial biocontrol agents, termed bioenhanced mulches, were tested for their ability to reduce Phytophthora root rot of avocado (Persea americana Mill.. Benomyl-resistant mutants of Gliocladium virens (KA 230-1 and Trichoderma harzianum (KA 159.2 isolated from suppressive soils and selected as efficient antagonists of P. cinnamomi were evaluated for their ability to colonize different mulches under controlled laboratory conditions. Sudangrass and a coarse yardwaste were found to be better substrates than a fine yardwaste, woodwaste or rice hulls for biocontrol agents propagules production. The most suitable conditions for colonization were an optimum temperature of 24°C, a moisture content of 20% for sudangrass and 30% for the coarse yardwaste, and a continuous light exposure during a 15-day incubation period. In the greenhouse, fresh sudangrass and a coarse yardwaste colonized with G. virens and used as a surface mulch proved to be the best combination for reducing the population of P. cinnamomi in 4-liter pots containing artificially-infested soil. Healthy avocado roots made up 31-37% of the roots in the G. virens-mulch combinations compared to 0% healthy in infested controls after two months.Compostos orgânicos colonizados com agentes de controle microbiológico, então denominados compostos bioativados, foram testados quanto a sua habilidadade controlar à podridão radicular de Phytophtora no abacateiro (Persea americana Mill. Mutantes de Gliocladium virens (KA 230-1 e Trichoderma harzianun (KA 159-2 resistentes a benomyl recuperados de solos supressivos e selecionados como eficientes antagonistas à P. cinnamoni foram avaliados quanto à sua capacidade de colonizar diversos compostos orgânicos em condições de laboratório. O Capim Sudão e um Composto de Jardim de alta granulação demonstraram quanto à sua capacidade de multiplicar propágulos de agentes de biocontrole, serem superiores à um

  14. Phytophthora porri in leek: epidemiology and resistance.

    NARCIS (Netherlands)

    Smilde, W.D.

    1996-01-01

    In winter, Phytophthora porri is an important pathogen of leek ( Allium porrum L.) in the Netherlands. The fungus survives the crop-free period in summer by oospores in soil, and infects the leaves in autumn. Field studies indicated that dispersal by rain splash is crucial for initiation of an epid

  15. Tomato late blight (Phytophthora infestans) in Uganda

    NARCIS (Netherlands)

    Tumwine, J.; Frinking, H.D.; Jeger, M.J.

    2002-01-01

    A survey on the tomato late blight situation and current practices for disease management was carried out in Uganda using an informal structured questionnaire approach. Ten districts from different agroclimatic zones were selected for the survey. Phytophthora infestans isolates from tomatoes were ob

  16. The nature of biotrophy in Phytophthora infestans

    NARCIS (Netherlands)

    Scheepens, P.C.

    1978-01-01

    Phytophthora infestans, being an intermediate type between the facultative and obligate parasites among the Peronosporales (class Oomycetes ), was used to study the factors which are responsible for the inability of

  17. Hot spots of Phytophthora in commercial nurseries

    Science.gov (United States)

    Corina Junker; Patrick Goff; Stefan Wagner; Sabine Werres

    2017-01-01

    Studies have shown that nurseries are an important source for the spread of Phytophthora. Most surveys and studies focusing on the epidemiology of these pathogens in nurseries are based on sampling of symptomatic plants or on samples like water of different sources used for irrigation. There is little knowledge, however, on the survival and...

  18. Phytophthora speelt verstoppertje bij NFT aardbei

    NARCIS (Netherlands)

    Evenhuis, B.; Verhoeven, J.T.W.

    2011-01-01

    Aardbeitelers worden 'blij' gemaakt met Phytophthora cactorum in hun gewas, terwijl ze daar niet op zitten te wachten. Onderzoekers worden teleurgesteld omdat infectie uitblijft terwijl ze er alles aan doen om aantasting te krijgen. Dat hindert ze bij het uitvinden wat het ontsmettingseffect is van

  19. Variation in Phytophthora infestans : sources and implications

    NARCIS (Netherlands)

    Flier, W.

    2001-01-01

    The oomycete pseudofungus Phytophthora infestans (Mont.) de Bary, the causal organism of late blight, is considered to be one of the most devastating pathogens affecting potatoes and tomatoes worldwide. In Europe, the pathogen caused severe epidemics on potatoes after its introduction in 1845. Late

  20. Phytophthora Genome Sequences Uncover Evolutionary Origins and Mechanisms of Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Lamour, Kurt H [ORNL; McDonald, W Hayes [ORNL; Savidor, Alon [ORNL

    2006-01-01

    Genome sequences of the soybean pathogen, Phytophthora sojae, and the sudden oak death pathogen, Phytophthora ramorum, suggest a photosynthetic past and reveal recent massive expansion and diversification of potential pathogenicity gene families. Abstract: Draft genome sequences of the soybean pathogen, Phytophthora sojae, and the sudden oak death pathogen, Phytophthora ramorum, have been determined. O mycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms and the presence of many Phytophthora genes of probable phototroph origin support a photosynthetic ancestry for the stramenopiles. Comparison of the two species' genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors and, in particular, a superfamily of 700 proteins with similarity to known o mycete avirulence genes.

  1. Phytophthora Genome Sequences Uncover Evolutionary Origins and Mechanisms of Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathy, Sucheta; Zhang, Xuemin; Dehal, Paramvir; Jiang, Rays H. Y.; Aerts, Andrea; Arredondo, Felipe D.; Baxter, Laura; Bensasson, Douda; Beynon, JIm L.; Chapman, Jarrod; Damasceno, Cynthia M. B.; Dorrance, Anne E.; Dou, Daolong; Dickerman, Allan W.; Dubchak, Inna L.; Garbelotto, Matteo; Gijzen, Mark; Gordon, Stuart G.; Govers, Francine; Grunwald, NIklaus J.; Huang, Wayne; Ivors, Kelly L.; Jones, Richard W.; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt H.; Lee, Mi-Kyung; McDonald, W. Hayes; Medina, Monica; Meijer, Harold J. G.; Nordberg, Erik K.; Maclean, Donald J.; Ospina-Giraldo, Manuel D.; Morris, Paul F.; Phuntumart, Vipaporn; Putnam, Nicholas J.; Rash, Sam; Rose, Jocelyn K. C.; Sakihama, Yasuko; Salamov, Asaf A.; Savidor, Alon; Scheuring, Chantel F.; Smith, Brian M.; Sobral, Bruno W. S.; Terry, Astrid; Torto-Alalibo, Trudy A.; Win, Joe; Xu, Zhanyou; Zhang, Hongbin; Grigoriev, Igor V.; Rokhsar, Daniel S.; Boore, Jeffrey L.

    2006-04-17

    Draft genome sequences have been determined for the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum. Oömycetes such as these Phytophthora species share the kingdom Stramenopila with photosynthetic algae such as diatoms, and the presence of many Phytophthora genes of probable phototroph origin supports a photosynthetic ancestry for the stramenopiles. Comparison of the two species' genomes reveals a rapid expansion and diversification of many protein families associated with plant infection such as hydrolases, ABC transporters, protein toxins, proteinase inhibitors, and, in particular, a superfamily of 700 proteins with similarity to known oömycete avirulence genes.

  2. The in Vitro Growth Inhibition Effect of Cortex Cinnamomi on Bacteria%肉桂体外抑菌作用研究

    Institute of Scientific and Technical Information of China (English)

    邱世翠; 李连锦; 刘云波; 彭启海; 高法彬

    2001-01-01

    Objective: To research on the in vitro growth inhibition effectof Cortex Cinnamomi on bacteria. Methods: K-B paper dispersion method was used, the circular filter paper pieces were presoaked with 100% Cortex Cinnamomi water extract and observed the effect of it on following bacteria: Escherichia Coli, Shigella, Salmonella typhi, staphylococcus aureus, staphylococcus albicans, candida albicans. Results: It had obvious effect of growth inhibition on bacteria. Conclusion: Cortex Cinnamomi has significant in vitro effect of growth inhibition on bacteria and anti-fungal effect.%目的:探讨肉桂的体外抑菌作用。方法:用K-B纸片扩散法100%肉桂水浸出液滤纸片对大肠杆菌、痢疾杆菌、伤寒杆菌、金黄色葡萄球菌、白色葡萄球菌及白色念珠抑菌作用进行了研究。结果:肉桂对以上细菌均有明显的抑菌作用。结论:肉桂在体外有明显的抑菌作用及抗真菌作用。

  3. Development of an ionic liquid-based microwave-assisted method for simultaneous extraction and distillation for determination of proanthocyanidins and essential oil in Cortex cinnamomi.

    Science.gov (United States)

    Liu, Ye; Yang, Lei; Zu, Yuangang; Zhao, Chunjian; Zhang, Lin; Zhang, Ying; Zhang, Zhonghua; Wang, Wenjie

    2012-12-15

    Cortex cinnamomi is associated with many health benefits and is used in the food and pharmaceutical industries. In this study, an efficient ionic liquid-based microwave-assisted simultaneous extraction and distillation (ILMSED) technique was used to extract cassia oil and proanthocyanidins from Cortex cinnamomi; these were quantified by gas chromatography/mass spectrometry (GC-MS) and the vanillin-HCl colorimetric method, respectively. 0.5M 1-butyl-3-methylimidazolium bromide ionic liquid was selected as solvent. The optimum parameters of dealing with 20.0 g sample were 230 W microwave irradiation power, 15 min microwave extraction time and 10 liquid-solid ratio. The yields of essential oil and proanthocyanidins were 1.24 ± 0.04% and 4.58 ± 0.21% under the optimum conditions. The composition of the essential oil was analysed by GC-MS. Using the ILMSED method, the energy consumption was reduced and the extraction yields were improved. The proposed method was validated using stability, repeatability, and recovery experiments. The results indicated that the developed ILMSED method provided a good alternative for the extraction of both the essential oil and proanthocyanidins from Cortex cinnamomi.

  4. Pathogenicity of Phytophthora isolates originating from several woody hosts in Bulgaria and Poland

    Directory of Open Access Journals (Sweden)

    Lyubenova Aneta B.

    2016-09-01

    Full Text Available Our aim was to examine the virulence of eight Phytophthora isolates belonging to three species (Phytophthora cryptogea, Phytophthora plurivora and Phytophthora quercina obtained from diverse European ecosystems (in Bulgaria, Poland and Germany towards three forest tree hosts – English oak (Quercus robur L., Turkey oak (Quercus cerris L. and European beech (Fagus sylvatica L..

  5. Phytophthora root rot resistance in soybean E00003

    Science.gov (United States)

    Phytophthora root rot (PRR), caused by the oomycete Phytophthora sojae, is a devastating disease in soybean production. Using resistant cultivars has been suggested as the best solution for disease management. Michigan elite soybean E00003 is resistant to P. sojae and has been used as a PRR resist...

  6. Host and habitat index for Phytophthora species in Oregon

    Science.gov (United States)

    Everett Hansen; Paul Reeser; Wendy Sutton; Laura. Sims

    2012-01-01

    In this contribution we compile existing records from available sources of reliably identified Phytophthora species from forests and forest trees in Oregon, USA. A searchable version of this information may be found in the Forest Phytophthoras of the World Disease Finder (select USA-Oregon). We have included isolations from soil and streams in...

  7. Forest Phytophthora diseases in the Americas: 2007 - 2010

    Science.gov (United States)

    S. J. Frankel; E. M. Hansen

    2011-01-01

    Recent findings, policy, regulation, and management relating to tree disease caused by Phytophthora species in wildlands and nurseries of North and South America are reviewed. These include the isolation of Phytophthora alni uniformis Brasier & S.A.Kirk in Alaska, and detection of population shifts in NA1, NA2 and EU1...

  8. The aspartic proteinase family of three Phytophthora species

    NARCIS (Netherlands)

    Kay, J.; Meijer, H.J.G.; Have, ten A.; Kan, van J.A.L.

    2011-01-01

    Background - Phytophthora species are oomycete plant pathogens with such major social and economic impact that genome sequences have been determined for Phytophthora infestans, P. sojae and P. ramorum. Pepsin-like aspartic proteinases (APs) are produced in a wide variety of species (from bacteria to

  9. Variation in capsidiol sensitivity between Phytophthora infestans and Phytophthora capsici is consistent with their host range.

    Science.gov (United States)

    Giannakopoulou, Artemis; Schornack, Sebastian; Bozkurt, Tolga O; Haart, Dave; Ro, Dae-Kyun; Faraldos, Juan A; Kamoun, Sophien; O'Maille, Paul E

    2014-01-01

    Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins.

  10. Phytophthora-ID.org: A sequence-based Phytophthora identification tool

    Science.gov (United States)

    N.J. Grünwald; F.N. Martin; M.M. Larsen; C.M. Sullivan; C.M. Press; M.D. Coffey; E.M. Hansen; J.L. Parke

    2010-01-01

    Contemporary species identification relies strongly on sequence-based identification, yet resources for identification of many fungal and oomycete pathogens are rare. We developed two web-based, searchable databases for rapid identification of Phytophthora spp. based on sequencing of the internal transcribed spacer (ITS) or the cytochrome oxidase...

  11. Variation in capsidiol sensitivity between Phytophthora infestans and Phytophthora capsici is consistent with their host range.

    Directory of Open Access Journals (Sweden)

    Artemis Giannakopoulou

    Full Text Available Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins.

  12. Variation in Capsidiol Sensitivity between Phytophthora infestans and Phytophthora capsici Is Consistent with Their Host Range

    Science.gov (United States)

    Giannakopoulou, Artemis; Schornack, Sebastian; Bozkurt, Tolga O.; Haart, Dave; Ro, Dae-Kyun; Faraldos, Juan A.; Kamoun, Sophien; O’Maille, Paul E.

    2014-01-01

    Plants protect themselves against a variety of invading pathogenic organisms via sophisticated defence mechanisms. These responses include deployment of specialized antimicrobial compounds, such as phytoalexins, that rapidly accumulate at pathogen infection sites. However, the extent to which these compounds contribute to species-level resistance and their spectrum of action remain poorly understood. Capsidiol, a defense related phytoalexin, is produced by several solanaceous plants including pepper and tobacco during microbial attack. Interestingly, capsidiol differentially affects growth and germination of the oomycete pathogens Phytophthora infestans and Phytophthora capsici, although the underlying molecular mechanisms remain unknown. In this study we revisited the differential effect of capsidiol on P. infestans and P. capsici, using highly pure capsidiol preparations obtained from yeast engineered to express the capsidiol biosynthetic pathway. Taking advantage of transgenic Phytophthora strains expressing fluorescent markers, we developed a fluorescence-based method to determine the differential effect of capsidiol on Phytophtora growth. Using these assays, we confirm major differences in capsidiol sensitivity between P. infestans and P. capsici and demonstrate that capsidiol alters the growth behaviour of both Phytophthora species. Finally, we report intraspecific variation within P. infestans isolates towards capsidiol tolerance pointing to an arms race between the plant and the pathogens in deployment of defence related phytoalexins. PMID:25203155

  13. Doenças virais associadas à toxicodependência

    OpenAIRE

    Rodrigues, Francisco

    2008-01-01

    Existe uma clara associação entre o consumo de drogas por via endovenosa e a existência de doenças concomitantes, nomeadamente virais. Neste trabalho pretende-se abordar a epidemiologia das principais doenças associadas, numa população específica.

  14. Genetic transformation of the plant pathogens Phytophthora capsici and Phytophthora parasitica.

    Science.gov (United States)

    Bailey, A M; Mena, G L; Herrera-Estrella, L

    1991-08-11

    Phytophthora capsici and P.parasitica were transformed to hygromycin B resistance using plasmids pCM54 and pHL1, which contain the bacterial hygromycin B phosphotransferase gene (hph) fused to promoter elements of the Ustilago maydis heat shock hsp70 gene. Enzymes Driselase and Novozyme 234 were used to generate protoplasts which were then transformed following exposure to plasmid DNA and polyethylene glycol 6000. Transformation frequencies of over 500 transformants per micrograms of DNA per 1 x 10(6) protoplasts were obtained. Plasmid pCM54 appears to be transmitted in Phytophthora spp. as an extra-chromosomal element through replication, as shown by Southern blot hybridization and by the loss of plasmid methylation. In addition, transformed strains retained their capacity of infecting Serrano pepper seedlings and Mc. Intosh apple fruits, the host plants for P.capsici and P.parasitica, respectively.

  15. Síndrome de Sweet associada à policitemia vera

    OpenAIRE

    Moreira, Ângela Puccini; Souza,Flávia Feijó de; Gaspar, Neide Kalil; Quattrino,Ada Lobato; Vilar,Enoi Aparecida Guedes

    2009-01-01

    A síndrome de Sweet pode estar associada a malignidades hematológicas, principalmente, à leucemia mieloide aguda, porém existem poucos relatos demonstrando a associação com a policitemia vera. Relata-se o caso de doente do sexo masculino, de 65 anos, portador de policitemia vera,que evoluiu com aparecimento de síndrome de Sweet na sua forma paraneoplásica.

  16. Genetic transformation of the plant pathogens Phytophthora capsici and Phytophthora parasitica.

    OpenAIRE

    Bailey, A. M.; Mena, G L; Herrera-Estrella, L

    1991-01-01

    Phytophthora capsici and P.parasitica were transformed to hygromycin B resistance using plasmids pCM54 and pHL1, which contain the bacterial hygromycin B phosphotransferase gene (hph) fused to promoter elements of the Ustilago maydis heat shock hsp70 gene. Enzymes Driselase and Novozyme 234 were used to generate protoplasts which were then transformed following exposure to plasmid DNA and polyethylene glycol 6000. Transformation frequencies of over 500 transformants per micrograms of DNA per ...

  17. Cortex cinnamomi extract prevents streptozotocin- and cytokine-induced β-cell damage by inhibiting NF-κB

    Institute of Scientific and Technical Information of China (English)

    Kang-Beom Kwon; Eun-Kyung Kim; Eun-Sil Jeong; Young-Hoon Lee; Young-Rae Lee; Jin-Woo Park; Do-Gon Ryu; Byung-Hyun Park

    2006-01-01

    AIM: To clarify the mechanism underlying the antidiabetic activities of cortex cinnamomi extract (CCE).METHODS: To induce in vivo diabetes, mice were injected with streptozotocin (STZ) via a tail vein (100 mg STZ/kg body weight). To determine the effects of CCE,mice were administered CCE twice daily for 7 d by oral gavage starting 1 wk before the STZ injection. Blood glucose and plasma insulin concentration were measured as an index of diabetes. Also, to induce cytotoxicity of RINm5F cells, we treated with cytokines (IL-1β (2.0 ng/mL) and IFN-γ (100 U/mL)). Cell viability and nitric oxide production were measured colorimetrically.Inducible nitric oxide synthase (iNOS) mRNA and protein expression were determined by RT-PCR and Western blotting, respectively. The activation of NF-KB was assayed by using gel mobility shift assays of nuclear extracts.RESULTS: Treatment of mice with STZ resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of STZ were completely prevented when mice were pretreated with CCE. The inhibitory effect of CCE on STZ-induced hyperglycemia was mediated through the suppression of iNOS expression. In rat insulinoma RINm5F cells,CCE completely protected against interleukin-1β and interferon-y-mediated cytotoxicity. Moreover, RINm5F cells incubated with CCE showed significant reductions in interleukin-1β and interferon-y-induced nitric oxide production and in iNOS mRNA and protein expression,and these findings correlated well with in vivo observations.CONCLUSION: The molecular mechanism by which CCE inhibits iNOS gene expression appears to involve the inhibition of NF-κB activation. These results reveal the possible therapeutic value of CCE for the prevention of diabetes mellitus progression.

  18. Phytophthora species, new threats to the plant health in Korea.

    Science.gov (United States)

    Hyun, Ik-Hwa; Choi, Woobong

    2014-12-01

    Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

  19. De rol van heterotrimere G-eiwitten in de ontwikkeling en virulentie van Phytophthora infestans

    NARCIS (Netherlands)

    Latijnhouwers, M.

    2003-01-01

    Onderzoek naar de ziekteverwekker Phytophthora infestans die de aardappelziekte veroorzaakt. Samenvatting van het proefschrift van Maita J.M. Latijnhouwers getiteld: 'The role of heterotrimeric G-proteins in development and virulence of Phytophthora infestans'

  20. Voetsporen van evolutie: de dynamiek van effectorgenen in het Phytophthora-genoom

    NARCIS (Netherlands)

    Jiang, R.H.Y.

    2007-01-01

    Het geslacht Phytophthora omvat meer dan 65 verwoestende plantenpathogene soorten die ernstige schade toebrengen aan landbouwgewassen en aan planten, struiken en bomen in de natuur. Economisch belangrijke pathogenen zijn onder andere Phytophthora infestans, de veroorzaker van de aardappelziekte, Phy

  1. Evaluation of Watermelon Germplasm for Resistance to Phytophthora Blight Caused by Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Min-Jeong Kim

    2013-03-01

    Full Text Available This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension (10⁶ sporangia/ml. At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840 showed moderate resistance and two accessions (IT185446 and IT187904 were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

  2. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Mee Kyung Sang

    2013-06-01

    Full Text Available We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107 among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05 reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05 reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

  3. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici

    Science.gov (United States)

    Sang, Mee Kyung; Shrestha, Anupama; Kim, Du-Yeon; Park, Kyungseok; Pak, Chun Ho; Kim, Ki Deok

    2013-01-01

    We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P < 0.05) reduced Phytophthora blight without influencing rhizosphere microbial populations; they showed similar or better levels of disease suppressions than in metalaxyl treatment in the 2007 and 2009 tests, but not in the 2008 test. In the 2-year plastic house tests, all the selected strains significantly (P < 0.05) reduced anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit. PMID:25288942

  4. Enhanced sensitivity of A549 cells to the cytotoxic action of anticancer drugs via suppression of Nrf2 by procyanidins from Cinnamomi Cortex extract

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, Tomokazu; Matsumoto, Takashi; Itoi, Ayano; Kawana, Ayako; Nishiyama, Takahito; Ogura, Kenichiro [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan); Hiratsuka, Akira, E-mail: hiratuka@toyaku.ac.jp [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan)

    2011-10-07

    Highlights: {yields} We found a novel inhibitor of Nrf2 known as a chemoresistance factor. {yields} Overexpressed Nrf2 in lung cancer cells was suppressed by Cinnamomi Cortex extract. {yields} Cytotoxic action of anticancer drugs in cells treated with the extract was enhanced. {yields} Procyanidin tetramers and pentamers were active components in suppressing Nrf2. -- Abstract: Nuclear factor-E2-related factor 2 (Nrf2) is an important cytoprotective transcription factor because Nrf2-regulated enzymes play a key role in antioxidant and detoxification processes. Recent studies have reported that lung cancer cells overexpressing Nrf2 exhibit increased resistance to chemotherapy. Suppression of overexpressed Nrf2 is needed for a new therapeutic approach against lung cancers. In the present study, we found that Cinnamomi Cortex extract (CCE) has an ability to suppress Nrf2-regulated enzyme activity and Nrf2 expression in human lung cancer A549 cells with high Nrf2 activity. Moreover, we demonstrated that CCE significantly enhances sensitivity of A549 cells to the cytotoxic action of doxorubicin and etoposide as well as increasing the intracellular accumulation of both drugs. These results suggest that CCE might be an effective concomitant agent to reduce anticancer drug resistance derived from Nrf2 overexpression. Bioactivity-guided fractionation revealed that procyanidin tetramers and pentamers contained in CCE were active components in suppressing Nrf2.

  5. 78 FR 58993 - Notice of Request for Extension of Approval of an Information Collection; Phytophthora Ramorum...

    Science.gov (United States)

    2013-09-25

    ... Collection; Phytophthora Ramorum; Quarantine and Regulations AGENCY: Animal and Plant Health Inspection... Phytophthora ramorum. DATES: We will consider all comments that we receive on or before November 25, 2013... of regulated articles to prevent the spread of Phytophthora ramorum, contact Dr. Prakash K....

  6. 40 CFR 180.1057 - Phytophthora palmivora; exemption from requirement of tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Phytophthora palmivora; exemption from... From Tolerances § 180.1057 Phytophthora palmivora; exemption from requirement of tolerance. Phytophthora palmivora is exempted from the requirement of a tolerance in or on the raw agricultural...

  7. Risico voor resistente rassen, Phytophthora doorbreekt resisten tiegen (interview met Geert Kessel)

    NARCIS (Netherlands)

    Engwerda, J.; Kessel, G.J.T.

    2009-01-01

    In phytophthora-resistente aardappelrassen Bionica en Toluca kan alsnog phytoph-thora ontstaan. Wageningen UR waarschuwt telers hiervoor. Bij laboratoriumexperimenten zijn drie phytophthora-isolaten gevonden die het resistentiegen Blb2 hebben doorbroken. Het is voor het eerst dat de aardappelziekte

  8. Mapping the Progression of Phytophthora Ramorum

    Science.gov (United States)

    Banh, T.; Li, J.; El-Askary, H. M.

    2013-12-01

    There has been a plant pathogen, Phytophthora Ramorum that has been causing trouble for the plant species in the forests of California and Oregon. Phytophthora is essentially a water mold that infects oak species like California black oak, coast live oak as well as California bay laurel (Lamsal). What this project aims to accomplish is to observe any changes in NDVI values between the years of 2002 and 1994. What the project hopes to observe is a decline of NDVI values between the two years because the infection of Phytophtora Ramorum will cause stress to the plant or kill the plant, which will lower the values of NDVI. The project will utilizes satellite data to create NDVI images over the study area and two types of change detection methods to observe the differences between the NDVI values of the two years. Preliminary results for the project, data obtained from Landsat 7 ETM+ with a resolution of 240 meters, was not able to observe any significant changes. A finer resolution to differentiate the NDVI values would be needed. In addition the best way to keep the pathogen from getting out of control is with ground level management, or complete eradication of the pathogen. These eradication methods include burning the infected host plants and spreading herbicide (Alexander). With that in mind it would be ideal to have an early detection of the pathogen infestation. Therefore another goal of the project is to continue to research if remote sensing could play a role in an early detection method for the presence of Phytophtora Ramorum.

  9. Fibras nervosas retinianas mielinizadas associadas a miopia e ambliopia

    OpenAIRE

    Borges, Bárbara; Cabugueira, Ana; Anjos, Rita; Paixão, Ana; Marques, Margarida; Toscano,Alcina

    2015-01-01

    Introdução: A presença de fibras nervosas mielinizadas na retina está descrita em cerca de 1% da população. Os doentes são habitualmente assintomáticos, embora possam coexistir outras alterações oculares como miopia e ambliopia.  Material e Métodos: Descrevem-se 3 casos de crianças com fibras nervosas retinianas mielinizadas unilaterais, associadas a miopia e ambliopia.  Resultados: A idade das crianças variou entre 1 e 7 anos. O olho afectado foi o olho direito. A melhor acuidade visual corr...

  10. A molecular method to assess Phytophthora diversity in environmental samples.

    Science.gov (United States)

    Scibetta, Silvia; Schena, Leonardo; Chimento, Antonio; Cacciola, Santa O; Cooke, David E L

    2012-03-01

    Current molecular detection methods for the genus Phytophthora are specific to a few key species rather than the whole genus and this is a recognized weakness of protocols for ecological studies and international plant health legislation. In the present study a molecular approach was developed to detect Phytophthora species in soil and water samples using novel sets of genus-specific primers designed against the internal transcribed spacer (ITS) regions. Two different rDNA primer sets were tested: one assay amplified a long product including the ITS1, 5.8S and ITS2 regions (LP) and the other a shorter product including the ITS1 only (SP). Both assays specifically amplified products from Phytophthora species without cross-reaction with the related Pythium s. lato, however the SP assay proved the more sensitive and reliable. The method was validated using woodland soil and stream water from Invergowrie, Scotland. On-site use of a knapsack sprayer and in-line water filters proved more rapid and effective than centrifugation at sampling Phytophthora propagules. A total of 15 different Phytophthora phylotypes were identified which clustered within the reported ITS-clades 1, 2, 3, 6, 7 and 8. The range and type of the sequences detected varied from sample to sample and up to three and five different Phytophthora phylotypes were detected within a single sample of soil or water, respectively. The most frequently detected sequences were related to members of ITS-clade 6 (i.e. P. gonapodyides-like). The new method proved very effective at discriminating multiple species in a given sample and can also detect as yet unknown species. The reported primers and methods will prove valuable for ecological studies, biosecurity and commercial plant, soil or water (e.g. irrigation water) testing as well as the wider metagenomic sampling of this fascinating component of microbial pathogen diversity.

  11. Biocontrol of Phytophthora Blight and Anthracnose in Pepper by Sequentially Selected Antagonistic Rhizobacteria against Phytophthora capsici.

    Science.gov (United States)

    Sang, Mee Kyung; Shrestha, Anupama; Kim, Du-Yeon; Park, Kyungseok; Pak, Chun Ho; Kim, Ki Deok

    2013-06-01

    We previously developed a sequential screening procedure to select antagonistic bacterial strains against Phytophthora capsici in pepper plants. In this study, we used a modified screening procedure to select effective biocontrol strains against P. capsici; we evaluated the effect of selected strains on Phytophthora blight and anthracnose occurrence and fruit yield in pepper plants under field and plastic house conditions from 2007 to 2009. We selected four potential biocontrol strains (Pseudomonas otitidis YJR27, P. putida YJR92, Tsukamurella tyrosinosolvens YJR102, and Novosphingobium capsulatum YJR107) among 239 bacterial strains. In the 3-year field tests, all the selected strains significantly (P anthracnose incidence in at least one of the test years, but their biocontrol activities were variable. In addition, strains YJR27, YJR92, and YJR102, in certain harvests, increased pepper fruit numbers in field tests and red fruit weights in plastic house tests. Taken together, these results indicate that the screening procedure is rapid and reliable for the selection of potential biocontrol strains against P. capsici in pepper plants. In addition, these selected strains exhibited biocontrol activities against anthracnose, and some of the strains showed plant growth-promotion activities on pepper fruit.

  12. Evaluation of Muscodor cinnamomi as an egg biofumigant for the reduction of microorganisms on eggshell surfaces and its effect on egg quality.

    Science.gov (United States)

    Suwannarach, Nakarin; Kaewyana, Chariya; Yodmeeklin, Arpaporn; Kumla, Jaturong; Matsui, Kenji; Lumyong, Saisamorn

    2017-03-06

    The presence of microorganisms on the eggshell surface is a factor of consideration in determining egg quality. These microorganisms can contribute to egg spoilage and can infect the egg. In this study, 18 morphotypes of microorganisms were isolated from eggshells. Morphological, biochemical, physiological and molecular analyses were used to identify these morphotypes into 7 species; Bacillus drentensis, Staphylococcus arlettae, Stap. cohnii, Stap. kloosii, Stap. saprophyticus, Stap. sciuri and Stap. xylosus. The potential of Muscodor cinnamomi to reduce the presence of microorganisms on eggshells by biological fumigation was investigated. The result showed that 16 strains of the tested microorganisms were inactivated after the exposure of the fungal volatile organic compounds. The most abundant compound was 2-methylpropanoic acid, followed by 3-methylbutan-1-ol. Our results indicated that a 24-h period of fumigation of 100g rye grain culture of M. cinnamomi was the minimum dose that could significantly reduce the number of microorganisms on the eggshell surface. Fumigated eggs from both box and cabinet fumigation trials showed significantly lower microbial numbers on the eggshell than non-fumigated eggs during the storage period of 14days. It was found that the values of the yolk index, albumen index and the Haugh unit of the eggs decreased during this storage time. However, those values of the fumigated eggs from both fumigation trials were found to be significantly higher than the non-fumigated eggs after the 24-h fumigation period and following storage for 5, 7 and 14days. However, the values of the albumen index were not found to have significantly increased over 5days of the box trial. This study is the first to report on mycofumigation activity for the purposes of reducing the presence of microorganisms on the surface of eggshells.

  13. Transformation of the oomycete pathogen, Phytophthora infestans.

    Science.gov (United States)

    Judelson, H S; Tyler, B M; Michelmore, R W

    1991-01-01

    A stable transformation procedure has been developed for Phytophthora infestans, an oomycete fungus that causes the late blight diseases of potato and tomato. This is the first description of reliable methods for transformation in an oomycete pathogen. Drug-resistant transformants were obtained by using vectors that contained bacterial genes for resistance to hygromycin B or G418 fused to promoters and terminators from the Hsp70 and Ham34 genes of the oomycete, Bremia lactucae. Using polyethylene glycol and CaCl2, vector DNA was introduced into protoplasts as a complex with cationic liposomes or with carrier DNA only. Transformants were obtained at similar frequencies with each combination of promoter and selectable marker and were confirmed by DNA and RNA hybridization and phosphotransferase assays. Transformation occurred through the integration of single or tandemly repeated copies of the plasmids into genomic DNA, conferring mitotically stable drug-resistant phenotypes. The sizes of the marker gene mRNAs in each transformant and the results of transcript mapping studies were consistent with the function of the B. lactucae regulatory sequences in P. infestans. A hygromycin-resistant transformant was tested and found to maintain pathogenicity, indicating that the gene transfer procedure will be useful for the molecular analysis of genes relevant to disease.

  14. Phytophthora infestans population structure: a worldwide scale

    Directory of Open Access Journals (Sweden)

    Cárdenas Toquica Martha

    2012-08-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep (Peptidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and the mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America expanding on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  15. PHYTOPHTHORA INFESTANS POPULATION STRUCTURE: A WORLDWIDE SCALE

    Directory of Open Access Journals (Sweden)

    MARTHA CÁRDENAS

    2012-01-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of the pathogen’s population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep (Peptidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America, expanding it on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  16. Survival of Phytophthora infestans in Surface Water.

    Science.gov (United States)

    Porter, Lyndon D; Johnson, Dennis A

    2004-04-01

    ABSTRACT Coverless petri dishes with water suspensions of sporangia and zoospores of Phytophthora infestans were embedded in sandy soil in eastern Washington in July and October 2001 and July 2002 to quantify longevity of spores in water under natural conditions. Effects of solar radiation intensity, presence of soil in petri dishes (15 g per dish), and a 2-h chill period on survival of isolates of clonal lineages US-8 and US-11 were investigated. Spores in water suspensions survived 0 to 16 days under nonshaded conditions and 2 to 20 days under shaded conditions. Mean spore survival significantly increased from 1.7 to 5.8 days when soil was added to the water. Maximum survival time of spores in water without soil exposed to direct sunlight was 2 to 3 days in July and 6 to 8 days in October. Mean duration of survival did not differ significantly between chilled and nonchilled sporangia, but significantly fewer chilled spores survived for extended periods than that of nonchilled spores. Spores of US-11 and US-8 isolates did not differ in mean duration of survival, but significantly greater numbers of sporangia of US-8 survived than did sporangia of US-11 in one of three trials.

  17. The Effect of Potassium Nitrate on the Reduction of Phytophthora Stem Rot Disease of Soybeans, the Growth Rate and Zoospore Release of Phytophthora Sojae

    Science.gov (United States)

    The effects of potassium nitrate (KNO3) application on Phytophthora stem rot disease reduction of Glycine max (L.) Merr. cvs. Chusei-Hikarikuro and Sachiyutaka, and fungal growth and zoospore release of a Phytophthora sojae isolate were investigated under laboratory conditions. The application of 4-...

  18. Detection, diversity, and population dynamics of waterborne Phytophthora ramorum populations

    Science.gov (United States)

    Catherine Eyre; Matteo Garbelotto

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed...

  19. Validation of a tuber blight (Phytophthora infestans) prediction model

    Science.gov (United States)

    Potato tuber blight caused by Phytophthora infestans accounts for significant losses in storage. There is limited published quantitative data on predicting tuber blight. We validated a tuber blight prediction model developed in New York with cultivars Allegany, NY 101, and Katahdin using independent...

  20. Interaction between the moss Physcomitrella patens and Phytophthora

    NARCIS (Netherlands)

    Overdijk, Elysa J.R.; Keijzer, De Jeroen; Groot, De Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

    2016-01-01

    Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for v

  1. Potato late blight epidemics and population structure of Phytophthora infestans.

    NARCIS (Netherlands)

    Zwankhuizen, M.J.

    1998-01-01

    Potato late blight is caused by the fungus Phytophthora infestans . To study the relative importance of oospores in the epidemiology, and to estimate the relative impact of various infection sources, late blight epidemics in Southern Flevoland (The Netherlands) were studied using epidemiological and

  2. Interactions between biosurfactant-producing Pseudomonas and Phytophthora species

    NARCIS (Netherlands)

    Tran, H.

    2007-01-01

    Fluorescent Pseudomonas bacteria produce a wide variety of antimicrobial metabolites, including soap-like compounds referred to as biosurfactants. The results of this thesis showed that biosurfactant-producing Pseudomonas bacteria are effective in controlling Phytophthora foot rot disease of black p

  3. Correlating Phytophthora ramorum infection rate and lesion expansion in tanoak

    Science.gov (United States)

    Katherine Hayden; Heather Rickard; Matteo Garbelotto

    2008-01-01

    To date, resistance to Phytophthora ramorum in its most susceptible hosts has most commonly been quantified by lesion growth, after wounding or non-wounding inoculations via mycelia or high concentrations of zoospores. However, even highly susceptible hosts may not always become infected when they are exposed to a pathogen under ecologically...

  4. Phytophthora ramorum and P. kernoviae: regulation in the European union

    Science.gov (United States)

    Stephen Hunter

    2008-01-01

    The history of the regulation of action against Phytophthora ramorum and P. kernoviae in the EU and U.K. is briefly summarised. For the former there are EU controls on the import of host plants, and the internal regime of plant passporting has been extended to cover Rhododendron, Viburnum and...

  5. Stable transformation of the oomycete, Phytophthora infestans, using microprojectile bombardment

    DEFF Research Database (Denmark)

    Cvitanich, Cristina; Judelson, Howard S.

    2003-01-01

    Germinated asexual sporangia, zoospores, and mycelia of Phytophthora infestans were transformed to G418-resistance by microprojectile bombardment. After optimization, an average of 14 transformants/shot were obtained, using 10(6) germinated sporangia and gold particles coated with 1 microg...

  6. A Surface Plasmon Resonance Immunobiosensor for Detection of Phytophthora infestans

    DEFF Research Database (Denmark)

    Skottrup, Peter; Frøkiær, Hanne; Hejgaard, Jørn;

    In this study we focused on the development of a Surface Plasmon Resonance (SPR) immunosensor for Phytophthora infestans detection. The fungus-like organism is the cause of potato late blight and is a major problem in potato growing regions of the world. Efficient control is dependent on early...

  7. Carbohydrate-related enzymes of important Phytophthora plant pathogens.

    Science.gov (United States)

    Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P

    2014-11-01

    Carbohydrate-Active enZymes (CAZymes) form particularly interesting targets to study in plant pathogens. Despite the fact that many CAZymes are pathogenicity factors, oomycete CAZymes have received significantly less attention than effectors in the literature. Here we present an analysis of the CAZymes present in the Phytophthora infestans, Ph. ramorum, Ph. sojae and Pythium ultimum genomes compared to growth of these species on a range of different carbon sources. Growth on these carbon sources indicates that the size of enzyme families involved in degradation of cell-wall related substrates like cellulose, xylan and pectin is not always a good predictor of growth on these substrates. While a capacity to degrade xylan and cellulose exists the products are not fully saccharified and used as a carbon source. The Phytophthora genomes encode larger CAZyme sets when compared to Py. ultimum, and encode putative cutinases, GH12 xyloglucanases and GH10 xylanases that are missing in the Py. ultimum genome. Phytophthora spp. also encode a larger number of enzyme families and genes involved in pectin degradation. No loss or gain of complete enzyme families was found between the Phytophthora genomes, but there are some marked differences in the size of some enzyme families.

  8. Phytophthora ramorum causes cryptic bole cankers in Canyon line Oak

    Science.gov (United States)

    Unusual mortality of large canyon live oaks was observed in natural stands in San Mateo, California starting in 2007. A survey of affected stands showed that symptomatic trees were spatially associated with California bay, the primary source of Phytophthora ramorum spores in this forest type. Trunk ...

  9. Production, survival and infectivity of oospores of Phytophthora infestans

    NARCIS (Netherlands)

    Turkensteen, L.J.; Flier, W.G.; Mulder, A.; Wanningen, R.

    2000-01-01

    The formation of oospores of Phytophthora infestans was studied in tomato and potato crops and volunteer plants under field conditions, and in laboratory tests with leaf discs of potato cultivars differing in their level of race-nonspecific resistance. Oospores were readily detected in

  10. The biology of Phytophthora infestans at its center of origin

    NARCIS (Netherlands)

    Grünwald, N.J.; Flier, W.G.

    2005-01-01

    The central highlands of Mexico are considered to be a center of genetic diversity for both the potato late blight pathogen and for tuber-bearing Solanum spp. Recent work conducted in Mexico and South America sheds new light on the biology and evolution of Phytophthora infestans and other related Ph

  11. Histology of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues

    Science.gov (United States)

    Molly Botts Giesbrecht; Everett M. Hansen; Peter Kitin

    2011-01-01

    Colonisation of Notholithocarpus densiflorus (Hook. and Arn.) Rehder tissues by Phytophthora ramorum Werres, De Cock & Man in't Veld is not well understood. The pathogen is able to colonise nearly all tissues of this host but it is unclear how a tree is ultimately killed. In this research,

  12. The maturation and germination of Phytophthora ramorum Chlamydospores

    Science.gov (United States)

    Aaron L. Smith; Everett M. Hansen

    2008-01-01

    Chlamydospores are a distinctive feature of Phytophthora ramorum. They are formed quickly in agar, and within colonized leaves. We followed their development and maturation in vitro and in vivo, and studied conditions affecting their germination. Cell walls of mature P. ramorum chlamydospores...

  13. Can Phytophthora ramorum be spread with contaminated irrigation water?

    Science.gov (United States)

    D. Seipp; T. Brand; K. Kaminski; S. Wagner; S. Werres

    2008-01-01

    In a two year study, the spread of Phytophthora ramorum with contaminated irrigation water and the survival of the pathogen in water reservoirs were studied (Werres and others 2007). In addition at the end of each experimental period root ball samples from asymptomatic plants were taken to look for contamination with P. ramorum....

  14. Can Epiphytes reduce disease symptoms caused by Phytophthora ramorum

    Science.gov (United States)

    Leaf infection of ornamental species by Phytophthora ramorum has a significant impact on the spread of this disease. Fungicides have had limited effects on controlling this disease. With increasing concerns that repeated fungicide applications will exasperate the potential for fungicide resistance...

  15. Multi-scale modelling of infection pressure from Phytophthora infestans

    NARCIS (Netherlands)

    Skelsey, P.; Werf, van der W.; Kessel, G.J.T.; Rossing, W.A.H.; Holtslag, A.A.M.

    2007-01-01

    Management of potato late blight could benefit from prediction of the risk posed to potato fields from external inoculum sources of Phytophthora infestans. Influx of inoculum depends on a complex interplay of population biological, atmospheric and spore survival processes, and is difficult to predic

  16. Genome-wide identification of laccase gene family in three Phytophthora species.

    Science.gov (United States)

    Feng, Baozhen; Li, Peiqian

    2012-12-01

    Phytophthora spp. is a primary pathogen in oomycete, causing economically and environmentally devastating epidemics of plants. Laccases have been found in all domains of life but have not been reported in oomycte. In this paper, laccase genes of Phytophthora spp. were identified in three genomes (Phytophthora capsici, Phytophthora sojae and Phytophthora ramorum). 18 laccase genes were identified in total, including four in P. capsici genome, six in P. sojae genome and eight in P. ramorum genome. Most of the predicted gene models shared typical fungal laccase character, possessing three conserved positions with one cysteine and ten histidine residues at these positions. Phylogenetic analysis illustrated that laccases from Phytophthora clustered into four clades, while fungal laccases clustered together. The results provided the theoretical ground for new hypotheses about the roles laccases in oomycetes and may guide the future research of these enzymes.

  17. Two novel species representing a new clade and cluster of Phytophthora.

    Science.gov (United States)

    Yang, Xiao; Copes, Warren E; Hong, Chuanxue

    2014-01-01

    Phytophthora stricta sp. nov. and Phytophthora macilentosa sp. nov. are described based on morphological, physiological and molecular characters in this study. Phytophthora stricta represents a previously unknown clade in the rRNA internal transcribed spacer (ITS)-based phylogeny. Phytophthora macilentosa, along with nine other species, consistently forms a high temperature-tolerant cluster within ITS clade 9. These observations are supported by the sequence analysis of the mitochondrial cytochrome c oxidase 1 gene. Both species are heterothallic and all examined isolates are A1 mating type. Phytophthora stricta produces nonpapillate and slightly caducous sporangia. This species is named after its characteristic constrictions on sporangiophores. Phytophthora macilentosa produces nonpapillate and noncaducous sporangia, which are mostly elongated obpyriform with a high length to breadth ratio. Both species were recovered from irrigation water of an ornamental plant nursery in Mississippi, USA and P. stricta was also recovered from stream water in Virginia, USA.

  18. Biological differences between the evolutionary lineages within Phytophthora ramorum and Phytophthora lateralis: Should the lineages be formally taxonomically designated?

    Science.gov (United States)

    Clive Brasier

    2017-01-01

    It is now generally accepted that the four evolutionary lineages of Phytophthora ramorum (informally designated NA1, NA2, EU1, and EU2) are relatively anciently divergent populations, recently introduced into Europe and North America from different, unknown geographic locations; that recombinants between them are genetically unstable and probably...

  19. Survival of Phytophthora alni, Phytophthora kernoviae, and Phytophthora ramorum in a simulated aquatic environment at different levels of pH.

    Science.gov (United States)

    Kong, Ping; Lea-Cox, John D; Moorman, Gary W; Hong, Chuanxue

    2012-07-01

    Phytophthora ramorum, Phytophthora alni, and Phytophthora kernoviae present significant threats to biosecurity. As zoosporic oomycetes, these plant pathogens may spread through natural waterways and irrigation systems. However, survival of these pathogens in aquatic systems in response to water quality is not well understood. In this study, we investigated their zoospore survival at pH 3-11 in a 10% Hoagland's solution over a 14-day period. The results showed that all three pathogens were most stable at pH 7, although the populations declined overnight irrespective of pH. Extended survival of these species depended on the tolerance of pH of their germinants. Germinants of P. alni ssp. alni and P. ramorum were more basic tolerant (pH 5-11), while those of P. kernoviae were more acidic tolerant (pH 3-9). These tolerant germinants formed compact hyphae or secondary sporangia to allow longer survival of these pathogens. Long-term survival at a broad pH range suggests that these pathogens, especially P. ramorum, are adapted to an aquatic environment and pose a threat to new production areas through water dispersal. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  20. A universal microarray detection method for identification of multiple Phytophthora spp. using padlock probes.

    Science.gov (United States)

    Sikora, Katarzyna; Verstappen, Els; Mendes, Odette; Schoen, Cor; Ristaino, Jean; Bonants, Peter

    2012-06-01

    The genus Phytophthora consists of many species that cause important diseases in ornamental, agronomic, and forest ecosystems worldwide. Molecular methods have been developed for detection and identification of one or several species of Phytophthora in single or multiplex reactions. In this article, we describe a padlock probe (PLP)-based multiplex method of detection and identification for many Phytophthora spp. simultaneously. A generic TaqMan polymerase chain reaction assay, which detects all known Phytophthora spp., is conducted first, followed by a species-specific PLP ligation. A 96-well-based microarray platform with colorimetric readout is used to detect and identify the different Phytophthora spp. PLPs are long oligonucleotides containing target complementary sequence regions at both their 5' and 3' ends which can be ligated on the target into a circular molecule. The ligation is point mutation specific; therefore, closely related sequences can be differentiated. This circular molecule can then be detected on a microarray. We developed 23 PLPs to economically important Phytophthora spp. based upon internal transcribed spacer-1 sequence differences between individual Phytophthora spp. Tests on genomic DNA of many Phytophthora isolates and DNA from environmental samples showed the specificity and utility of PLPs for Phytophthora diagnostics.

  1. Phytophthora x pelgrandis, a new natural hybrid pathogenic to Pelargonium grandiflorum hort.

    Science.gov (United States)

    Nirenberg, Helgard I; Gerlach, Wolfram F; Gräfenhan, Tom

    2009-01-01

    A new Phytophthora hybrid of Ph. cactorum (Leb. & Cohn) Schroet. and Ph. nicotianaevan Breda de Haan pathogenic to cultivars of Pelargonium grandiflorum hort. is described as Phytophthora X pelgrandis and its morphological features are documented. Morphological, physiological (e.g., temperature requirements) and molecular data (DNA sequencing, random amplified polymorphic DNA-PCR) are presented for isolates of the Phytophthora hybrid. Pathogenicity was tested on cultivars of P. grandiflorum and Nicotiana tabacum. For comparison cultures of the parental species and additional Phytophthora taxa also were examined.

  2. Insuficiência renal aguda associada à leptospirose

    Directory of Open Access Journals (Sweden)

    Elizabeth De Francesco Daher

    2010-12-01

    Full Text Available A leptospirose é a zoonose mais importante do mundo. Os pacientes são tipicamente homens jovens. Vários fatores estão envolvidos na insuficiência renal aguda (IRA na leptospirose, incluindo ação nefrotóxica direta da leptospira, hiperbilirrubinemia, rabdomiólise e hipovolemia. Os principais achados histológicos são nefrite intersticial aguda e necrose tubular aguda. A IRA na leptospirose é geralmente não oligúrica e hipocalêmica. Alterações da função tubular precedem a queda na taxa de filtração glomerular, o que poderia explicar a alta frequência de hipocalemia. O tratamento antibiótico é eficaz nas fases precoces e tardias e/ou graves. Para pacientes críticos com IRA na leptospirose, as seguintes condutas são recomendadas: hemodiálise precoce e diária; baixa infusão de volume (devido ao risco de hemorragia pulmonar, e estratégias de proteção pulmonar. A mortalidade na IRA associada à leptospirose está em torno de 22%.

  3. Caquexia associada à insuficiência cardíaca

    Directory of Open Access Journals (Sweden)

    Marina Politi Okoshi

    2013-05-01

    Full Text Available Pacientes com insuficiência cardíaca frequentemente desenvolvem estado de caquexia, que constitui fator independente de redução da sobrevida. Caquexia pode ser diagnosticada quando ocorre perda de peso corporal maior que 6% do peso habitual, na ausência de outras doenças. Embora sua fisiopatologia não esteja completamente esclarecida, vários fatores parecem estar envolvidos, como diminuição da ingestão alimentar, anormalidades do trato gastrointestinal, ativação imunológica e neuro-hormonal e alteração da relação entre processos anabólicos e catabólicos. Como não há terapia específica para a caquexia associada à insuficiência cardíaca, o tratamento baseia-se no suporte nutricional, bloqueio neuro-hormonal, controle do edema e anemia e exercícios físicos. Fármacos com propriedades imunomodulatórias e anabólicas encontram-se em investigação clínica e experimental.

  4. Primeiro caso de febre maculosa brasileira branda associada à artrite

    Directory of Open Access Journals (Sweden)

    Virgínia Lucia Nazario Bonoldi

    2014-06-01

    Full Text Available Descrevemos o primeiro caso brasileiro de Riquetsiose branda, agravada por monoartrite em joelho, em adulto jovem picado por carrapato na perna esquerda na região de Camburi, localizada no município de São Sebastião, sul da região costeira do estado de São Paulo, Mata Atlântica, Brasil. O paciente apresentou uma escara de inoculação no local da picada do carrapato, associada ao aumento ganglionar em virilha esquerda, febre, poliartralgia, cefaleia e erupção macular. Vinte dias após o episódio da picada de carrapato, o paciente apresentou monoartrite em joelho direito. O diagnóstico de Riquetsiose branda foi estabelecido pela análise imunológica sequencial em amostras de soro e líquido sinovial, tendo sido empregada a técnica de imunofluorescência (IF indireta para anticorpos reativos contra Rickettsia parkeri e Rickettsia rickettsii. A Riquetsiose branda é uma zoonose emergente, que deve ser investigada pelos médicos, incluindo reumatologistas, em pacientes que apresentem erupção macular, febre e, eventualmente, artrite, após visita ao sul da região costeira da Mata Atlântica no Brasil.

  5. Acatisia associada à bromoprida em um paciente deprimido usando fluvoxamina

    Directory of Open Access Journals (Sweden)

    Tábita Juliana Tomelin

    2012-01-01

    Full Text Available CONTEXTO: A acatisia é definida clinicamente como uma sensação de agitação associada à necessidade de produção de movimentos, comumente deflagrada por bloqueadores dopaminérgicos, como os neurolépticos, podendo ocorrer também durante o tratamento com inibidores seletivos de recaptação de serotonina. É possível que drogas não psiquiátricas que bloqueiem receptores dopaminérgicos, como a bromoprida, possam causar sintomas extrapiramidais. OBJETIVOS: Descrever um desfecho desfavorável caracterizado por acatisia em um paciente depressivo previamente estabilizado com fluvoxamina, após usar bromoprida. MÉTODOS: Descrição de um caso. RESULTADOS: Sr. J., paciente deprimido de 47 anos, estava estabilizado com fluvoxamina 200 mg por dia. Iniciou abruptamente com quadro de inquietação e necessidade de produzir movimentos voluntariamente a fim de aliviar esse desconforto. Há quatro dias havia iniciado o uso de bromoprida 30 mg por dia para tratamento de dispepsia. A suspensão da bromoprida promoveu alívio imediato dos sintomas. CONCLUSÃO: A bromoprida, um bloqueador dopaminérgico, pode ter deflagrado acatisia em um paciente em uso de fluvoxamina. Os mecanismos farmacológicos relacionados a esse desfecho são discutidos.

  6. Epilepsia parcial associada a tumores cerebrais primários

    Directory of Open Access Journals (Sweden)

    Brainer-Lima Paulo Thadeu

    2002-01-01

    Full Text Available OBJETIVO: Estudar as características clínicas da epilepsia em pacientes com tumores cerebrais primários de crescimento lento. MÉTODO: Quarenta e dois pacientes com epilepsia refratária ao tratamento medicamentoso associada a tumor cerebral de crescimento lento foram avaliados entre junho de 1992 e setembro de 1999. RESULTADOS: Setenta e cinco por cento dos pacientes tinha menos de 15 anos quando iniciaram-se as crises convulsivas. O exame neurológico foi normal em 67,7% dos pacientes. Predominaram as crises epilépticas do tipo parcial complexa (90,4%, com até 16 crises mensais. As crises foram do tipo parcial simples (PS evoluindo para parcial complexa (PC em 10 pacientes, PC isoladas em 11 e PC evoluindo para generalizada em 11. CONCLUSÃO: Noventa e cinco por cento dos pacientes com tumores cerebrais de crescimento lento apresentaram crises parciais, mesmo que com baixa frequência. Estas últimas podem ser uma manifestação precoce de tumor de crescimento lento nas crianças, mesmo sem nenhuma alteração no exame neurológico.

  7. Phytophthora Root and Crown Rot on Apples in Bulgaria

    Directory of Open Access Journals (Sweden)

    Mariana Nakova

    2010-01-01

    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  8. Occurrence of Phytophthora plurivora and other Phytophthora species in oak forests of southern Poland and their association with site conditions and the health status of trees.

    Science.gov (United States)

    Jankowiak, R; Stępniewska, H; Bilański, P; Kolařík, M

    2014-11-01

    Phytophthora plurivora and other Phytophthora species are known to be serious pathogens of forest trees. Little is known, however, about the presence of P. plurivora in Polish oak forests and their role in oak decline. The aims of this study were to identify P. plurivora in healthy and declining Quercus robur stands in southern Poland and to demonstrate the relationship between different site factors and the occurrence of P. plurivora. In addition, the virulence of P. plurivora and other Phytophthora species was evaluated through inoculations using 2-year-old oak seedlings. Rhizosphere soil was investigated from 39 oak stands representing different healthy tree statuses. The morphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the mitochondrial cox1 gene were used for identifications. P. plurivora, an oak fine root pathogen, was isolated from rhizosphere soil samples in 6 out of 39 stands. Additionally, Phytophthora cambivora, Phytophthora polonica and Phytophthora rosacearum-like were also obtained from several stands. The results showed a significant association between the presence of P. plurivora and the health status of oak trees. Similar relationships were also observed for all identified Phytophthora species. In addition, there was evidence for a connection between the presence of all identified Phytophthora species and some site conditions. Phytophthora spp. occurred more frequently in declining stands and in silt loam and sandy loam soils with pH ≥ 3.66. P. plurivora and P. cambivora were the only species capable of killing whole plants, producing extensive necrosis on seedling stems.

  9. Identification of Phytophthora fragariae var. rubi by PCR.

    Science.gov (United States)

    Schlenzig, Alexandra

    2009-01-01

    The following chapter describes a PCR method for the identification of the raspberry root rot pathogen Phytophthora fragariae var. rubi. Furthermore, a nested PCR suitable for the detection of the pathogen in infected raspberry roots and validated against the "Duncan bait test" (EPPO Bull 35:87-91, 2005) is explained. Protocols for different DNA extraction methods are given which can be transferred to other fungal pathogens.

  10. Phytophthora Species, New Threats to the Plant Health in Korea

    OpenAIRE

    Ik-Hwa Hyun; Woobong Choi

    2014-01-01

    Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries ...

  11. Does infection by southern root-knot nematode influence development of Phytophthora blight in pepper?

    Science.gov (United States)

    The southern root-knot nematode, Meloidogyne incognita, and Phytophthora capsici, the causal agent of Phytophthora blight, are both important pathogens of pepper (Capsicum annuum L.) in the U.S. and worldwide. Although there is significant information in the literature about the responses of pepper...

  12. Multiplex-detectie van Phytophthora: "padlock-based Universal Multiplex detection Array" (pUMA)

    NARCIS (Netherlands)

    Gaszczyk, K.; Mendes, O.; Verstappen, E.C.P.; Bonants, P.J.M.; Schoen, C.D.

    2010-01-01

    Plant Research International heeft een diagnostische methode ontwikkeld die toe te passen is 'in planta', en ook de meest recent beschreven (quarantaine-) soorten omvat. De methode omvat de ontwikkeling van een generieke Phytophthora-methode gevolgd door een Phytophthora-identificatie.

  13. Whole Genome Sequences of the Raspberry and Strawberry Pathogens Phytophthora rubi and P. fragariae.

    Science.gov (United States)

    Tabima, Javier F; Kronmiller, Brent A; Press, Caroline M; Tyler, Brett M; Zasada, Inga A; Grünwald, Niklaus J

    2017-10-01

    Phytophthora rubi and P. fragariae are two closely related oomycete plant pathogens that exhibit strong morphological and physiological similarities but are specialized to infect different hosts of economic importance, namely, raspberry and strawberry. Here, we report the draft genome sequences of these two Phytophthora species as a first step toward understanding the genomic processes underlying plant host adaptation in these pathogens.

  14. Host resistance to phytophthora fruit rot in U.S. watermelon plant introductions

    Science.gov (United States)

    Phytophthora capsici, distributed worldwide, is an aggressive pathogen with a broad host range, infecting solanaceous, leguminaceous, and cucurbitaceous crops. Phytophthora fruit rot of watermelon (Citrullus lanatus) caused by P. capsici was first reported in the U.S. in 1940. Since then, the dise...

  15. The expansion of Phytophthora clade 8b: three new species associated with winter grown vegetable crops

    NARCIS (Netherlands)

    Bertier, L.; Brouwer, H.; Cock, de A.W.A.M.; Cooke, D.E.L.; Olsson, C.H.B.; Höfte, M.

    2013-01-01

    Despite its association with important agricultural crops, Phytophthora clade 8b is a poorly studied group of species. The clade currently consists of three officially described species (Phytophthora porri, P. brassicae and P. primulae) that are host-specific pathogens of leek, cabbages and Primula

  16. Survival of southern highbush blueberry cultivars in Phytophthora Root Rot Infested fields in South Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of commercial blueberries and is most severe when blueberries are grown in wet soils with poor drainage. Symptoms of Phytophthora root rot include small, yellow or red leaves, lack of new growth, root necrosis, and a smaller root system than healthy plan...

  17. Fruit age and development of Phytophthora fruit rot on resistant and susceptible watermelon lines

    Science.gov (United States)

    Phytophthora fruit rot caused by Phytophthora capsici is an emerging disease in most watermelon producing regions of Southeast U.S. and has resulted in severe losses to watermelon growers especially in GA, SC, and NC. We recently released four germplasm lines (USVL203-PFR, USVL020-PFR, USVL782-PFR,...

  18. Molecular tools to unravel the role of genes from Phytophthora infestans

    NARCIS (Netherlands)

    West, van P.

    2000-01-01

    The oomycete plant pathogen Phytophthora infestans is the causal agent of potato late blight. P. infestans is undoubtedly the best known and most studied Phytophthora species today. This is mainly because it is such a

  19. Novel quantitative trait loci for partial resistance to Phytophthora sojae in soybean PI 398841

    Science.gov (United States)

    Phytophthora root and stem rot caused by Phytophthora sojae Kaufmann and Gerdmann is one of the most severe soybean [Glycine max (L.) Merr] diseases in the US. Partial resistance is as effective in managing this disease as single-gene (Rps) mediated resistance and is more durable. The objective of t...

  20. Amino terminal region of Phytophthora sojae cel12 endoglucanase confers tissue collapse function in Nicotiana

    Science.gov (United States)

    Phytophthora encodes an unusually large number of glycosyl hydrolases (GH), with many large gene families resulting from duplication events. There are ten copies of GH 12 (cel12) present in Phytophthora sojae. This is the only pathogen endoglucanase family to which plants produce an inhibitory pr...

  1. Molecular tools to unravel the role of genes from Phytophthora infestans

    NARCIS (Netherlands)

    West, van P.

    2000-01-01

    The oomycete plant pathogen Phytophthora infestans is the causal agent of potato late blight. P. infestans is undoubtedly the best known and most studied Phytophthora species today. This is mainly because it is such a devastating pathogen that can cause complete destruction of a potato field in only

  2. Phytophthora megakarya, a causal agent of black pod rot in Africa

    Science.gov (United States)

    In most parts of the world where Theobroma cacao is grown, Phytophthora palmivora is the major concern for causing black pod rot (BPR). Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest ...

  3. Influence of fruit age on Phytophthora fruit rot development on susceptible and resistant watermelon germplasm

    Science.gov (United States)

    Phytophthora fruit rot of watermelon caused by Phytophthora capsici is an emerging disease in the southeastern United States. The disease has resulted in severe losses to watermelon growers in GA, SC, and NC, and is considered a top-research priority by the National Watermelon Association. We releas...

  4. Validation of the bait test with Rhododendron leaves for Phytophthora diagnosis

    Science.gov (United States)

    Corina Junker; Sabine Werres

    2017-01-01

    Bait tests are very helpful for diagnosis of Phytophthora in for example soil, substrate, water, sediment, and rootball samples (Werres and others 2014). By attracting the motile zoospores of the Phytophthora species with the baits these pathogens can be separated from other organisms. Bait tests are simple and cost...

  5. Urban activities influence on Phytophthora species diversity in British Columbia, Canada

    Science.gov (United States)

    Angela Dale; Nicolas Feau; Julien Ponchart; Guillaume Bilodeau; Jean Berube; R.C. Hamelin

    2017-01-01

    Phytophthora de Bary, a genus of Oomycetes, is known as a plant pathogenic genus. The best-known species infect a wide range of hosts, including economically valuable angiosperm and gymnosperm tree species and important agricultural crops. Many Phytophthora are invasive and have been disseminated through nursery and...

  6. Phytophthora andina sp nov., a newly identified heterothallic pathogen of solanaceous hosts in the Andean highlands

    NARCIS (Netherlands)

    Oliva, R.F.; Kroon, L.P.N.M.; Chacon, G.; Flier, W.G.; Ristaino, J.B.; Forbes, G.A.

    2010-01-01

    A blight disease on fruits and foliage of wild and cultivated Solanum spp. was found to be associated with a new species of Phytophthora. The proposed novel species is named Phytophthora andina Adler & Flier, sp. nov. based on morphological characteristics, pathogenicity assays, mitochondrial DN

  7. Phylogenetic Analysis of Phytophthora Species Based on Mitochondrial and Nuclear DNA Sequences

    NARCIS (Netherlands)

    Kroon, L.P.N.M.; Bakker, F.T.; Bosch, van den G.B.M.; Bonants, P.J.M.; Flier, W.G.

    2004-01-01

    A molecular phylogenetic analysis of the genus Phytophthora was performed, 113 isolates from 48 Phytophthora species were included in this analysis. Phylogenetic analyses were performed on regions of mitochondrial (cytochrome c oxidase subunit 1; NADH dehydrogenase subunit 1) and nuclear gene sequen

  8. Toluca nog steeds resistent tegen phytophthora (interview met o.a. Geert Kessel)

    NARCIS (Netherlands)

    Engwerda, J.; Kessel, G.J.T.

    2009-01-01

    Het biologische aardappelras Toluca is nog steeds volledig resistent tegen phytophthora. Dat in een laboratorium drie isolaten van phytophthora de resistentie hebben omzeild, is een theoretisch gegeven, vindt commercieel directeur Jan van Hoogen van Agrico. Toluca is gekweekt door Agrico en in 2007

  9. Invasion of xylem of mature tree stems by Phytophthora ramorum and P. kernoviae

    Science.gov (United States)

    Anna Brown; Clive Brasier

    2008-01-01

    The aetiology and frequency of Phytophthoras in discoloured xylem tissue beneath phloem lesions was investigated in a range of broadleaved trees infected with P. ramorum, P. kernoviae and several other Phytophthoras. Isolation was attempted from the inner surface of 81, 6 x 4 cm sterilised...

  10. The interplay between a Phytophthora RXLR effector and an Arabidopsis lectin receptor kinase

    NARCIS (Netherlands)

    Bouwmeester, K.

    2010-01-01

    Phytophthora infestans – the causal agent of potato late blight – secretes a plethora of effector proteins to facilitate plant infection. The central subject of this thesis is ipiO, one of the first cloned Phytophthora genes with a putative function in pathogenicity as was anticipated based on its i

  11. Sporulation of Phytophthora ramorum and P. kernoviae on asymptomatic foliage and fruit

    Science.gov (United States)

    S. Denman; E. Moralejo; S.A. Kirk; E. Orton; A. Whybrow

    2008-01-01

    Phytophthora ramorum and P. kernoviae are newly discovered invasive Phytophthoras causing leaf necrosis, shoot tip dieback (mostly on ornamental and forest understorey host species) and bleeding cankers on tree trunks of a wide range of plant species. Both pathogens are now present in south-west England....

  12. Neuroprotective Effect of Gui Zhi (Ramulus Cinnamomi on Ma Huang- (Herb Ephedra- Induced Toxicity in Rats Treated with a Ma Huang-Gui Zhi Herb Pair

    Directory of Open Access Journals (Sweden)

    Fang-hao Zheng

    2015-01-01

    Full Text Available Herb Ephedra (Ma Huang in Chinese and Ramulus Cinnamomi (Gui Zhi in Chinese are traditional Chinese herbs, often used together to treat asthma, nose and lung congestion, and fever with anhidrosis. Due to the adverse effects of ephedrine, clinical use of Ma Huang is restricted. However, Gui Zhi extract has been reported to decrease spontaneous activity in rats and exert anti-inflammatory and neuroprotective effects. The present study explored the possible inhibitory effect of Gui Zhi on Ma Huang-induced neurotoxicity in rats when the two herbs were used in combination. All Ma Huang and Ma Huang-Gui Zhi herb pair extracts were prepared using methods of traditional Chinese medicine and were normalized based on the ephedrine content. Two-month-old male Sprague-Dawley rats (n=6 rats/group were administered Ma Huang or the Ma Huang-Gui Zhi herb pair extracts for 7 days (ephedrine = 48 mg/kg, and locomotor activity was measured. After 7 days, oxidative damage in the prefrontal cortex was measured. Gui Zhi decreased hyperactivity and sensitization produced by repeated Ma Huang administration and attenuated oxidative stress induced by Ma Huang. The results of this study demonstrate the neuroprotective potential of Gui Zhi in Ma Huang-induced hyperactivity and oxidative damage in the prefrontal cortex of rats when used in combination.

  13. Neuroprotective effect of gui zhi (ramulus cinnamomi) on ma huang- (herb ephedra-) induced toxicity in rats treated with a ma huang-gui zhi herb pair.

    Science.gov (United States)

    Zheng, Fang-Hao; Wei, Ping; Huo, Hui-Ling; Xing, Xue-Feng; Chen, Fei-Long; Tan, Xiao-Mei; Luo, Jia-Bo

    2015-01-01

    Herb Ephedra (Ma Huang in Chinese) and Ramulus Cinnamomi (Gui Zhi in Chinese) are traditional Chinese herbs, often used together to treat asthma, nose and lung congestion, and fever with anhidrosis. Due to the adverse effects of ephedrine, clinical use of Ma Huang is restricted. However, Gui Zhi extract has been reported to decrease spontaneous activity in rats and exert anti-inflammatory and neuroprotective effects. The present study explored the possible inhibitory effect of Gui Zhi on Ma Huang-induced neurotoxicity in rats when the two herbs were used in combination. All Ma Huang and Ma Huang-Gui Zhi herb pair extracts were prepared using methods of traditional Chinese medicine and were normalized based on the ephedrine content. Two-month-old male Sprague-Dawley rats (n = 6 rats/group) were administered Ma Huang or the Ma Huang-Gui Zhi herb pair extracts for 7 days (ephedrine = 48 mg/kg), and locomotor activity was measured. After 7 days, oxidative damage in the prefrontal cortex was measured. Gui Zhi decreased hyperactivity and sensitization produced by repeated Ma Huang administration and attenuated oxidative stress induced by Ma Huang. The results of this study demonstrate the neuroprotective potential of Gui Zhi in Ma Huang-induced hyperactivity and oxidative damage in the prefrontal cortex of rats when used in combination.

  14. Efficacy of fungicides against Phytophthora cactorum on Viola.

    Science.gov (United States)

    Blindeman, L; Heungens, K; Goossens, F; Gobin, B

    2009-01-01

    Phytophthora cactorum caused significant losses to pansies during the heat wave at the end of the summer of 2006. Infected plants showed foliage that appeared stunted and chlorotic, with wilting occurring even when soil moisture was adequate. When uprooted, symptomatic plants typically possess a surprisingly healthy looking and well-developed root system, but stem and root tissue at the soil interface is discoloured (purple to dark brown) and soft. Older Leaves turn yellow and when the stem base is attacked, the plant dies. Phytophthora cactorum was identified from stem and root tissue with both morphological and molecular techniques. To evaluate the efficacy of different fungicides against this pathogen, healthy plants were infected with zoospores of a Phytophthora cactorum isolate collected from commercial plants. Eleven fungicides were evaluated and compared to an untreated control. Two fungicides were applied via root drenching, 7 days before inoculation with zoospores of P. cactorum. The other fungicides were applied by spraying 24 hours after inoculation with P. cactorum. Preventive drenching with the combined formulation of fenamidone + fosethyl offered the best protection against P. cactorum, while drenching with dimethomorf also resulted in an obvious reduction in the number of infected plants. Foliar application was less successful, as only a combined formulation of mancozeb + metalaxyl-M gave sufficient protection. In conclusion, preventive drenching appears to be the best solution to prevent infection with P. cactorum, especially during warm weather periods, which are conducive to pathogen and disease development.

  15. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  16. Small homologous blocks in phytophthora genomes do not point to an ancient whole-genome duplication.

    Science.gov (United States)

    van Hooff, Jolien J E; Snel, Berend; Seidl, Michael F

    2014-05-01

    Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) and by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presence of 2HOM blocks, have been attributed to a whole-genome duplication (WGD) at the last common ancestor of Phytophthora. However, large intraspecies synteny-compelling evidence for a WGD-has not been detected. Here, we revisited the WGD hypothesis by deducing the age of 2HOM blocks. Two independent timing methods reveal that the majority of 2HOM blocks arose after divergence of the Phytophthora lineages. In addition, a large proportion of the 2HOM block copies colocalize on the same scaffold. Therefore, the presence of 2HOM blocks does not support a WGD at the last common ancestor of Phytophthora. Thus, genome evolution of Phytophthora is likely driven by alternative mechanisms, such as bursts of transposon activity.

  17. Spatial analysis of the incidence of Phytophthora infestans (Mont. De Bary and Phytophthora nicotianae Breda de Haan on potato

    Directory of Open Access Journals (Sweden)

    Leónides Castellanos González

    2016-03-01

    Full Text Available The objective of this research was to conduct a spatial analysis of the incidence of Phytophthora nicotianae Breda de Haan and Phytophthora infestans (Mont. De Bary, during five seasons of potato in Fields Company Miscellaneous Crops in Horquita, Cienfuegos (2003-2004 to 2007-2008. Information about pathogens, collected by the Plant Protection Station of Yaguaramas, was used in order to do so. An alpha numerical database was made, oriented to a group of areas under center pivot irrigation machines (Kubans and Bayamón and its quadrants. Parallel to this, mapping of center pivot machines and quadrants was generated in MapInfo GIS 8.5. Several automatic geo codifications were made in order to relate the alphanumeric database and the mapping, and thematic maps were generated in the presence or absence of pathogens. The two study agents have presented high spatial variability during the five planting seasons. Both have influenced the same geographical area with similar appearance date. P. infestans has not expressed a defined dispersion pattern and it has spread at random from the primary source of incidence, while Phytophthora nicotianae has become an endemic agent which shows a dispersion pattern towards neighboring areas or areas connected by the road network from the primary sources, which have been associated with poor land leveling and late or intermediate planting seasons.

  18. Phytophthora infestans POPULATION STRUCTURE: A WORLDWIDE SCALE Estructura poblacional de Phytophthora infestans: una escala global

    Directory of Open Access Journals (Sweden)

    MARTHA CÁRDENAS

    2012-05-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of the pathogen's population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep ( Pep tidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America, expanding it on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.Phytophthora infestans, el agente causal del tizón tardío de la papa y otros miembros de la familia de las Solanáceas, es el responsable de la gran hambruna irlandesa y aún hoy sigue causando grandes pérdidas económicas alrededor del planeta. Para establecer estrategias de control adecuadas contra este patógeno se requiere comprender la estructura poblacional del mismo. Mundialmente se han utilizado como marcadores las aloenzimas, Gpi (Glucosa-6-fosfato isomerasa y Pep (Peptidasa y la sonda de fingerprinting de RFLP (Polimorfismos de la Longitud de los Fragmentos de Restricción, RG57. De igual forma, la resistencia al fungicida metalaxyl y el tipo de apareamiento, han sido

  19. Hepatotoxicity associated with microcystin/ Hepatotoxicidade associada à microcistina

    Directory of Open Access Journals (Sweden)

    Ana Paula Frederico Rodrigues Loureiro Bracarense

    2008-08-01

    .Efluentes industriais e urbanos e a intensa exploração agrícola e de pescado têm levado à eutrofização de muitos mananciais de água, destinados ao consumo e às atividades recreacionais. A eutrofização das águas, freqüentemente, tem como conseqüência o desenvolvimento expressivo de cianobactérias. Estas florações induzem a sérios problemas, visto que a ocorrência de Microcystis aeruginosa, uma das cianobactérias mais difundidas, pode produzir microcistinas (MCs. O efeito citotóxico da MC tem sido descrito no fígado, pulmões, estômago e intestino. Mortes de seres humanos, de animais silvestres e domésticos têm sido associadas à exposição a MC. Esta pode ocorrer diretamente por ingestão, inalação, contato, inoculação intravenosa (hemodiálise ou indiretamente, pelo consumo de animais, dentre os quais os peixes e moluscos, que podem ingerir as cianobactérias e suas toxinas. A mais tóxica e também mais comum das MCs é a microcistina-LR (MC-LR, cujo órgão alvo é o fígado. A MC chega ao fígado especificamente por transporte dos ácidos biliares e, uma vez no citoplasma, inibe as proteínas fosfatases 1 e 2A, induzindo ao aumento da fosforilação protéica. Esta reação tem duas conseqüências: destruição do citoesqueleto, causando efeitos citotóxicos e descontrole da divisão celular, levando à promoção tumoral. A exposição aguda à MC induz severa hemorragia intra-hepática, necrose e apoptose, enquanto a exposição crônica pode causar neoplasia hepática ou intestinal. Também tem sido relatado que a hepatotoxicidade da MC está intimamente associada à formação intracelular de espécies reativas de oxigênio. A MC pode ser naturalmente degradada por bactérias ou pela radiação solar. Contudo, se não houver eficiente degradação, a MC poderá persistir na cadeia alimentar aquática. A contaminação de águas pela MC representa, portanto, perigo à saúde humana e de animais. Assim, esforços para evitar a eutrofização de

  20. The expansion of Phytophthora clade 8b: three new species associated with winter grown vegetable crops.

    Science.gov (United States)

    Bertier, L; Brouwer, H; de Cock, A W A M; Cooke, D E L; Olsson, C H B; Höfte, M

    2013-12-01

    Despite its association with important agricultural crops, Phytophthora clade 8b is a poorly studied group of species. The clade currently consists of three officially described species (Phytophthora porri, P. brassicae and P. primulae) that are host-specific pathogens of leek, cabbages and Primula spp., respectively. However, over the past few decades, several other clade 8b-like Phytophthoras have been found on a variety of different host plants that were all grown at low temperatures in winter seasons. In this study, a collection of 30 of these isolates was subjected to a phylogenetic study using two loci (the rDNA ITS region and the mitochondrial cox1 gene). This analysis revealed a clear clustering of isolates according to their host plants. To verify whether these isolates belong to separate species, a detailed morphological study was conducted. On the basis of genetic and morphological differences and host specificity, we now present the official description of three new species in clade 8b: Phytophthora cichorii sp. nov., P. dauci sp. nov. and P. lactucae sp. nov. Two other groups of isolates (Phytophthora taxon castitis and Phytophthora taxon parsley) might also represent new species but the data available at this time are insufficient for an official description. This brings Phytophthora clade 8b to a group of six species that are all host-specific, slow-growing and specifically infect herbaceous crops at low temperatures.

  1. Four different Phytophthora species that are able to infect Scots pine seedlings in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2016-09-01

    Full Text Available To investigate susceptibility of young Scots pine seedlings to four Phytophthora species: Phytophthora cactorum, Phytophthora cambivora, Phytophthora plurivora and Phytophthora pini; seven-day-old seedlings of Scots pine (15 seedlings per experiment were infected using agar plugs of the respective species. Control group also consisted of 15 seedlings and was inoculated with sterile agar plugs. Results unambiguously show that after 4.5 days, all seedlings show clear signs of infection and display severe symptoms of tissue damage and necrosis. Moreover, three and two seedlings in the P. cactorum and P. cambivora infected seedlings groups, respectively, collapsed. The length of largest necrosis measured 13.4±3.90 mm and was caused by P. cactorum. To rule out any putative contamination or infection by secondary pathogens, re-isolations of pathogens from infection sites were performed and were positive in 100% of plated pieces of infected seedlings. All re-isolations were, however, negative in the case of the control group. Detailed microscopic analyses of infected tissues of young seedlings confirmed the presence of numerous Phytophthora species inside and on the surface of infected seedlings. Therefore, our results suggest Phytophthora spp. and mainly P. cactorum and P. cambivora as aggressive pathogens of Scots pine seedlings and highlight a putative involvement of these species in the damping off of young Scots pine seedlings frequently observed in forest nurseries.

  2. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Science.gov (United States)

    Amini, Jahanshir; Farhang, Vahid; Javadi, Taimoor; Nazemi, Javad

    2016-01-01

    In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC50) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC50 values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean EC50 values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases. PMID:26889111

  3. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Directory of Open Access Journals (Sweden)

    Jahanshir Amini

    2016-02-01

    Full Text Available In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC₅₀ values (ppm of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm. Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC₅₀ values for inhibition of the mycelial growth of P. capsici (31.473, P. melonis (33.097 and P. drechsleri (69.112, respectively. The mean EC₅₀ values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral (39.16% and z-citral (30.95% were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05. Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

  4. Morphological and Molecular Description of Phytophthora insolita Isolated from Citrus Orchard in India

    Directory of Open Access Journals (Sweden)

    Swapnil Bawage

    2013-01-01

    Full Text Available Citrus, an important cash crop in India, is adversely affected by Phytophthora nicotianae, P. palmivora, and P. citrophthora. Phytophthora insolita is known to be associated with citrus and reported for the first time in India. It is a rare and poorly characterized Phytophthora species, as its natural host and pathogenic impact are unclear. Previously, it was reported only in Taiwan and China; so to confirm our suspected isolate is P. insolita, regions of internal transcribed spacer, elongation factor, beta-tubulin, and cytochrome oxidase genes were sequenced. This study provides description of the lone Indian P. insolita isolate with respect to molecular identity, morphology, mating behaviour, and pathogenicity.

  5. Distribution and Virulence Diversity of Phytophthora sojae in China

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhen-dong; WANG Hua-bo; WANG Xiao-ming; CHANG Ru-zhen; WU Xiao-fei

    2004-01-01

    By investigating occurrence of Phytophthora root rot in fields and isolating P. sojae from diseased plants and soils, the distribution of P. sojae in China was surveyed. In addition to northeast region, P. sojae existed in Huanghe-Huaihe basin and Yangtze basin too. Eighty- three isolates of P. sojae isolated from different areas were identified on virulence using 13differential soybean cultivars, abundant virulence diversity was found in P. sojae. The greater diversity in virulence of P. sojae was in isolates from soil than from plants. And the greatest virulence diversity of P.sojae was found in Yangtze basin.

  6. The Thought of Ramulus Cinnamomi be Decocted Later in Guizhi Renshen Decoction by Reading Shanghan Lun%读《伤寒论》桂枝人参汤桂枝后下之感悟

    Institute of Scientific and Technical Information of China (English)

    沈双

    2015-01-01

    Ramulus Cinnamomi was widely used in Shanghan Lun of Zhang Zhongjing.But Ramulus Cinnamomi is needed to be decocted later only in Guizhi Renshen decoction.This detail attracted me and got me thinking.It’ s necessary in modern pharmacological research or the theory of traditional Chinese Medicine.At last, this phenomenon also caused my thinking about the rapid development of modern medicine forms.%桂枝在医圣张仲景的著作《伤寒论》中应用广泛,唯独在桂枝人参汤中桂枝后下,这引起了笔者的思考。无论从现代药理研究,还是古人的中医理论中桂枝在这张方子中后下无疑是必须的,但是也引发了笔者对现代药物剂型快速发展的思考。

  7. Slow sand filters effectively reduce Phytophthora after a pathogen switch from Fusarium and a simulated pump failure.

    Science.gov (United States)

    Lee, Eric; Oki, Lorence R

    2013-09-15

    Slow sand filtration has been shown to effectively reduce Phytophthora zoospores in irrigation water. This experiment tested the reduction of Phytophthora colony forming units (CFUs) by slow sand filtration systems after switching the pathogen contaminating plant leachate from Fusarium to Phytophthora and the resilience of the system to a short period without water, as might be caused by a pump failure. The slow sand filtration system greatly reduced Phytophthora CFUs and transmission after switching the pathogens. In addition, Phytophthora reduction by the slow sand filter was equally effective before and after the simulated pump failure. Reduction of Fusarium was not seen by the SSFs, before or after the simulated pump failure. The results suggest that slow sand filters are effective at reducing larger organisms, such as Phytophthora zoospores, even after a pump failure or a change in pathogens.

  8. Phytophthora gemini sp. nov., a new species isolated from the halophilic plant Zostera marina in the Netherlands.

    Science.gov (United States)

    Man in 't Veld, Willem A; Rosendahl, Karin C H M; Brouwer, Henk; de Cock, Arthur W A M

    2011-08-01

    Eight strains belonging to the Oomycete genus Phytophthora were isolated from Zostera marina (seagrass) in The Netherlands over the past 25 y. Based on morphology, isozymes, temperature-growth relationships and ITS sequences, these strains were found to belong to two different Phytophthora species. Five strains, four of them isolated from rotting seeds and one isolated from decaying plants, could not be assigned to a known species and hence belong to a new species for which we propose the name Phytophthora gemini sp. nov. Three strains were isolated from decaying plants and were identified as Phytophthora inundata, thereby expanding the known habitat range of this species from fresh to brackish-saline areas. The possible role of both Phytophthora species in the decline of Z. marina in The Netherlands and the evolutionary significance of the presence of Phytophthora species in marine environments are discussed.

  9. Infection of Phytophthora capsici on pepper——Models and affecting factors

    Institute of Scientific and Technical Information of China (English)

    Xuemin LIU; Yanling ZHOU; Lijun LI

    2008-01-01

    Under controlled conditions in a growth chamber, we studied the mortality of pepper seedlings caused by Phytophthora capsici. The results showed that soil temperature and soil water content were important factors affecting their infection with P. capsici and the optimum condition for infection was found to be a soil temperature of 22℃-28℃ and a soil water content of 40%. The relationships of pepper seedling mortality caused by P. capsici along with soil temperature, soil water content and their interactions can be described by mathematical models. Field observations suggested that the Gompertz model was the best one for describing the epidemiological dynamics of the disease. The incidence of pepper phytophthora blight was significantly related to the initial incidence of pepper phytophthora blight, soil temperature, soil water content and air temperature. A forecasting model for pepper phytophthora blight in the field was developed.

  10. Disease Severity Rating of Chile Pepper Plants Inoculated with Phytophthora Capsici Collected in Taiwan

    Data.gov (United States)

    US Agency for International Development — The data are the phenotypic host reactions of a recombinant inbred line population of Capsicum annuum developed to differentiate races of Phytophthora capsici. The...

  11. Rapid isothermal detection of Phytophthora species on plant samples using recombinase polymerase amplification

    Science.gov (United States)

    Recently several isothermal amplification techniques have been developed that are extremely tolerant towards inhibitors present in many plant extracts. Recombinase polymerase amplification (RPA) assays for the genus Phytophthora have been developed which provide a simple and rapid method to macerate...

  12. Beleidsondersteunend Onderzoek Plantgezondheid BO-06 Resultaten 2009 : Phytophthora infestans (BO-06-008)

    NARCIS (Netherlands)

    Boonekamp, P.M.

    2010-01-01

    Een verzameling artikelen of rapporten over plantgezondheid. Het thema is Phytophthora infestans. Het plantgezondheidsonderzoek richt zich nog veel op het optimaliseren van bestaande methoden en technieken en korte termijnsuccesjes, vindt Piet Boonekamp. Voor een wezenlijke verduurzaming van plantge

  13. Kaliumfosfiet helpt kalanchoë tegen phytophthora (interview met Filip van Noort)

    NARCIS (Netherlands)

    Neefjes, H.; Noort, van F.R.

    2009-01-01

    Toevoegen van plantversterker kaliumfosfiet maakt kalanchoë weerbaar tegen phytophthora. Onderzoek bij WUR Glastuinbouw heeft dit aangetoond in een deel van een proef. De praktijk is voorzichtig met het middel

  14. Stability of partial resistance in potato cultivars exposed to aggressive strains of Phytophthora infestans

    NARCIS (Netherlands)

    Flier, W.G.; Bosch, van den G.B.M.; Turkensteen, L.J.

    2003-01-01

    Potato cultivars were evaluated for their resistance responses to aggressive strains of Phytophthora infestans in field and laboratory experiments. Analysis of variance revealed differential cultivar-by-isolate interactions for both foliar and tuber blight resistance. Differential responses occur as

  15. Piomiosite associada ao diabetes mellitus e cirrose hepática

    OpenAIRE

    2010-01-01

    A piomiosite é uma infecção primária do músculo esquelético mais comum nos países tropicais. Adultos que desenvolvem a doença apresentam, na maioria dos casos, comorbidades associadas que comprometem o sistema imunológico, entre elas diabetes mellitus e cirrose hepática

  16. Assessment of inoculation methods for screening black alder resistance to Phytophthora ×alni

    OpenAIRE

    Husson, Claude; Druart, P.; Marcais, Benoit

    2015-01-01

    Identification of resistance to Phytophthora xalni could provide the basis for a management strategy against alder decline in riparian ecosystems in Europe.[br/] This study aimed to test methods to evaluate the resistance of riparian alders to the disease, and to screen alder genotypes for resistance.[br/] Phytophthora xalni isolates were compared for their aggressiveness (lesion length on stem) and sporulation capacity (sporangia). While no difference in lesion lengths was found bet...

  17. Pyrosequencing of environmental soil samples reveals biodiversity of the Phytophthora resident community in chestnut forests.

    Science.gov (United States)

    Vannini, Andrea; Bruni, Natalia; Tomassini, Alessia; Franceschini, Selma; Vettraino, Anna Maria

    2013-09-01

    Pyrosequencing analysis was performed on soils from Italian chestnut groves to evaluate the diversity of the resident Phytophthora community. Sequences analysed with a custom database discriminated 15 pathogenic Phytophthoras including species common to chestnut soils, while a total of nine species were detected with baiting. The two sites studied differed in Phytophthora diversity and the presence of specific taxa responded to specific ecological traits of the sites. Furthermore, some species not previously recorded were represented by a discrete number of reads; among these species, Phytophthora ramorum was detected at both sites. Pyrosequencing was demonstrated to be a very sensitive technique to describe the Phytophthora community in soil and was able to detect species not easy to be isolated from soil with standard baiting techniques. In particular, pyrosequencing is an highly efficient tool for investigating the colonization of new environments by alien species, and for ecological and adaptive studies coupled with biological detection methods. This study represents the first application of pyrosequencing for describing Phytophthoras in environmental soil samples.

  18. Membrane-based oligonucleotide array developed from multiple markers for the detection of many Phytophthora species.

    Science.gov (United States)

    Chen, Wen; Djama, Zeinab Robleh; Coffey, Michael D; Martin, Frank N; Bilodeau, Guillaume J; Radmer, Lorien; Denton, Geoff; Lévesque, C André

    2013-01-01

    Most Phytophthora spp. are destructive plant pathogens; therefore, effective monitoring and accurate early detection are important means of preventing potential epidemics and outbreaks of diseases. In the current study, a membrane-based oligonucleotide array was developed that can detect Phytophthora spp. reliably using three DNA regions; namely, the internal transcribed spacer (ITS), the 5' end of cytochrome c oxidase 1 gene (cox1), and the intergenic region between cytochrome c oxidase 2 gene (cox2) and cox1 (cox2-1 spacer). Each sequence data set contained ≈250 sequences representing 98 described and 15 undescribed species of Phytophthora. The array was validated with 143 pure cultures and 35 field samples. Together, nonrejected oligonucleotides from all three markers have the ability to reliably detect 82 described and 8 undescribed Phytophthora spp., including several quarantine or regulated pathogens such as Phytophthora ramorum. Our results showed that a DNA array containing signature oligonucleotides designed from multiple genomic regions provided robustness and redundancy for the detection and differentiation of closely related taxon groups. This array has the potential to be used as a routine diagnostic tool for Phytophthora spp. from complex environmental samples without the need for extensive growth of cultures.

  19. Phytophthora terminalis sp. nov. and Phytophthora occultans sp. nov., two invasive pathogens of ornamental plants in Europe.

    Science.gov (United States)

    Man In 't Veld, Willem A; Rosendahl, Karin C H M; van Rijswick, Patricia C J; Meffert, Johan P; Westenberg, Marcel; van de Vossenberg, Bart T L H; Denton, Geoff; van Kuik, Fons A J

    2015-01-01

    In the past decade several Phytophthora strains were isolated from diseased Pachysandra terminalis plants suffering stem base and root rot, originating from the Netherlands and Belgium. All isolates were homothallic and had a felt-like colony pattern, produced semi-papillate sporangia, globose oogonia and had a maximum growth at ~ 27 C. Several additional Phytophthora strains were isolated from diseased Buxus sempervirens plants, originating from the Netherlands and Belgium, which had sustained stem base and root rot; similar strains also were isolated from Acer palmatum, Choisya ternata and Taxus in the United Kingdom. All isolates were homothallic and had a stellate colony pattern, produced larger semi-papillate sporangia and smaller globose oogonia than the isolates from Pa. terminalis and had a maximum growth temperature of ~ 30 C. Phylogenetic analyses of both species using the internal transcribed spacer region of the nuc rDNA (ITS), mt cytochrome oxidases subunit I gene (CoxI) and nuc translation elongation factor 1-α gene (TEF1α) revealed that all sequences of each species were identical at each locus and unique to that species, forming two distinct clusters in subclade 2a. Sequence analysis of partial β-tubulin genes showed that both taxa share an identical sequence that is identical to that of Ph. himalsilva, a species originating from Asia, suggesting a common Asian origin. Pathogenicity trials demonstrated disease symptoms on their respective hosts, and re-isolation and re-identification of the inoculated pathogens confirmed Koch's postulates.

  20. Phytophthora aquimorbida sp. nov. and Phytophthora taxon 'aquatilis' recovered from irrigation reservoirs and a stream in Virginia, USA.

    Science.gov (United States)

    Hong, Chuanxue; Richardson, Patricia A; Hao, Wei; Ghimire, Sita R; Kong, Ping; Moorman, Gary W; Lea-Cox, John D; Ross, David S

    2012-01-01

    Two distinct subgroups (L2 and A(-2)) were recovered from irrigation reservoirs and a stream in Virginia, USA. After molecular, morphological and physiological examinations, the L2 subgroup was named Phytophthora aquimorbida and the A(-2) designated as Phytophthora taxon 'aquatilis'. Both taxa are homothallic. P. aquimorbida is characterized by its noncaducous and nonpapillate sporangia, catenulate and radiating hyphal swellings and thick-walled plerotic oospores formed in globose oogonia mostly in the absence of an antheridium. P. taxon 'aquatilis' produces plerotic oospores in globose oogonia mostly with a paragynous antheridium. It has semi-papillate, caducous sporangia with variable pedicels, but it does not have hyphal swelling. Analyses of ITS, CO1, β-tubulin and NADH1 sequences revealed that P. aquimorbida is closely related to P. hydropathica, P. irrigata and P. parsiana, and P. taxon 'aquatilis' is related to P. multivesiculata. The optimum temperature for culture growth is 30 and 20 C for P. aquimorbida and P. taxon 'aquatilis' respectively. Both taxa were pathogenic to rhododendron plants and caused root discoloration, pale leaves, wilting, tip necrosis and dieback. Their plant biosecurity risk also is discussed.

  1. [Field resistance of Phytophthora melonis to metalaxyl in South China].

    Science.gov (United States)

    Wu, Yongguan; Lu, Shaofeng; Huang, Siliang; Fu, Gang; Chen, Liang; Xie, Dasen; Li, Qiqin; Cen, Zhenlu

    2011-08-01

    Phytophthora melonis is the casual agent of wax gourd and cucumber Phytophthora blight which becomes a constraint for sustainable production of the related crops. Metalaxyl is one of the principal fungicides for controlling the disease now. The objectives of the present study were: (1) to investigate the baseline sensitivity and field resistance of P. melonis to metalaxyl in South China; (2) to test the occurrence of metalaxyl-resistant mutants from metalaxyl-sensitive wild type strains exposed to the fungicide; and (3) to monitor the development of metalaxyl resistance in P. melonis population. Over 400 samples of wax gourd and cucumber Phytophthora blight were collected from Guangxi Zhuang Autonomous Region and Guangdong province during 2007-2010, and 193 strains of P. melonis were isolated and purified. The sensitivity of the isolated strains to metalaxyl was tested using mycelial growth rate method in vitro and floating-leaf-disk method in vivo, respectively. The metalaxyl-sensitive strains were induced on PDA plates containing 10 microg/mL metalaxyl. The sensitive, moderately resistant and resistant strains were recorded as 29.0% , 18.1% and 52.8%, respectively, among 193 tested strains. The frequency and level of resistance of P. melonis from Guangdong were higher than that from Guangxi. The strains from cucumber was generally more resistant to metalaxyl than those from wax gourd. The metalaxyl-resistant strains were frequently detected as predominant populations in most of the sampling sites and the highest resistance index (4226.9) was confirmed. Metalaxyl-resistant (M1r) mutants could be isolated from approximately 60% of the sensitive wild-type strains. The resistance level of the M mutants was 189-407 times higher than that of their sensitive parental strains. The EC50 values of 9 sensitive strains from a sampling site without a record of phenylamide fungicide application ranged from 0.0429 to 0.5461 microg/mL. Their mean EC50 value (0.3200 +/- 0

  2. Development of Phytophthora fruit rot resistant watermelon germplasm lines: USVL489-PFR, USVL782-PFR, USVL203-PFR and USVL020-PFR

    Science.gov (United States)

    Phytophthora capsici, distributed worldwide, is an aggressive pathogen with a broad host range, infecting solanaceous, leguminaceous, and cucurbitaceous crops. Phytophthora fruit rot of watermelon (Citrullus lanatus) caused by Phytophthora capsici was first reported in the U.S. in 1940. Since then...

  3. Five Reasons to Consider Phytophthora infestans a Reemerging Pathogen.

    Science.gov (United States)

    Fry, W E; Birch, P R J; Judelson, H S; Grünwald, N J; Danies, G; Everts, K L; Gevens, A J; Gugino, B K; Johnson, D A; Johnson, S B; McGrath, M T; Myers, K L; Ristaino, J B; Roberts, P D; Secor, G; Smart, C D

    2015-07-01

    Phytophthora infestans has been a named pathogen for well over 150 years and yet it continues to "emerge", with thousands of articles published each year on it and the late blight disease that it causes. This review explores five attributes of this oomycete pathogen that maintain this constant attention. First, the historical tragedy associated with this disease (Irish potato famine) causes many people to be fascinated with the pathogen. Current technology now enables investigators to answer some questions of historical significance. Second, the devastation caused by the pathogen continues to appear in surprising new locations or with surprising new intensity. Third, populations of P. infestans worldwide are in flux, with changes that have major implications to disease management. Fourth, the genomics revolution has enabled investigators to make tremendous progress in terms of understanding the molecular biology (especially the pathogenicity) of P. infestans. Fifth, there remain many compelling unanswered questions.

  4. Phenotypic and genotypic characterization of Italian Phytophthora infestans isolates

    Directory of Open Access Journals (Sweden)

    Federica SAVAZZINI

    2015-12-01

    Full Text Available Phytophthora infestans (Mont. de Bary causes late blight of potato. After the 1970s, several changes have occurred in the European P. infestans population, frequently associated with an increased virulence. While the genotypic and phenotypic diversity of P. infestans has been studied in-depth in northern and central Europe, only a few reports are available regarding Italian isolates, mainly based on phenotypic traits. We report data of phenotypic and genotypic characteristics of isolates collected from infected potato and tomato plants in different Italian regions in 2006‒2008. A prevalence of the A1 mating type and a majority of metalaxyl-resistant isolates were found. Tomato-derived isolates showed fungicide sensitivity, confirming previous reports. One of the isolates showed the rare IIb mitochondrial DNA haplotype. Genetic analyses of the single-sequence repeats (SSRs and of the internal transcribed spacers gave similar results, although SSRs gave the best discrimination of genotypes.

  5. Phytophthora cactorum and Colletotrichum acutatum: Survival and Detection

    Directory of Open Access Journals (Sweden)

    Arja T. Lilja

    2006-12-01

    Full Text Available Phytophthora cactorum and Colletotrichum acutatum are pathogens which are transported with plant material as latent infections and can also survive in soil and plant debris. Since the beginning of 1990’s P. cactorum caused losses in strawberries in Finland and increased culling of silver birch seedlings in forest nurseries because of stem lesions. In this study primers specific for the pathogen were designed, and in a simple PCR they gave an amplification product from pure cultures only when P. cactorum was used as a template. No cross reactions were found with other Phytophthoras in group I or other microbes. Inoculated strawberry plants gave also a clear band in PCR-analyses when the template concentration was diluted. However, amplification was not always reproducible with birch seedlings. With soil samples the best result was gained by a combination of baiting and isolation. C. acutatum is a quarantine pathogen on strawberry in the European Union and thus the infected plants are destroyed in Finland to avoid further spread of the pathogen. The pathogen has earlier been found to survive over one winter in infected plant debris and soil. In the survival test (2003-2005 done in this study, specific amplification products were obtained from test plants inoculated with artificially infected plant residues after 20 months of storage outdoors on soil surface. More positive results were achieved from bait plants grown in soil collected from the field where infected plants had been destroyed two years before, than from samples collected a year after the plant destruction.

  6. Infection of Phytophthora palmivora from Soil in Cocoa Plantation

    Directory of Open Access Journals (Sweden)

    Agus Purwantara

    2008-12-01

    Full Text Available Phytophthora palmivora causes serious losses on cocoa in Indonesia and world-wide. The research aimed to assess the potential of soil as source of inocula for Phytophthora diseases in cocoa. Soil samples were baited using a healthy cocoa pod tissue, and the pathogen was isolated for morphological and molecular identification. Baiting technique was successfully used to detect the presence of P. palmivora in soil samples, and this was confirmed by morphological and molecular identification. P. palmivora can be detected in soil in all year around in wet areas indicating that soil is a massive and consistent source of inocula. Surveys conducted on the soil of Amazonian, Amelonado and Trinitario blocks of various ages showed that P. palmivora can be found in old and young cocoa blocks, even as young as 3 or 4 years. P. palmivora infection from soil to the pods appears to be mainly through contact or rain splash. Baiting with whole healthy pods exposed at different heights above undisturbed litter and above bare soil showed that the infection still occurred at 100 cm above the soil, even though it decreased gradually with the height. Infection from litter was not different to that from bare soil, indicating that the litter layer is not acting physically as a shield preventing rain from splashing the inocula up from wet soil to the pods. However, in tests for the possibility of P. palmivora carried through air convection, no pod was found to be infected, suggesting that the pathogen was not carried through convective accend of aerosol droplets from soil surface up to pods in the canopy.Key words : Theobroma cacao, pod rot, stem canker, baiting.

  7. The hidden duplication past of the plant pathogen Phytophthora and its consequences for infection

    Directory of Open Access Journals (Sweden)

    Martens Cindy

    2010-06-01

    Full Text Available Abstract Background Oomycetes of the genus Phytophthora are pathogens that infect a wide range of plant species. For dicot hosts such as tomato, potato and soybean, Phytophthora is even the most important pathogen. Previous analyses of Phytophthora genomes uncovered many genes, large gene families and large genome sizes that can partially be explained by significant repeat expansion patterns. Results Analysis of the complete genomes of three different Phytophthora species, using a newly developed approach, unveiled a large number of small duplicated blocks, mainly consisting of two or three consecutive genes. Further analysis of these duplicated genes and comparison with the known gene and genome duplication history of ten other eukaryotes including parasites, algae, plants, fungi, vertebrates and invertebrates, suggests that the ancestor of P. infestans, P. sojae and P. ramorum most likely underwent a whole genome duplication (WGD. Genes that have survived in duplicate are mainly genes that are known to be preferentially retained following WGDs, but also genes important for pathogenicity and infection of the different hosts seem to have been retained in excess. As a result, the WGD might have contributed to the evolutionary and pathogenic success of Phytophthora. Conclusions The fact that we find many small blocks of duplicated genes indicates that the genomes of Phytophthora species have been heavily rearranged following the WGD. Most likely, the high repeat content in these genomes have played an important role in this rearrangement process. As a consequence, the paucity of retained larger duplicated blocks has greatly complicated previous attempts to detect remnants of a large-scale duplication event in Phytophthora. However, as we show here, our newly developed strategy to identify very small duplicated blocks might be a useful approach to uncover ancient polyploidy events, in particular for heavily rearranged genomes.

  8. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam

    Science.gov (United States)

    Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano

    2017-01-01

    Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with ‘King’ mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch’s postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on ‘Carrizo’ citrange (C. sinensis ‘Washington Navel’ x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity. PMID:28208159

  9. 桂枝抑制柑橘采后两种病原菌活性物质研究%Antifungal Activity of Ramulus cinnamomi extracts against two key Citrus Postharvest Pathogens

    Institute of Scientific and Technical Information of China (English)

    万春鹏; 周梦娇; 刘洋; 陈金印

    2014-01-01

    In order to screen Chinese herbal medicine with potential antifungal activity from Chinese herb -al medicine extracts against two key Citrus postharvest pathogens ,namely Penicillium italicum and Penicillium digitatum.Solvent extract and silica gel chromatography were used to determine the antifungal materials from the active herb extracts .The results suggested that Ramulus cinnamomi,Cinnamomum cassia,Asarum sieboldii, Herba Moslae,Cortex Moutan and Artemisia apiacea had powerful inhibitive effects on the two pathogens and the inhibition zones were all over 20 mm.Moreover,the antifungal materials of Ramulus cinnamomi,Cinnamo-mum cassia and Asarum sieboldii all existed in the ethyl acetate fraction .Ramulus cinnamomi showed the best inhibitive effects on the two pathogens ,and the inhibitive zones were 34.57 mm and 31.56 mm,respectively. While the MIC were 3.125 mg/mL and 6.25 mg/mL,respectively;the MFC were 6.25 mg/mL and 12.5 mg/mL,respectively.The inhibition zones of the ethyl acetate fraction of Ramulus cinnamomi were 45.33 mm and 40.53 mm,respectively.Four subfractions (Fr.1-Fr.4) were obtained from the ethyl acetate fraction by the silica gel chromatography .Fr.1 showed the best antifungal activity and cinnamaldehyde was the main antifungal material in Fr.1 detected by HPLC .%从中草药提取物中筛选对引起柑橘采后主要病害的两株真菌---意大利青霉( Penicillium italicum)和指状青霉( Penicillium digitatum)有抑菌活性的中草药;采用溶剂萃取和硅胶柱色谱对具有较好抑菌活性的中草药提取物进一步分离纯化,确定其抑菌活性物质。结果表明:桂枝、桂皮、细辛、香薷、牡丹皮和青蒿6种提取物对这两株真菌均有较好的抑菌效果,抑菌圈直径均达20 mm以上。其中桂枝、桂皮和细辛的抗菌活性物质主要存在于乙酸乙酯部位,且桂枝的抑菌活性最强,对意大利青霉和指状青霉的抑菌圈直径分别为34.57 mm和31

  10. Hemicorporectomia associada à colostomia úmida: procedimento de exceção

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    Marco Antonio Ricci

    Full Text Available Por ser um procedimento de alta complexidade, a Hemicorporectomia associada a Colostomia úmida em alça deve ser empregada como procedimento de exceção. Por ser uma medida heróica trata-se do último recurso utilizado para tratamento de doenças pélvicas localmente avançadas e sem evidências de metástases à distância. Analisamos retrospectivamente os detalhes da técnica cirúrgica utilizada em um caso de carcinoma epidermóide desenvolvido em ulcera de pressão de região sacra e os resultados da primeira Hemicorporectomia associada a colostomia úmida em alça em um único tempo.

  11. A novel method for efficient and abundant production of Phytophthora brassicae zoospores on Brussels sprout leaf discs

    NARCIS (Netherlands)

    Bouwmeester, K.; Govers, F.

    2009-01-01

    Background - Phytophthora species are notorious oomycete pathogens that cause diseases on a wide range of plants. Our understanding how these pathogens are able to infect their host plants will benefit greatly from information obtained from model systems representative for plant-Phytophthora interac

  12. Molecular mapping and characterization of two genes conferring resistance to Phytophthora sojae in a soybean landrace PI 567139B

    Science.gov (United States)

    Phytophthora root and stem rot (PRR), caused by the soil-borne oomycete pathogen Phytophthora sojae, is one of the most destructive diseases of soybean. PRR can be effectively controlled by race-specific genes conferring resistance to P. sojae (Rps). However, the Rps genes are usually non-durable, a...

  13. Mapping of quantitative trait loci associated with partial resistance to phytophthora sojae and flooding tolerance in soybean

    Science.gov (United States)

    Phytophthora root rot (PRR) caused by Phytophthora sojae Kaufm. & Gerd. and flooding can limit growth and productivity, of soybean [Glycine max (L.) Merr.], especially on poorly drained soils. The primary objective of this research project was to map quantitative trait loci (QTL) associated with f...

  14. Molecular response to the pathogen Phytophthora sojae among ten soybean near isogenic lines revealed by comparative transcriptomics

    Science.gov (United States)

    Phytophthora root and stem rot (PRR) of soybean, caused by Phytophthora sojae, is effectively controlled by Rps genes in soybean. Rps genes are race-specific, yet the mechanism of resistance, as well as susceptibility, remains largely unclear. Taking advantage of RNA-seq technology, we sequenced the...

  15. Genome-wide association mapping of partial resistance to Phytophthora sojae in soybean plant introductions from the Republic of Korea

    Science.gov (United States)

    Phytophthora root and stem rot is one of the most yield-limiting diseases of soybean [Glycine max (L.) Merr], caused by the oomycete Phytophthora sojae. Partial resistance is controlled by several genes and, compared to single gene (Rps gene) resistance to P. sojae, places less selection pressure on...

  16. Comparative analysis of Phytophthora genes encoding secreted proteins reveals conserved synteny and lineage-specific gene duplications and deletions

    NARCIS (Netherlands)

    Jiang, R.H.Y.; Tyler, B.M.; Govers, F.

    2006-01-01

    Comparative analysis of two Phytophthora genomes revealed overall colinearity in four genomic regions consisting of a 1.5-Mb sequence of Phytophthora sojae and a 0.9-Mb sequence of R ramorum. In these regions with conserved synteny, the gene order is largely similar; however, genome rearrangements a

  17. Fungicide rotation schemes for managing Phytophthora fruit rot of watermelon across Southeastern United States (NC, SC, and GA)

    Science.gov (United States)

    Phytophthora capsici has been documented as a pathogen on a wide variety of vegetable crops in the family Solanaceae, Cucurbitaceae, Fabaceae, and plants belonging to 23 other families. Phytophthora fruit rot of watermelons caused by P. capsici is particularly severe in southeastern U.S where optima...

  18. Pathogenicity, fungicide resistance, and genetic variability of Phytophthora rubi isolates from raspberry (Rubus idaeus) in the Western United States

    Science.gov (United States)

    Root rot of raspberry (Rubus idaeus), thought to be primarily caused by Phytophthora rubi, is an economically important disease in the western United States. The objectives of this study were to determine which Phytophthora species are involved in root rot, examine the efficacy of different isolatio...

  19. The Arabidopsis lectin receptor kinase LecRK-I.9 enhances resistance to Phytophthora infestans in Solanaceous plants

    NARCIS (Netherlands)

    Bouwmeester, K.; Han, M.; Blanco-Portales, R.; Song, W.; Weide, R.; Guo, L.Y.; Vossen, van der E.A.G.; Govers, F.

    2014-01-01

    Phytophthora species are notorious plant pathogens which cause a variety of devastating crop diseases. Phytophthora pathogens secrete a plethora of effector proteins, several of which are known to interact with receptors in the host cell thereby either activating or suppressing defense responses. Un

  20. Phytophthora ipomoeae, a new homothallic species causing leaf blight on Ipomoea longipedunculata in the Toluca Valley of central Mexico

    NARCIS (Netherlands)

    Flier, W.G.; Grunwald, N.J.; Kroon, L.P.N.M.; Bosch, van den G.B.M.; Garay-Serrano, E.; Lozoya-Saldan, H.; Bonants, P.J.M.; Turkensteen, L.J.

    2002-01-01

    A Phytophthora species was found on blighted foliage of Ipomoea longipedunculata, a morning glory native to the highlands of central Mexico. Based on host range, morphology, allozymes, mitochondrial DNA haplotype and rDNA sequences it is concluded that a new Phytophthora species, P. ipomoeae sp. nov

  1. Meningite pneumocócica: Tratamento pela penicilina associada a sulfapiridina

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    J. M. Taques Bittencourt

    1945-09-01

    Full Text Available E' relatado um caso de meningite pneumocócica pós-otite e mastoidite, tratado com sucesso pela penicilina associada à sulfapiridina. Tanto o composto sulfonamídico como a penicilina isoladamente não tiveram efeito terapêutico satisfatório. A evolução da meningite é estudada por exames diários do liqüido cefalorraquidiano.

  2. Polimiosite associada a infecção por HTLV-I: relato de caso

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    OLIVEIRA HÉLIO ARAÚJO

    2000-01-01

    Full Text Available Apresentamos o caso de mulher com 57 anos de idade apresentando polimiosite, associada a infecção pelo HTLV-I, sem manifestações clínicas de acomentimento do sistema nervoso central e periférico. Fazemos alguns comentários sobre os aspectos fisiopatológicos do envolvimento muscular nas infecções pelo HTLV-I.

  3. Tuberculose associada a nefrocalcinose em um lactente = Tuberculosis associated with nephrocalcinosis in an infant

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    Afonso, Paula

    2014-01-01

    Conclusões: Este caso clínico destaca-se pela forma incomum de apresentação da tuberculose, com a presença de nefrocalcinose. As perturbações do metabolismo do cálcio associadas à tuberculose são raras, mas têm implicação no seguimento e no prognóstico

  4. Polimiosite associada à arterite linfocítica do sistema nervoso central

    OpenAIRE

    Costa,Izaias Pereira da; Pradebon,Elisangela Possebon; Campos,Julia Villegas; Melo,Fabrícia Santos; Tavares,Flávia Midori Arakaki Ayres

    2010-01-01

    Complicações do Sistema Nervoso Central (SNC) raramente são descritas em miopatias inflamatórias idiopáticas. Os autores relatam o caso de uma paciente de 48 anos com diagnóstico de polimiosite com autoanticorpo anti-Jo-1 positivo que, após cinco anos de evolução, apresentou extensa lesão desmielinizante do SNC associada à arterite linfocítica.

  5. CHARACTERIZATION OF Phytophthora infestans POPULATIONS IN ANTIOQUIA, COLOMBIA CARACTERIZACIÓN DE LAS POBLACIONES DE Phytophthora infestan EN ANTIOQUIA, COLOMBIA

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    Elizabeth Gilchrist Ramelli

    2009-12-01

    Full Text Available From the Phytophthora infestans collection of the Universidad Nacional de Colombia, the isolates collected in different locations in Antioquia, Colombia between 1994 and 2000 were evaluated. These isolates were obtained from late blight lessons in different hosts. In 2000, these isolates were characterized by mating type, mitochondrial haplotype and virulence races. All isolates were of the A1 mating type and two mitochondrial haplotypes were identified: IIa, present in isolates from all the hosts tested, and Ib present only in isolates from tomato and water cucumber (Solanum muricatum. The Antioquia population of P. infestans showed a large complexity of virulence factors (10 out 11, especially those isolates collected from potato, while the tomato population was less complex. The A1 mating type and the mitochondrial haplotype IIa has been associated with the EC1 population that possibly is replacing the US1 population.De la colección de Phytophthora infestans de la Universidad Nacional de Colombia, se evaluaron aquellos aislamientos provenientes de diferentes localidades de Antioquia, Colombia entre 1994 y 2000. Dichos aislamientos fueron obtenidos de lesiones de tizón tardío en diferentes hospederos. En el año 2000 se caracterizaron por el tipo de apareamiento, haplotipo mitocondrial y razas de virulencia. Todos los aislamientos correspondieron al tipo de apareamiento A1 y se presentaron dos haplotipos mitocondriales: IIa, en aislamientos de todos los hospederos evaluados, y Ib solamente en aislamientos colectados de tomate y pepino de agua (Solanum muricatum. La población antioqueña de P. infestans presenta una amplia complejidad de factores de virulencia (10 de 11, especialmente para los aislamientos colectados de papa, mientras que la población de tomate fue menos compleja. El tipo de apareamiento A1 y el haplotipo mitocondrial IIa han sido asociados a la población EC1 que posiblemente está desplazando la población US1.

  6. Reaction of Phytophthora fruit rot resistant germplasm lines to a broad range of Phytophthora capsici isolates from across the United States of America

    Science.gov (United States)

    Phytophthora fruit rot limits watermelon production in most states in the Southeastern US (FL, GA, SC, NC and VA). It has also become a serious problem in recent years in northern states (IN, MD, DE). About 50% of the US watermelons are grown in the southeastern states where environmental conditions...

  7. Activation of defense against Phytophthora infestans in potato by down-regulation of syntaxin gene expression.

    Science.gov (United States)

    Eschen-Lippold, Lennart; Landgraf, Ramona; Smolka, Ulrike; Schulze, Sebastian; Heilmann, Mareike; Heilmann, Ingo; Hause, Gerd; Rosahl, Sabine

    2012-03-01

    The oomycete Phytophthora infestans is the causal agent of late blight, the most devastating disease of potato. The importance of vesicle fusion processes and callose deposition for defense of potato against Phytophthora infestans was analyzed. Transgenic plants were generated, which express RNA interference constructs targeted against plasma membrane-localized SYNTAXIN-RELATED 1 (StSYR1) and SOLUBLE N-ETHYLMALEIMIDE-SENSITIVE FACTOR ADAPTOR PROTEIN 33 (StSNAP33), the potato homologs of Arabidopsis AtSYP121 and AtSNAP33, respectively. Phenotypically, transgenic plants grew normally, but showed spontaneous necrosis and chlorosis formation at later stages. In response to infection with Phytophthora infestans, increased resistance of StSYR1-RNAi plants, but not StSNAP33-RNAi plants, was observed. This increased resistance correlated with the constitutive accumulation of salicylic acid and PR1 transcripts. Aberrant callose deposition in Phytophthora infestans-infected StSYR1-RNAi plants coincided with decreased papilla formation at penetration sites. Resistance against the necrotrophic fungus Botrytis cinerea was not significantly altered. Infiltration experiments with bacterial solutions of Agrobacterium tumefaciens and Escherichia coli revealed a hypersensitive phenotype of both types of RNAi lines. The enhanced defense status and the reduced growth of Phytophthora infestans on StSYR1-RNAi plants suggest an involvement of syntaxins in secretory defense responses of potato and, in particular, in the formation of callose-containing papillae.

  8. The Irish potato famine pathogen Phytophthora infestans originated in central Mexico rather than the Andes.

    Science.gov (United States)

    Goss, Erica M; Tabima, Javier F; Cooke, David E L; Restrepo, Silvia; Fry, William E; Forbes, Gregory A; Fieland, Valerie J; Cardenas, Martha; Grünwald, Niklaus J

    2014-06-17

    Phytophthora infestans is a destructive plant pathogen best known for causing the disease that triggered the Irish potato famine and remains the most costly potato pathogen to manage worldwide. Identification of P. infestan's elusive center of origin is critical to understanding the mechanisms of repeated global emergence of this pathogen. There are two competing theories, placing the origin in either South America or in central Mexico, both of which are centers of diversity of Solanum host plants. To test these competing hypotheses, we conducted detailed phylogeographic and approximate Bayesian computation analyses, which are suitable approaches to unraveling complex demographic histories. Our analyses used microsatellite markers and sequences of four nuclear genes sampled from populations in the Andes, Mexico, and elsewhere. To infer the ancestral state, we included the closest known relatives Phytophthora phaseoli, Phytophthora mirabilis, and Phytophthora ipomoeae, as well as the interspecific hybrid Phytophthora andina. We did not find support for an Andean origin of P. infestans; rather, the sequence data suggest a Mexican origin. Our findings support the hypothesis that populations found in the Andes are descendants of the Mexican populations and reconcile previous findings of ancestral variation in the Andes. Although centers of origin are well documented as centers of evolution and diversity for numerous crop plants, the number of plant pathogens with a known geographic origin are limited. This work has important implications for our understanding of the coevolution of hosts and pathogens, as well as the harnessing of plant disease resistance to manage late blight.

  9. Universality of the Phytophthora mating hormones and diversity of their production profile.

    Science.gov (United States)

    Tomura, Tomohiko; Molli, Shylaja D; Murata, Ryo; Ojika, Makoto

    2017-07-10

    Sexual reproduction of the plant pest Phytophthora is regulated by two mating hormones α1 and α2, which are acyclic oxygenated diterpenes first isolated from P. nicotianae A1 and A2 mating types, respectively. A previous report suggested the universality of these factors within this genus. To confirm this concept, we investigated 80 strains (19 species) of Phytophthora and a related genus, not only for the responsiveness to mating hormones but also for their productivity. The results indicated that among the 55 heterothallic strains, 24 (44%) responded to a mating hormone and 40 (73%) produced one or both hormones. These findings demonstrate the interspecies universality of mating hormones within the genus Phytophthora. Hormone productivity was found to be highly diverse and dependent on the strains used. Although the A2 mating type has been regarded as the α2 producer, 19 (59%) of the 32 A2-type strains produced both the hormones and two A2-type strains exclusively produced α1 in high yields. These results indicate that hormone biosynthesis in Phytophthora is universal but highly diverse and complex, and varies with culture conditions, providing us valuable information for future studies on the mechanism of mating hormone biosynthesis of Phytophthora.

  10. Occurrence and characterization of a Phytophthora sp. pathogenic to asparagus (Asparagus officinalis) in Michigan.

    Science.gov (United States)

    Saude, C; Hurtado-Gonzales, O P; Lamour, K H; Hausbeck, M K

    2008-10-01

    A homothallic Phytophthora sp. was recovered from asparagus (Asparagus officinalis) spears, storage roots, crowns, and stems in northwest and central Michigan in 2004 and 2005. Isolates (n = 131) produced ovoid, nonpapillate, noncaducous sporangia 45 microm long x 26 microm wide and amphigynous oospores of 25 to 30 microm diameter. Mycelial growth was optimum at 25 degrees C with no growth at 5 and 30 degrees C. All isolates were sensitive to 100 ppm mefenoxam. Pathogenicity studies confirmed the ability of the isolates to infect asparagus as well as cucurbits. Amplified fragment length polymorphism analysis of 99 isolates revealed identical fingerprints, with 12 clearly resolved fragments present and no clearly resolved polymorphic fragments, suggesting a single clonal lineage. The internal transcribed spacer regions of representative isolates were homologous with a Phytophthora sp. isolated from diseased asparagus in France and a Phytophthora sp. from agave in Australia. Phylogenetic analysis supports the conclusion that the Phytophthora sp. isolated from asparagus in Michigan is a distinct species, and has been named Phytophthora asparagi.

  11. Metabarcoding Analysis of Phytophthora Diversity Using Genus-Specific Primers and 454 Pyrosequencing.

    Science.gov (United States)

    Prigigallo, Maria I; Abdelfattah, Ahmed; Cacciola, Santa O; Faedda, Roberto; Sanzani, Simona M; Cooke, David E L; Schena, L

    2016-03-01

    A metabarcoding method based on genus-specific primers and 454 pyrosequencing was utilized to investigate the genetic diversity of Phytophthora spp. in soil and root samples of potted plants, from eight nurseries. Pyrosequencing enabled the detection of 25 Phytophthora phylotypes distributed in seven different clades and provided a much higher resolution than a corresponding cloning/Sanger sequencing approach. Eleven of these phylotypes, including P. cactorum, P. citricola s.str., P. palmivora, P. palmivora-like, P. megasperma or P. gonapodyides, P. ramorum, and five putative new Phytophthora species phylogenetically related to clades 1, 2, 4, 6, and 7 were detected only with the 454 pyrosequencing approach. We also found an additional 18 novel records of a phylotype in a particular nursery that were not detected with cloning/Sanger sequencing. Several aspects confirmed the reliability of the method: (i) many identical sequence types were identified independently in different nurseries, (ii) most sequence types identified with 454 pyrosequencing were identical to those from the cloning/Sanger sequencing approach and/or perfectly matched GenBank deposited sequences, and (iii) the divergence noted between sequence types of putative new Phytophthora species and all other detected sequences was sufficient to rule out sequencing errors. The proposed method represents a powerful tool to study Phytophthora diversity providing that particular attention is paid to the analysis of 454 pyrosequencing raw read sequences and to the identification of sequence types.

  12. Multiple Phytophthora species associated with a single riparian ecosystem in South Africa.

    Science.gov (United States)

    Nagel, Jan H; Slippers, Bernard; Wingfield, Michael J; Gryzenhout, Marieka

    2015-01-01

    The diversity of Phytophthora spp. in rivers and riparian ecosystems has received considerable international attention, although little such research has been conducted in South Africa. This study determined the diversity of Phytophthora spp. within a single river in Gauteng province of South Africa. Samples were collected over 1 y including biweekly river baiting with Rhododendron indicum leaves. Phytophthora isolates were identified with phylogenetic analyses of sequences for the internal transcribed spacer (ITS) region of the ribosomal DNA and the mitochondrial cytochrome oxidase c subunit I (coxI) gene. Eight Phytophthora spp. were identified, including a new taxon, P. taxon Sisulu-river, and two hybrid species from Cooke's ITS clade 6. Of these, species from Clade 6 were the most abundant, including P. chlamydospora and P. lacustris. Species residing in Clade 2 also were encountered, including P. multivora, P. plurivora and P. citrophthora. The detection of eight species in this investigation of Phytophthora diversity in a single riparian river ecosystem in northern South Africa adds to the known diversity of this genus in South Africa and globally.

  13. Examination of some morphologically unusual cultures of Phytophthora species using a mitochondrial DNA miniprep technique and a standardised sporangium caducity assessment.

    Science.gov (United States)

    Hall, G S

    Using the mitochondrial DNA miniprep technique, the identity of sixteen morphologically unusual cultures allocated to Phytophthora nicotianae, Phytophthora mexicana or Phytophthora porri was determined by comparison with a library of mtDNA band patterns obtained from reference cultures. Seven cultures were identified as Phytophthora nicotianae (including those assigned to Phytophthora mexicana and Phytophthora porri), six as strains of Phytophthora palmivora with small, ovoid, weakly caducous sporangia, and one as Phytophthora citrophthora. Some cultures of P. nicotianae had a low percentage of caducous sporangia. Percentage sporangium caducity, but not sporangium L:B ratio, is considered a useful taxonomic criterion for separating species morphologically similar to Phytophthora nicotianae. One culture from tobacco in New Zealand had a highly unusual morphology and a unique DNA band pattern, but was not identifiable. One culture from Acacia mearnsii in South Africa had a unique DNA band pattern which was identical to that of an isolate from Annona squamosa from Australia previously identified as Phytophthora palmivora, the precise identity of which is still unclear. The identity of most isolates from diseased durian was found to be Phytophthora palmivora, confirming its role as the main pathogen, but P. nicotianae was also identified from this host.

  14. A conceptual model for the development of Phytophthora disease in Quercus robur.

    Science.gov (United States)

    Jönsson, U

    2006-01-01

    Here, a conceptual model is presented for the development of Phytophthora disease in pedunculate oak. The model is presented using the causal loop diagram tool and gives an overview of how various abiotic and biotic factors, such as soil moisture, nutrient availability and mycorrhizal colonization, may affect the reproduction and the infective capacity of soil-borne Phytophthora species, the susceptibility of the host and subsequent disease development. It is suggested that the link between the root damage caused by Phytophthora species and overall tree vitality is in the assimilation and allocation of carbon within the plants. The potential impact of environmental factors on these processes is discussed. The model is presented with reference to scenarios related to variation in soil moisture and nutrient availability. The need for species-specific validation of the model and the implications of the model are discussed.

  15. [Effect of pentachloronitrobenzene (PCNB) on the ultrastructure of Mucor mucedo and Phytophthora cactorum].

    Science.gov (United States)

    Casperson, G; Lyr, H

    1982-01-01

    The effect of PCNB in various concentrations on the ultrastructure of Mucor mucedo and phytophthora cactorum was analyzed after an incubation period of 2 hours. The most striking effect in both fungi was a diffuse lysis of the internal structure of the mitochondria which differs markedly from the lysis induced by etridiazol (terrazol). Moreover an enlargement of the perinuclear space and an increased formation of vacuoles was observed. In Mucor mucedo, but not in Phytophthora cactorum a pathological thickening of the cell wall was observed. Although after 2 hours incubation with PCNB Phytophthora gave similar ultrastructural reactions in the mitochondria as Mucor, in growth experiments on agar dishes this species was 5-10 times less sensitive to PCNB compared to Mucor.

  16. FIRST REPORT OF Phytophthora nicotianae CAUSING ROOT ROT OF SOURSOP IN NORTHEASTERN BRAZIL

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    JAQUELINE FIGUEREDO DE OLIVEIRA COSTA

    Full Text Available ABSTRACT In 2013, soursop trees showing symptoms of root rot were observed in a field in Maceió, state of Alagoas, Brazil. It was isolated Phytophthora sp. which pathogenicity was confirmed in the host seedlings. Morphological and physiological characteristics in carrot-agar modified medium were consistent with Phytophthora nicotianae description. The PCR sequences products obtained with ITS1/ITS4 primers were compared to sequences of ribosomal DNA of Phytophthora species from the GenBank database observing high identity with other P. nicotianae isolates. A phylogenetic tree was performed to compare the isolate with other sequences of P. nicotianae, which clustering has been verified with 99% of bootstrap, confirming the morphophysiological studies. This is the first report of this pathogen on annonaceous plants in the Northeastern Brazil.

  17. Use of genome sequence data in the design and testing of SSR markers for Phytophthora species

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    Cardle Linda

    2008-12-01

    Full Text Available Abstract Background Microsatellites or single sequence repeats (SSRs are a powerful choice of marker in the study of Phytophthora population biology, epidemiology, ecology, genetics and evolution. A strategy was tested in which the publicly available unigene datasets extracted from genome sequences of P. infestans, P. sojae and P. ramorum were mined for candidate SSR markers that could be applied to a wide range of Phytophthora species. Results A first approach, aimed at the identification of polymorphic SSR loci common to many Phytophthora species, yielded 171 reliable sequences containing 211 SSRs. Microsatellites were identified from 16 target species representing the breadth of diversity across the genus. Repeat number ranged from 3 to 16 with most having seven repeats or less and four being the most commonly found. Trinucleotide repeats such as (AAGn, (AGGn and (AGCn were the most common followed by pentanucleotide, tetranucleotide and dinucleotide repeats. A second approach was aimed at the identification of useful loci common to a restricted number of species more closely related to P. sojae (P. alni, P. cambivora, P. europaea and P. fragariae. This analysis yielded 10 trinucleotide and 2 tetranucleotide SSRs which were repeated 4, 5 or 6 times. Conclusion Key studies on inter- and intra-specific variation of selected microsatellites remain. Despite the screening of conserved gene coding regions, the sequence diversity between species was high and the identification of useful SSR loci applicable to anything other than the most closely related pairs of Phytophthora species was challenging. That said, many novel SSR loci for species other than the three 'source species' (P. infestans, P. sojae and P. ramorum are reported, offering great potential for the investigation of Phytophthora populations. In addition to the presence of microsatellites, many of the amplified regions may represent useful molecular marker regions for other studies as

  18. Phytophthora species recovered from the Connecticut River Valley in Massachusetts, USA.

    Science.gov (United States)

    Brazee, Nicholas J; Wick, Robert L; Hulvey, Jonathan P

    2016-01-01

    Little is currently known about the assemblage of Phytophthora species in northeastern North America, representing a gap in our understanding of species incidence. Therefore, Phytophthora species were surveyed at 20 sites in Massachusetts, with 16 occurring in the Connecticut River Valley. Many of the sampled waterways were adjacent to active agricultural lands, yet were buffered by mature floodplain forests composed of Acer, Platanus, Populus and Ulmus. Isolates were recovered with three types of baits (rhododendron leaves, pear, green pepper) in 2013 and water filtration in 2014. Overall, 457 isolates of Phytophthora were recovered and based on morphological characters and rDNA internal transcribed spacer (ITS), β-tubulin (β-tub) and cytochrome oxidase c subunit I (cox1) sequences, 18 taxa were identified, including three new species: P. taxon intercalaris, P. taxon caryae and P. taxon pocumtuck. In addition, 49 isolates representing five species of Phytopythium also were identified. Water filtration captured a greater number of taxa (18) compared to leaf and fruit baits (12). Of the three bait types rhododendron leaves yielded the greatest number of isolates and taxa, followed by pear and green pepper, respectively. Despite the proximity to agricultural lands, none of the Phytophthora species baited are considered serious pathogens of vegetable crops in the region. However, many of the recovered species are known woody plant pathogens, including four species in the P. citricola s.l. complex that were identified: P. plurivora, P. citricola III, P. pini and a putative novel species, referred to here as P. taxon caryae. An additional novel species, P. taxon pocumtuck, is a close relative of P. borealis based on cox1 sequences. The results illustrate a high level of Phytophthora species richness in the Connecticut River Valley and that major rivers can serve as a source of inoculum for pathogenic Phytophthora species in the northeast.

  19. Biological characteristics and mating type distribution of Phytophthora capsici from China.

    Science.gov (United States)

    Du, Y; Gong, Z-H; Liu, G-Z; Chai, G-X; Li, C

    2014-01-21

    Phytophthora capsici from seven provinces of China were investigated for their mating type, hyphal growth, zoospore production, and virulence. All of the morphological characteristics and the results of polymerase chain reaction confirmed that these isolates were indeed Phytophthora capsici. The test of mating type showed that the mating types of 19 representative isolates from China varied. The hyphal growth and the amount of zoospores produced from these isolates differed and there was no evident relationship between them, which indicated the existence of genetic diversity among the isolates in China. Also, the isolates that were more virulent on the pepper cultivars that we checked produced more zoospores than other isolates.

  20. Strain Specific Factors Control Effector Gene Silencing in Phytophthora sojae.

    Directory of Open Access Journals (Sweden)

    Sirjana Devi Shrestha

    Full Text Available The Phytophthora sojae avirulence gene Avr3a encodes an effector that is capable of triggering immunity on soybean plants carrying the resistance gene Rps3a. P. sojae strains that express Avr3a are avirulent to Rps3a plants, while strains that do not are virulent. To study the inheritance of Avr3a expression and virulence towards Rps3a, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 X P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F5 generation. However, test-crosses of F1 progeny (ACR10 X P7076 with strain P6497 result in the release of silencing of Avr3a. Expression of Avr3a in the progeny is variable and correlates with the phenotypic penetrance of the avirulence trait. The F1 progeny from a direct cross of P6497 X ACR10 segregate for inheritance for Avr3a expression, a result that could not be explained by parental imprinting or heterozygosity. Analysis of small RNA arising from the Avr3a gene sequence in the parental strains and hybrid progeny suggests that the presence of small RNA is necessary but not sufficient for gene silencing. Overall, we conclude that inheritance of the Avr3a gene silenced phenotype relies on factors that are variable among P. sojae strains.

  1. Characterization of Phytophthora infestans resistance to mefenoxam using FTIR spectroscopy.

    Science.gov (United States)

    Pomerantz, A; Cohen, Y; Shufan, E; Ben-Naim, Y; Mordechai, S; Salman, A; Huleihel, M

    2014-12-01

    Phytophthora infestans (P. infestans) is the causal agent of late blight in potato and tomato. This pathogen devastated the potato crops in Ireland more than a century years ago and is still causing great losses worldwide. Although fungicides controlling P. infestans have been used successfully for almost 100 years, some isolates have developed resistance to most common fungicides. Identification and characterization of these resistant isolates is required for better control of the disease. Current methods that are based on microbiological and molecular techniques are both expensive and time consuming. Fourier Transform Infra-Red spectroscopy (FTIR) is an inexpensive and reagent-free technique that provides accurate results in only a few minutes. In this study the infrared absorption spectra of the sporangia of P. infestans were measured to evaluate the potential of FTIR spectroscopy in tandem with multivariate analysis in order to classify those sporangia into those that were resistant and those that were non-resistant to the phenylamide fungicide mefenoxam. Based on individual measurements, our results show that FTIR spectroscopy enables classification of P. infestans isolates into mefenoxam resistant and mefenoxam non-resistant types with specificity of 81.9% and sensitivity of 75.5%. Using average spectra per leaf, it was possible to improve the classification results to 88% sensitivity and 95% specificity.

  2. Phytophthora infestans specific phosphorylation patterns and new putative control targets.

    Science.gov (United States)

    Frades, Itziar; Andreasson, Erik

    2016-04-01

    In this study we applied biomathematical searches of gene regulatory mechanisms to learn more about oomycete biology and to identify new putative targets for pesticides or biological control against Phytophthora infestans. First, oomycete phylum-specific phosphorylation motifs were found by discriminative n-gram analysis. We found 11.600 P. infestans specific n-grams, mapping 642 phosphoproteins. The most abundant group among these related to phosphatidylinositol metabolism. Due to the large number of possible targets found and our hypothesis that multi-level control is a sign of usefulness as targets for intervention, we identified overlapping targets with a second screen. This was performed to identify proteins dually regulated by small RNA and phosphorylation. We found 164 proteins to be regulated by both sRNA and phosphorylation and the dominating functions where phosphatidylinositol signalling/metabolism, endocytosis, and autophagy. Furthermore we performed a similar regulatory study and discriminative n-gram analysis of proteins with no clear orthologs in other species and proteins that are known to be unique to P. infestans such as the RxLR effectors, Crinkler (CRN) proteins and elicitins. We identified CRN proteins with specific phospho-motifs present in all life stages. PITG_12626, PITG_14042 and PITG_23175 are CRN proteins that have species-specific phosphorylation motifs and are subject to dual regulation.

  3. Detection, Diversity, and Population Dynamics of Waterborne Phytophthora ramorum Populations.

    Science.gov (United States)

    Eyre, C A; Garbelotto, M

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed routinely; however, little is known about the nature of water-borne P. ramorum populations. Two drainages in an infested California forest were monitored intensively using stream-baiting for 2 years between 2009 and 2011. Pathogen presence was determined both by isolation and polymerase chain reaction (PCR) from symptomatic bait leaves. Isolates were analyzed using simple sequence repeats to study population dynamics and genetic structure through time. Isolation was successful primarily only during spring conditions, while PCR extended the period of pathogen detection to most of the year. Water populations were extremely diverse, and changed between seasons and years. A few abundant genotypes dominated the water during conditions considered optimal for aerial populations, and matched those dominant in aerial populations. Temporal patterns of genotypic diversification and evenness were identical among aerial, soil, and water populations, indicating that all three substrates are part of the same epidemiological cycle, strongly influenced by rainfall and sporulation on leaves. However, there was structuring between substrates, likely arising due to reduced selection pressure in the water. Additionally, water populations showed wholesale mixing of genotypes without the evident spatial autocorrelation present in leaf and soil populations.

  4. Identification of Phytophthora sojae genes involved in asexual sporogenesis

    Indian Academy of Sciences (India)

    Ziying Wang; Xhaoxia Wang; Jie Shen; Guangyue Wang; Xiaoxi Zhu; Hongxia Lu

    2009-08-01

    To explore the molecular mechanisms involved in asexual spore development in Phytophthora sojae, the zoospores of strain PS26 were treated with ultraviolet (UV) irradiation. After selection, a mutant progeny, termed PS26-U03, was obtained and demonstrated to exhibit no oospore production. A suppression subtractive hybridization (SSH) approach was developed to investigate differences in gene expression between PS26 and PS26-U03 during asexual sporogenesis. Of the 126 sequences chosen for examination, 39 putative unigenes were identified that exhibit high expression in PS26. These sequences are predicted to encode proteins involved in metabolism, cell cycle, protein biosynthesis, cell signalling, cell defence, and transcription regulation. Seven clones were selected for temporal expression analysis using RT-PCR based on the results of the dot-blot screens. Three of the selected genes, developmental protein DG1037 (UB88), glycoside hydrolase (UB149) and a hypothetical protein (UB145), were expressed only in PS26, whereas the transcripts of phosphatidylinositol-4-phosphate 5-kinase (UB36), FAD-dependent pyridine nucleotide-disulphide oxidoreductase (UB226) and sugar transporter (UB256) were expressed at very low levels in PS26-U03 but at high levels in PS26.

  5. Distinctive Nuclear Localization Signals in the Oomycete Phytophthora sojae.

    Science.gov (United States)

    Fang, Yufeng; Jang, Hyo Sang; Watson, Gregory W; Wellappili, Dulani P; Tyler, Brett M

    2017-01-01

    To date, nuclear localization signals (NLSs) that target proteins to nuclei in oomycetes have not been defined, but have been assumed to be the same as in higher eukaryotes. Here, we use the soybean pathogen Phytophthora sojae as a model to investigate these sequences in oomycetes. By establishing a reliable in vivo NLS assay based on confocal microscopy, we found that many canonical monopartite and bipartite classical NLSs (cNLSs) mediated nuclear import poorly in P. sojae. We found that efficient localization of P. sojae nuclear proteins by cNLSs requires additional basic amino acids at distal sites or collaboration with other NLSs. We found that several representatives of another well-characterized NLS, proline-tyrosine NLS (PY-NLS) also functioned poorly in P. sojae. To characterize PY-NLSs in P. sojae, we experimentally defined the residues required by functional PY-NLSs in three P. sojae nuclear-localized proteins. These results showed that functional P. sojae PY-NLSs include an additional cluster of basic residues for efficient nuclear import. Finally, analysis of several highly conserved P. sojae nuclear proteins including ribosomal proteins and core histones revealed that these proteins exhibit a similar but stronger set of sequence requirements for nuclear targeting compared with their orthologs in mammals or yeast.

  6. Strain Specific Factors Control Effector Gene Silencing in Phytophthora sojae.

    Science.gov (United States)

    Shrestha, Sirjana Devi; Chapman, Patrick; Zhang, Yun; Gijzen, Mark

    2016-01-01

    The Phytophthora sojae avirulence gene Avr3a encodes an effector that is capable of triggering immunity on soybean plants carrying the resistance gene Rps3a. P. sojae strains that express Avr3a are avirulent to Rps3a plants, while strains that do not are virulent. To study the inheritance of Avr3a expression and virulence towards Rps3a, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 X P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F5 generation. However, test-crosses of F1 progeny (ACR10 X P7076) with strain P6497 result in the release of silencing of Avr3a. Expression of Avr3a in the progeny is variable and correlates with the phenotypic penetrance of the avirulence trait. The F1 progeny from a direct cross of P6497 X ACR10 segregate for inheritance for Avr3a expression, a result that could not be explained by parental imprinting or heterozygosity. Analysis of small RNA arising from the Avr3a gene sequence in the parental strains and hybrid progeny suggests that the presence of small RNA is necessary but not sufficient for gene silencing. Overall, we conclude that inheritance of the Avr3a gene silenced phenotype relies on factors that are variable among P. sojae strains.

  7. Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralis.

    Science.gov (United States)

    Brasier, Clive M; Franceschini, Selma; Vettraino, Anna Maria; Hansen, Everett M; Green, Sarah; Robin, Cecile; Webber, Joan F; Vannini, Andrea

    2012-12-01

    Until recently Phytophthora lateralis was known only as the cause of dieback and mortality of Chamaecyparis lawsoniana in its native range in the Pacific Northwest (PNW). Since the 1990s however disease outbreaks have occurred increasingly on ornamental C. lawsoniana in Europe; and in 2007 the pathogen was discovered in soil around old growth Chamaecyparis obtusa in Taiwan, where it may be endemic. When the phenotypes of over 150 isolates of P. lateralis from Taiwan, across the PNW (British Columbia to California) and from France, the Netherlands and the UK were compared three growth rate groups were resolved: one slow growing from Taiwan, one fast growing from the PNW and Europe, and one of intermediate growth from a small area of the UK. Within these growth groups distinct subtypes were identified based on colony patterns and spore metrics and further discriminated in a multivariate analysis. The assumption that the three main growth groups represented phylogenetic units was tested by comparative sequencing of two mitochondrial and three nuclear genes. This assumption was confirmed. In addition two phenotype clusters within the Taiwan growth group were also shown to be phylogenetically distinct. These four phenotypically and genotypically unique populations are informally designated as the PNW lineage, the UK lineage, the Taiwan J lineage, and the Taiwan K lineage. Their characteristics and distribution are described and their evolution, taxonomic, and plant health significance is discussed.

  8. Production of gametangia by Phytophthora ramorum in vitro.

    Science.gov (United States)

    Brasier, Clive; Kirk, Susan

    2004-07-01

    Until now gametangia have not been obtained between paired European A1 and American A2 isolates of Phytopthora ramorum in vitro. Their production in artificial culture relies on interspecific pairings. Using P. drechsleri and P. cambivora testers, 51 of 110 P. ramorum isolates from across Europe were all shown to be A1s; while 32 of 38 American isolates from across California and southwest Oregon were shown to be A2s. However, these interspecific pairings are complex, unusually slow and unpredictable. A range of culture media and conditions are described that were tested, unsuccessfully, with a view to enhancing the efficiency of the interspecific pairings. In further tests, gametangia were obtained between A1 and A2 isolates of P. ramorum when juvenile, pre-chlamydospore producing mycelia were mixed together on carrot agar. The gametangia formed in 3-10 d, sparsely to frequently, initially only within the boundaries of the mixed inocula but subsequently in the extended mycelial growth. Chlamydospores were also produced. This inoculum-mixing method, though again sometimes unpredictable, should enhance efficiency of testing for compatibility types and facilitate further studies on whether the sexual outcrossing system of P. ramorum is functional. Differences between sexual reproduction of P. ramorum and that of other heterothallic Phytophthora species are discussed.

  9. Phytophthora austrocedri Elicitates Changes in Diterpene Profile of Austrocedrus chilensis.

    Science.gov (United States)

    Olate, Verónica Rachel; Vélez, María Laura; Greslebin, Alina; Schmeda-Hirschmann, Guillermo

    2015-08-18

    The populations of the Andean Cupressaceae Austrocedrus chilensis have been severely affected by a disease caused by the phytopathogenic fungus Phytophthora austrocedri. A study was undertaken to disclose changes in the resin composition of P. austrocedri-infected individuals, including naturally infected and artificially inoculated trees, compared with healthy A. chilensis trees. GC-MS and (1)H-NMR studies showed a clear differentiation among healthy and infected resins, with the diterpene isopimara-8(9),15-dien-19-ol as a relevant constituent in resins from infected trees. The effect of resin fractions from P. austrocedri infected trees on the pathogen was assessed by measuring the mycelial growth in agar plates. The most active fractions from resin obtained from infected trees inhibited fungal growth by nearly 50% at 1 mg/dish (35.37 µg/cm(2)). The main constituent in the active fractions were 18-hydroxymanool and the aldehyde torulosal. Both compounds are oxidation products of manool and can be a chemical response of the tree to the pathogen or be formed from the pathogen as a biotransformation product of manool by microbial oxidation. While the diterpene profiles from A. chilensis tree resins can easily differentiate healthy and P. austrocedri infected individuals, the possible conversion of manool to the antifungal derivatives 4 and 6 by the microorganism remains to be established.

  10. Distinctive Nuclear Localization Signals in the Oomycete Phytophthora sojae

    Science.gov (United States)

    Fang, Yufeng; Jang, Hyo Sang; Watson, Gregory W.; Wellappili, Dulani P.; Tyler, Brett M.

    2017-01-01

    To date, nuclear localization signals (NLSs) that target proteins to nuclei in oomycetes have not been defined, but have been assumed to be the same as in higher eukaryotes. Here, we use the soybean pathogen Phytophthora sojae as a model to investigate these sequences in oomycetes. By establishing a reliable in vivo NLS assay based on confocal microscopy, we found that many canonical monopartite and bipartite classical NLSs (cNLSs) mediated nuclear import poorly in P. sojae. We found that efficient localization of P. sojae nuclear proteins by cNLSs requires additional basic amino acids at distal sites or collaboration with other NLSs. We found that several representatives of another well-characterized NLS, proline-tyrosine NLS (PY-NLS) also functioned poorly in P. sojae. To characterize PY-NLSs in P. sojae, we experimentally defined the residues required by functional PY-NLSs in three P. sojae nuclear-localized proteins. These results showed that functional P. sojae PY-NLSs include an additional cluster of basic residues for efficient nuclear import. Finally, analysis of several highly conserved P. sojae nuclear proteins including ribosomal proteins and core histones revealed that these proteins exhibit a similar but stronger set of sequence requirements for nuclear targeting compared with their orthologs in mammals or yeast. PMID:28210240

  11. Phytophthora austrocedri Elicitates Changes in Diterpene Profile of Austrocedrus chilensis

    Directory of Open Access Journals (Sweden)

    Verónica Rachel Olate

    2015-08-01

    Full Text Available The populations of the Andean Cupressaceae Austrocedrus chilensis have been severely affected by a disease caused by the phytopathogenic fungus Phytophthora austrocedri. A study was undertaken to disclose changes in the resin composition of P. austrocedri-infected individuals, including naturally infected and artificially inoculated trees, compared with healthy A. chilensis trees. GC-MS and 1H-NMR studies showed a clear differentiation among healthy and infected resins, with the diterpene isopimara-8(9,15-dien-19-ol as a relevant constituent in resins from infected trees. The effect of resin fractions from P. austrocedri infected trees on the pathogen was assessed by measuring the mycelial growth in agar plates. The most active fractions from resin obtained from infected trees inhibited fungal growth by nearly 50% at 1 mg/dish (35.37 µg/cm2. The main constituent in the active fractions were 18-hydroxymanool and the aldehyde torulosal. Both compounds are oxidation products of manool and can be a chemical response of the tree to the pathogen or be formed from the pathogen as a biotransformation product of manool by microbial oxidation. While the diterpene profiles from A. chilensis tree resins can easily differentiate healthy and P. austrocedri infected individuals, the possible conversion of manool to the antifungal derivatives 4 and 6 by the microorganism remains to be established.

  12. A Novel Phytophthora sojae Resistance Rps12 Gene Mapped to a Genomic Region That Contains Several Rps Genes

    Science.gov (United States)

    Sahoo, Dipak K.; Abeysekara, Nilwala S.; Cianzio, Silvia R.; Robertson, Alison E.

    2017-01-01

    Phytophthora sojae Kaufmann and Gerdemann, which causes Phytophthora root rot, is a widespread pathogen that limits soybean production worldwide. Development of Phytophthora resistant cultivars carrying Phytophthora resistance Rps genes is a cost-effective approach in controlling this disease. For this mapping study of a novel Rps gene, 290 recombinant inbred lines (RILs) (F7 families) were developed by crossing the P. sojae resistant cultivar PI399036 with the P. sojae susceptible AR2 line, and were phenotyped for responses to a mixture of three P. sojae isolates that overcome most of the known Rps genes. Of these 290 RILs, 130 were homozygous resistant, 12 heterzygous and segregating for Phytophthora resistance, and 148 were recessive homozygous and susceptible. From this population, 59 RILs homozygous for Phytophthora sojae resistance and 61 susceptible to a mixture of P. sojae isolates R17 and Val12-11 or P7074 that overcome resistance encoded by known Rps genes mapped to Chromosome 18 were selected for mapping novel Rps gene. A single gene accounted for the 1:1 segregation of resistance and susceptibility among the RILs. The gene encoding the Phytophthora resistance mapped to a 5.8 cM interval between the SSR markers BARCSOYSSR_18_1840 and Sat_064 located in the lower arm of Chromosome 18. The gene is mapped 2.2 cM proximal to the NBSRps4/6-like sequence that was reported to co-segregate with the Phytophthora resistance genes Rps4 and Rps6. The gene is mapped to a highly recombinogenic, gene-rich genomic region carrying several nucleotide binding site-leucine rich repeat (NBS-LRR)-like genes. We named this novel gene as Rps12, which is expected to be an invaluable resource in breeding soybeans for Phytophthora resistance. PMID:28081566

  13. Phytophthora suppressor of RNA silencing 2 is a conserved RxLR effector that promotes infection in soybean and Arabidopsis thaliana.

    Science.gov (United States)

    Xiong, Qin; Ye, Wenwu; Choi, Duseok; Wong, James; Qiao, Yongli; Tao, Kai; Wang, Yuanchao; Ma, Wenbo

    2014-12-01

    The genus Phytophthora consists of notorious and emerging pathogens of economically important crops. Each Phytophthora genome encodes several hundreds of cytoplasmic effectors, which are believed to manipulate plant immune response inside the host cells. However, the majority of Phytophthora effectors remain functionally uncharacterized. We recently discovered two effectors from the soybean stem and root rot pathogen Phytophthora sojae with the activity to suppress RNA silencing in plants. These effectors are designated Phytophthora suppressor of RNA silencing (PSRs). Here, we report that the P. sojae PSR2 (PsPSR2) belongs to a conserved and widespread effector family in Phytophthora. A PsPSR2-like effector produced by P. infestans (PiPSR2) can also suppress RNA silencing in plants and promote Phytophthora infection, suggesting that the PSR2 family effectors have conserved functions in plant hosts. Using Agrobacterium rhizogenes-mediated hairy roots induction, we demonstrated that the expression of PsPSR2 rendered hypersusceptibility of soybean to P. sojae. Enhanced susceptibility was also observed in PsPSR2-expressing Arabidopsis thaliana plants during Phytophthora but not bacterial infection. These experiments provide strong evidence that PSR2 is a conserved Phytophthora effector family that performs important virulence functions specifically during Phytophthora infection of various plant hosts.

  14. Parestesia do Nervo Alveolar Inferior associada a Exodontia de Terceiros Molares Mandibulares

    OpenAIRE

    Costa, Gil Pereira Vieira da

    2011-01-01

    Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária. Nos dias actuais, a exodontia de terceiros molares é um procedimento cada vez mais comum no campo da Medicina Dentária, encontrando-se associado a uma série de problemas e complicações. Parestesia é uma condição localizada que consiste na perda de sensibilidade da região inervada pelo nervo que lhe está associada e que ocorre quando existe ou se pr...

  15. Factors de risc de mortalitat en la diarrea associada a Clostridium difficile

    OpenAIRE

    Franco Arenaz, María

    2012-01-01

    Identificar els possibles factors de risc de mortalitat en els pacients amb un primer episodi de diarrea associada a Clostridium difficile (DACD) mitjançant un estudi observacional retrospectiu. Després d'una anàlisi uni i multivariant amb les següents variables (sexe, edat, índex de Charlson, número d'antibiòtics previs i la seva retirada, ús de corticoids, inhibidors de la bomba de protons o antihistamínics antiH2, antiàcids, procedència de residència geriàtrica, dies de tractament per a la...

  16. Síndrome de Sweet associada à policitemia vera Sweet’s syndrome associated withpolycythemiavera

    OpenAIRE

    Ângela Puccini Moreira; Flávia Feijó de Souza; Neide Kalil Gaspar; Ada Lobato Quattrino; Enoi Aparecida Guedes Vilar

    2009-01-01

    A síndrome de Sweet pode estar associada a malignidades hematológicas, principalmente, à leucemia mieloide aguda, porém existem poucos relatos demonstrando a associação com a policitemia vera. Relata-se o caso de doente do sexo masculino, de 65 anos, portador de policitemia vera,que evoluiu com aparecimento de síndrome de Sweet na sua forma paraneoplásica.Sweet’s syndrome may be associated with hematological malignancies, particularly with acute myelogenous leukemia, but there are few r...

  17. Polimiosite associada à síndrome nefrótica

    OpenAIRE

    Freire,Renato Oliveira; MACIEIRA,JOSÉ CAETANO; Brito,Hugo Leite de Farias

    2010-01-01

    A polimiosite (PM) é uma doença sistêmica do grupo das miopatias inflamatórias idiopáticas, clinicamente caracterizada por fraqueza muscular proximal e simétrica. Há relatos na literatura de PM associada a neoplasias, doenças autoimunes e infecções virais. Entretanto, a associação entre PM e nefropatia não é frequente. Descrevemos o caso de um paciente com polimiosite que evoluiu com síndrome nefrótica devido à presença de glomerulonefrite mesangial

  18. The in vitro culture of Phytophthora infestans isolates occurring on the tomato - their pathogenicity and usefulness for artificial inoculations

    Directory of Open Access Journals (Sweden)

    Elżbieta Horodecka

    2013-12-01

    Full Text Available In investigations on the fungus, Phytophthora infestans, isolated from open air, field-grown tomatoes, particular attention was paid to the pathogenicity of 32 isolates and the suitability of 10 kinds of natural media. It is concluded that Phytophthora races in Poland have highly varied pathogenicities and that they belong to race 0 or 1. The races were divided into subgroups of various aggressiveness. It was found that the best medium to obtain an inoculum was the agar-oat medium without vitamin B1. Vitamin B1 as well as tomatine added to agar media stimulated growth, but inhibited sporulation of Phytophthora infestans.

  19. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-12-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  20. Genomic Characterization of a South American Phytophthora Hybrid Mandates Reassessment of the Geographic Origins of Phytophthora infestans.

    Science.gov (United States)

    Martin, Michael D; Vieira, Filipe G; Ho, Simon Y W; Wales, Nathan; Schubert, Mikkel; Seguin-Orlando, Andaine; Ristaino, Jean B; Gilbert, M Thomas P

    2016-02-01

    As the oomycete pathogen causing potato late blight disease, Phytophthora infestans triggered the famous 19th-century Irish potato famine and remains the leading cause of global commercial potato crop destruction. But the geographic origin of the genotype that caused this devastating initial outbreak remains disputed, as does the New World center of origin of the species itself. Both Mexico and South America have been proposed, generating considerable controversy. Here, we readdress the pathogen's origins using a genomic data set encompassing 71 globally sourced modern and historical samples of P. infestans and the hybrid species P. andina, a close relative known only from the Andean highlands. Previous studies have suggested that the nuclear DNA lineage behind the initial outbreaks in Europe in 1845 is now extinct. Analysis of P. andina's phased haplotypes recovered eight haploid genome sequences, four of which represent a previously unknown basal lineage of P. infestans closely related to the famine-era lineage. Our analyses further reveal that clonal lineages of both P. andina and historical P. infestans diverged earlier than modern Mexican lineages, casting doubt on recent claims of a Mexican center of origin. Finally, we use haplotype phasing to demonstrate that basal branches of the clade comprising Mexican samples are occupied by clonal isolates collected from wild Solanum hosts, suggesting that modern Mexican P. infestans diversified on Solanum tuberosum after a host jump from a wild species and that the origins of P. infestans are more complex than was previously thought.

  1. Gene flow analysis demonstrates that Phytophthora fragariae var. rubi constitutes a distinct species, Phytophthora rubi comb. nov.

    Science.gov (United States)

    Man in 't Veld, Willem A

    2007-01-01

    Isozyme analysis and cytochrome oxidase sequences were used to examine whether differentiation of P. fragariae var. fragariae and P. fragariae var. rubi at the variety level is justified. In isozyme studies six strains of both P. fragariae varieties were analyzed with malate dehydrogenase (MDH), glucose phosphate isomerase (GPI), aconitase (ACO), isocitrate dehydrogenase (IDH) and phosphogluconate dehydrogenase (PGD), comprising altogether seven putative loci. Five unique alleles (Mdh-1(A), Mdh-2(B), Gpi(A), Aco(B) and Idh-1(B)) were found in strains of P. fragariae var. fragariae, whereas five unique alleles (Mdh-1(B), Mdh-2(A), Gpi(B), Aco(A) and Idh-1(A)) were present in strains of P. fragariae var. rubi. It was inferred from these data that there is no gene flow between the two P. fragariae varieties. Cytochrome oxidase I (Cox I) sequences showed consistent differences at 15 positions between strains of Fragaria and Rubus respectively. Based on isozyme data, cytochrome oxidase I sequences, and previously published differences in restyriction enzyme patterns of mitochondrial DNA, sequences of nuclear and mitochondrial genes, AFLP patterns and pathogenicity, it was concluded that both specific pathogenic varieties of P. fragariae are reproductively isolated and constitute a distinct species. Consequently strains isolated from Rubus idaeus are assigned to Phytophthora rubi comb. nov.

  2. 致病疫霉(Phytophthora infestans)对杀菌剂 抗药性研究进展%Advance on fungicides resistance of Phytophthora infestans

    Institute of Scientific and Technical Information of China (English)

    杨志辉; 张志铭; 朱杰华; 赵会欣

    2001-01-01

    综述了致病疫霉(Phytophthora infestans)对内吸性杀菌剂甲霜灵、霜脲氰和保护性杀菌剂代森锰锌和百菌清的抗性研究进展,总结了当前用于防治晚疫病的药剂种类并提出了抗性治理策略。对于致病疫霉抗性遗传研究和抗性治理及药剂防治都具有一定的参考价值。%Progress on the resistance of systemic fungicides (metalaxyl and cymoxanil) and protectant fungicidies ( mancozeb and chlorothalonil) to Phytophthora infestans was reviewed. Fungicides used in controlling late blight were listed and strategies on resistance management were proposed. It might be referred.on resistance inheritance research, resistance management and fungicide control.

  3. The plant pathogen Phytophthora andina emerged via hybridization of an unknown Phytophthora species and the Irish potato famine pathogen, P. infestans.

    Science.gov (United States)

    Goss, Erica M; Cardenas, Martha E; Myers, Kevin; Forbes, Gregory A; Fry, William E; Restrepo, Silvia; Grünwald, Niklaus J

    2011-01-01

    Emerging plant pathogens have largely been a consequence of the movement of pathogens to new geographic regions. Another documented mechanism for the emergence of plant pathogens is hybridization between individuals of different species or subspecies, which may allow rapid evolution and adaptation to new hosts or environments. Hybrid plant pathogens have traditionally been difficult to detect or confirm, but the increasing ease of cloning and sequencing PCR products now makes the identification of species that consistently have genes or alleles with phylogenetically divergent origins relatively straightforward. We investigated the genetic origin of Phytophthora andina, an increasingly common pathogen of Andean crops Solanum betaceum, S. muricatum, S. quitoense, and several wild Solanum spp. It has been hypothesized that P. andina is a hybrid between the potato late blight pathogen P. infestans and another Phytophthora species. We tested this hypothesis by cloning four nuclear loci to obtain haplotypes and using these loci to infer the phylogenetic relationships of P. andina to P. infestans and other related species. Sequencing of cloned PCR products in every case revealed two distinct haplotypes for each locus in P. andina, such that each isolate had one allele derived from a P. infestans parent and a second divergent allele derived from an unknown species that is closely related but distinct from P. infestans, P. mirabilis, and P. ipomoeae. To the best of our knowledge, the unknown parent has not yet been collected. We also observed sequence polymorphism among P. andina isolates at three of the four loci, many of which segregate between previously described P. andina clonal lineages. These results provide strong support that P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species also belonging to Phytophthora clade 1c.

  4. Research Progress in Physiological Race of Phytophthora Sojae%大豆疫霉菌(Phytophthora sojae)生理小种研究进展

    Institute of Scientific and Technical Information of China (English)

    王颖; 臧忠婧

    2002-01-01

    综述了大豆疫霉菌 (phytophthora sojae)的生理分化和生理小种的研究进展,包括传统的毒性分析到分子技术的应用,探讨了小种鉴定中发现的无毒菌株的成因及其特征.

  5. The plant pathogen Phytophthora andina emerged via hybridization of an unknown Phytophthora species and the Irish potato famine pathogen, P. infestans.

    Directory of Open Access Journals (Sweden)

    Erica M Goss

    Full Text Available Emerging plant pathogens have largely been a consequence of the movement of pathogens to new geographic regions. Another documented mechanism for the emergence of plant pathogens is hybridization between individuals of different species or subspecies, which may allow rapid evolution and adaptation to new hosts or environments. Hybrid plant pathogens have traditionally been difficult to detect or confirm, but the increasing ease of cloning and sequencing PCR products now makes the identification of species that consistently have genes or alleles with phylogenetically divergent origins relatively straightforward. We investigated the genetic origin of Phytophthora andina, an increasingly common pathogen of Andean crops Solanum betaceum, S. muricatum, S. quitoense, and several wild Solanum spp. It has been hypothesized that P. andina is a hybrid between the potato late blight pathogen P. infestans and another Phytophthora species. We tested this hypothesis by cloning four nuclear loci to obtain haplotypes and using these loci to infer the phylogenetic relationships of P. andina to P. infestans and other related species. Sequencing of cloned PCR products in every case revealed two distinct haplotypes for each locus in P. andina, such that each isolate had one allele derived from a P. infestans parent and a second divergent allele derived from an unknown species that is closely related but distinct from P. infestans, P. mirabilis, and P. ipomoeae. To the best of our knowledge, the unknown parent has not yet been collected. We also observed sequence polymorphism among P. andina isolates at three of the four loci, many of which segregate between previously described P. andina clonal lineages. These results provide strong support that P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species also belonging to Phytophthora clade 1c.

  6. Bescherming van nieuwe groei tegen Phytophthora in de teelt van aardappelen

    NARCIS (Netherlands)

    Kalkdijk, J.R.; Schepers, H.T.A.M.; Evenhuis, A.

    2005-01-01

    Onderzoek naar de werking van fungiciden tijdens de teelt van poot- en consumptieaardappelen. Tijdens de periode dat het loof snel groeit zijn er delen van de plant onbeschermd tegen Phytophthora. De werking van fungiciden op de bescherming van de nieuwe groei is in biotoetsen regelmatig getoetst. E

  7. Biologically active Phytophthora mating hormone prepared by catalytic asymmetric total synthesis

    NARCIS (Netherlands)

    Harutyunyan, Syuzanna R.; Zhao, Zhijian; den Hartog, Tim; Bouwmeester, Klaas; Minnaard, Adriaan J.; Feringa, Ben L.; Govers, Francine

    2008-01-01

    A Phytophthora mating hormone with an array of 11,5-stereogenic centers has been synthesized by using our recently developed methodology of catalytic enantioselective conjugate addition of Grignard reagents. We applied this methodology in a diastereo-and enantioselective iterative route and obtained

  8. Incidence of Phytophthora infestans (Mont.) de Bary on potato and tomato in Maine, 2006-2010

    Science.gov (United States)

    Late blight, caused by Phytophthora infestans, is a devastating disease globally. In Maine, we recorded late blight on potato and tomato during the 2006-2010 cropping seasons. From 2006 to 2008, over 90% of diseased samples were collected in potato fields from northern and central Aroostook County i...

  9. Understanding the molecular basis of the resistance of Phytophthora infestans to fungicides by functional genomics

    Science.gov (United States)

    Development of resistance to fungicides is a major concern in managing potato late blight disease caused by Phytophthora infestans. The problem is P. infestans is capable of sexual recombination contributing to increased strain variability and high adaptability that hastens the development of resis...

  10. Discovering the next generation of late blight resistance genes – can we battle Phytophthora infestans evolution

    Science.gov (United States)

    Potato late blight, caused by the oomycete pathogen Phytophthora infestans, is one of the most destructive plant diseases. RB from Solanum bulbocastanum encodes a CC-NB-LRR (CNL) protein that confers partial resistance to most P. infestans isolates through its recognition of the corresponding pathog...

  11. Tuber blight development in potato cultivars in response to different genotypes of Phytophthora infestans

    Science.gov (United States)

    Potato late blight, caused by Phytophthora infestans, is one of the most devastating diseases in potatoes, causing significant loses under disease-conducive conditions. Migrations or introduction of new genotypes to a specific region impose a different set of criteria for consideration for potato gr...

  12. Survival potential of Phytophthora infestans sporangia in relation to meteorological factors

    Science.gov (United States)

    Assessment of meteorological factors coupled with sporangia survival curves may enhance effective management of potato late blight, caused by Phytophthora infestans. We utilized a non-parametric density estimation approach to evaluate the cumulative probability of occurrence of temperature and relat...

  13. Doseringsverlaging op basis van loof- en knolresistentie tegen Phytophthora infestans in aardappel

    NARCIS (Netherlands)

    Spits, H.G.

    2007-01-01

    Een mogelijkheid om het middelengebruik omlaag te krijgen is een bestrijdingsstrategie te ontwikkelen waarbij de gevoeligheid van het ras gebruikt wordt bij de beheersing van de aardappelziekte. Bij zo’n strategie zou een ras dat weinig gevoelig is voor Phytophthora met een lagere dosering net zo go

  14. Molecular determinants of resistance activation and suppression by Phytophthora infestans effector IPI-O

    Science.gov (United States)

    The potato late blight pathogen, Phytophthora infestans, is able to rapidly evolve to overcome resistance genes. The pathogen accomplishes this by secreting an arsenal of proteins, termed effectors, that function to modify host cells. Although hundreds of candidate effectors have been identified in ...

  15. Variability in virulence and the race concept in Phytophthora infestans (Mont. de Bary

    Directory of Open Access Journals (Sweden)

    Ludwik S. Sujkowski

    2014-08-01

    Full Text Available Variability in virulence and aggressiveness was studied in 102 single zoospore isolates originating from 4 field isolates of Phytophthora infestans. Field isolates appeared to be mixtures of a wide spectrum of phenotypes differing in both characters as mentioned above. Race concept in P. infestans has been discussed.

  16. Draft genome sequences of seven isolates of Phytophthora ramorum EU2 from Northern Ireland

    Directory of Open Access Journals (Sweden)

    Lourdes de la Mata Saez

    2015-12-01

    Full Text Available Here we present draft-quality genome sequence assemblies for the oomycete Phytophthora ramorum genetic lineage EU2. We sequenced genomes of seven isolates collected in Northern Ireland between 2010 and 2012. Multiple genome sequences from P. ramorum EU2 will be valuable for identifying genetic variation within the clonal lineage that can be useful for tracking its spread.

  17. Chemical control of Phytophthora ramorum causing foliar disease in hardy nursery stock in the United Kingdom

    Science.gov (United States)

    Judith Turner; Philip Jennings; Sam McDonough; Debbie Liddell; Jackie Stonehouse

    2006-01-01

    A range of fungicides have been tested for activity against P. ramorum using both in vitro and in vivo tests. All fungicides had proven activity against Phytophthora species and either had full approval for use on hardy ornamental nursery stock in the United Kingdom, or could be used under the Revised Long Term Arrangements for Extension of Use (2002...

  18. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  19. Genetic mapping and characterization of two novel Phytophthora resistance genes from soybean landrace PI567139B

    Science.gov (United States)

    Phytophthora root and stem rot (PRR) disease, caused by P. sojae, is a widespread soybean disease resulting in an annual yield loss of $1~2 billion worldwide. To control the disease, breeders primarily employ race-specific resistant genes which are named Rps genes which have been identified to be lo...

  20. Alternative methods to control Phytophthora cactorum in strawberry cultivated in soilless growing media

    NARCIS (Netherlands)

    Evenhuis, B.; Nijhuis, E.H.; Lamers, J.G.; Verhoeven, J.T.W.; Postma, J.

    2014-01-01

    Phytophthora cactorum is an important threat in strawberry propagation and production. No reliable non-chemical control measures are available. Therefore different control strategies were tested. Spread of pathogen infection can be reduced by disinfection of the irrigation water. Slow sand

  1. The Phytophthora infestans avirulence gene PiaAvr4 and its potato counterpart R4

    NARCIS (Netherlands)

    Poppel, van P.M.J.A.

    2009-01-01

    The potato late blight disease that is caused by the oomycete pathogen Phytophthora infestans is a major threat for potato crops worldwide. In recent years research on oomycete plant pathogens was boosted by the availability of novel genomic tools and resources for several oomycete genera, such as

  2. Durable cisgenic resistance to Phytophthora infestans in potato and perspectives for applications in Africa

    NARCIS (Netherlands)

    Gheysen, G.; Heremans, B.; Droogenbroeck, van B.; Custers, R.; Vossen, J.H.; Visser, R.G.F.; Jacobsen, E.; Hutten, R.C.B.; Haverkort, A.J.

    2015-01-01

    Late blight caused by Phytophthora infestans is a major constraint in potato production. A promising strategy to combat late blight in potato is to combine different resistance genes to achieve durable resistance. Resistance genes from wild relatives can be introduced by breeding or by

  3. Correlation of isozyme profiles with genomic sequences of Phytophthora ramorum and its P. sojae orthologues

    NARCIS (Netherlands)

    Man in 't Veld, W.A.; Govers, F.; Meijer, H.J.G.

    2007-01-01

    A correct interpretation of isozyme patterns can be seriously hampered by the lack of supporting genetic data. The availability of the complete genome sequence of Phytophthora ramorum, enabled us to correlate isozyme profiles with the gene models predicted for these enzymes. Thirty-nine P. ramorum s

  4. Identification and validation of polymorphic microsatellite loci for the analysis of Phytophthora nicotianae populations

    Science.gov (United States)

    A large number of SSR loci were screened in the genomic assemblies of 14 different isolates of Phytophthora nicotianae and primers were developed for amplification of 17 markers distributed among different contigs. These loci were highly polymorphic and amplified from genetically distant isolates of...

  5. Methods for screening Port-Orford-cedar for resistance to Phytophthora lateralis

    Science.gov (United States)

    Everett M. Hansen; Paul Reeser; Wendy Sutton; Richard A. Sniezko

    2012-01-01

    Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murray) Parl.) (POC) is an economically and ecologically valuable tree in the forests of southwest Oregon and northern California and in the horticultural trade worldwide. Phytophthora lateralis, the aggressive, invasive cause of POC root disease, was introduced to the native...

  6. Stream Monitoring for Detection of Phytophthora ramorum in Oregon Tanoak Forests

    Science.gov (United States)

    W. Sutton; E. M. Hansen; P. W. Reeser; A. Kanaskie

    2009-01-01

    Stream monitoring using leaf baits for early detection of Phytophthora ramorum has been an important part of the Oregon Sudden Oak Death (SOD) program since 2002. Sixty-four streams in and near the Oregon quarantine area in the southwest corner of the state were monitored in 2008. Leaves of rhododendron (Rhododendron macrophyllum...

  7. Phytophthora species associated with stem cankers on tanoak in southwestern Oregon

    Science.gov (United States)

    Paul Reeser; Wendy Sutton; Everett Hansen

    2008-01-01

    In effort to eradicate Phytophthora ramorum from Oregon forests, tanoak over its entire range in southwestern Oregon is surveyed intensively for stem disease. Pieces of bark from the leading edge of tanoak stem cankers were plated on cornmeal agar amended with 10 ppm natamycin, 200 ppm a-ampicillin, and 10 ppm rifamycin SV (CARP) to favor the...

  8. The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood

    Science.gov (United States)

    Bradley R. Collins; Jennifer L. Parke; Barb Lachenbruch; Everett M. Hansen

    2009-01-01

    Tanoak (Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood, but recent research indicates that...

  9. Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis: a new threat for European countries

    Science.gov (United States)

    C. Robin; D. Piou; N. Feau; G. Douzon; N. Schenck; E. M. Hansen

    2010-01-01

    Phytophthora lateralis has been isolated from root and collar lesions in Port-Orford Cedar (POC) trees (Chamaecyparis lawsoniana) in north-western France (Brittany). These trees, planted in hedgerows, displayed symptoms similar to the typical symptoms of POC root disease. Until now, the disease has been found outside of the...

  10. Spatial relationship between Phytophthora ramorum and roads or streams in Oregon tanoak forests

    Science.gov (United States)

    Ebba Peterson; Everett Hansen; Alan Kanaskie

    2014-01-01

    The pathogen, Phytophthora ramorum, causal agent of sudden oak death (SOD) of oaks and tanoaks, continues to expand its range within Oregon despite an effort to eradicate it from native forests. With its early detection and prompt removal of infected hosts, the Oregon SOD eradication program has produced a landscape distribution of disease...

  11. Small Homologous Blocks in Phytophthora Genomes Do Not Point to an Ancient Whole-Genome Duplication

    NARCIS (Netherlands)

    Hooff, van J.J.E.; Snel, B.; Seidl, M.F.

    2014-01-01

    Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) and by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presence of 2HOM blocks, have been attributed to a whol

  12. Small homologous blocks in phytophthora genomes do not oint to an ancient whole-genome duplication

    NARCIS (Netherlands)

    Van Hooff, Jolien J E; Snel, Berend; Seidl, Michael F.

    2014-01-01

    Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) as well as by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presences of 2HOM blocks, have been attributed t

  13. Evaluation of watermelon varieties for tolerance to powdery mildew and Phytophthora fruit rot, 2014

    Science.gov (United States)

    This experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand. This study was undertaken to determine the performance of seeded and seedless commercial watermelon varieties for tolerance to powdery mildew (PM) and Phytophthora fruit rot as...

  14. Towards the development of integrated cultural control of tomato late blight (Phytophthora infestans) in Uganda

    NARCIS (Netherlands)

    Tumwine, J.

    1999-01-01

    Tomato ( Lycopersicon esculentum ) is a major vegetable crop in Uganda. Moneymaker, Marglobe, Heinz and Roma are the major commercial varieties grown in the country, the first two being the most popular. Late blight ( Phytophthora infestans ) is the most important disease of Ugandan tomatoes. Tomato

  15. Effect of plant sterols and tannins on Phytophthora ramorum growth and sporulation

    Science.gov (United States)

    The acquisition of plant sterols, mediated via elicitins, is required for growth and sporulation of Phytophthora spp. In this paper, we looked at the interaction between elicitins, sterols, and tannins. When ground leaf tissue was added to growth media, P. ramorum growth and sporulation was greates...

  16. Phytophthora infestans has a plethora of phospholipase D enzymes including a subclass that has extracellular activity

    NARCIS (Netherlands)

    Meijer, H.J.G.; Hassen, H.H.; Govers, F.

    2011-01-01

    In eukaryotes phospholipase D (PLD) is involved in many cellular processes. Currently little is known about PLDs in oomycetes. Here we report that the oomycete plant pathogen Phytophthora infestans has a large repertoire of PLDs divided over six subfamilies: PXPH-PLD, PXTM-PLD, TM-PLD, PLD-likes, an

  17. Genetic characterization of Phytophthora nicotianae by the analysis of polymorphic regions of the mitochondrial DNA.

    Science.gov (United States)

    A new method based on the analysis of mitochondrial intergenic regions characterized by intraspecific variation in DNA sequences was developed and applied to the study of the plant pathogen Phytophthora nicotianae. Two regions flanked by genes trny and rns and trnw and cox2 were identified by compa...

  18. A combined mitochondrial and nuclear multilocus phylogeny of the genus Phytophthora

    Science.gov (United States)

    The most recent phylogenetic analysis of the genus Phytophthora was completed in 2008 (Blair et al. 2008) and utilized 8.1 kb of sequence data from seven nuclear loci. Given the large number of species that have recently been described, this study was undertaken to broaden the available information...

  19. New technologies to detect and monitor Phytophthora ramorum in plant, soil, and water samples

    Science.gov (United States)

    Paul Russell; Nathan McOwen; Robert Bohannon

    2013-01-01

    The focus of our research efforts has been to develop methods to quickly identify plants, soil, and water samples infested with Phytophthora spp., and to rapidly confirm the findings using novel isothermal DNA technologies suitable for field use. These efforts have led to the development of a rapid Immunostrip® that reliably detects...

  20. Genetical studies of resistance to Phytophthora porri in Allium porrum, using a new early screening method.

    NARCIS (Netherlands)

    Smilde, W.D.; Nes, van M.; Reinink, K.; Kik, C.

    1997-01-01

    A new screening method was developed to evaluate resistance of leek (Allium porrum) to Phytophthora porri, based on inoculation by 24 h-immersion of leek plantlets in the 3–6 leaf stage in a suspension of ca. 100 zoospores.ml-1. The immersion test was used for identifying new sources of resistance a

  1. Genes for and molecular markers linked with resistance to Phytophthora fragariae in strawberry

    NARCIS (Netherlands)

    Weg, van de W.E.; Henken, B.; Haymes, K.M.; den Nijs, A.P.M.

    1998-01-01

    A gene-for-gene model is presented which explains interactions between cultivars of strawberry and races of Phytophthora fragariae var. fragariae, the causal agent of red core (red stele) root rot. The model allows the constitution of a universal differential set of strawberry genotypes and the char

  2. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  3. Rapid Determination of Phytophthora infestans sporangia Using a Surface Plasmon Resonance Immunosensor

    DEFF Research Database (Denmark)

    Skottrup, Peter; Nicolaisen, Mogens; Justesen, Annemarie Fejer

    2007-01-01

    Phytophthora infestans is the cause of late blight disease in potato and is an economically important pathogen worldwide. Early disease detection is important to implement disease control measures. In this study a surface plasmon resonance (SPR) immunosensor for detection of P. infestans sporangia...

  4. Aggressiveness of Phytophthora infestans on detached potato leaflets in four Nordic countries

    DEFF Research Database (Denmark)

    Lehtinen, A; Andersson, B; Le, V H;

    2009-01-01

    Potato fields in Denmark, Finland, Norway and Sweden were sampled for single-lesion isolates of Phytophthora infestans. The aggressiveness of the isolates was determined on detached leaflets of potato cvs Bintje (susceptible) and Matilda (moderately resistant). The aggressiveness tests were carried...

  5. Identification of quantitative trait loci conditioning partial resistance to Phytophthora sojae in soybean PI 407861A

    Science.gov (United States)

    Improving resistance for Phytophthora root and stem rot is an important goal in soybean [Glycine max (L.) Merr.] breeding. Partial resistance can be as effective in managing this disease as single-gene (Rps) mediated resistance and is more durable. The objective of this study was to identify QTL con...

  6. A Multiplexed, Probe-Based Quantitative PCR Assay for DNA of Phytophthora sojae

    Science.gov (United States)

    Phytophthora sojae (Kaufm. & Gerd.) causes seed rot, pre- and post-emergence damping off, and sometimes foliar blight in soybean (Glycine max). Crop loss may approach 100% with susceptible cultivars. We report here the development of a unique quantitative PCR assay specific to DNA of P. sojae, and a...

  7. Multi-Year Evaluation of Commercial Soybean Cultivars for Resistance to Phytophthora sojae

    Science.gov (United States)

    Phytophthora sojae causes damping off, root rot, and stem rot of soybean, particularly in poorly drained soils. The use of resistance has been one of the primary management tools used to control this disease, with the most commonly used genes being Rps1c and Rps1k, followed by Rps1a. The Varietal In...

  8. First results with a lab-on-a-chip system for a fast Phytophthora diagnosis.

    Science.gov (United States)

    Sonja Horatzek; Stephan König; Stefan Wagner; Sabine Werres; Lydia Schwenkbier; Karina Weber; Jörg. Weber

    2013-01-01

    For Phytophthora spp. that are quarantine or regulated organisms, highly specific and sensitive diagnostic tools are recommended for surveys and monitoring. Furthermore, these diagnostic techniques should give results within a short time and should be not be too expensive. The techniques currently used for routine diagnosis of ...

  9. Lineage, temperature, and host species have interacting effects on lesion development in Phytophthora ramorum

    Science.gov (United States)

    C. Eyre; K. Hayden; M. Kozanitas; N. Grunwald; M. Garbelotto

    2014-01-01

    There are four recognized clonal lineages of the pathogen Phytophthora ramorum. The two major lineages present in North America are NA1 and NA2. With a few exceptions, NA1 is found in natural forest ecosystems and nurseries, and NA2 is generally restricted to nurseries. Isolates from the NA1 and NA2 lineages were used to infect rhododendron,...

  10. Stability of resistance to Phytophthora infestans in potato: an international evaluation

    NARCIS (Netherlands)

    Forbes, G.A.; Chacon, M.G.; Kirk, H.G.; Huarte, M.A.; Damme, van M.M.A.; Distel, S.; Mackay, G.R.; Stewart, H.E.; Lowe, R.; Duncan, J.M.; Mayton, H.S.; Fry, W.E.; Andrivon, D.; Ellisseche, D.; Pelle, R.; Platt, H.W.; MacKenzie, G.; Tarn, T.R.; Colon, L.T.; Budding, D.J.; Lozoya-Saldana, H.

    2005-01-01

    Ten institutions in nine countries joined together to test the stability of resistance of 14 potato genotypes to the oomycete pathogen Phytophthora infestans in three separate trials. Seven of the genotypes were tested in one trial involving seven locations, and all 14 were tested in two subsequent

  11. The effect of salinity on the growth, sporulation and infection of Phytophthora ramorum

    Science.gov (United States)

    Phytophthora ramorum, a threat to Eastern U.S. forests, has been found in waterways outside the boundaries of infested ornamental nurseries. Very little is known about what factors are conducive to its survival and sporulation in water. This study examined the effect of salt on growth, sporulation,...

  12. Anaerobic soil disinfestation reduces survival and infectivity of Phytophthora nicotianae chlamydospores in pepper

    Science.gov (United States)

    Phytophthora nicotianae is the principal causal agent of root and crown rot disease of pepper plants in Extremadura (western Spain), a spring-summer crop in this region. Preplant soil treatment by anaerobic soil disinfestation (ASD) may effectively control plant pathogens in many crop production sys...

  13. Phytophthora effector targets a novel component of small RNA pathway in plants to promote infection.

    Science.gov (United States)

    Qiao, Yongli; Shi, Jinxia; Zhai, Yi; Hou, Yingnan; Ma, Wenbo

    2015-05-05

    A broad range of parasites rely on the functions of effector proteins to subvert host immune response and facilitate disease development. The notorious Phytophthora pathogens evolved effectors with RNA silencing suppression activity to promote infection in plant hosts. Here we report that the Phytophthora Suppressor of RNA Silencing 1 (PSR1) can bind to an evolutionarily conserved nuclear protein containing the aspartate-glutamate-alanine-histidine-box RNA helicase domain in plants. This protein, designated PSR1-Interacting Protein 1 (PINP1), regulates the accumulation of both microRNAs and endogenous small interfering RNAs in Arabidopsis. A null mutation of PINP1 causes embryonic lethality, and silencing of PINP1 leads to developmental defects and hypersusceptibility to Phytophthora infection. These phenotypes are reminiscent of transgenic plants expressing PSR1, supporting PINP1 as a direct virulence target of PSR1. We further demonstrate that the localization of the Dicer-like 1 protein complex is impaired in the nucleus of PINP1-silenced or PSR1-expressing cells, indicating that PINP1 may facilitate small RNA processing by affecting the assembly of dicing complexes. A similar function of PINP1 homologous genes in development and immunity was also observed in Nicotiana benthamiana. These findings highlight PINP1 as a previously unidentified component of RNA silencing that regulates distinct classes of small RNAs in plants. Importantly, Phytophthora has evolved effectors to target PINP1 in order to promote infection.

  14. Rapid Determination of Phytophthora infestans sporangia Using a Surface Plasmon Resonance Immunosensor

    DEFF Research Database (Denmark)

    Skottrup, Peter Durand; Nicolaisen, Mogens; Justesen, Annemarie Fejer

    2007-01-01

    Phytophthora infestans is the cause of late blight disease in potato and is an economically important pathogen worldwide. Early disease detection is important to implement disease control measures. In this study a surface plasmon resonance (SPR) immunosensor for detection of P. infestans sporangi...

  15. Photosynthetic declines are induced by Phytophthora ramorum infection and exposure to elicitins

    Science.gov (United States)

    Daniel K. Manter; Rick G. Kelsey; Joseph J. Karchesy

    2008-01-01

    Infection of compatible plants by Phytophthora spp. often leads to a decline in stomatal conductance and photosynthesis, although the mechanistic basis for such declines is not completely understood. In many cases, declines in leaf gas exchange rates have been linked to losses in water supply capacity associated with root and/or xylem. However, the...

  16. Multiplex SSR analysis of Phytophthora infestans in different countries and the importance for potato breeding

    NARCIS (Netherlands)

    Li, Y.

    2012-01-01

    Potato is the most important non-cereal crop in the world. Late blight, caused by the oomycete pathogen Phytophthora infestans, is the most devastating disease of potato. In the mid-19th century, P. infestans attacked the European potato fields and this resulted in a widespread famine in Ireland and

  17. Biologically active Phytophthora mating hormone prepared by catalytic asymmetric total synthesis

    NARCIS (Netherlands)

    Harutyunyan, S.R.; Zhao, Z.; Hartog, den T.; Bouwmeester, K.; Minnaard, A.J.; Feringa, B.L.; Govers, F.

    2008-01-01

    A Phytophthora mating hormone with an array of 1,5-stereogenic centers has been synthesized by using our recently developed methodology of catalytic enantioselective conjugate addition of Grignard reagents. We applied this methodology in a diastereo- and enantioselective iterative route and obtained

  18. Biologically active Phytophthora mating hormone prepared by catalytic asymmetric total synthesis

    NARCIS (Netherlands)

    Harutyunyan, Syuzanna R.; Zhao, Zhijian; den Hartog, Tim; Bouwmeester, Klaas; Minnaard, Adriaan J.; Feringa, Ben L.; Govers, Francine

    2008-01-01

    A Phytophthora mating hormone with an array of 11,5-stereogenic centers has been synthesized by using our recently developed methodology of catalytic enantioselective conjugate addition of Grignard reagents. We applied this methodology in a diastereo-and enantioselective iterative route and obtained

  19. Antifungal activity of extracts and select compounds in heartwood of seven western conifers toward Phytophthora ramorum

    Science.gov (United States)

    Individual compounds and ethyl acetate extracts from heartwood of seven conifer species were tested for fungicidal activity against Phytophthora ramorum. Extracts from incense and western red cedar exhibited the strongest activity (EC50 589 and 646 ppm, respectively), yellow-cedar, western juniper,...

  20. Spatial and temporal aspects of tylosis formation in tanoak inoculated with Phytophthora ramorum

    Science.gov (United States)

    Brad Collins; Jennifer Parke

    2008-01-01

    Phytophthora ramorum is an oomycete pathogen that causes sudden oak death in several species of Fagaceae including tanoak (Lithocarpus densiflorus). Symptoms on tanoak include stem cankers and crown death. Stem infection was thought to be restricted to bark and cambium, but has recently been shown to include sapwood....

  1. Survival potential of Phytophthora infestans in relation to environmental factors and late blight occurrence

    Science.gov (United States)

    Potato is an important crop globally and late blight (Phytophthora infestans) often results in severe crop loss. The cost for late blight control can be in excess of $210 million in the United States. We utilized a non-parametric density distribution analysis of local temperature (Temp) and relative...

  2. Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans

    NARCIS (Netherlands)

    Haas, B.J.; Kamoun, S.; Zody, M.C.; Jiang, R.H.Y.; Handsaker, R.E.; Cano, L.M.; Grabherr, M.; Kodira, C.D.; Raffaele, S.; Torto-Alalibo, T.; Bozkurt, T.O.; Ah-Fong, A.M.V.; Alvarado, L.; Anderson, V.L.; Armstrong, M.R.; Avrova, A.; Baxter, L.; Beynon, J.; Boevink, P.C.; Bollmann, S.R.; Bos, J.I.B.; Bulone, V.; Cai, G.; Cakir, C.; Carrington, J.C.; Chawner, M.; Conti, L.; Costanzo, S.; Ewan, R.; Fahlgren, N.; Fischbach, M.A.; Fugelstad, J.; Gilroy, E.M.; Gnerre, S.; Green, P.J.; Grenville-Briggs, L.J.; Griffith, J.; Grunwald, N.J.; Horn, K.; Horner, N.R.; Hu, C.H.; Huitema, E.; Jeong, D.H.; Jones, A.M.E.; Jones, J.D.G.; Jones, R.W.; Karlsson, E.K.; Kunjeti, S.G.; Lamour, K.; Liu, Z.; Ma, L.; Maclean, D.; Chibucos, M.C.; McDonald, H.; McWalters, J.; Meijer, H.J.G.; Morgan, W.; Morris, P.F.; Munro, C.A.; O'Neill, K.; Ospina-Giraldo, M.; Pinzon, A.; Pritchard, L.; Ramsahoye, B.; Ren, Q.; Restrepo, S.; Roy, S.; Sadanandom, A.; Savidor, A.; Schornack, S.; Schwartz, D.C.; Schumann, U.D.; Schwessinger, B.; Seyer, L.; Sharpe, T.; Silvar, C.; Song, J.; Studholme, D.J.; Sykes, S.; Thines, M.; Vondervoort, van de P.J.I.; Phuntumart, V.; Wawra, S.; Weide, R.; Win, J.; Young, C.; Zhou, S.; Fry, W.; Meyers, B.C.; West, van P.; Ristaino, J.; Govers, F.; Birch, P.R.J.; Whisson, S.C.; Judelson, H.S.; Nusbaum, C.

    2009-01-01

    Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans ha

  3. Four years experience with filtration systems in commercial nurseries for eliminating Phytophthora species from recirculation water

    Science.gov (United States)

    T. Ufer; M. Posner; H.-P. Wessels; S. Wagner; K. Kaminski; T. Brand; Werres S.

    2008-01-01

    In a four year project, three different filtration systems were tested under commercial nursery conditions to eliminate Phytophthora spp. from irrigation water. Five nurseries were involved in the project. Slow sand filtration systems were tested in three nurseries. In the fourth nursery, a filtration system with lava grains (Shieer® Bio filtration)...

  4. Differentiating Phytophthora ramorum and P. kernoviae from other species isolated from foliage of rhododendrons

    Science.gov (United States)

    Phytophthora species are among plant pathogens that are the most threatening to agriculture. After the discovery of P. ramorum, surveys have identified new species and new reports on Rhododendrons. Based upon propagule production and characteristics and colony growth, a dichotomous key was produce...

  5. The Phytophthora infestans avirulence gene PiaAvr4 and its potato counterpart R4

    NARCIS (Netherlands)

    Poppel, van P.M.J.A.

    2009-01-01

    The potato late blight disease that is caused by the oomycete pathogen Phytophthora infestans is a major threat for potato crops worldwide. In recent years research on oomycete plant pathogens was boosted by the availability of novel genomic tools and resources for several oomycete genera, such as P

  6. Interactions of Phytophthora capsici with Resistant and Susceptible Pepper Roots and Stems.

    Science.gov (United States)

    Dunn, Amara R; Smart, Christine D

    2015-10-01

    Using host resistance is an important strategy for managing pepper root and crown rot caused by Phytophthora capsici. An isolate of P. capsici constitutively expressing a gene for green fluorescent protein was used to investigate pathogen interactions with roots, crowns, and stems of Phytophthora-susceptible bell pepper 'Red Knight', Phytophthora-resistant bell pepper 'Paladin', and Phytophthora-resistant landrace Criollos de Morelos 334 (CM-334). In this study, the same number of zoospores attached to and germinated on roots of all cultivars 30 and 120 min postinoculation (pi), respectively. At 3 days pi, significantly more secondary roots had necrotic lesions on Red Knight than on Paladin and CM-334 plants. By 4 days pi, necrotic lesions had formed on the taproot of Red Knight but not Paladin or CM-334 plants. Although hyphae were visible in the crowns and stems of all Red Knight plants observed at 4 days pi, hyphae were observed in crowns of only a few Paladin and in no CM-334 plants, and never in stems of either resistant cultivar at 4 days pi. These results improve our understanding of how P. capsici infects plants and may contribute to the use of resistant pepper cultivars for disease management and the development of new cultivars.

  7. Lineage, Temperature, and Host Species Have Interacting Effects on Lesion Development in Phytophthora Ramorum

    Science.gov (United States)

    There are four recognized clonal lineages of the pathogen Phytophthora ramorum. The two major lineages present in North America are NA1 and NA2. With a few exceptions, NA1 is found in natural forest ecosystems and nurseries, and NA2 is generally restricted to nurseries. Isolates from the NA1 and NA2...

  8. Evaluation of fungicide rotations for management of Phytophthora fruit rot of watermelon, 2015

    Science.gov (United States)

    The experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand. For the past 6 years, the field has been infested with Phytophthora capsici. The experimental design was a randomized complete block with four replications. Five-week-old seedli...

  9. Development of a loop-mediated isothermal amplification assay for detection of Phytophthora sojae.

    Science.gov (United States)

    Dai, Ting-Ting; Lu, Chen-Chen; Lu, Jing; Dong, SuoMeng; Ye, WenWu; Wang, YuanChao; Zheng, XiaoBo

    2012-09-01

    Phytophthora sojae is a devastating pathogen that causes soybean Phytophthora root rot. This study reports the development of a loop-mediated isothermal amplification (LAMP) assay targeting the A3aPro element for visual detection of P. sojae. The A3aPro-LAMP assay efficiently amplified the target element in Phytophthora spp., Pythium spp., and true fungi isolates. Magnesium pyrophosphate resulting from the LAMP of P. sojae could be detected by real-time measurement of turbidity. Phytophthora sojae DNA products were visualized as a ladder-like banding pattern on 2% gel electrophoresis. A positive colour (sky blue) was only observed in the presence of P. sojae with the addition of hydroxynaphthol blue prior to amplification, whereas none of other isolates showed a colour change. The detection limit of the A3aPro-specific LAMP assay for P. sojae was 10 pg μL(-1) of genomic DNA per reaction. The assay also detected P. sojae from diseased soybean tissues and residues. These results suggest that the A3aPro-LAMP assay reported here can be used for the visual detection of P. sojae in plants and production fields.

  10. Diverse evolutionary trajectories for small RNA biogenesis genes in the oomycete genus Phytophthora

    Science.gov (United States)

    Gene regulation by small RNA pathways is ubiquitous among eukaryotes, but little is known about small RNA pathways in the Stramenopile kingdom. Phytophthora, a genus of filamentous oomycetes, contains many devastating plant pathogens, causing multibillion-dollar damage to crops, ornamental plants, ...

  11. The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA.

    Science.gov (United States)

    Sims, Laura Lee; Sutton, Wendy; Reeser, Paul; Hansen, Everett M

    2015-01-01

    Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described "P. taxon Pgchlamydo", and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in downstream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described "P. taxon Oaksoil", which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides.

  12. Roles of small RNAs in soybean defense against Phytophthora sojae infection.

    Science.gov (United States)

    Wong, James; Gao, Lei; Yang, Yang; Zhai, Jixian; Arikit, Siwaret; Yu, Yu; Duan, Shuyi; Chan, Vicky; Xiong, Qin; Yan, Jun; Li, Shengben; Liu, Renyi; Wang, Yuanchao; Tang, Guiliang; Meyers, Blake C; Chen, Xuemei; Ma, Wenbo

    2014-09-01

    The genus Phytophthora consists of many notorious pathogens of crops and forestry trees. At present, battling Phytophthora diseases is challenging due to a lack of understanding of their pathogenesis. We investigated the role of small RNAs in regulating soybean defense in response to infection by Phytophthora sojae, the second most destructive pathogen of soybean. Small RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), are universal regulators that repress target gene expression in eukaryotes. We identified known and novel small RNAs that differentially accumulated during P. sojae infection in soybean roots. Among them, miR393 and miR166 were induced by heat-inactivated P. sojae hyphae, indicating that they may be involved in soybean basal defense. Indeed, knocking down the level of mature miR393 led to enhanced susceptibility of soybean to P. sojae; furthermore, the expression of isoflavonoid biosynthetic genes was drastically reduced in miR393 knockdown roots. These data suggest that miR393 promotes soybean defense against P. sojae. In addition to miRNAs, P. sojae infection also resulted in increased accumulation of phased siRNAs (phasiRNAs) that are predominantly generated from canonical resistance genes encoding nucleotide binding-leucine rich repeat proteins and genes encoding pentatricopeptide repeat-containing proteins. This work identifies specific miRNAs and phasiRNAs that regulate defense-associated genes in soybean during Phytophthora infection.

  13. Identification of stable resistance to Phytophthora infestans in potato genotypes evaluated in field experiments in Peru

    DEFF Research Database (Denmark)

    Wulff, Ednar Gadelha; Pérez, W.; Nelson, R.J.;

    2007-01-01

    Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non...

  14. Recommended industry best management practices for the prevention of Phytophthora ramorum introduction in nursery operations

    Science.gov (United States)

    Karen Suslow

    2008-01-01

    The following industry recommended best management practices (BMPs), designed for growers and/or interstate shippers of host and associated host plants of Phytophthora ramorum, consists of biosecurity guidelines created by and for nursery growers in order to reduce the risks associated with P. ramorum. The control of P....

  15. An in planta induced gene of Phytophthora infestans codes for ubiquitin

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Risseeuw, E.P.; Davidse, L.C.

    1991-01-01

    An in planta induced gene of Phytophthora infestans (the causal organism of potato late blight) was selected from a genomic library by differential hybridization using labelled cDNA derived from poly(A)+ RNA of P. infestans grown in vitro and labelled cDNA made from potato-P. infestans interaction

  16. An in planta induced gene of Phytophthora infestans codes for ubiquitin

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Risseeuw, E.P.; Davidse, L.C.

    1991-01-01

    An in planta induced gene of Phytophthora infestans (the causal organism of potato late blight) was isolated from a genomic library by differential hybridization using labelled cDNA derived from poly(A)⁺ RNA of P. infestans grown in vitro and labelled cDNA made from potato-P,

  17. Multiplex SSR analysis of Phytophthora infestans in different countries and the importance for potato breeding

    NARCIS (Netherlands)

    Li, Y.

    2012-01-01

    Potato is the most important non-cereal crop in the world. Late blight, caused by the oomycete pathogen Phytophthora infestans, is the most devastating disease of potato. In the mid-19th century, P. infestans attacked the European potato fields and this resulted in a widespread famine in Ireland and

  18. Detection and identification of Phytophthora fragariae Hickman by the polymerase chain reaction

    NARCIS (Netherlands)

    Bonants, P.; Hagenaar-de Weerdt, M.; Gent-Pelzer, van M.; Lacourt, I.; Cooke, D.; Duncan, J.

    1997-01-01

    Phytophthora fragariae Hickman, which causes strawberry red stele and raspberry root rot, is a quarantine organism for which specific and sensitive detection methods are required to test the health of planting material. Sequences of the internal transcribed spacer regions of the ribosomal gene

  19. 'Cisgenese kan handje helpen in bestrijding phytophthora' (interview met Geert Kessel)

    NARCIS (Netherlands)

    Engwerda, J.; Kessel, G.J.T.

    2009-01-01

    Toluca en Bionica zijn prima biologische aardappelrassen. Maar WUR vindt een waarschuwing nodig omdat in het lab de resistentie tegen phytophthora omzeild kan worden. "Cisgenese kan helpen om resistentie tegen te gaan." Toluca en Bionica zijn prima rassen voor de biologische aardappelteelt. Ondanks

  20. Population structure of Phytophthora infestans in the Toluca Valley region of Central Mexico

    NARCIS (Netherlands)

    Grünwald, N.J.; Flier, W.G.; Sturbaum, A.K.; Garay-Serrano, E.; Bosch, van den G.B.M.; Smart, C.D.; Matuszak, J.M.; Turkensteen, L.J.; Fry, W.E.

    2001-01-01

    We tested the hypothesis that the population of Phytophthora infestans in the Toluca valley region is genetically differentiated according to habitat. Isolates were sampled in three habitats from (i) wild Solanum spp. (WILD), (ii) land-race varieties in low-input production systems (RURAL), and (iii

  1. A Rapid Diagnostic Test to Distinguish Between American and European Populations of Phytophthora ramorum

    NARCIS (Netherlands)

    Kroon, L.P.N.M.; Verstappen, E.C.P.; Kox, L.F.F.; Flier, W.G.; Bonants, P.J.M.

    2004-01-01

    A new devastating disease in the United States, commonly known as Sudden Oak Death, is caused by Phytophthora ramorum. This pathogen, which previously was described attacking species of Rhododendron and Viburnum in Germany and the Netherlands, has established itself in forests on the central coast o

  2. Epidemiological importance of Solanum sisymbriifolium, S. nigrum and S. dulcamara as alternative hosts for Phytophthora infestans

    NARCIS (Netherlands)

    Flier, W.G.; Bosch, van den G.B.M.; Turkensteen, L.J.

    2003-01-01

    Lesions of Phytophthora infestans were found on woody nightshade (Solanum dulcamara), black nightshade (S. nigrum) and S. sisymbriifolium during a nationwide late blight survey in the Netherlands in 1999 and 2000. Pathogenicity and spore production of P. infestans isolates collected from potato (S.

  3. A systems approach for detecting sources of Phytophthora contamination in nurseries

    Science.gov (United States)

    Jennifer L. Parke; Niklaus Grünwald; Carrie Lewis; Val Fieland

    2010-01-01

    Nursery plants are also important long-distance vectors of non-indigenous pathogens such as P. ramorum and P. kernoviae. Pre-shipment inspections have not been adequate to ensure that shipped plants are free from Phytophthora, nor has this method informed growers about sources of contamination in their...

  4. Bioassay conditions for infection of Pinus radiata seedlings with Phytophthora pinifolia zoospores

    Science.gov (United States)

    Phytophthora pinifolia is known to cause a devastating disease on Monterey pines in Chile. Although this pathogen is not yet present in the U.S., there is reason for concern. The main source of Monterey pine genetic material is found in California and there is potential for other important tree sp...

  5. Resistance to Phytophthora infestans in Solanum tuberosum and wild Solanum species

    NARCIS (Netherlands)

    Colon, L.T.

    1994-01-01

    Resistance to Phytophthora infestans , the causal agent of late blight, is present in the potato, Solanum tuberosum , and in many wild relatives of this crop. The resistance of S. tuberosum is partial and, though helpful in reducing the use of fungicides, is not sufficient to fully solve the problem

  6. THE INFLUENCE OF NATURAL ESSENTIAL OILS ON THE GROWTH OF PHYTOPHTHORA SPP. ISOLATED FROM PELARGONIUM CUTTINGS

    Directory of Open Access Journals (Sweden)

    Marcelina Machura

    2017-10-01

    Full Text Available Ornamental plants play an important role in human life. Plants positively influence the psyche and improve the well-being of people around them. They produce oxygen, provide a barrier to dust and noise, lower the temperature and increase air humidity, thereby positively impacting the microclimate. The unmatched appeal of pelargonium, ease of cultivation and care, abundance of flowering from spring to late autumn and its decorative qualities make it a universal application. The aim of the study was to isolate the microorganisms that inhabit the cuttings of pelargonium, identify fungal isolates, investigate the pathogenicity of selected isolates and evaluate the influence of certain essential oils (Carum carvi L. essential oils, Citrus limon L. essential oils, Citrus reticulatae aetheroleum essential oils, essential oil of tea tree in in vitro circumstances on the linear growth of the mycelium: Phytophthora cryptogea, Phytophthora nicotianae var. nicotianae. Previcur Energy 840 SL was used as a standard chemical protection. The most numerous isolated fungi were: Phytophthora, Botrytis, Cylindrocladium, Alternaria and Cylindrocarpon. The highest efficiency in relation to Phytophthora cryptogea characterized the Citrus limon L. essential oils (concentration 0.1% and 1% and Carum carvi L. essential oil (concentration 1%.

  7. Efficient multiplex simple sequence repeat genotyping of the oomycete plant pathogen Phytophthora infestans

    NARCIS (Netherlands)

    Li, Y.; Cooke, D.E.L.; Jacobsen, E.; Lee, van der T.A.J.

    2013-01-01

    Genotyping is fundamental to population analysis. To accommodate fast, accurate and cost-effective genotyping, a one-step multiplex PCR method employing twelve simple sequence repeat (SSR) markers was developed for high-throughput screening of Phytophthora infestans populations worldwide. The SSR

  8. Agrobacterium tumefaciens mediated transformation of the oomycete plant pathogen Phytophthora infestans

    NARCIS (Netherlands)

    Vijn, I.; Govers, F.

    2003-01-01

    Agrobacterium tumefaciens is widely used for plant DNA transformation and, more recently, has also been used to transform yeast and filamentous fungi. Here we present a protocol for Agrobacterium-mediated DNA transformation of the oomycete Phytophthora infestans, the causal agent of potato late blig

  9. Phytophthora infestans avirulence genes: mapping, cloning and diversity in field isolates

    NARCIS (Netherlands)

    Guo, J.

    2008-01-01

    Potato late blight, caused by the oomycete pathogen Phytophthora infestans (Mont.) de Bary, is the most disastrous disease on potato worldwide and also the greatest threat to potato production in China. Loss of yield and quality, and the costs of chemical control of potato late blight account for

  10. Differential expression of G protein alpha and ß subunit genes during development of Phytophthora infestans

    NARCIS (Netherlands)

    Laxalt, A.M.; Latijnhouwers, M.; Hulten, van M.; Govers, F.

    2002-01-01

    A G protein subunit gene (pigpa1) and a G protein subunit gene (pigpb1) were isolated from the oomycete Phytophthora infestans, the causal agent of potato late blight. Heterotrimeric G proteins are evolutionary conserved GTP-binding proteins that are composed of ,, and subunits and participate in di

  11. Molecular evolution of an Avirulence Homolog (Avh) gene subfamily in Phytophthora ramorum

    Science.gov (United States)

    GossErica M.; Caroline M. Press; Niklaus J. Grünwald

    2008-01-01

    Pathogen effectors can serve a virulence function on behalf of the pathogen or trigger a rapid defense response in resistant hosts. Sequencing of the Phytophthora ramorum genome and subsequent analysis identified a diverse superfamily of approximately 350 genes that are homologous to the four known avirulence genes in plant pathogenic oomycetes and...

  12. Identification of potato genes involved in Phytophthora infestans resistance by transposon mutagenesis

    NARCIS (Netherlands)

    Enckevort, van L.J.G.

    2000-01-01

    The late blight disease, caused by the oomycete Phytophthora infestans (Mont.) de Bary, is a serious threat to the potato crop every growing season. This has, for example, led to the disastrous Irish famine in the middle of the 19 th century, and

  13. Response of U.S. bottle gourd (Lagenaria siceraria) Plant Introductions to Phytophthora capsici

    Science.gov (United States)

    Phytophthora capsici causes severe damage to cucurbit crops grown in open fields in southeast U.S. Most cucurbit species are susceptible to damping-off, root and crown rot, and/or fruit rot caused by P. capsici. Bottle gourd plants (Lagenaria siceraria), which are resistant to Fusarium wilt, are b...

  14. Germination of Phytophthora ramorum chlamydospores: a comparison of separation method and chlamydospore age

    Science.gov (United States)

    Justin P. Shaffer; Jennifer L. Parke

    2013-01-01

    Phytophthora ramorum characteristically produces large amounts of chlamydospores in vitro, but the role of these propagules in the disease cycle remains unclear. Germination is difficult to observe and quantify if chlamydospores are not free of mycelium, and the low frequency of germination commonly reported suggests that...

  15. Large subclonal variation in Phytophthora infestans populations associated with Ecuadorian potato landraces

    NARCIS (Netherlands)

    Delgado, R.A.; Monteros-Altamiro, A.R.; Li, Y.; Visser, R.G.F.; Lee, van der T.A.J.; Vosman, B.

    2013-01-01

    The population of Phytophthora infestans on potato landraces in three provinces (Carchi, Chimborazo and Loja) of Ecuador was analysed. All isolates (n = 66) were of the A1 mating type. Simple sequence repeats (SSR) were used to assess the genetic diversity of the isolates. The P. infestans isolates

  16. Profilaxia das úlceras associadas ao estresse Prophylaxis of ulcers associated with stress

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Pompilio

    2010-06-01

    Full Text Available INTRODUÇÃO: As úlceras da mucosa gastroduodenal que aparecem após graves insultos têm sido chamadas de úlceras associadas ao estresse ou, mais genericamente, de "doença mucosa associada ao estresse" (DMAE. São conhecidas desde a Antiguidade e apesar de relacionarem-se com altos índices de morbidade e mortalidade, esquemas de profilaxia no intuito de minimizar seus riscos, só foram introduzidos recentemente. Os inibidores da bomba de prótons têm desempenhado papel importante nesse cenário. MÉTODOS: O presente artigo é uma breve revisão sobre seu uso dentro do contexto clínico da profilaxia do sangramento gastrointestinal relacionado ao estresse.INTRODUCTION: Gastroduodenal mucosal ulcers that appear after severe insults have been called ulcers associated with stress or, more generally, "mucosal disease associated with stress" (DMAE. Are known since antiquity and although linked with high morbidity and mortality, prevention schemes in order to minimize their risk, were introduced only recently. The proton pump inhibitors have played an important role in this scenario. METHODS: This article is a brief review of its use within the clinical context of prophylaxis of gastrointestinal bleeding due to stress.

  17. Diffuse plane xanthomatosis associated with monoclonal gammopathy Xantomatose plana difusa associada a gamopatia monoclonal

    Directory of Open Access Journals (Sweden)

    Aristóteles Rosmaninho

    2011-08-01

    Full Text Available Diffuse plane normolipemic xanthomatosis (DPNX is a rare, non-inherited disease that is often associated with systemic diseases, mainly malignant hematological (especially multiple myeloma or lymph proliferative disorders. The DPNX can precede the appearance of such conditions by several years, so careful follow-up and periodic laboratory examinations are recommended even for patients that seemed to have no underlying disease. We describe a case associated with monoclonal gammopathy. This case shows that dermatological lesions can be the first manifestation of important hematological diseases and so physicians should be familiarized with this entityA xantomatose plana difusa normolipêmica (XPDN é uma dermatose adquirida rara, muitas vezes associada a doenças sistêmicas, nomeadamente neoplasias hematológicas(sobretudo o mieloma múltiplo ou a processos linfoproliferativos. A XPDN pode preceder o aparecimento dessas doenças em vários anos, sendo por isso recomendada uma vigilância clínica e laboratorial periódica, mesmo para os doentes que aparentemente não apresentam uma doença associada. Descrevemos um caso associado à gamopatia monoclonal. Este caso demonstra a importância das manifestações cutâneas como primeira manifestação de doenças hematológicas importantes e por isso os clínicos devem estar familiarizados com esta entidade

  18. Acarofauna em cultivo de pinhão-manso e plantas espontâneas associadas

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    Wilton Pires da Cruz

    2012-03-01

    Full Text Available O objetivo deste trabalho foi identificar ácaros na cultura de pinhão-manso e em espécies de plantas espontâneas associadas. Para isso, foram avaliadas a riqueza e a abundância de ácaros em plantas de pinhão-manso e em 14 espécies de plantas espontâneas associadas. As amostragens foram realizadas por meio de coletas mensais de folhas de plantas de pinhão-manso e de plantas espontâneas, nas entrelinhas do cultivo. Foram encontradas quatro espécies de ácaros predadores - Amblyseius tamatavensis, Paraphytoseius multidentatus, Typhlodromalus aripo e Typhlodromalus clavicus -, com potencial para uso no controle biológico de ácaros-praga na cultura do pinhão-manso, e duas importantes espécies de ácaros fitófagos - Brevipalpus phoenicis e Tarsonemus confusus - desconhecidas como praga da cultura. Entre as plantas espontâneas avaliadas, quatro espécies - Hyptis suaveolens, Peltaea riedelii, Urochloa mutica e Andropogon gayanus - abrigam grande riqueza e abundância de ácaros predadores, enquanto oito destacaram-se pela diversidade de ácaros fitófagos.

  19. Genetic diversity of Phytophthora infestans in the Northern Andean region

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    Grünwald Niklaus J

    2011-02-01

    Full Text Available Abstract Background Phytophthora infestans (Mont. de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. Countries in the northern part of the Andes dedicate a large proportion of the highlands to the production of potato, and more recently, solanaceous fruits such as cape gooseberry (Physalis peruviana and tree tomato (Solanum betaceum, all of which are hosts of this oomycete. In the Andean region, P. infestans populations have been well characterized in Ecuador and Peru, but are poorly understood in Colombia and Venezuela. To understand the P. infestans population structure in the Northern part of the Andes, four nuclear regions (ITS, Ras, β-tubulin and Avr3a and one mitochondrial (Cox1 region were analyzed in isolates of P. infestans sampled from different hosts in Colombia and Venezuela. Results Low genetic diversity was found within this sample of P. infestans isolates from crops within several regions of Colombia and Venezuela, revealing the presence of clonal populations of the pathogen in this region. We detected low frequency heterozygotes, and their distribution patterns might be a consequence of a high migration rate among populations with poor effective gene flow. Consistent genetic differentiation exists among isolates from different regions. Conclusions The results here suggest that in the Northern Andean region P. infestans is a clonal population with some within-clone variation. P. infestans populations in Venezuela reflect historic isolation that is being reinforced by a recent self-sufficiency of potato seeds. In summary, the P. infestans population is mainly shaped by migration and probably by the appearance of variants of key effectors such as Avr3a.

  20. Sensitivities of Phytophthora infestans to Metalaxyl, Cymoxanil, and Dimethomorph

    Institute of Scientific and Technical Information of China (English)

    ZHU Gui-ning; HUANG Fu-xin; FENG Lan-xiang; QIN Bi-xia; YANG Yu-hong; CHEN Yong-hui; LU Xiu-hong

    2008-01-01

    The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg mL-1 and their resistance levels were over 100000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean EC50 value [cymoxanil (0.1647±0.0255) μg mL-1, dimethomorph (0.0970±0.0052) μg mL-1] could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.

  1. Genetic mapping of resistance factors to Phytophthora palmivora in cocoa.

    Science.gov (United States)

    Flament, M H; Kebe, I; Clément, D; Pieretti, I; Risterucci, A M; N'Goran, J A; Cilas, C; Despréaux, D; Lanaud, C

    2001-02-01

    Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in C te d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.

  2. Biological and epidemiological aspects of the quarantine pathogen Phytophthora ramorum

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    Beatrice Ginetti

    2015-12-01

    Full Text Available Phytophthora ramorum is a quarantine pathogen that causes leaf blight and shoot dieback of the crown, bark cankers and death on a number of both ornamental and forest trees, especially in North America and northern Europe, where it has produced severe outbreaks.In Italy it was first reported in 2002, on Rhodondendron yakushimanum in a Piedmont nursery; after that it seemed to have disappeared, only to re-emerge in 2013 when numerous isolates were detected on batches of Viburnum tinus plants growing in some nurseries in the Pistoia area (Tuscany, which is an important district in the trade of nursery plants world-wide. This work reports on a number of laboratory tests that were carried out on isolates from infected plant samples. The micromorphological and macromorphological characteristics of the pathogen growing on carrot agar (CA, corn meal agar (CMA, malt extract agar (MEA potato dextrose agar, and V8 agar with added PARPNH (see text were determined, as was the growth rate at 10º, 15º, 20º, 25°, 30º, 32º and 35ºC. Molecular analysis was employed to identify the isolates more precisely. Inoculation trials under the bark were also carried out to ascertain the isolate virulence and the Koch’s Postulates.The Plant Protection Service of the Tuscan Region (SFR, Servizio Fitosanitario Regionale was alerted as soon as the pathogen infection was detected and it took the prescribed steps to eradicate the infection in the field and prevent the recurrence of an epidemic.

  3. SNP-based differentiation of Phytophthora infestans clonal lineages using locked nucleic acid probes and high resolution melt analysis

    Science.gov (United States)

    Phytophthora infestans, the cause of the devastating late blight disease of potato and tomato, exhibits a clonal reproductive lifestyle in North America. Phenotypes such as fungicide sensitivity and host preference are conserved among individuals within clonal lineages, while substantial phenotypic ...

  4. Phytophthora capsici - Loss of Heterozygosity (LOH): A Widespread Mechanism for Rapid Adaptation ( 7th Annual SFAF Meeting, 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Mudge, Joanne [NCGR

    2012-06-01

    Joanne Mudge on "Phytophthora capsici - Loss of Heterozygosity (LOH): A Widespread Mechanism for Rapid Mutation" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  5. A Phytophthora sojae effector suppresses endoplasmic reticulum stress-mediated immunity by stabilizing plant Binding immunoglobulin Proteins

    Science.gov (United States)

    Jing, Maofeng; Guo, Baodian; Li, Haiyang; Yang, Bo; Wang, Haonan; Kong, Guanghui; Zhao, Yao; Xu, Huawei; Wang, Yan; Ye, Wenwu; Dong, Suomeng; Qiao, Yongli; Tyler, Brett M.; Ma, Wenbo; Wang, Yuanchao

    2016-01-01

    Phytophthora pathogens secrete an array of specific effector proteins to manipulate host innate immunity to promote pathogen colonization. However, little is known about the host targets of effectors and the specific mechanisms by which effectors increase susceptibility. Here we report that the soybean pathogen Phytophthora sojae uses an essential effector PsAvh262 to stabilize endoplasmic reticulum (ER)-luminal binding immunoglobulin proteins (BiPs), which act as negative regulators of plant resistance to Phytophthora. By stabilizing BiPs, PsAvh262 suppresses ER stress-triggered cell death and facilitates Phytophthora infection. The direct targeting of ER stress regulators may represent a common mechanism of host manipulation by microbes. PMID:27256489

  6. Development of Rapid Isothermal Amplification Assays for Detection of Phytophthora spp. in Plant Tissue.

    Science.gov (United States)

    Miles, Timothy D; Martin, Frank N; Coffey, Michael D

    2015-02-01

    Several isothermal amplification techniques recently have been developed that are tolerant of inhibitors present in many plant extracts, which can reduce the need for obtaining purified DNA for running diagnostic assays. One such commercially available technique that has similarities with real-time polymerase chain reaction (PCR) for designing primers and a labeled probe is recombinase polymerase amplification (RPA). This technology was used to develop two simple and rapid approaches for detection of Phytophthora spp.: one genus-specific assay multiplexed with a plant internal control and the other species-specific assays for Phytophthora ramorum and P. kernoviae. All assays were tested for sensitivity (ranging from 3 ng to 1 fg of DNA) and specificity using DNA extracted from more than 136 Phytophthora taxa, 21 Pythium spp., 1 Phytopythium sp., and a wide range of plant species. The lower limit of linear detection using purified DNA was 200 to 300 fg of DNA in all pathogen RPA assays. Six different extraction buffers were tested for use during plant tissue maceration and the assays were validated in the field by collecting 222 symptomatic plant samples from over 50 different hosts. Only 56 samples were culture positive for Phytophthora spp. whereas 91 were positive using the Phytophthora genus-specific RPA test and a TaqMan real-time PCR assay. A technique for the generation of sequencing templates from positive RPA amplifications to confirm species identification was also developed. These RPA assays have added benefits over traditional technologies because they are rapid (results can be obtained in as little as 15 min), do not require DNA extraction or extensive training to complete, use less expensive portable equipment than PCR-based assays, and are significantly more specific than current immunologically based methods. This should provide a rapid, field-deployable capability for pathogen detection that will facilitate point-of-sample collection processing

  7. Internetprogramma geeft inzicht in eigen Phytophthora-strategie. (Internet site gives insight in effectiveness of growers personal potato late blight control strategies)

    NARCIS (Netherlands)

    Kessel, G.J.T.; Hanse, L.

    2005-01-01

    Om telers te helpen met hun bestrijdingsstrategie is het Agrobiocon programma 'Visualisatie infectie Phytophthora' ontwikkeld. Uitleg van mede ontwikkelaar Geert Kessel van Plant Research International van Wageningen UR

  8. Sequencing of the Litchi Downy Blight Pathogen Reveals It Is a Phytophthora Species With Downy Mildew-Like Characteristics.

    Science.gov (United States)

    Ye, Wenwu; Wang, Yang; Shen, Danyu; Li, Delong; Pu, Tianhuizi; Jiang, Zide; Zhang, Zhengguang; Zheng, Xiaobo; Tyler, Brett M; Wang, Yuanchao

    2016-07-01

    On the basis of its downy mildew-like morphology, the litchi downy blight pathogen was previously named Peronophythora litchii. Recently, however, it was proposed to transfer this pathogen to Phytophthora clade 4. To better characterize this unusual oomycete species and important fruit pathogen, we obtained the genome sequence of Phytophthora litchii and compared it to those from other oomycete species. P. litchii has a small genome with tightly spaced genes. On the basis of a multilocus phylogenetic analysis, the placement of P. litchii in the genus Phytophthora is strongly supported. Effector proteins predicted included 245 RxLR, 30 necrosis-and-ethylene-inducing protein-like, and 14 crinkler proteins. The typical motifs, phylogenies, and activities of these effectors were typical for a Phytophthora species. However, like the genome features of the analyzed downy mildews, P. litchii exhibited a streamlined genome with a relatively small number of genes in both core and species-specific protein families. The low GC content and slight codon preferences of P. litchii sequences were similar to those of the analyzed downy mildews and a subset of Phytophthora species. Taken together, these observations suggest that P. litchii is a Phytophthora pathogen that is in the process of acquiring downy mildew-like genomic and morphological features. Thus P. litchii may provide a novel model for investigating morphological development and genomic adaptation in oomycete pathogens.

  9. Different tree ages and change of ash content in Cinnamomi Cortex%肉桂树龄与其灰分含量变化的关系研究

    Institute of Scientific and Technical Information of China (English)

    李玲; 杨炯珍; 姜平川

    2012-01-01

    objective To describe the relation between different tree ages and quality of Cinnamomi Cortex. Methods The ash of cinnamon of different ages in 16 Guangxi geographic mark protection was determined. Results When the age of cinnamon was less than 10 years, the ash content was in line with the Pharmacopoeia; when the tree age of cinnamon more than 15 years, the ash content of most did not meet the Pharmacopoeia. Conclusion We suggest that Chinese Pharmacopoeia for the total ash part of cinnamon should be modified.%目的 对肉桂树龄与其灰分含量变化的关系进行研究.方法 对广西肉桂地理标志保护范围内的16个地区、市、县的不同树龄的肉桂进行灰分测定.结果 当肉桂树龄<10年,其总灰分含量符合药典规定;而当肉桂树龄≥15年时,其灰分含量大多数不符合药典规定.结论 建议对中国药典2010版一部中对于肉桂检查项下的总灰分部分的相关规定进行修改.

  10. BUSCA PELA "MUSCULARIDADE" E VARIÁVEIS ASSOCIADAS EM ADULTOS JOVENS

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Berbert de Carvalho

    2016-04-01

    Full Text Available Introdução: A busca pela "muscularidade" parece estar associada a diversas variáveis que impactam a saúde e a qualidade de vida dos sujeitos. No entanto, há uma carência de estudos sobre o construto, um baixo número de instrumentos de medida específicos para sua avaliação, além de reduzida avaliação de indivíduos do sexo masculino. Objetivo: Avaliar a busca pela "muscularidade" e associá-la a sintomas depressivos, autoestima, comportamentos de risco de transtornos alimentares e ao grau de comprometimento psicológico com o exercício físico. Métodos: Realizou-se um estudo transversal com 246 jovens adultos do sexo masculino. Foram utilizados instrumentos de autorrelato para avaliar a busca pela "muscularidade" (Drive for Muscularity Scale, autoestima (Rosenberg Self-Esteem Scale, sintomas depressivos (Beck Depression Inventory, comportamentos de risco de transtornos alimentares (Eating Attitudes Test-26 e o grau de comprometimento psicológico com o exercício físico (Commitment Exercise Scale. Foi utilizado o teste de associação de Pearson para verificar relação entre as variáveis do estudo e Análise de Regressão Linear Múltipla (forward para verificação do quanto as variáveis do estudo influenciam na busca pela "muscularidade". Resultados: A busca pela "muscularidade" esteve associada à autoestima (rpearson = 0,13; p < 0,05, aos comportamentos de risco de transtornos alimentares (rpearson = 0,20; p < 0,05 e ao grau de comprometimento psicológico ao exercício (rpearson = 0,62; p < 0,05. O grau de comprometimento psicológico com o exercício explicou 38,4% da variância total da busca pela "muscularidade", 12,3% da insatisfação com a "muscularidade" e 51,0% dos comportamentos orientados para a "muscularidade". Conclusão: A busca pela "muscularidade" está associada à baixa autoestima, aos comportamentos de risco de transtornos alimentares e, em especial, ao grau de comprometimento psicológico com o exerc

  11. Neurolues congênita associada a hidrocefalia Congenital neurosyphilis associated with hydrocephalus

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    Julinho Aisen

    1970-09-01

    Full Text Available É apresentado um caso de neurolues congênita (meningovascular e parenquimatosa associada a hidrocefalia do tipo bloqueado. A natureza luética da afecção foi confirmada por exames paraclínicos e histopatológico. O registro do caso se justifica pelo fato da não existência na literatura compulsada de outro semelhante comprovado histopatològicamente. A hidrocefalia ocorreu em conseqüência do bloqueio do sistema ventricular pelo processo inflamatório de natureza crônica.A case of meningovascular and parenchymatous neurosyphilis associated with a non-communicating hydrocephalus is reported. The syphilitic nature of the disease was confirmed by laboratory and histopathological findings. The authors were unable to find in the medical literature other reports of histologically documented cases of hydrocephalus secondary to a block of the ventricular system determined by neurosyphilis.

  12. Síndrome de Sweet associada à policitemia vera Sweet’s syndrome associated withpolycythemiavera

    Directory of Open Access Journals (Sweden)

    Ângela Puccini Moreira

    2009-12-01

    Full Text Available A síndrome de Sweet pode estar associada a malignidades hematológicas, principalmente, à leucemia mieloide aguda, porém existem poucos relatos demonstrando a associação com a policitemia vera. Relata-se o caso de doente do sexo masculino, de 65 anos, portador de policitemia vera,que evoluiu com aparecimento de síndrome de Sweet na sua forma paraneoplásica.Sweet’s syndrome may be associated with hematological malignancies, particularly with acute myelogenous leukemia, but there are few reports of its association with polycythemiavera. We describethe case of a 65-year-old male patient, diagnosed with polycythemiavera, which developedinto paraneoplastic Sweet's syndrome.

  13. Hemorragia alveolar associada a nefrite lúpica Alveolar hemorrhage associated with lupus nephritis

    Directory of Open Access Journals (Sweden)

    Ricardo Henrique de Oliveira Braga Teixeira

    2003-12-01

    Full Text Available Hemorragia alveolar, como causa de insuficiência respiratória, é pouco freqüente, com diversas etiologias possíveis. Entre elas, o lúpus eritematoso sistêmico, que se apresenta geralmente como síndrome pulmão-rim, possui alta morbimortalidade. Acredita-se que a patogênese da microangiopatia, tanto renal como pulmonar, esteja associada ao depósito de imunocomplexos, que ativariam as vias de apoptose celular. Relatam-se dois casos de pacientes com nefrite lúpica que evoluíram com hemorragia alveolar associada à insuficiência respiratória necessitando de ventilação mecânica com evoluções totalmente distintas frente às terapias farmacológicas. O achado de anticorpos antimembrana basal em um dos casos evidencia a multiplicidade de mecanismos fisiopatológicos possivelmente envolvidos, que poderiam justificar as respostas heterogêneas frente aos tratamentos disponíveis.Alveolar hemorrhage leading to respiratory failure is uncommon. Various etiologies have been reported, including systemic lupus erythematosus, which generally presents as pulmonary-renal syndrome. It is believed that the pathogenesis of microangiopathy is related to deposits of immune complexes that lead to activation of cellular apoptosis. The authors report two cases of alveolar hemorrhage and respiratory failure, both requiring mechanical ventilation. The two cases had opposite outcomes after pharmacological therapy. The presence of anti-glomerular basement membrane antibodies in one of the cases demonstrates the multiplicity of physiopathological mechanisms that may be involved. This multiplicity of mechanisms provides a possible explanation for the heterogeneous responses to the available treatments.

  14. Doenças e síndromes associadas à miastenia grave em um grupo de 304 pacientes

    Directory of Open Access Journals (Sweden)

    J. Lamartine de Assis

    1984-09-01

    Full Text Available Foram realizados estudos epidemiológico e clínico de doenças e síndromes associadas em um grupo de 304 pacientes miastênicos. Foram apresentadas projeções comparativas entre os casos presentes e os de outros autores.

  15. [Environmental fitness of metalaxyl-resistant isolate of Phytophthora capsici].

    Science.gov (United States)

    Wang, Guangfei; Ma, Yan

    2015-05-04

    The environmental fitness of metalaxyl-resistant isolate of Phytophthora capsici was studied for assessing the risk of metalaxyl-resistant P. capsici. We studied the main biological characteristics, competitive ability on plate, pathogenicity on pepper plant and adaptability in soil of the laboratory-induced metalaxyl-resistant isolate of P. capsici (Pc2-3 strain), with the metalaxyl-sensitive isolate (Pc2 strain, the wild-type) as the control. The zoosporangia production, releasing rate of zoosporangia and germination rate of zoospores of Pc2-3 were less than that of Pc2. The temperature range, optimum temperature range and initial pH range for mycelia growth of Pc2-3 were consistent with that of Pc2, but mycelia growth rate of Pc2-3 was lower than that of Pc2. Pc2-3 exhibited significantly weak competitive ability compared with Pc2 on carrots plate. Disease incidence of pepper inoculated with Pc2-3 (14.3%) was significantly lower than that of Pc2 (88. 6% ). When pepper plant was inoculated by mixtures of zoospore suspension of Pc2-3 and Pc2 at same ratio, the disease incidence, closing to that by Pc2 strain, was 75.7% . And all the strains isolated from diseased plants in the treatment were metalaxyl-sensitive. The density of P. capsis Pc2-3 was 0.28 times of Pc2 after the soil inoculated with Pc2-3 and Pc2 respectively at same zoospores density was incubated for 20 days. Otherwise, the ratio of Pc2-3 to Pc2 was 0.42 if the metalaxyl concentration in the soil was 300 mg/kg dry soil. No matter the soil temperature and humidity were beneficial to survival of P. capsici or not, Pc2-3 showed lower soil adaptability than Pc2. The environmental fitness of metalaxyl-resistant P. capsis Pc2-3 was weaker than the metalaxyl- sensitive strain Pc2 (the wild-type).

  16. Síndrome de Moebius associada a artrogripose: relato de caso e revisão da literatura

    Directory of Open Access Journals (Sweden)

    Moreira Ana Tereza Ramos

    2001-01-01

    Full Text Available Os autores descrevem um caso de síndrome de Moebius associada a artogripose múltipla congênita, uma situação rara, sem relatos prévios na literatura latino-americana. A síndrome de Moebius é caracterizada por paralisia dos VII e VI pares cranianos, geralmente associada a outras anomalias ósseas e musculares, mais freqüentemente localizadas na parte distal das extremidades. A artrogripose múltipla congênita consiste de um grupo heterogêneo de alterações, sendo caracterizada por extrema rigidez e contratura das articulações, associada a hipoplasia ou ausência de desenvolvimento muscular e de tecidos moles. Pode ser parte de um complexo de anomalias congênitas multissistêmicas. Uma criança do sexo masculino, de cor branca, 3 anos, apresentava estrabismo convergente, oftalmoplegia, paralisia do VII par craniano e disgenesia da musculatura lingual, alterações compatíveis com a síndrome de Moebius. Associada às alterações oculares, foram encontradas alterações músculo-esqueléticas - mãos e antebraços em flexão e hipotrofia da cintura escapular - compatíveis com artrogripose. Foi realizado o tratamento cirúrgico do estrabismo com boa evolução pós-operatória. Sugerimos que, nos pacientes que apresentam síndrome de Moebius associada a alterações congênitas ósseas e musculares de extremidades, seja investigada a presença de artrogripose, pois acreditamos que tal síndrome não está sendo bem diagnosticada por ser pouco conhecida.

  17. Race Structure and Distribution of Phytophthora infestans in the Investigated Areas of China

    Institute of Scientific and Technical Information of China (English)

    ZHU Jie-hua; YANG Zhi-hui; SHAO Tie-mei; TIAN Shi-min; ZHANG Zhi-ming

    2003-01-01

    Ninety isolates collected from five different provinces and cities (Hebei, Yunan, Sichuan,Chongqing, Inner Mongolia ) during 1997 -1998 were tested with potato clones possessed 8 dominant mono-genes R1, R3, R4, R6, R7, R9, R10, R11 and the combination of R1-R4 of the international late blight dif-ferential host. It concluded that: (1) in the 90 isolates tested 21 different races were detected, of which the 1.3. 4. 7. 9. 10. 11 was very common with frequency of 32.2%, followed by 1. 3. 4. 6. 7. 9. 10. 11 and 3.4. 7. 9. 11 with frequency of 10.0%; (2) all tested resistant genes were compatible to the virulent gene of iso-lates of Phytophthora infestans assayed, which indicated that the virulent genes were very common in thetested population of Phytophthora infestans.

  18. Evaluation of Soybean Germplasm from Provinces in Northeast China for Resistance to Phytophthora sojae

    Institute of Scientific and Technical Information of China (English)

    XU Xiu-hong; PAN Jun-bo; QU Juan-juan; YANG Qing-kai

    2004-01-01

    Soybean Phytophthora root rot (Phytophthora sojae) is a severe disease all over the world. Soybean germplasm from central and southern China for resistance has been evaluated by American researchers on a large scale. P. sojae has been found frequently in northeast of China in recent years, but not systematic evaluation of soybean germplasm for resistance has occurred there. By means of hypocotyl inoculation, 922 cultivars/lines from northeast of China were screened and evaluated for their response to race 1, and 25 of P. sojae. Generally resistance was less frequent in northeast of China than in central and southern China. Five cultivars/lines were identified that confer resistant responses to race 1, 3, 8, 25 and four additional isolates of P. sojae. These cultivars/lines may provide valuable sources of resistance for future breeding programs.

  19. Chemical control trials against Phytophthora capsici (Leon on pepper cultivations in Morocco

    Directory of Open Access Journals (Sweden)

    Pussemier, L.

    1988-01-01

    Full Text Available Chemical control trials against Phytophthora capsici (Leon on pepper cultivations in Morocco. Pepper protection trials against collar and root rot have been undertaken under laboratory and culture conditions using Aliette (80 % of phosethylaluminium and Ridomil M 58 (10 % of metalaxyl associated to 48 % of maneb. It has been proved that, contrary to Ridomil M 58, Aliette does not protect the hostplant when the Phytophthora capsici (Leon zoospores are used as inoculum. But both fongicides are active when inoculating with a mycelian suspension. Trials undertaken under plastic glasshouses confirmed the laboratory results both with an artificial inoculation and with a natural one on contaminated soil. Only Ridomil M 58 provides satisfactory protection during the first weeks after the treatment. When disease propagation conditions are particularly favorable (permanent presence of an active inoculum source, the protection given by repeated Ridomil M 58 applications gradually disappears after a few weeks.

  20. Phytophthora nicotianae diseases worldwide: new knowledge of a long-recognised pathogen

    Directory of Open Access Journals (Sweden)

    Franck PANABIERES

    2016-05-01

    Full Text Available Phytophthora nicotianae was first isolated from tobacco at the end of the 19th century. This organism is now considered as one of the most devastating oomycete plant pathogens, with a recognized host range of more than 255 species over five continents and a wide diversity of climates. The economic losses caused by P. nicotianae are difficult to estimate, because of the diversity of its hosts and ecological niches. For these reasons, this pathogen represents a continuous challenge to plant disease management programmes, which frequently rely solely on the use of chemicals. Phytophthora nicotianae is better adapted than its competitors to abiotic stresses, especially to climate warming. As a result, its importance is increasing. This review illustrates, with some examples, how P. nicotianae currently impacts plant economies worldwide, and how it may constitute more severe threats to agriculture and natural ecosystems in the context of global climate change.

  1. E-beam irradiation for the control of Phytophthora nicotianae var. nicotianae in stonewool cubes

    Directory of Open Access Journals (Sweden)

    Ptaszek Magdalena

    2015-09-01

    Full Text Available Effectiveness of electron beam irradiation was evaluated against Phytophthora nicotianae var. nicotianae, the causal agent of stem base and root rot of tomato. In laboratory trials, irradiation of 7-day-old Phytophthora cultures growing on potato-dextrose-agar (PDA medium with 1 kGy resulted in the disintegration of the pathogen’s hyphae. Increasing the irradiation dose to 3 kGy caused decay of the hyphae. Irradiation of infested stonewool with 5 kGy caused decrease of the pathogen population about 5 times. Application of 20 kGy completely eliminated the pathogen from stonewool. Irradiation of substratum resulted in significant increase of tomato seedlings healthiness, especially when the dose 20 kGy was applied.

  2. Identification of Phytophthora Species on Phytophthora Blight of Vanilla%香草兰疫病疫霉菌种的鉴定

    Institute of Scientific and Technical Information of China (English)

    曾会才; 张开明; 李锐; 贺春萍

    2000-01-01

    从云南西双版纳的景洪、勐腊两地的热带作物园香草兰疫病果荚、茎节、叶片上分离到10个疫霉分离菌,根据孢子囊、厚垣孢子、藏卵器、雄器形态、菌落形态及主要生长温度,鉴定为烟草疫霉(寄生疫霉)Phytophthora nicotianae(P.parasitice)10个分离菌株均属于A1交配型.

  3. Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans

    OpenAIRE

    Haas, Brian J.; Kamoun, Sophien; Michael C Zody; Jiang, Rays H.Y.; Handsaker, Robert E.; Liliana M Cano; Grabherr, Manfred; Kodira, Chinnappa D.; Raffaele, Sylvain; Torto-Alalibo, Trudy; Bozkurt, Tolga O.; Ah-Fong, Audrey M. V.; Alvarado, Lucia; Anderson, Vicky L.; Armstrong, Miles R.

    2009-01-01

    Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the four...

  4. Levels of Polyamines and Kinetic Characterization of Their Uptake in the Soybean Pathogen Phytophthora sojae

    OpenAIRE

    Chibucos, M. Constantine; Paul F Morris

    2006-01-01

    Polyamines are ubiquitous biologically active aliphatic cations that are at least transiently available in the soil from decaying organic matter. Our objectives in this study were to characterize polyamine uptake kinetics in Phytophthora sojae zoospores and to quantify endogenous polyamines in hyphae, zoospores, and soybean roots. Zoospores contained 10 times more free putrescine than spermidine, while hyphae contained only 4 times as much free putrescine as spermidine. Zoospores contained no...

  5. The Phytophthora mating hormone α2 is an antagonist of the counterhormone α1.

    Science.gov (United States)

    Zhang, Li; Yajima, Arata; Ojika, Makoto

    2016-06-01

    The crop destroyer Phytophthora uses mating hormones α1 and α2 to commence its sexual reproduction. The α1-induced sexual reproduction of the A2 mating type was unexpectedly found to be interfered with by the counterhormone α2 that the A2 type itself produces to induce the sexual reproduction of the A1 type. A plausible mechanism is proposed based on structure-activity relationships.

  6. Phytophthora fruit rot-resistant watermelon germplasm lines: USVL489-PFR, USVL782-PFR, USVL203-PFR, and USVL020-PFR

    Science.gov (United States)

    USVL489-PFR, USVL782-PFR, USVL203-PFR, and USVL020-PFR are watermelon (Citrullus lanatus var. lanatus (Thunb.) Matsum. & Nakai) germplasm lines that exhibit high levels of resistance to Phytophthora fruit rot caused by the plant pathogen Phytophthora capsici. Resistance in these germplasm lines is ...

  7. Fine Mapping of a Phytophthora Resistance Gene RpsWY in Soybean (Glycine max L.) by High-Throughput Genome-Wide Sequencing

    Science.gov (United States)

    Phytophthora root rot (PRR) caused by Phytophthora sojae is one of the most important soil-borne diseases in many soybean-production regions in the world. Identification of resistant gene(s) is an effective way for breeding to prevent soybean from being harmed by this disease. Here, two soybean popu...

  8. Phytophthora megakarya and P. palmivora, closely related causal agents of cacao black pod induce similar reactions when infecting pods of a susceptible cacao genotype

    Science.gov (United States)

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) cause black pod rot of Theobroma cacao. Of these two clade 4 species; Pmeg is more virulent and is displacing Ppal on cacao in many cacao production areas in Africa. To understand the advantages Pmeg has over Ppal, we compared symptom...

  9. The use of genus-specific amplicon pyrosequencing to assess phytophthora species diversity using eDNA from soil and water in Northern Spain.

    Science.gov (United States)

    Català, Santiago; Pérez-Sierra, Ana; Abad-Campos, Paloma

    2015-01-01

    Phytophthora is one of the most important and aggressive plant pathogenic genera in agriculture and forestry. Early detection and identification of its pathways of infection and spread are of high importance to minimize the threat they pose to natural ecosystems. eDNA was extracted from soil and water from forests and plantations in the north of Spain. Phytophthora-specific primers were adapted for use in high-throughput Sequencing (HTS). Primers were tested in a control reaction containing eight Phytophthora species and applied to water and soil eDNA samples from northern Spain. Different score coverage threshold values were tested for optimal Phytophthora species separation in a custom-curated database and in the control reaction. Clustering at 99% was the optimal criteria to separate most of the Phytophthora species. Multiple Molecular Operational Taxonomic Units (MOTUs) corresponding to 36 distinct Phytophthora species were amplified in the environmental samples. Pyrosequencing of amplicons from soil samples revealed low Phytophthora diversity (13 species) in comparison with the 35 species detected in water samples. Thirteen of the MOTUs detected in rivers and streams showed no close match to sequences in international sequence databases, revealing that eDNA pyrosequencing is a useful strategy to assess Phytophthora species diversity in natural ecosystems.

  10. Microsatellite markers reveal low breeding system efficacy and pollen contamination can limit production of full-sib avocado progeny

    Science.gov (United States)

    Phytophthora cinnamomi causes a severe root rot in avocado, Persea americana. Breeding tolerant rootstocks is thought to be the most promising method for phytophthora root rot disease control but breeding avocado is challenging. The avocado flowering syndrome (synchronous protogynous dichogamy), com...

  11. Identification and characterization of differentially expressed genes from Fagus sylvatica roots after infection with Phytophthora citricola.

    Science.gov (United States)

    Schlink, Katja

    2009-05-01

    Phytophthora species are major plant pathogens infecting herbaceous and woody plants including European beech, the dominant or co-dominant tree in temperate Europe and an economically important species. For the analysis of the interaction of Phytophthora citricola with Fagus sylvatica suppression subtractive hybridization was used to isolate transcripts induced during infection and 1,149 sequences were generated. Hybridizations with driver and tester populations demonstrated differential expression in infected roots as compared to controls and verify efficient enrichment of these cDNAs during subtraction. Up regulation of selected genes during pathogenesis demonstrated using RT-PCR is consistent with these results. Pathogenesis-related proteins formed the largest group among functionally categorized transcripts. Cell wall proteins and protein kinases were also frequently found. Several transcription factors were isolated that are reactive to pathogens or wounding in other plants. The library contained a number of jasmonic acid, salicylic acid and ethylene responsive genes as well as genes directly involved in signaling pathways. Besides a mechanistic interconnection among signaling pathways another factor explaining the activation of different pathways could be the hemibiotrophic life style of Phytophthora triggering different signals in both stages.

  12. Mitochondrial DNA assessment of Phytophthora infestans isolates from potato and tomato in Ethiopia reveals unexpected diversity.

    Science.gov (United States)

    Shimelash, Daniel; Hussien, Temam; Fininsa, Chemeda; Forbes, Greg; Yuen, Jonathan

    2016-08-01

    Mitochondrial DNA (mtDNA) haplotypes were determined using restriction fragment length polymorphism (RFLP) for P. infestans sampled from 513 foliar lesions of late blight found on potato and tomato in different regions of Ethiopia. Among the four reported mitochondrial haplotypes of Phytophthora infestans, Ia, Ib and IIb were detected in 93 % of the samples analyzed but the vast majority of these were Ia. The remaining 7 % represented a previously unreported haplotype. DNA sequencing of this new haplotype also confirmed a single base nucleotide substitution that resulted in loss of EcoRI restriction site and gain of two additional MspI sites in cox1 and atp1 genes, respectively. There were 28 polymorphic sites among all nucleotide sequences including five reference isolates. Sites with alignment gaps were observed in P4 with one nucleotide deletion in 11 Ethiopian isolates. None of the reference sequence produced frame-shifts, with the exception of the 3-nucleotide deletion in the P4 region by Phytophthora andina, a feature that can be used to distinguish the new Ethiopian isolates from P. andina. While a distinguishing molecular data presented here clearly separated them from P. infestans, 7 % of the isolates that share this feature formed an important component of the late blight pathogen causing disease on Solanum tuberosum in Ethiopia. Thus, these Ethiopian isolates could represent a novel Phytophthora species reported for the first time here.

  13. Mitochondrial genome sequences reveal evolutionary relationships of the Phytophthora 1c clade species.

    Science.gov (United States)

    Lassiter, Erica S; Russ, Carsten; Nusbaum, Chad; Zeng, Qiandong; Saville, Amanda C; Olarte, Rodrigo A; Carbone, Ignazio; Hu, Chia-Hui; Seguin-Orlando, Andaine; Samaniego, Jose A; Thorne, Jeffrey L; Ristaino, Jean B

    2015-11-01

    Phytophthora infestans is one of the most destructive plant pathogens of potato and tomato globally. The pathogen is closely related to four other Phytophthora species in the 1c clade including P. phaseoli, P. ipomoeae, P. mirabilis and P. andina that are important pathogens of other wild and domesticated hosts. P. andina is an interspecific hybrid between P. infestans and an unknown Phytophthora species. We have sequenced mitochondrial genomes of the sister species of P. infestans and examined the evolutionary relationships within the clade. Phylogenetic analysis indicates that the P. phaseoli mitochondrial lineage is basal within the clade. P. mirabilis and P. ipomoeae are sister lineages and share a common ancestor with the Ic mitochondrial lineage of P. andina. These lineages in turn are sister to the P. infestans and P. andina Ia mitochondrial lineages. The P. andina Ic lineage diverged much earlier than the P. andina Ia mitochondrial lineage and P. infestans. The presence of two mitochondrial lineages in P. andina supports the hybrid nature of this species. The ancestral state of the P. andina Ic lineage in the tree and its occurrence only in the Andean regions of Ecuador, Colombia and Peru suggests that the origin of this species hybrid in nature may occur there.

  14. Genetic diversity, population structure, and resistance to Phytophthora capsici of a worldwide collection of eggplant germplasm.

    Directory of Open Access Journals (Sweden)

    Rachel P Naegele

    Full Text Available Eggplant (Solanum melongena L. is an important solanaceous crop with high phenotypic diversity and moderate genotypic diversity. Ninety-nine genotypes of eggplant germplasm (species (S. melongena, S. incanum, S. linnaeanum and S. gilo, landraces and heirloom cultivars from 32 countries and five continents were evaluated for genetic diversity, population structure, fruit shape, and disease resistance to Phytophthora fruit rot. Fruits from each line were measured for fruit shape and evaluated for resistance to two Phytophthora capsici isolates seven days post inoculation. Only one accession (PI 413784 was completely resistant to both isolates evaluated. Partial resistance to Phytophthora fruit rot was found in accessions from all four eggplant species evaluated in this study. Genetic diversity and population structure were assessed using 22 polymorphic simple sequence repeats (SSRs. The polymorphism information content (PIC for the population was moderate (0.49 in the population. Genetic analyses using the program STRUCTURE indicated the existence of four genetic clusters within the eggplant collection. Population structure was detected when eggplant lines were grouped by species, continent of origin, country of origin, fruit shape and disease resistance.

  15. Phytophthora parasitica transcriptome, a new concept in the understanding of the citrus gummosis

    Directory of Open Access Journals (Sweden)

    Daniel D. Rosa

    2007-01-01

    Full Text Available Due to the economic importance of gummosis disease for the citriculture, studies on P. parasitica-Citrus interaction comprise a significant part in the Brazilian Citrus genome data bank (CitEST. Among them, two cDNA libraries constructed from two different growth conditions of the P. parasitica pathogen are included which has generated the PP/CitEST database (CitEST - Center APTA Citros Sylvio Moreira/IAC- Millennium Institute. Through this genomic approach and clustering analyses the following has been observed: out of a total of 13,285 available in the Phytophthora parasitica database, a group of 4,567 clusters was formed, comprising 2,649 singlets and 1,918 contigs. Out of a total of 4,567 possible genes, only 2,651 clusters were categorized; among them, only 4.3% shared sequence similarities with pathogenicity factors and defense. Some of these possible genes (103 corresponding to 421 ESTs, were characterized by phylogenetic analysis and discussed. A comparison made with the COGEME database has shown homology which may be part of an evolutionary pathogenicity pathway present in Phytophthora and also in other fungi. Many of the genes which were identified here, which may encode proteins associated to mechanisms of citrus gummosis pathogenicity, represent only one facet of the pathogen-host Phytophthora - Citrus interaction.

  16. Morphological and molecular identification of phytophthora species from maple trees in Serbia

    Directory of Open Access Journals (Sweden)

    Milenković Ivan

    2014-01-01

    Full Text Available The paper presents the results of the study performed with aims to determine the presence and diversity of Phytophthora species on maple trees in Serbia. Due to high aggressiveness and their multicyclic nature, presence of these pathogens is posing significant threat to forestry and biodiversity. In total, 29 samples of water, soil and tissues were taken from 10 different localities, and six different maple hosts were tested. After the isolation tests, 17 samples from five different maple hosts were positive for the presence of Phytophthora spp., and 31 isolates were obtained. After the detailed morphological and physiological classification, four distinct groups of isolates were separated. DNA was extracted from selected representative isolates and molecular identification with sequencing of ITS region was performed. Used ITS4 and ITS6 primers successfully amplified the genomic DNA of chosen isolates and morphological identification of obtained isolates was confirmed after the sequencing. Four different Phytophthora species were detected, including P. cactorum, P. gonapodyides, P. plurivora and P. lacustris. The most common isolated species was homothallic, and with very variable and semipapillate sporangia, P. plurivora with 22 obtained isolates. This is the first report of P. plurivora and P. gonapodyides on A. campestre, P. plurivora and P. lacustris on Acer heldreichii and first report of P. lacustris on A. pseudoplatanus and A. tataricum in Serbia. [Projekat Ministarstva nauke Republike Srbije, br. TR 37008

  17. Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity

    Science.gov (United States)

    Stam, Remco; Jupe, Julietta; Howden, Andrew J. M.; Morris, Jenny A.; Boevink, Petra C.; Hedley, Pete E.; Huitema, Edgar

    2013-01-01

    Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN) gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions. PMID:23536880

  18. Antifungal Activity and Biochemical Response of Cuminic Acid against Phytophthora capsici Leonian

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2016-06-01

    Full Text Available Phytophthora blight of pepper caused by Phytophthora capsici Leonian is a destructive disease throughout the world. Cuminic acid, extracted from the seed of Cuminum cyminum L., belongs to the benzoic acid chemical class. In this study, the sensitivity and biochemical response of P. capsici to cuminic acid was determined. The mean EC50 (50% effective concentration values for cuminic acid in inhibiting mycelial growth and zoospore germination of the 54 studied P. capsici isolates were 14.54 ± 5.23 μg/mL and 6.97 ± 2.82 μg/mL, respectively. After treatment with cuminic acid, mycelial morphology, sporangium formation and mycelial respiration were significantly influenced; cell membrane permeability and DNA content increased markedly, but pyruvic acid content, adenosine triphosphate (ATP content, and ATPase activity decreased compared with the untreated control. In pot experiments, cuminic acid exhibited both protective and curative activity. Importantly, POD and PAL activity of the pepper leaves increased after being treated with cuminic acid. These indicated that cuminic acid not only showed antifungal activity, but also could improve the defense capacity of the plants. All the results suggested that cuminic acid exhibits the potential to be developed as a new phytochemical fungicide, and this information increases our understanding of the mechanism of action of cuminic acid against Phytophthora capsici.

  19. Effect of plant sterols and tannins on Phytophthora ramorum growth and sporulation.

    Science.gov (United States)

    Stong, Rachel A; Kolodny, Eli; Kelsey, Rick G; González-Hernández, M P; Vivanco, Jorge M; Manter, Daniel K

    2013-06-01

    Elicitin-mediated acquisition of plant sterols is required for growth and sporulation of Phytophthora spp. This study examined the interactions between elicitins, sterols, and tannins. Ground leaf tissue, sterols, and tannin-enriched extracts were obtained from three different plant species (California bay laurel, California black oak, and Oregon white oak) in order to evaluate the effect of differing sterol/tannin contents on Phytophthora ramorum growth. For all three species, high levels of foliage inhibited P. ramorum growth and sporulation, with a steeper concentration dependence for the two oak samples. Phytophthora ramorum growth and sporulation were inhibited by either phytosterols or tannin-enriched extracts. High levels of sterols diminished elicitin gene expression in P. ramorum; whereas the tannin-enriched extract decreased the amount of 'functional' or ELISA-detectable elicitin, but not gene expression. Across all treatment combinations, P. ramorum growth and sporulation correlated strongly with the amount of ELISA-detectable elicitin (R (2) = 0.791 and 0.961, respectively).

  20. Cross-species global proteomics reveals conserved and unique processes in Phytophthora sojae and P. ramorum

    Energy Technology Data Exchange (ETDEWEB)

    Savidor, Alon [ORNL; Donahoo, Ryan S [ORNL; Hurtado-Gonzales, Oscar [University of Tennessee, Knoxville (UTK); Land, Miriam L [ORNL; Shah, Manesh B [ORNL; Lamour, Kurt H [ORNL; McDonald, W Hayes [ORNL

    2008-08-01

    Phytophthora ramorum and Phytophthora sojae are destructive plant pathogens. Phytophthora sojae has a narrow host range whereas P. ramorum has a wide host range. A global proteomic comparison of the vegetative (mycelium) and infective (germinating-cyst) life-stages of P. sojae and P. ramorum was conducted to identify candidate proteins involved in host range, early infection and vegetative growth. Sixty-two candidates for early infection, 26 candidates for vegetative growth, and numerous proteins that may be involved in defining host specificity were identified. In addition, common life stage proteomic trends between the organisms were observed. In mycelia, proteins involved in transport and metabolism of amino acids, carbohydrates and other small molecules were up-regulated. In the germinating cysts, up-regulated proteins associated with lipid transport and metabolism, cytoskeleton and protein synthesis were observed. It appears that the germinating cyst catabolizes lipid reserves through the -oxidation pathway to drive the extensive protein synthesis necessary to produce the germ tube and initiate infection. Once inside the host, the pathogen switches to vegetative growth, where energy is derived from glycolysis and utilized for synthesis of amino acids and other molecules that assist survival in the plant tissue.

  1. Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity.

    Directory of Open Access Journals (Sweden)

    Remco Stam

    Full Text Available Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions.

  2. Phytophthora parasitica elicitor-induced reactions in cells of Petroselinum crispum.

    Science.gov (United States)

    Fellbrich, G; Blume, B; Brunner, F; Hirt, H; Kroj, T; Ligterink, W; Romanski, A; Nürnberger, T

    2000-06-01

    Cultured parsley (Petroselinum crispum) cells respond to treatment with elicitors derived from different species of the genus Phytophthora with transcript accumulation of defense-associated genes and the production of furanocoumarin phytoalexins. Pep-25, an oligopeptide fragment of a Phytophthora sojae 42-kDa cell wall protein, and a cell wall elicitor preparation derived from Phytophthora parasitica (Pp-elicitor) stimulate accumulation of the same gene transcripts and formation of the same pattern of furanocoumarins. Treatment of cultured cells and protoplasts with proteinase-digested Pp-elicitor identified proteinaceous constituents as active eliciting compounds in parsley. Similar to Pep- 25, Pp-elicitor induced effluxes of K+ and Cl- and influxes of protons and Ca2+. Concomitantly, as monitored in aequorin-transgenic parsley cell lines both elicitors induced an immediate increase in the cytoplasmic Ca2+ concentration up to sustained levels of 175 nM (Pp-elicitor) or 300 nM (Pep-25), respectively. The signature of the Ca2+ response differed greatly between the two elicitors tested. Extracellular Ca2+ proved essential for activation of an oxidative burst, MAP kinase activity and phytoalexin production by either elicitor. While Pp-elicitor induced a qualitatively similar spectrum of defense responses as did Pep-25, elicitor-specific quantitative differences in response intensity and kinetics suggest activation of a conserved signaling cascade through separate ligand binding sites.

  3. Copper treatment during storage reduces Phytophthora and Halophytophthora infection of Zostera marina seeds used for restoration

    Science.gov (United States)

    Govers, Laura L.; van der Zee, Els M.; Meffert, Johan P.; van Rijswick, Patricia C. J.; Man in ‘t Veld, Willem A.; Heusinkveld, Jannes H. T.; van der Heide, Tjisse

    2017-01-01

    Restoration is increasingly considered an essential tool to halt and reverse the rapid decline of vital coastal ecosystems dominated by habitat-forming foundation species such as seagrasses. However, two recently discovered pathogens of marine plants, Phytophthora gemini and Halophytophthora sp. Zostera, can seriously hamper restoration efforts by dramatically reducing seed germination. Here, we report on a novel method that strongly reduces Phytophthora and Halophytophthora infection of eelgrass (Zostera marina) seeds. Seeds were stored in seawater with three different copper sulphate concentrations (0.0, 0.2, 2.0 ppm) crossed with three salinities (0.5, 10.0, 25.0 ppt). Next to reducing seed germination, infection significantly affected cotyledon colour: 90% of the germinated infected seeds displayed a brown cotyledon upon germination that did not continue development into the seedling stage, in contrast to only 13% of the germinated non-infected seeds. Copper successfully reduced infection up to 86% and the 0.2 ppm copper sulphate treatment was just as successful as the 2.0 ppm treatment. Infection was completely eliminated at low salinities, but green seed germination was also dramatically lowered by 10 times. We conclude that copper sulphate treatment is a suitable treatment for disinfecting Phytophthora or Halophytophthora infected eelgrass seeds, thereby potentially enhancing seed-based restoration success. PMID:28225072

  4. Signatures of selection and host-adapted gene expression of the Phytophthora infestans RNA silencing suppressor PSR2.

    Science.gov (United States)

    de Vries, Sophie; von Dahlen, Janina K; Uhlmann, Constanze; Schnake, Anika; Kloesges, Thorsten; Rose, Laura E

    2017-01-01

    Phytophthora infestans is a devastating pathogen in agricultural systems. Recently, an RNA silencing suppressor (PSR2, 'Phytophthora suppressor of RNA silencing 2') has been described in P. infestans. PSR2 has been shown to increase the virulence of Phytophthora pathogens on their hosts. This gene is one of the few effectors present in many economically important Phytophthora species. In this study, we investigated: (i) the evolutionary history of PSR2 within and between species of Phytophthora; and (ii) the interaction between sequence variation, gene expression and virulence. In P. infestans, the highest PiPSR2 expression was correlated with decreased symptom expression. The highest gene expression was observed in the biotrophic phase of the pathogen, suggesting that PSR2 is important during early infection. Protein sequence conservation was negatively correlated with host range, suggesting host range as a driver of PSR2 evolution. Within species, we detected elevated amino acid variation, as observed for other effectors; however, the frequency spectrum of the mutations was inconsistent with strong balancing selection. This evolutionary pattern may be related to the conservation of the host target(s) of PSR2 and the absence of known corresponding R genes. In summary, our study indicates that PSR2 is a conserved effector that acts as a master switch to modify plant gene regulation early during infection for the pathogen's benefit. The conservation of PSR2 and its important role in virulence make it a promising target for pathogen management.

  5. Claritromicina associada com pirímetamina na toxoplasmose cerebral - relato de dois casos

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    Marcos Olivicr Dalston

    1995-12-01

    Full Text Available Os autores relatam a resposta terapêutica da claritromicina associada com pirímetamina em dois casos de toxoplasmose cerebral ocorridos em pacientes com Síndrome de Imunodeficiência Adquirida (SIDA. Nos dois casos o diagnóstico foi presuntivo, baseando-se nas manifestações clínicas e na presença de lesões expansivas hipercaptantes detectadas na tomografia computadorizada (TC de crânio. Em ambos os casos, observou-se exantema com o uso da sulfadiazina e da clindamicina, razão pela qual tais medicamentos foram substituídos pela claritromicina (1,5 a 2g/dia associada à pirímetamina (25mg/dia. A resposta terapêutica foi favorável nos dois casos com melhora das manifestações neurológicas e dos achados neurorradiológicos. Os autores sugerem que a associação claritromicina com pirímetamina pode ser útil como opção terapêutica na toxoplasmose cerebral em pacientes com SIDA que apresentam intolerância ou outra contra-indicação ao emprego das sulfonamidas.The authors report the use and tbe outcome of claritromycin associated with pyrimethamine in the treatment of toxoplasma encephalites in two patients with AIDS. Both patients had the diagnosis stablished on clinical grounds, positive sorology (IgG for toxoplasmosis and computed-tomographic (CT scan of the brain showing lesions consistent with T. gondii encephalitis. The two patients were initially treated with pyrimethamine and sulfadiazme, which was changed to clindamycin due to allergic reactions. These reactions (skin rash occurred with clindamycin as well and the patients were treated with claritromycin and pyrimethamine. The scheduled regimens were 1.5 to 2g of clarithromycin plus 25mg of pyrimethamine. The clinical response was very good in both cases with regression of neurologic signs and encephalitic abnormalities observed on CT scan. The authors suggest that clarithromycin associated with pyrimethamine may be an alternative treatment for toxoplasmosis in AIDS

  6. Ruptura de menisco associada à ruptura de ligamento cruzado cranial em cães

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    Cássio Ricardo Auada Ferrigno

    2012-08-01

    Full Text Available O trabalho descreve as lesões de menisco associadas com ruptura do ligamento cruzado cranial em 82 pacientes de diferentes raças, idades e pesos, com o objetivo de avaliar o tipo de ruptura de menisco associada a lesões do ligamento cruzado cranial. No período pré-operatório, os animais foram submetidos à avaliação clínica e radiológica. Todos os animais apresentaram ruptura total ou parcial do ligamento cruzado cranial; 21 (24,14% animais não apresentaram nenhuma lesão de menisco, os restantes (75,86% apresentaram apenas lesão no menisco medial. As lesões encontradas no menisco medial foram as seguintes: 33 joelhos (37,93% apresentaram eversão do corno caudal (Tipo 1; 15 (17,24% apresentaram lesão em alça de balde (Tipo 6; 3 (3,45% lesão de fibrilação (Tipo 4; 3 (3,45% ruptura longitudinal múltipla (Tipo 3; 3 (3,45% lesão longitudinal (Tipo 2; 1 (1,15% lesão tipo 7; e 10 (11,49 apresentaram lesões múltiplas. A meniscectomia parcial do menisco medial foi realizada em 63 (72,41% joelhos e a meniscectomia total em 3 (13,04%. O procedimento cirúrgico para a resolução da ruptura do ligamento cruzado cranial incluiu: avanço da tuberosidade tibial (TTA (49 joelhos, osteotomia niveladora do platô tibial (TPLO (15 joelhos, osteotomia em cunha da tíbia (CWO (14 joelhos, extracapsular (quatro joelhos e meniscectomia (cinco joelhos. Todos os casos evoluíram com o retorno à função habitual do membro pélvico acometido na primeira semana do período pós-operatório, e com a ausência de complicações. A alta porcentagem (75,86% de ruptura do menisco medial encontrada no presente trabalho demonstra a importância da avaliação prévia dos meniscos antes da realização da técnica de estabilização da articulação femorotibiopatelar.

  7. Comorbidities associated with epilepsy and headaches Comorbidades associadas às epilepsias e cefaleias

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    Thalles P. Ferreira

    2012-04-01

    Full Text Available Comorbidities are often associated with chronic neurological diseases, such as headache and epilepsy. OBJECTIVES: To identify comorbidities associated with epilepsy and headaches, and to determine possible drug interactions. METHODS: A standardized questionnaire with information about type of epilepsy/headache, medical history, and medication was administered to 80 adult subjects (40 with epilepsy and 40 with chronic headache. RESULTS: Patients with epilepsy had an average of two comorbidities and those with headache of three. For both groups, hypertension was the most prevalent. On average, patients with epilepsy were taking two antiepileptic medications and those with headache were taking only one prophylactic medication. Regarding concomitant medications, patients with epilepsy were in use, on average, of one drug and patients with headache of two. CONCLUSIONS: Patients with chronic neurological diseases, such as epilepsy and headaches, have a high number of comorbidities and they use many medications. This may contribute to poor adherence and interactions between different medications.As comorbidades geralmente estão associadas a doenças neurológicas crônicas, tais como cefaleia e epilepsia. OBJETIVOS: Identificar comorbidades associadas à epilepsia e cefaleia e determinar as possíveis interações de drogas. MÉTODOS: Questionário padronizado com informações sobre o tipo de epilepsia/cefaleia, os antecedentes médicos e as medicações foi aplicado a 80 indivíduos adultos (40 com epilepsia e 40 com cefaleia crônica. RESULTADOS: Pacientes com epilepsia e cefaleia apresentaram uma média de duas e três comorbidades, respectivamente, sendo, para ambos, hipertensão arterial sistêmica a mais prevalente. Em média, os pacientes com epilepsia estavam em uso de duas medicações antiepilépticas; aqueles com cefaleia, uma medicação profilática. Em relação às medicações concomitantes, os pacientes com epilepsia estavam em uso

  8. Fatores de risco e medidas preventivas das infecções associadas a cateteres venosos centrais

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    Viviane Rosado

    2011-12-01

    Full Text Available OBJETIVO: Rever os fatores de risco para infecção associada a cateteres venosos centrais e as recomendações para a sua prevenção. FONTES DOS DADOS: Foram revisados artigos publicados sobre o tema no PubMed, Cochrane Collaboration e Bireme. Os seguintes critérios de inclusão foram levados em consideração: trabalhos publicados entre 2000 e 2010, delineamento do estudo, população pediátrica hospitalizada com utilização de cateteres venosos centrais e artigos sobre infecção associada a cateteres venosos centrais. Além disso, foram utilizados documentos de referência dos Centers for Disease Control and Prevention e da Agência Nacional de Vigilância Sanitária. SÍNTESE DOS DADOS: Os fatores de risco associados foram: tempo de utilização de acesso central, duração da internação e uso de cateter central de longa permanência, colocação de cateter venoso central em Unidade de Terapia Intensiva, doença cardiovascular não cirúrgica, recebimento de nutrição parenteral e de transfusão de hemoderivados. Entre as medidas preventivas, a literatura recomenda a implementação de protocolos e diretrizes multidisciplinares de cuidados na inserção e manutenção dos cateteres centrais, cuidados com a técnica de inserção dos cateteres venosos centrais, utilização de curativos impregnados com clorexidina, retirada precoce do cateter e adoção de programas de educação continuada para a equipe assistencial. CONCLUSÃO: O controle dos fatores de risco pode levar a uma redução igual ou superior a 40% na incidência dessas infecções. A vigilância do processo de inserção e cuidados com os cateteres vasculares centrais na população pediátrica orienta a padronização de rotinas dos serviços de saúde para a obtenção de taxas de referência para comparação intra e interinstitucionais.

  9. Treinamento físico na distrofia muscular de becker associada à insuficiência cardíaca

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    Jean Marcelo Roque

    2011-12-01

    Full Text Available A distrofia muscular de Becker (DMB integra as distrofinopatias que ocorrem devido a mutações genéticas que expressam a proteína distrofina no cromossomo X. O início dos sintomas neuromusculares normalmente precede o comprometimento da função cardíaca, podendo acontecer inversamente pela insuficiência cardíaca (IC. O treinamento físico é bem estabelecido na IC, porém, quando associada à DMB, é controverso e sem fundamento científico. Apresentamos o caso de um paciente com DMB associada à IC em fila de transplante cardíaco submetido a um programa de treinamento físico.

  10. Acarofauna associada à vegetação espontânea de vinhedos

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    Raquel Bottini de Moura

    2013-09-01

    Full Text Available Objetivou-se identificar a acarofauna associada à vegetação espontânea presente em vinhedos de Vitis vinifera (L. var. Cabernet Sauvignon, Merlot e Sémillon e V. labrusca (L. var. Isabel. Amostragens mensais foram realizadas de junho a setembro/2009 e junho a setembro/2010 em Caxias do Sul e de junho/2010 a junho/2011 em Sant'Ana do Livramento, RS, Brasil. Foram registrados 474 ácaros pertencentes a 14 morfoespécies, nove gêneros e cinco famílias (Phytoseiidae, Tarsonemidae, Tenuipalpidae, Tydeidae e Winterschmidtiidae. A maior abundância de ácaros ocorreu em Caxias do Sul, entretanto a maior riqueza de espécies foi registrada em Sant'Ana do Livramento. De acordo com os resultados deste trabalho, a acarofauna presente nos nove vinhedos amostrados foi registrada em sua maioria em Sida rhombifolia L. e caracterizou-se pela ocorrência dominante de Lorryia sp., seguida por Typhlodromalus aripo (Muma, 1967 e Steneotarsonemus sp..

  11. Anoftalmia associada à catarata congênita: relato de caso Anophthalmia and congenital cataract: case report

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    Alessandro Santana

    2005-06-01

    Full Text Available Apresentação de um caso de anoftalmia e catarata congênita associada a malformações sistêmicas. Paciente, 6 meses, do sexo masculino, com anoftalmia à esquerda e catarata congênita polar posterior à direita. Instituiu-se terapêutica cirúrgica por meio de aspiração do núcleo e córtex com pequena incisão sem implante de lente intra-ocular, e capsulorrexe posterior com vitrectomia. A associação entre anoftalmia e catarata congênita é condição rara em que o diagnóstico e tratamento precoces são fundamentais para adequada reabilitação do paciente.The authors report a case of anophthalmia, congenital cataract and systemic malformations. Male patient, 6 months old, left anophthalmia and congenital posterior polar cataract in the right eye. The patient was treated with manual aspiration of the crystalline lens, with no intraocular lens implantation with primary posterior capsulorhexis and anterior vitrectomy through a small incision. The association of anophthalmia and congenital cataract is rare. The early diagnosis and management in these cases is very important for the best visual rehabilitation.

  12. Amyloidotic muscle pseudohypertrophy: case report Pseudo-hipertrofia muscular associada com amiloidose: relato de caso

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    Rosana Herminia Scola

    2001-09-01

    Full Text Available The authors report one case of amyloidosis associated with muscular pseudohypertrophy in a 46-year-old woman, who developed weakness, macroglossia and muscle hypertrophy associated with primary systemic amyloidosis. Electromyography showed a myopathic pattern and bilateral carpal tunnel syndrome. The muscle biopsy presented with a type I and II fiber hypertrophy and infiltration of amyloid material in the interstitious space and artery walls. She underwent bone marrow transplantation with stabilization and subjective improvement of the clinical picture.Descreve-se um caso de pseudo-hipertrofia muscular associada a amiloidose primária em uma paciente do sexo feminino, com 46 anos, que apresentava astenia e macroglossia. O estudo eletromiográfico mostrou padrão miopático e síndrome do túnel do carpo, bilateral. A biópsia muscular revelou hipertrofia de fibras tipo I e II, com infiltração de material amilóide no interstício e parede dos vasos, principalmente arteriais. A paciente foi submetida a transplante autólogo de medula óssea, evoluindo com estabilização do quadro e um sentimento subjetivo de melhora.

  13. Dor crônica associada à AIDS: perspectiva de enfermeiros e médicos

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    Roberta Meneses Oliveira

    2014-01-01

    Full Text Available Objetivou-se identificar as características e o manejo da dor crônica associada à síndrome da imunodeficiência adquirida (AIDS na perspectiva de enfermeiros e médicos. Estudo qualitativo realizado em hospital de referência de Fortaleza-CE, Brasil, com 20 profissionais. Aplicou-se entrevista semiestruturada e os discursos foram analisados pela técnica de análise de conteúdo de Bardin, emergindo três categorias: Caracterização da dor; Avaliação clínica da dor; e Cuidado Clínico da dor. Encontrou-se que a dor na AIDS manifesta-se como persistente, incapacitante e de difícil controle, sendo seu manejo baseado na identificação acurada dos fatores causais e na implementação do tratamento farmacológico e não farmacológico prestado pela equipe interdisciplinar. O estudo traz dados relevantes sobre a dor em pacientes com AIDS hospitalizados, demonstrando a necessidade de repensar o modelo gerencial de cuidado para promover intervenções de maior eficácia analgésica e de aprimorar o atendimento interdisciplinar à dor para sua melhor avaliação e tratamento.

  14. Polimiosite associada à síndrome nefrótica Polymyositis associated with nephrotic syndrome

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    Renato Oliveira Freire

    2010-08-01

    Full Text Available A polimiosite (PM é uma doença sistêmica do grupo das miopatias inflamatórias idiopáticas, clinicamente caracterizada por fraqueza muscular proximal e simétrica. Há relatos na literatura de PM associada a neoplasias, doenças autoimunes e infecções virais. Entretanto, a associação entre PM e nefropatia não é frequente. Descrevemos o caso de um paciente com polimiosite que evoluiu com síndrome nefrótica devido à presença de glomerulonefrite mesangialPolymyositis (PM is a systemic disease of the idiopathic inflammatory myopathy group, clinically characterized by symmetric and proximal muscle weakness. There are reports in literature of PM associated with malignancies, autoimmune diseases, and viral infections. However, the association between PM and nephropathy is not common. We describe a case report of a patient with polymyositis who developed nephrotic syndrome due to mesangial glomerulonephritis

  15. Uso da eritropoetina recombinante humana no tratamento da anemia associada à insuficiência renal crônica

    OpenAIRE

    Carvalho, Mauricio de

    2013-01-01

    Resumo: A anemia acompanha a insuficiencia renal cronica e esta presente na maioria dos pacientes em dialise. O objetivo deste estudo foi analisar o efeito de seis meses de tratamento com a eritropoetina recombinante humana (EPO-rHu) na anemia associada a insuficiencia renal cronica terminal em vinte pacientes mantidos em programa de hemodialise. Os criterios de inclusao foram: pacientes que estivessem em hemodialise por pelo menos 3 meses, com idade maior que 18 ou menor que 70 anos; hematoc...

  16. Antagonistic in vitro activity of Trichoderma spp. isolates to the fungi Phytophthora citrophthora / Atividade antagônica in vitro de isolados de Trichoderma spp. ao fungo Phytophthora citrophthora

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    Cleiton Gredson Sabin Benett

    2008-07-01

    Full Text Available Gummosis is among the main fungal diseases of the citrus. It is caused by Phytophthora sp. and usually shows up in the lap of the plant, provoking rottenness and gum exudation, and expands causing the plant death for constrictions in the cambium or phloem which interrupts the descending fow of sap. The objective of this work was to evaluate the antagonistic in vitro activity of Trichoderma spp. to the fungi Phytophthora citrophthora. Phytophthora citrophthora was exposed to fve environments of antagonism (without antagonist and with four strains of Trichoderma viride, T. virens, T. harzianu and T. stromaticum. The in vitro essay was accomplished through the method of paired cultures. A completely randomized desing was used with fve treatments and three replications, and each plot was represented by three petri dishes. The isolates of Trichoderma demonstrated signifcant effect in the inhibition of the mycelial growth of the fungi Phytophthora citrophthora, and the fungi Trichoderma stromaticum presented larger antagonism to the fungi P. citrophthora while the T. harzianum presented antagonism smaller.A citricultura nacional apresenta inúmeras pragas e doenças que limitam sua produção dentre as principais doenças fúngicas da cultura dos citros pode se destacar a gomose. A gomose causada por Phytophthora sp. geralmente se manifesta no colo da planta, provocando podridão e exsudação de goma, podendo expandir-se ocasionando a morte da planta por estrangulamento devido ao ataque do cambio ou foema, o que interrompe o fuxo descendente de seiva. Este trabalho foi realizado com o objetivo de se avaliar a atividade antagônica in vitro, de isolados de Trichoderma spp. ao fungo Phytophthora citrophthora. O fator em estudo foi um patógeno (Phytophthora citrophthora em cinco ambientes de antagonismo (sem antagonista e com os isolados de Trichoderma viride, T. virens, T. harzianu e T. stromaticum. O ensaio in vitro foi realizado por meio do m

  17. Influence of the toxin of Phytophthora capsici for the microconstruction of pumpkin leaves%南瓜疫病菌(Phytophthora capsici)毒素对寄主叶片超微结构的影响

    Institute of Scientific and Technical Information of China (English)

    马丽艳; 张俊华; 崔崇士

    2006-01-01

    文章对南瓜疫病菌(Phytophthora capsici)进行了毒素提取,并用该毒素处理南瓜幼苗,然后观察南瓜叶片超微结构变化.Phytophthora capsici毒素处理后,随着其浓度的增加和处理时间的延长,细胞质壁分离严重,质膜断裂;叶绿体膨胀严重,膜消失,基粒片层紊乱;线粒体膜、脊被破坏;核膜不均一.

  18. Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis.

    Science.gov (United States)

    Larroque, Mathieu; Belmas, Elodie; Martinez, Thomas; Vergnes, Sophie; Ladouce, Nathalie; Lafitte, Claude; Gaulin, Elodie; Dumas, Bernard

    2013-09-01

    The cellulose binding elicitor lectin (CBEL) of the genus Phytophthora induces necrosis and immune responses in several plant species, including Arabidopsis thaliana. However, the role of CBEL-induced responses in the outcome of the interaction is still unclear. This study shows that some of CBEL-induced defence responses, but not necrosis, required the receptor-like kinase BAK1, a general regulator of basal immunity in Arabidopsis, and the production of a reactive oxygen burst mediated by respiratory burst oxidases homologues (RBOH). Screening of a core collection of 48 Arabidopsis ecotypes using CBEL uncovered a large variability in CBEL-induced necrotic responses. Analysis of non-responsive CBEL lines Ws-4, Oy-0, and Bla-1 revealed that Ws-4 and Oy-0 were also impaired in the production of the oxidative burst and expression of defence genes, whereas Bla-1 was partially affected in these responses. Infection tests using two Phytophthora parasitica strains, Pp310 and Ppn0, virulent and avirulent, respectively, on the Col-0 line showed that BAK1 and RBOH mutants were susceptible to Ppn0, suggesting that some immune responses controlled by these genes, but not CBEL-induced cell death, are required for Phytophthora parasitica resistance. However, Ws-4, Oy-0, and Bla-1 lines were not affected in Ppn0 resistance, showing that natural variability in CBEL responsiveness is not correlated to Phytophthora susceptibility. Overall, the results uncover a BAK1- and RBOH-dependent CBEL-triggered immunity essential for Phytophthora resistance and suggest that natural quantitative variation of basal immunity triggered by conserved general elicitors such as CBEL does not correlate to Phytophthora susceptibility.

  19. Causas básicas e associadas de morte por Aids, Estado de São Paulo, Brasil, 1998

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    Santo Augusto Hasiak

    2000-01-01

    Full Text Available OBJETIVOS: Descrever o padrão da mortalidade devida a Aids segundo causas básica e associadas de morte no Estado de São Paulo, em 1998. MÉTODOS: Os dados sobre a mortalidade e a população residente no Estado de São Paulo, SP, para 1998, foram obtidos na Fundação Sistema Estadual de Análise de Dados (Seade. As causas de morte foram codificadas pelas disposições da Décima Revisão da Classificação Estatística Internacional de Doenças e Problemas Relacionados à Saúde. Os registros de Aids como causa básica e associada de morte foram recuperados e revistos. RESULTADOS: A Aids foi a causa básica em 4.619 mortes, correspondendo à décima causa (2,0% e ao coeficiente de mortalidade de 13,1 por 100.000 habitantes. As razões das mortes e os respectivos coeficientes entre homens e mulheres foram de 2,4 e 2,5. A Aids foi a segunda causa entre os homens de 20 a 34 anos de idade e entre as mulheres de 25 a 34. A idade média ao morrer entre as mulheres (34,1±12,2 anos foi estatisticamente menor que a dos homens (36,4±10,7 anos -- p<0,001. As principais causas associadas em mortes por Aids foram a insuficiência respiratória (36,1%, pneumonias (27,0%, tuberculose (19,6%, septicemias (18,6%, toxoplasmose (12,2%, pneumonia por P. carinii (8,3% e caquexia (7,9%. A Aids apresentou-se como causa associada em outras 84 mortes. As principais causas básicas destas mortes foram neoplasias malignas (28/84, afecções devidas ao uso do álcool (23/84 e diabetes mellitus (7/84. A idade média ao morrer por Aids como causa básica (35,7±11,2 anos foi estatisticamente menor que a idade média nas mortes em que Aids foi mencionada como causa associada (39,9±11,8 anos -- p<0,001. CONCLUSÕES: As causas múltiplas de morte resgatam parcialmente a história natural da Aids e oferecem subsídios para medidas preventivas adequadas e específicas.

  20. The CAZyome of Phytophthora spp.: A comprehensive analysis of the gene complement coding for carbohydrate-active enzymes in species of the genus Phytophthora

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    Laird Emma W

    2010-09-01

    Full Text Available Abstract Background Enzymes involved in carbohydrate metabolism include Carbohydrate esterases (CE, Glycoside hydrolases (GH, Glycosyl transferases (GT, and Polysaccharide lyases (PL, commonly referred to as carbohydrate-active enzymes (CAZymes. The CE, GH, and PL superfamilies are also known as cell wall degrading enzymes (CWDE due to their role in the disintegration of the plant cell wall by bacterial and fungal pathogens. In Phytophthora infestans, penetration of the plant cells occurs through a specialized hyphal structure called appressorium; however, it is likely that members of the genus Phytophthora also use CWDE for invasive growth because hyphal forces are below the level of tensile strength exhibited by the plant cell wall. Because information regarding the frequency and distribution of CAZyme coding genes in Phytophthora is currently unknown, we have scanned the genomes of P. infestans, P. sojae, and P. ramorum for the presence of CAZyme-coding genes using a homology-based approach and compared the gene collinearity in the three genomes. In addition, we have tested the expression of several genes coding for CE in cultures grown in vitro. Results We have found that P. infestans, P. sojae and P. ramorum contain a total of 435, 379, and 310 CAZy homologs; in each genome, most homologs belong to the GH superfamily. Most GH and PL homologs code for enzymes that hydrolyze substances present in the pectin layer forming the middle lamella of the plant cells. In addition, a significant number of CE homologs catalyzing the deacetylation of compounds characteristic of the plant cell cuticle were found. In general, a high degree of gene location conservation was observed, as indicated by the presence of sequential orthologous pairs in the three genomes. Such collinearity was frequently observed among members of the GH superfamily. On the other hand, the CE and PL superfamilies showed less collinearity for some of their putative members

  1. Estudo temporal das doenças associadas à AIDS no Brasil, 1980-1999

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    Mark Drew Crosland Guimarães

    Full Text Available Neste trabalho foram estimadas as incidências de condições associadas (CA à AIDS/100 casos de AIDS em adultos (> 12 anos, a nível nacional, de 1980 a maio de 1999. A análise incluiu qui-quadrado e regressão linear simples. As CA analisadas foram candidíase (CD, tuberculose (TB, pneumonia por Pneumocystis carinii (PCP, neurotoxoplasmose(NT, Herpes, Sarcoma de Kaposi (SK, meningite criptocócica (MC e infecções por protozoários (IP. As incidências acumuladas/100 casos de AIDS foram: CD = 59, TB = 26, PCP = 23, NT = 15, Herpes = 12, SK = 5, MC = 4 e IP = 4. A tendência anual indicou queda estatisticamente significativa em todas as CA. Entretando, houve aumento na incidência de TB (b = 0,39 e NT (b = 0,20, para as regiões Nordeste e Centro-Oeste, respectivamente. TB apresentou maior incidência entre aqueles com baixa escolaridade (< 8 anos, enquanto que PCP e SK tiveram maiores incidências entre aqueles com melhor escolaridade (8+ anos, apesar de declínios semelhantes. Acesso à terapia anti-retroviral e profilaxias para as CA explicam parcialmente estes resultados. Entretanto, a confiabilidade dos dados, o atraso na notificação, a incidência de CA pós-AIDS, bem como os critérios de notificação e diagnóstico, são fatores que devem ser avaliados.

  2. Estudo temporal das doenças associadas à AIDS no Brasil, 1980-1999

    Directory of Open Access Journals (Sweden)

    Guimarães Mark Drew Crosland

    2000-01-01

    Full Text Available Neste trabalho foram estimadas as incidências de condições associadas (CA à AIDS/100 casos de AIDS em adultos (> 12 anos, a nível nacional, de 1980 a maio de 1999. A análise incluiu qui-quadrado e regressão linear simples. As CA analisadas foram candidíase (CD, tuberculose (TB, pneumonia por Pneumocystis carinii (PCP, neurotoxoplasmose(NT, Herpes, Sarcoma de Kaposi (SK, meningite criptocócica (MC e infecções por protozoários (IP. As incidências acumuladas/100 casos de AIDS foram: CD = 59, TB = 26, PCP = 23, NT = 15, Herpes = 12, SK = 5, MC = 4 e IP = 4. A tendência anual indicou queda estatisticamente significativa em todas as CA. Entretando, houve aumento na incidência de TB (b = 0,39 e NT (b = 0,20, para as regiões Nordeste e Centro-Oeste, respectivamente. TB apresentou maior incidência entre aqueles com baixa escolaridade (< 8 anos, enquanto que PCP e SK tiveram maiores incidências entre aqueles com melhor escolaridade (8+ anos, apesar de declínios semelhantes. Acesso à terapia anti-retroviral e profilaxias para as CA explicam parcialmente estes resultados. Entretanto, a confiabilidade dos dados, o atraso na notificação, a incidência de CA pós-AIDS, bem como os critérios de notificação e diagnóstico, são fatores que devem ser avaliados.

  3. Resistência antimicrobiana associada em isolados clínicos de Enterococcus spp

    Directory of Open Access Journals (Sweden)

    Cláudia Castelo Branco Artiaga Kobayashi

    2011-06-01

    Full Text Available INTRODUÇÃO: O aumento da prevalência de isolados de enterococos em hospitais, particularmente Enterococcus resistente à vancomicina (VRE, é importante por causa da limitada terapia antimicrobiana efetiva para o tratamento de infecções enterocócicas. MÉTODOS: O presente trabalho apresentou uma investigação retrospectiva de dados de suscetibilidade in vitro quantitativa para uma variedade de antimicrobianos frente aos isolados de Enterococcus spp. e avaliação da associação de resistência entre os agentes antimicrobianos apontados como escolha para o tratamento de infecções causadas por VRE, através do cálculo do risco relativo. RESULTADOS: Dos 156 isolados de enterococos, 40 (25,6% foram resistentes a três ou mais antimicrobianos, incluindo 7,7% (n = 12/156 resistentes à vancomicina. A associação de resistência elevada foi mais pronunciada entre os isolados de VREs com antimicrobianos alternativos e primários para o tratamento de infecções causadas por estes patógenos, incluindo ampicilina (100%, RR = 7,2, estreptomicina (90,9%, RR = 4,9, rifampicina (91,7%, RR = 3,1 e linezolida (50%, RR = 11,5, apesar da alta taxa de suscetibilidade a esta droga (94,9%. CONCLUSÕES: A resistência associada significativa aos antimicrobianos de primeira escolha e alternativos, usados no tratamento de infecções graves por cepas com o fenótipo VRE e que requerem um regime terapêutico combinado, evidencia alternativas terapêuticas ainda mais limitadas na instituição analisada.

  4. Caquexia associada à insuficiência cardíaca Heart failure-induced cachexia

    Directory of Open Access Journals (Sweden)

    Marina Politi Okoshi

    2013-05-01

    Full Text Available Pacientes com insuficiência cardíaca frequentemente desenvolvem estado de caquexia, que constitui fator independente de redução da sobrevida. Caquexia pode ser diagnosticada quando ocorre perda de peso corporal maior que 6% do peso habitual, na ausência de outras doenças. Embora sua fisiopatologia não esteja completamente esclarecida, vários fatores parecem estar envolvidos, como diminuição da ingestão alimentar, anormalidades do trato gastrointestinal, ativação imunológica e neuro-hormonal e alteração da relação entre processos anabólicos e catabólicos. Como não há terapia específica para a caquexia associada à insuficiência cardíaca, o tratamento baseia-se no suporte nutricional, bloqueio neuro-hormonal, controle do edema e anemia e exercícios físicos. Fármacos com propriedades imunomodulatórias e anabólicas encontram-se em investigação clínica e experimental.Heart failure patients often develop cachexia, which is an independent factor for survival reduction. Cachexia can be diagnosed when there is loss of more than 6% of the body weight, in the absence of other diseases. Even though its pathophysiology has not yet been completely clarified, various factors seem to be involved, such as reduction in food consumption, gastrointestinal tract abnormalities, immunologic and neuro-hormonal activarion and changes in the relationship between anabolic and catabolic processes. Since there is not specific therapy for heart failure-induced cachexia, management is based on nutritional support, neuro-hormonal blockade, control of edema and anemia and exercise. Drugs with anabolic and immunomodulating properties are being evaluated and clinical and non-clinical trials.

  5. Phytophthora have distinct endogenous small RNA populations that include short interfering and microRNAs.

    Directory of Open Access Journals (Sweden)

    Noah Fahlgren

    Full Text Available In eukaryotes, RNA silencing pathways utilize 20-30-nucleotide small RNAs to regulate gene expression, specify and maintain chromatin structure, and repress viruses and mobile genetic elements. RNA silencing was likely present in the common ancestor of modern eukaryotes, but most research has focused on plant and animal RNA silencing systems. Phytophthora species belong to a phylogenetically distinct group of economically important plant pathogens that cause billions of dollars in yield losses annually as well as ecologically devastating outbreaks. We analyzed the small RNA-generating components of the genomes of P. infestans, P. sojae and P. ramorum using bioinformatics, genetic, phylogenetic and high-throughput sequencing-based methods. Each species produces two distinct populations of small RNAs that are predominantly 21- or 25-nucleotides long. The 25-nucleotide small RNAs were primarily derived from loci encoding transposable elements and we propose that these small RNAs define a pathway of short-interfering RNAs that silence repetitive genetic elements. The 21-nucleotide small RNAs were primarily derived from inverted repeats, including a novel microRNA family that is conserved among the three species, and several gene families, including Crinkler effectors and type III fibronectins. The Phytophthora microRNA is predicted to target a family of amino acid/auxin permeases, and we propose that 21-nucleotide small RNAs function at the post-transcriptional level. The functional significance of microRNA-guided regulation of amino acid/auxin permeases and the association of 21-nucleotide small RNAs with Crinkler effectors remains unclear, but this work provides a framework for testing the role of small RNAs in Phytophthora biology and pathogenesis in future work.

  6. Phytophthora have distinct endogenous small RNA populations that include short interfering and microRNAs.

    Science.gov (United States)

    Fahlgren, Noah; Bollmann, Stephanie R; Kasschau, Kristin D; Cuperus, Josh T; Press, Caroline M; Sullivan, Christopher M; Chapman, Elisabeth J; Hoyer, J Steen; Gilbert, Kerrigan B; Grünwald, Niklaus J; Carrington, James C

    2013-01-01

    In eukaryotes, RNA silencing pathways utilize 20-30-nucleotide small RNAs to regulate gene expression, specify and maintain chromatin structure, and repress viruses and mobile genetic elements. RNA silencing was likely present in the common ancestor of modern eukaryotes, but most research has focused on plant and animal RNA silencing systems. Phytophthora species belong to a phylogenetically distinct group of economically important plant pathogens that cause billions of dollars in yield losses annually as well as ecologically devastating outbreaks. We analyzed the small RNA-generating components of the genomes of P. infestans, P. sojae and P. ramorum using bioinformatics, genetic, phylogenetic and high-throughput sequencing-based methods. Each species produces two distinct populations of small RNAs that are predominantly 21- or 25-nucleotides long. The 25-nucleotide small RNAs were primarily derived from loci encoding transposable elements and we propose that these small RNAs define a pathway of short-interfering RNAs that silence repetitive genetic elements. The 21-nucleotide small RNAs were primarily derived from inverted repeats, including a novel microRNA family that is conserved among the three species, and several gene families, including Crinkler effectors and type III fibronectins. The Phytophthora microRNA is predicted to target a family of amino acid/auxin permeases, and we propose that 21-nucleotide small RNAs function at the post-transcriptional level. The functional significance of microRNA-guided regulation of amino acid/auxin permeases and the association of 21-nucleotide small RNAs with Crinkler effectors remains unclear, but this work provides a framework for testing the role of small RNAs in Phytophthora biology and pathogenesis in future work.

  7. Evidence for homoploid speciation in Phytophthora alni supports taxonomic reclassification in this species complex.

    Science.gov (United States)

    Husson, C; Aguayo, J; Revellin, C; Frey, P; Ioos, R; Marçais, B

    2015-04-01

    Alder decline has been a problem along European watercourses since the early 1990s. Hybridization was identified as the main cause of this emerging disease. Indeed, the causal agent, a soil-borne pathogen named Phytophthora alni subsp. alni (Paa) is the result of interspecific hybridization between two taxa, Phytophthora alni subsp. multiformis (Pam) and Phytophthora alni subsp. uniformis (Pau), initially identified as subspecies of Paa. The aim of this work was to characterize the ploidy level within the P. alni complex that is presently poorly understood. For that, we used two complementary approaches for a set of 31 isolates of Paa, Pam and Pau: (i) quantification of allele copy number of three single-copy nuclear genes using allele-specific real-time PCR and (ii) comparison of the genome size estimated by flow cytometry. Relative quantification of alleles of the three single-copy genes showed that the copy number of a given allele in Paa was systematically half that of its parents Pau or Pam. Moreover, DNA content estimated by flow cytometry in Paa was equal to half the sum of those in Pam and Pau. Our results therefore suggest that the hybrid Paa is an allotriploid species, containing half of the genome of each of its parents Pam and Pau, which in turn are considered to be allotetraploid and diploid, respectively. Paa thus results from a homoploid speciation process. Based on published data and on results from this study, a new formal taxonomic name is proposed for the three taxa Paa, Pam and Pau which are raised to species status and renamed P. ×alni, P. ×multiformis and P. uniformis, respectively.

  8. Intracellular and extracellular phosphatidylinositol 3-phosphate produced by Phytophthora species is important for infection.

    Science.gov (United States)

    Lu, Shan; Chen, Linlin; Tao, Kai; Sun, Nannan; Wu, Yuren; Lu, Xiaoxue; Wang, Yuanchao; Dou, Daolong

    2013-09-01

    RxLR effectors produced by Phytophthora pathogens have been proposed to bind to phosphatidylinositol 3-phosphate (PtdIns(3)P) to mediate their translocation into host cells and/or to increase their stability in planta. Since the levels of PtdIns(3)P in plants are low, we examined whether Phytophthora species may produce PtdIns(3)P to promote infection. We observed that PtdIns(3)P-specific GFP biosensors could bind to P. parasitica and P. sojae hyphae during infection of Nicotiana benthamiana leaves transiently secreting the biosensors, suggesting that the hyphae exposed PtdIns(3)P on their plasma membrane and/or secreted PtdIns(3)P. Silencing of the phosphatidylinositol 3-kinases (PI3K) genes, treatment with LY294002, or expression of PtdIns(3)P-binding proteins by P. sojae reduced the virulence of the pathogen on soybean, indicating that pathogen-synthesized PtdIns(3)P was required for full virulence. Secretion of PtdIns(3)P-binding proteins or of a PI3P-5-kinase by N. benthamiana leaves significantly increased the level of resistance to infection by P. parasitica and P. capsici. Together, our results support the hypothesis that Phytophthora species produce external PtdIns(3)P to aid in infection, such as to promote entry of RxLR effectors into host cells. Our results derived from P. sojae RxLR effector Avr1b confirm that both the N-terminus and the C-terminus of this effector can bind PtdIns(3)P.

  9. Phytophthora infestans has a plethora of phospholipase D enzymes including a subclass that has extracellular activity.

    Directory of Open Access Journals (Sweden)

    Harold J G Meijer

    Full Text Available In eukaryotes phospholipase D (PLD is involved in many cellular processes. Currently little is known about PLDs in oomycetes. Here we report that the oomycete plant pathogen Phytophthora infestans has a large repertoire of PLDs divided over six subfamilies: PXPH-PLD, PXTM-PLD, TM-PLD, PLD-likes, and type A and B sPLD-likes. Since the latter have signal peptides we developed a method using metabolically labelled phospholipids to monitor if P. infestans secretes PLD. In extracellular medium of ten P. infestans strains PLD activity was detected as demonstrated by the production of phosphatidic acid and the PLD specific marker phosphatidylalcohol.

  10. Analysis on Genotypic Differentiation of Phytophthora infestans by Using Random Amplified Polymorphic DNA (RAPD)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A total of 104 isolates including two Korean isolates and three Japanese isolates of Phytophthora infestans collected from Heilongjiang and Jilin Provinces from 2006 to 2008 were used to determine their mating types,metalaxyl resistance,and RAPD genotypes.All the isolates of P.infestans collected from Heilongjiang and Jilin Provinces belonged to A 1 mating type,and no A 2 mating type was detected.Frequencies of metalaxyl resistant isolates were 94.4%,47.8% and 75.0% in 2006,2007 and 2008,respectively.Accord...

  11. Phytophthora tropicalis on Hedera helix and Epipremnum aureum in Polish greenhouses.

    Science.gov (United States)

    Orlikowski, L B; Trzewik, A; Wiejacha, K

    2006-01-01

    Phytophthora tropicalis was isolated from Hedera helix and Epipremnum aureum showing discoloration of leaves, necrosis of shoot base, spread upwards and on roots. The species was detected from 7/8 plants of Hedera and 3/4 of Epipremnum. Additionally Botrytis cinerea, Fusarium avenaceum and Rhizoctonia solani were recovered from some of diseased plants. P. tropicalis caused leaf necrosis of 13 plant species and tomato seedlings. The quickest spread of necrosis was observed on leaves of Peperomia magnoliaefolia, Pelargonium zonale and Phalaenopsis x hybridum. The disease developed at temperature ranged from 10 degrees to 32.5 degrees C with optimum 30 degrees C.

  12. Stage-specific gene expression during sexual development in Phytophthora infestans

    DEFF Research Database (Denmark)

    Fabritius, Anna-Liisa; Cvitanich, Cristina; Judelson, Howard S.

    2002-01-01

    Eight genes that are upregulated during sexual development in the heterothallic oomycete, Phytophthora infestans, were identified by suppression subtractive hybridization. Two genes showed very low but detectable expression in vegetative hyphae and became induced about 40- to >100-fold early...... in mating, before gametangial initials appeared. The remaining six loci were not induced until later in mating, coincident with the formation of gametangia and oospores, with induction levels ranging from 60- to >100-fold. Five genes were single copy, and three were members of families. Sequence analysis...

  13. Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere

    OpenAIRE

    Jin, Fengli; Ding, Yanqin; Ding, Wei; Reddy, M. S.; Fernando, W. G. Dilantha; Du,Binghai

    2011-01-01

    The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were i...

  14. Preemergence infection of potato sprouts by Phytophthora infestans in the highland tropics of Ecuador

    DEFF Research Database (Denmark)

    Kromann, Peter; Taipe, Arturo; Andrade-Piedra, Jorge L.

    2008-01-01

    Experiments were conducted to determine whether preemergence infection of potato sprouts by Phytophthora infestans occurs in the highland tropics of Ecuador. In three separate experiments in the field, P. infestans was identified on the preemerged sprouts of 49, 5, and 43% of tubers, respectively...... over 24 h in the field. Deposition had been measured at 1 m from a severely infected potato plot. Our study demonstrated the potential for preemergence infection of potato sprouts by P. infestans in the highlands of Ecuador, where year-round aerial inoculum is present. Preemergence infection...

  15. Population structure of the emerging plant pathogen Phytophthora ramorum on the west coast of the United States

    Science.gov (United States)

    S. Prospero; E.M. Hansen; N.J. Grünwald; J. Britt; L.M. Winton.

    2009-01-01

    Phytophthora ramorum is a devastating pathogen in native forests in California and southwestern Oregon and in nursery crops in California, Oregon and Washington. In this study we analyzed the population structure of P. ramorum in the west coast (CA, OR, and WA) of the United States by screening 579 isolates recovered...

  16. Assessment of SIMBLIGHT1, SIMPHYT1, and NOBLIGHT models for predicting Phytophthora infestans in the northeastern U.S.

    Science.gov (United States)

    Accurate prediction of Phytophthora infestans outbreaks is crucial for effective late blight management. The SIMBLIGHT1, SIMPHYT1, and modified SIMPHYT1 models were assessed for predicting late blight outbreaks relative to the NOBLIGHT model using climatic data from field experiments at Presque Isle...

  17. Genetic variation within clonal lineages of Phytophthora infestans revealed through genotyping-by-sequencing, and implications for late blight epidemiology

    Science.gov (United States)

    Genotyping-by-sequencing (GBS) was performed on 257 Phytophthora infestans isolates belonging to four clonal lineages to study within-lineage diversity. The four lineages used in the study included US-8 (n=28), US-11 (n=27), US-23 (n=166), and US-24 (n=36), with isolates originating from 23 of the U...

  18. Effectiveness of SIMBLIGHT1 and SIMPHYT1 models for predicting Phytophthora infestans in the Northeastern United States

    Science.gov (United States)

    Accurate prediction of Phytophthora infestans outbreaks is crucial for effective late blight management. The SIMBLIGHT1, SIMPHYT1, and modified SIMPHYT1 models were assessed for predicting late blight outbreaks relative to the NOBLIGHT model using climatic data from field experiments at Presque Isle...

  19. Fungicide sensitivity of US genotypes of Phytophthora infestans (Mont.) de Bary to six oomycete-targeted compounds.

    Science.gov (United States)

    Phytophthora infestans (Mont.) de Bary causes potato late blight, an important and costly disease of potato and tomato crops. The baseline sensitivity of recent clonal lineages of P. infestans was tested for six oomycete-targeted fungicides. Forty five isolates collected between 2004 and 2012 were t...

  20. Determination of virulence contributions from Phytophthora infestans effectors IPI-O1 and IPI-O4

    Science.gov (United States)

    Potato late blight, caused by the oomycete pathogen Phytophthora infestans, is one of the most destructive plant diseases. Despite decades of intensive breeding efforts, it remains a threat to potato production worldwide, in part because newly evolved pathogen isolates quickly overcome major resista...

  1. Presence of the potato late blight resistance gene RB does not promote adaptive parasitism of phytophthora infestans

    Science.gov (United States)

    The gene RB is derived from the wild potato species S. bulbocastanum and confers partial resistance to late blight, caused by the oomycete pathogen Phytophthora infestans. In order to investigate whether a single strain of P. infestans can adapt to overcome this partial resistance source, we subject...

  2. Interaction between the moss Physcomitrella patens and Phytophthora: a novel pathosystem for live-cell imaging of subcellular defence.

    Science.gov (United States)

    Overdijk, Elysa J R; DE Keijzer, Jeroen; DE Groot, Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

    2016-08-01

    Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for visualizing interactions with the pathogen over time using high-resolution microscopy. We tested four Phytophthora species for their ability to infect P. patens and showed that P. sojae and P. palmivora were only rarely capable to infect P. patens. In contrast, P. infestans and P. capsici frequently and successfully penetrated moss protonemal cells, showed intracellular hyphal growth and formed sporangia. Next to these successful invasions, many penetration attempts failed. Here the pathogen was blocked by a barrier of cell wall material deposited in papilla-like structures, a defence response that is common in higher plants. Another common response is the upregulation of defence-related genes upon infection and also in moss we observed this upregulation in tissues infected with Phytophthora. For more advanced analyses of the novel pathosystem we developed a special set-up that allowed live-cell imaging of subcellular defence processes by high-resolution microscopy. With this set-up, we revealed that Phytophthora infection of moss induces repositioning of the nucleus, accumulation of cytoplasm and rearrangement of the actin cytoskeleton, but not of microtubules.

  3. Phenotypic diversification is associated with host-induced transposon derepression in the sudden oak death pathogen Phytophthora ramorum

    Science.gov (United States)

    T. Kasuga; M. Kozanitas; M. Bui; D. Huberli; D. M. Rizzo; M. Garbelotto

    2012-01-01

    The oomycete pathogen Phytophthora ramorum is responsible for sudden oak death (SOD) in California coastal forests. P. ramorum is a generalist pathogen with over 100 known host species. Three or four closely related genotypes of P. ramorum (from a single lineage) were...

  4. Pathogenicity of Phytophthora austrocedrae on Austrocedrus chilensis and its relation with mal del ciprés in Patagonia

    Science.gov (United States)

    A. G. Greslebin; E. M. Hansen

    2010-01-01

    Field observations, isolations and pathogenicity tests were performed on Austrocedrus chilensis (Cupressaceae) trees to determine the pathogenicity of Phytophthora austrocedrae and its role in the aetiology of the cypress disease mal del ciprés (MDC) in Argentina. It was found that P. austrocedrae...

  5. Real-time PCR assay to distinguish the four Phytophthora ramorum lineages using cellulose binding elicitor lectin (CBEL) locus

    Science.gov (United States)

    Phytophthora ramorum is a pathogenic oomycete responsible for causing sudden oak death in the Western United States and sudden larch death in the United Kingdom. This pathogen has so far caused extensive mortality of oak and tanoak in California and of Japanese larch in the United Kingdom. Until rec...

  6. Factors influencing Phytophthora ramorum infectivity on Umbellularia californica and testing of a defoliation-based control method

    Science.gov (United States)

    Christine Windsor Colijn; Michael Cohen; Steve Johnston; Whalen Dillon; Nathan Rank

    2013-01-01

    The primary foliar host for Phytophthora ramorum is California bay laurel, Umbellularia californica (Hook. & Arn.) Nutt., a main reservoir for the pathogen in California woodlands. We investigated environmental and pathogen-mediated influences on incidence and severity of P. ramorum infection of

  7. Biological control of Black Pod Disease and Seedling Blight of cacao caused by Phytophthora Species using Trichoderma from Aceh Sumatra

    Science.gov (United States)

    The cocoa tree, Theobroma cacao L., suffers large yield losses in Aceh Indonesia to the disease black pod rot, caused by Phytophthora spp. Despite having the largest area under cacao production in Sumatra, farmers in the Aceh region have low overall production because of losses to insect pests and b...

  8. Gene-for-gene relationships between strawberry and the causal agent of red stele root rot, Phytophthora fragariae var. fragariae.

    NARCIS (Netherlands)

    Weg, van de W.E.

    1997-01-01

    Red stele (red core) root rot is the major soil-borne disease of strawberries (Fragaria spp.) in many areas with cool, moist soil conditions. It is caused by the soil-borne fungus Phytophthora fragariae var. fragariae. Red stele is a quarantine disease in Europe with a zero tolerance for commercial

  9. Large-scale gene discovery in the oomycete Phytophthora infestans reveals likely components of phytopathogenicity shared with true fungi

    NARCIS (Netherlands)

    Randall, T.A.; Dwyer, R.A.; Huitema, E.; Beyer, K.; Cvitanich, C.; Kelkar, H.; Ah Fong, A.M.V.; Gates, K.; Roberts, S.; Yatzkan, E.; Gaffney, T.; Law, M.; Testa, A.; Torto-Alalibo, T.; Zhang Meng,; Zheng Li,; Mueller, E.; Windass, J.; Binder, A.; Birch, P.R.J.; Gisi, U.; Govers, F.; Gow, N.A.; Mauch, F.; West, van P.; Waugh, M.E.; Yu Jun,; Boller, T.; Kamoun, S.; Lam, S.T.; Judelson, H.S.

    2005-01-01

    o overview the gene content of the important pathogen Phytophthora infestans, large-scale cDNA and genomic sequencing was performed. A set of 75,757 high-quality expressed sequence tags (ESTs) from P. infestans was obtained from 20 cDNA libraries representing a broad range of growth conditions, stre

  10. Letter to the Editor : Standardizing the nomenclature for clonal lineages of the sudden oak death pathogen, Phytophthora ramorum

    NARCIS (Netherlands)

    Grünwald, N.J.; Goss, E.M.; Ivors, K.; Garbelotto, M.; Martin, F.N.; Prospero, S.; Hansen, E.; Bonants, P.J.M.; Hamelin, R.C.; Chastagner, M.; Werres, S.; Rizzo, D.M.; Abad, G.; Beales, P.; Bilodeau, G.J.; Blomquist, C.L.; Brasier, C.; Brière, S.C.; Chandelier, A.; Davidson, J.M.; Denman, S.; Elliott, M.; Frankel, S.J.; Goheen, E.M.; Gruyter, de H.; Heungens, K.; James, D.; Kanaskie, A.; McWilliams, M.G.; Man in't Veld, W.; Moralejo, E.; Osterbauer, N.K.; Palm, M.E.; Parke, J.L.; Perez Sierra, A.M.; Shamoun, S.F.; Shishkoff, N.; Tooley, P.W.; Vettraino, A.M.; Webber, J.; Widmer, T.L.

    2009-01-01

    Phytophthora ramorum, the causal agent of sudden oak death and ramorum blight, is known to exist as three distinct clonal lineages which can only be distinguished by performing molecular marker-based analyses. However, in the recent literature there exists no consensus on naming of these lineages. H

  11. Joint QTL analyses for partial resistance to Phytophthora sojae using six nested inbred populations with heterogeneous conditions

    Science.gov (United States)

    Partial resistance to Phytophthora sojae in soybean is controlled by multiple quantitative trait loci (QTL). With traditional QTL mapping approaches, power to detect these QTL, frequently of small effect, can be limited by population size. Joint linkage QTL analysis of nested recombinant inbred li...

  12. In vitro testing of biological control agents on A1 and A2 isolates of Phytophthora ramorum

    Science.gov (United States)

    Marianne Elliott; Simon Shamoun

    2008-01-01

    Biological control products were tested in vitro with six isolates of Phytophthora ramorum. These isolates were geographically diverse and were selected based on their pathogenicity to detached Rhododendron leaves. In addition to five commercially available biocontrol products, nine species of Trichoderma were tested. The in vitro...

  13. Phytophthora ramorum is a generalist plant pathogen with differences in virulence between isolates from infectious and dead-end hosts

    Science.gov (United States)

    D. Huberli; M. Garbelotto

    2011-01-01

    Variation in virulence was examined among isolates of Phytophthora ramorum from epidemiologically important or infectious (non-oak) and transmissive dead-end (oak) hosts from North America. Twelve isolates representative of the genetic, geographic and host range of P. ramorum in the western United States were inoculated on...

  14. Spatial variation in effects of temperature on Phenotypic characteristics of Phytophthora ramorum isolates from eastern Sonoma county

    Science.gov (United States)

    Valerie Sherron; Nathan E. Rank; Michael Cohen; Brian L. Anacker; Ross K. Meentemeyer

    2008-01-01

    Quantifying the growth rates of plant pathogens in the laboratory can be useful for predicting rates of disease spread and impact in nature. The purpose of this study was to examine phenotypic variation among isolates of Phytophthora ramorum collected from a foliar host plant species, Umbellularia californica (California bay laurel...

  15. Effect of environmental conditions and lesion age on sporulation of Phytophthora ramorum on California bay laurel, rhododendron, and camellia

    Science.gov (United States)

    Steve Tjosvold; David Chambers; Sylvia Mori

    2013-01-01

    The objective of our research was to determine the environmental conditions and lesion age favorable for Phytophthora ramorum sporulation under field conditions. For 2 years, new camellia, rhododendron, and California bay laurel (Umbellaria californica (Hook. & Arn.) Nutt.) nursery stock were seasonally inoculated (every 3 months) on foliage....

  16. Antimicrobial activity of extracts and select compounds in the heartwood of seven western conifers toward Phytophthora ramorum

    Science.gov (United States)

    Daniel K. Manter; Rick G. Kelsey; Joseph J. Karchesy

    2008-01-01

    Previously, we demonstrated that wood chips, essential oil, and four individual compounds from Alaska yellow-cedar (Chamaecyparis nootkatensis [D. Don] Spach) heartwood strongly inhibit the germination f Phytophthora ramorum (Werres, de Cock, Man int Veld) zoospores or sporangia, and reduce hyphal growth in culture (Manter and...

  17. COST action FP801- established and emerging Phytophthora: incresasing threats to woodland and forest ecosystems in Europe

    NARCIS (Netherlands)

    Woodward, S.; Vannini, A.; Werres, S.; Osswald, W.; Bonants, P.J.M.; Jung, T.

    2011-01-01

    With the rapidly growing international trade in plants and ongoing impacts of climate change, impacts of plant pathogens in the genus Phytophthora are increasing, threatening the biodiversity and sustainability of European forest ecosystems. Through the European Cooperation in Science and Technology

  18. Characterization of Phytophthora hybrids from ITS clade 6 associated with riparian ecosystems in South Africa and Australia.

    Science.gov (United States)

    Nagel, Jan H; Gryzenhout, Marieka; Slippers, Bernard; Wingfield, Michael J; Hardy, Giles E St J; Stukely, Michael J C; Burgess, Treena I

    2013-05-01

    Surveys of Australian and South African rivers revealed numerous Phytophthora isolates residing in clade 6 of the genus, with internal transcribed spacer (ITS) gene regions that were either highly polymorphic or unsequenceable. These isolates were suspected to be hybrids. Three nuclear loci, the ITS region, two single copy loci (antisilencing factor (ASF) and G protein alpha subunit (GPA)), and one mitochondrial locus (cytochrome oxidase c subunit I (coxI)) were amplified and sequenced to test this hypothesis. Abundant recombination within the ITS region was observed. This, combined with phylogenetic comparisons of the other three loci, confirmed the presence of four different hybrid types involving the three described parent species Phytophthora amnicola, Phytophthora thermophila, and Phytophthora taxon PgChlamydo. In all cases, only a single coxI allele was detected, suggesting that hybrids arose from sexual recombination. All the hybrid isolates were sterile in culture and all their physiological traits tended to resemble those of the maternal parents. Nothing is known regarding their host range or pathogenicity. Nonetheless, as several isolates from Western Australia were obtained from the rhizosphere soil of dying plants, they should be regarded as potential threats to plant health. The frequent occurrence of the hybrids and their parent species in Australia strongly suggests an Australian origin and a subsequent introduction into South Africa.

  19. Gene duplication and fragment recombination drive functional diversification of a superfamily of cytoplasmic effectors in Phytophthora sojae.

    Science.gov (United States)

    Shen, Danyu; Liu, Tingli; Ye, Wenwu; Liu, Li; Liu, Peihan; Wu, Yuren; Wang, Yuanchao; Dou, Daolong

    2013-01-01

    Phytophthora and other oomycetes secrete a large number of putative host cytoplasmic effectors with conserved FLAK motifs following signal peptides, termed crinkling and necrosis inducing proteins (CRN), or Crinkler. Here, we first investigated the evolutionary patterns and mechanisms of CRN effectors in Phytophthora sojae and compared them to two other Phytophthora species. The genes encoding CRN effectors could be divided into 45 orthologous gene groups (OGG), and most OGGs unequally distributed in the three species, in which each underwent large number of gene gains or losses, indicating that the CRN genes expanded after species evolution in Phytophthora and evolved through pathoadaptation. The 134 expanded genes in P. sojae encoded family proteins including 82 functional genes and expressed at higher levels while the other 68 genes encoding orphan proteins were less expressed and contained 50 pseudogenes. Furthermore, we demonstrated that most expanded genes underwent gene duplication or/and fragment recombination. Three different mechanisms that drove gene duplication or recombination were identified. Finally, the expanded CRN effectors exhibited varying pathogenic functions, including induction of programmed cell death (PCD) and suppression of PCD through PAMP-triggered immunity or/and effector-triggered immunity. Overall, these results suggest that gene duplication and fragment recombination may be two mechanisms that drive the expansion and neofunctionalization of the CRN family in P. sojae, which aids in understanding the roles of CRN effectors within each oomycete pathogen.

  20. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  1. A review of research advances in Phytophthora boehmeriae%苎麻疫霉研究进展

    Institute of Scientific and Technical Information of China (English)

    高智谋

    2007-01-01

    In this paper, the advances in the study on Phytophthora boehmeriae,including geographical distribution, host range, morphology, biology, ecology, detection, control etc,are reviewed to provide a useful information for the integrated management of the diseases caused by the oomycete and for the related research.

  2. Phytophthora species recovered from irrigation reservoirs in Mississippi and Alabama nurseries and pathogenicity of three new species

    Science.gov (United States)

    From a survey of containment ponds for Phytophthora spp. at one nursery each in Alabama and Mississippi, eight species and one taxon were recovered with P. gonapodyides dominant in cooler months and P. hydropathica in warmer months, accounting for 39.6% and 46.6% overall recovery, respectively. Amo...

  3. First report of the EU1 clonal lineage of Phytophthora ramorum on tanoak in an Oregon forest

    Science.gov (United States)

    Initially reported in California as the causal agent of sudden oak death (SOD), efforts to limit spread of Phytophthora ramorum in Oregon natural forests have concentrated on quarantine regulations and eradication of the pathogen from infested areas. P. ramorum has four clonal lineages NA1, NA2, EU1...

  4. Gene duplication and fragment recombination drive functional diversification of a superfamily of cytoplasmic effectors in Phytophthora sojae.

    Directory of Open Access Journals (Sweden)

    Danyu Shen

    Full Text Available Phytophthora and other oomycetes secrete a large number of putative host cytoplasmic effectors with conserved FLAK motifs following signal peptides, termed crinkling and necrosis inducing proteins (CRN, or Crinkler. Here, we first investigated the evolutionary patterns and mechanisms of CRN effectors in Phytophthora sojae and compared them to two other Phytophthora species. The genes encoding CRN effectors could be divided into 45 orthologous gene groups (OGG, and most OGGs unequally distributed in the three species, in which each underwent large number of gene gains or losses, indicating that the CRN genes expanded after species evolution in Phytophthora and evolved through pathoadaptation. The 134 expanded genes in P. sojae encoded family proteins including 82 functional genes and expressed at higher levels while the other 68 genes encoding orphan proteins were less expressed and contained 50 pseudogenes. Furthermore, we demonstrated that most expanded genes underwent gene duplication or/and fragment recombination. Three different mechanisms that drove gene duplication or recombination were identified. Finally, the expanded CRN effectors exhibited varying pathogenic functions, including induction of programmed cell death (PCD and suppression of PCD through PAMP-triggered immunity or/and effector-triggered immunity. Overall, these results suggest that gene duplication and fragment recombination may be two mechanisms that drive the expansion and neofunctionalization of the CRN family in P. sojae, which aids in understanding the roles of CRN effectors within each oomycete pathogen.

  5. Resequencing of the Phytophthora ramorum genome to characterize genetic variation and population dynamics of the invasive pathogen

    Science.gov (United States)

    Jennifer Yuzon; David M. Rizzo; Mathu Malar C; Sucheta Tripathy; Takao Kasuga

    2017-01-01

    Phytophthora ramorum has spread and diversified throughout California’s northwestern coast since its introduction in the 1990s. Tracking the spread of P. ramorum and the functional response of the pathogen to the environment is of particular interest to managing the epidemic. Using genetic tools such as microsatellite...

  6. Improved Phytophthora resistance in commercial chickpea (Cicer arietinum) varieties negatively impacts symbiotic gene signalling and symbiotic potential in some varieties.

    Science.gov (United States)

    Plett, Jonathan M; Plett, Krista L; Bithell, Sean L; Mitchell, Chris; Moore, Kevin; Powell, Jeff R; Anderson, Ian C

    2016-08-01

    Breeding disease-resistant varieties is one of the most effective and economical means to combat soilborne diseases in pulse crops. Commonalities between pathogenic and mutualistic microbe colonization strategies, however, raises the concern that reduced susceptibility to pathogens may simultaneously reduce colonization by beneficial microbes. We investigate here the degree of overlap in the transcriptional response of the Phytophthora medicaginis susceptible chickpea variety 'Sonali' to the early colonization stages of either Phytophthora, rhizobial bacteria or arbuscular mycorrhizal fungi. From a total of 6476 genes differentially expressed in Sonali roots during colonization by any of the microbes tested, 10.2% were regulated in a similar manner regardless of whether it was the pathogenic oomycete or a mutualistic microbe colonizing the roots. Of these genes, 49.7% were oppositely regulated under the same conditions in the moderately Phytophthora resistant chickpea variety 'PBA HatTrick'. Chickpea varieties with improved resistance to Phytophthora also displayed lower colonization by rhizobial bacteria and mycorrhizal fungi leading to an increased reliance on N and P from soil. Together, our results suggest that marker-based breeding in crops such as chickpea should be further investigated such that plant disease resistance can be tailored to a specific pathogen without affecting mutualistic plant:microbe interactions.

  7. Phytophthora taxa associated with cultivated Agathosma, with emphasis on the P. citricola complex and P. capensis sp. nov.

    NARCIS (Netherlands)

    Bezuidenhout, C.M.; Denman, S.; Kirk, S.A.; Botha, W.J.; Mostert, L.; McLeod, A.

    2010-01-01

    Agathosma species, which are indigenous to South Africa, are also cultivated for commercial use. Recently growers experienced severe plant loss, and symptoms shown by affected plants suggested that a soilborne disease could be the cause of death. A number of Phytophthora taxa were isolated from dise

  8. Identification of a resistance gene Rpi-dlc1 to Phytophthora infestans in European accessions of Solanum dulcamara

    NARCIS (Netherlands)

    Golas, T.M.; Sikkema, A.; Gros, J.; Feron, R.M.C.; Berg, van den R.G.; Weerden, van der G.M.; Mariani, C.; Allefs, J.J.H.M.

    2010-01-01

    Initial screening of 14 Solanum dulcamara accessions enabled the identification of individuals resistant and susceptible to Phytophthora infestans. Crosses between contrasting genotypes resulted in three F2–BC1 populations segregating for resistance to late blight in a laboratory assay and under fie

  9. Pyrosequencing as a tool for the detection of Phytophthora species: error rate and risk of false Molecular Operational Taxonomic Units

    NARCIS (Netherlands)

    Vettraino, A.M.; Bonants, P.J.M.; Tomassini, A.; Bruni, N.; Vannini, A.

    2012-01-01

    Aims: To evaluate the accuracy of pyrosequencing for the description of Phytophthora communities in terms of taxa identification and risk of assignment for false Molecular Operational Taxonomic Units (MOTUs). Methods and Results: Pyrosequencing of Internal Transcribed Spacer 1 (ITS1) amplicons was u

  10. Formation, production and viability of oospores of Phytophthora infestans from potato and Solanum demissum in the Toluca Valley, central Mexico

    NARCIS (Netherlands)

    Flier, W.G.; Grünwald, N.J.; Fry, W.E.; Turkensteen, L.J.

    2001-01-01

    Aspects of the ecology of oospores of Phytophthora infestans were studied in the highlands of central Mexico. From an investigation of a random sample of strains, it was found that isolates differed in their average capability to form oospores when engaged in compatible pairings. Most crosses produc

  11. Variation in phenotype for resistance to Phytophthora ramorum in a range of species and cultivars of the genus Viburnum

    Science.gov (United States)

    Niklaus J. Grunwald; E. Anne Davis; Robert G. Linderman

    2006-01-01

    Phytophthora ramorum is a recently introduced plant pathogen causing a range of diseases including sudden oak death, Ramorum shoot dieback and Ramorum blight (Rizzo and others 2002, 2004; Werres and others 2001). P. ramorum also attacks several nursery crops including viburnum and rhododendron (Werres and others 2001). Since its...

  12. Phytophthora infestans field isolates from Gansu Province, China are genetically highly diverse and show a high frequency of self fertility

    NARCIS (Netherlands)

    Han, M.; Liu, G.; Li, J.P.; Govers, F.; Zhu, X.Q.; Shen, C.Y.; Guo, L.Y.

    2013-01-01

    The genetic diversity of 85 isolates of Phytophthora infestans collected in 2007 from Gansu province in China was determined and compared with 21 isolates collected before 2004. Among them, 70 belonged to the A1 mating type and 15 were self-fertile (SF). The mitochondrial DNA haplotypes revealed

  13. Downstream targets of the Phytophthora infestans G alpha subunit PiGPA1 revealed by cDNA-AFLP

    NARCIS (Netherlands)

    Dong, W.; Latijnhouwers, M.; Jiang, R.H.Y.; Meijer, H.J.G.; Govers, F.

    2004-01-01

    In many plant pathogens heterotrimeric G-proteins are essential signalling components involved in development and pathogenicity. In the late blight oomycete pathogen Phytophthora infestans the G-protein (x subunit PiGPA1 controls zoospore motility and is required for virulence. To identify G-protein

  14. Phytophthora infestans isolates lacking class I ipiO variants are virulent on Rpi-blb1 potato

    NARCIS (Netherlands)

    Champouret, N.; Bouwmeester, K.; Rietman, H.; Lee, van der T.; Maliepaard, C.A.; Heupink, A.; Vondervoort, van de P.J.I.; Jacobsen, E.; Visser, R.G.F.; Vossen, van der E.A.G.; Govers, F.; Vleeshouwers, V.G.A.A.

    2009-01-01

    A strategy to control the devastating late blight disease is providing potato cultivars with genes that are effective in resistance to a broad spectrum of Phytophthora infestans isolates. Thus far, most late blight resistance (R) genes that were introgressed in potato were quickly defeated. In contr

  15. Genetic diversity of Phytophthora infestans sensu lato in Ecuador provides new insight into the origin of this important plant pathogen

    NARCIS (Netherlands)

    Adler, N.E.; Erselius, L.J.; Chacón, G.M.; Flier, W.G.; Ordonez, M.E.; Kroon, L.P.N.M.; Forbes, G.A.

    2004-01-01

    The metapopulation structure of Phytophthora infestans sensu lato is genetically diverse in the highlands of Ecuador. Previous reports documented the diversity associated with four putative clonal lineages of the pathogen collected from various hosts in the genus Solanum. This paper simultaneously a

  16. Competitive Interaction Between Phytophthora Infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-spectrum Late Blight Resistance

    Science.gov (United States)

    The resistance (R) gene RB confers broad-spectrum resistance to potato late blight and belongs. The RB protein recognizes the presence of members of the Phytophthora infestans effector family IPI-O to elicit resistance. Most isolates of the pathogen contain IPI-O variants that are recognized by R...

  17. Competitive Between Phytophthora Infestans Effectors Leads to Increased Aggressiveness on Plants Containing Broad-Spectrum Late Blight Resistance

    Science.gov (United States)

    Potato late blight is a particularly destructive plant disease caused by the oomycete pathogen Phytophthora infestans (Mont.) de Bary. Late blight has remained particularly problematic despite intensive breeding efforts to integrate resistance into cultivated potato. This is due to the pathogen’s ab...

  18. Response of U.S. Bottle Gourd (Lagenaria siceraria) Plant Introductions (PI) to Crown Rot caused by Phytophthora Capsici

    Science.gov (United States)

    Phytophthora capsici can cause severe damage to cucurbit crops grown in open fields in the southeast regions of US. In recent years, there has been a growing interest in the US in grafting watermelon plants onto various cucurbit rootstocks including bottle gourds for managing soil borne diseases. ...

  19. Entomofauna Associada a Galhos de Acacia mangium Willd. Roletados por Oncideres saga (Dalman (Coleoptera: Cerambycidae

    Directory of Open Access Journals (Sweden)

    Gláucia Cordeiro

    2010-04-01

    Full Text Available O estudo da entomofauna associada aos galhos e fustes roletados por Oncideres saga (Dalman é importante para conhecermos seus possíveis inimigos naturais. Portanto, este trabalho teve como objetivo registrar os insetos associados aos galhos e fustes de Acacia mangium Willd. roletados por O. saga, em Coimbra-MG. Galhos e fustes roletados de A. mangium foram coletados de janeiro a abril de 2007. Este material foi vistoriado, armazenados em sacolas, feitas com tela plástica, e mantidos em sala com condições controladas (25,4±0,3°C e 66,7±1,4%. Constatou-se a presença de uma espécie, não determinada, de Scolytidae e a emergência de quatro espécies de Cerambycidae: Engyum quadrinotatum Thomsom; Eburodacrys sexmaculata (Olivier; Achryson surinamum (Linnaeus e Neoclytus pusillus (Laporte & Gory. Isto posto, fica evidenciada a necessidade de estudos com o objetivo de verificar qual o comportamento destes insetos em relação ao serrador O. saga.Insects associated with branches of Acacia mangium Willd. girdled by Oncideres saga (Dalman (Coleoptera: CerambycidaeAbstract. The study of the insects associated with branches and stems girdled by Oncideres saga (Dalman is important to know its possible natural enemies. Therefore, these work had the objective of register the insects associated with branches and stems girdled of Acacia mangium Willd. by this twig girdler beetle, in Coimbra, state of Minas Gerais, Brazil. Stems and branches of A. mangium were collected in January/2007 to April/2007. This material has been inspected, stored in plastic bags, and kept in a room with controlled conditions (25.4 ± 0.3°C and 66.7 ± 1.4%. It was noted the presence of a non-determined species of Scolytidae and the emergence of four species of Cerambycidae: Engyum quadrinotatum Thomsom; Eburodacrys sexmaculata (Olivier; Achryson surinamum (Linnaeus and Neoclytus pusillus (Laporte & Gory. It can be concluded that studies are needed with the objective of

  20. Hemofilia A adquirida associada à artrite reumatoide Acquired hemophilia associated with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Marlene Freire

    2009-06-01

    Full Text Available O aparecimento do anticorpo contra fator VIII é um fenômeno bem estabelecido na hemofilia A, ocorrendo em 5 a 15% dos pacientes hemofílicos dos Estados Unidos, Inglaterra, Suécia e França. Nos pacientes não-hemofílicos o seu aparecimento é raro, podendo ocorrer em indivíduos saudáveis, principalmente idosos e mulheres no puerpério, pacientes com neoplasia maligna ou doenças autoimunes, como lúpus eritematoso sistêmico, artrite reumatoide e síndrome de Sjögren. Descrevemos o caso de uma paciente de 64 anos de idade, portadora de artrite reumatoide soropositiva há 23 anos, que há 10 dias desenvolveu equimoses e hematomas progressivos cuja investigação foi compatível com a presença de anticorpo contra fator VIII. Foi instituída terapia com metilprednisolona, ciclofosfamida endovenosa, imunoglobulina e reposição de complexo protrombínico, com remissão do quadro hemorrágico e negativação do anticorpo contra o fator VIII. Concluímos com esse caso que, apesar de ser rara, a presença de inibidores adquiridos do fator VIII deve ser pesquisada quando pacientes portadores de doença autoimune desenvolvem manifestações hemorrágicas associadas ao prolongamento do TTPA com TAP e contagem plaquetária normais.The occurrence of the antibody against factor VIII is a well-known phenomenon in hemophilia A, occuring in 5 to 15% of the hemophilic patients in the United States, England, Sweden and France. The development of factor VIII in non-hemophilic patients is rare and may occur in healthy individuals, mostly elderly and women in postpartum period, and in patients with malignant neoplasia or autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. We described the case of a 64-year-old female patient who has had seropositive rheumatoid arthritis for 23 years and presented with a ten-day history of progressive ecchymosis. Therapy with methylprednisolone, intravenous

  1. Mortalidade em idosos por diabetes mellitus como causa básica e associada

    Directory of Open Access Journals (Sweden)

    Cláudia Medina Coeli

    2002-04-01

    Full Text Available OBJETIVO:Analisar a mortalidade por diabetes mellitus em idosos e a subenumeração do diabetes como causa do óbito de acordo com estatísticas baseadas unicamente em causa básica de óbito. MÉTODOS:Foram revisadas todas as 2.974 declarações de óbito ocorridas em 1994 de idosos residentes em um núcleo habitacional localizado na cidade do Rio de Janeiro, RJ. Destas, foram estudados 291 óbitos, tendo o diabetes mellitus como causa básica (150 e associada (141. A proporção de óbitos em que a diabetes aparece como causa básica em relação ao total de óbitos por diabetes foi calculada de forma global e segundo sexo e faixa etária. RESULTADOS:Dos 291 óbitos estudados, 138 (47,4% ocorreram em homens, e 153, em mulheres (52,6%. As taxas de mortalidade apresentaram crescimento contínuo com o avançar da idade, sendo superiores no sexo masculino, embora a diferença entre sexos tenha sido menor para a análise baseada unicamente na causa básica. Observou-se proporção elevada de óbitos domiciliares (22%. A proporção de óbitos por diabetes como causa básica foi de 51,5%, sendo maior nas mulheres do que nos homens. CONCLUSÕES:A análise das estatísticas de mortalidade baseadas unicamente na causa básica do óbito pode levar a perfis distorcidos, em função da subenumeração não ocorrer aleatoriamente. Estudos adicionais em coortes de idosos brasileiros diabéticos são necessários para permitir uma avaliação mais acurada da mortalidade nesse grupo.

  2. Finasteride-associated male infertility Infertilidade masculina associada ao uso de finasterida

    Directory of Open Access Journals (Sweden)

    Sidney Glina

    2004-01-01

    Full Text Available Finasteride is a potent and specific inhibitor of the 5alpha-reductase enzyme in men. Clinical studies have shown that finasteride 1mg/day is effective for promoting hair growth in men with male pattern hair loss. However, there is a concern about the use of finasteride, especially in young fertile patients, because of its action on testosterone metabolism. This paper describes 3 cases of young patients who had very poor seminal quality during finasteride treatment (1 mg/day, and their seminal quality greatly improved after cessation of finasteride treatment. Two of them presented with a left varicocele and the other was obese. We hypothesize that finasteride may not dramatically change the spermatogenesis process in healthy men, but in patients with conditions related to infertility, an amplification of the negative influence of finasteride could occur. Future studies should be done to clarify the extent of the effect of finasteride in patients fertility problems.A finasterida é um potente e específico inibidor da enzima 5alfa-redutase em homens. Estudos clínicos demonstraram que finasterida 1mg/dia diminui a progressão da queda e aumenta o crescimento do cabelo em homens que sofrem de queda de cabelo hereditária. Por sua influência no metabolismo dos andrógenos existe uma preocupação a respeito do seu uso, principalmente em pacientes em idade fértil. Neste trabalho são descritos 3 casos de pacientes jovens, que apresentaram piora do espermograma durante o uso continuado de finasterida 1mg revertida após a suspensão do mesmo. Dois deles tinham varicocele unilateral e o terceiro era obeso. Aparentemente o tratamento com finasterida promoveu alteração significativa na qualidade seminal. Pode-se especular que talvez a finasterida por si só não traga alteração para a espermatogênese como reportado por Overstreet et al. (1999, mas que em pacientes de risco com possíveis causas de infertilidade associadas, possa ocorrer a

  3. Dermatose perfurante adquirida associada à insuficiência hepática em paciente transplantado de fígado

    OpenAIRE

    Badziak,Daniela; Lenhardt,Carolina; Barros,Michele F. de; Mandelli,Fernando Luiz; Serafini,Sérgio Zuñeda; Santamaria,Jesus Rodriguez

    2007-01-01

    A dermatose perfurante adquirida é entidade clinicopatológica caracterizada por eliminação transepitelial de material dérmico degenerado, ocorrendo em muitas condições, entre elas diabetes mellitus, insuficiência renal crônica e colangite esclerosante. Relata-se o caso de paciente de 17 anos, com dermatose perfurante adquirida associada à insuficiência hepática crônica, conseqüente à complicação hepática de transplante de fígado para tratamento de sua doença de base, a glicogenose tipo I....

  4. Mielite Transversa Associada a Infecção por Mycoplasma Pneumoniae: Caso Clínico

    OpenAIRE

    Guimarães, Paulo; Teixeira, Fernanda; Oliveira, Maria José; Temudo, Teresa; Costa, Gomes da

    2014-01-01

    Mycoplasma pneumoniae é um agente infeccioso frequentemente implicado em infecções respiratórias em crianças e adolescentes.Complicações não respiratórias podem ocorrer, nomeadamente mucocutâneas, cardíacas, articulares, hematológicas e neurológicas, entre as quais a mielite transversa. Esta é uma entidade relativamente rara em idade pediátrica, embora potencialmente grave. Apesar da sua patogenia ser desconhecida, tem sido associada a infecção (nomeadamente vírica ou por micoplasma), lupus e...

  5. Mielite Transversa Associada a Infecção por Mycoplasma Pneumoniae: Caso Clínico

    OpenAIRE

    Guimarães, Paulo; Teixeira, Fernanda; Oliveira, Maria José; Temudo, Teresa; Costa, Gomes da

    2014-01-01

    Mycoplasma pneumoniae é um agente infeccioso frequentemente implicado em infecções respiratórias em crianças e adolescentes.Complicações não respiratórias podem ocorrer, nomeadamente mucocutâneas, cardíacas, articulares, hematológicas e neurológicas, entre as quais a mielite transversa. Esta é uma entidade relativamente rara em idade pediátrica, embora potencialmente grave. Apesar da sua patogenia ser desconhecida, tem sido associada a infecção (nomeadamente vírica ou por micoplasma), lupus e...

  6. Caracterização das metaloproteinases associadas ao desenvolvimento do germe dental do primeiro molar de ratos

    OpenAIRE

    Ricardo Della Coletta

    1996-01-01

    Resumo: A participação das metaloproteinases durante o desenvolvimento dental ainda não está bem estabelecida. Neste trabalho foram realizados estudos no intuito de caracterizar e detenninar o sítio principal de atuação dos grupos de metaloproteinases associadas ao germe dental' do primeiro molar em desenvolvimento. Verificou-se a presença de enznnas gelatinolíticas e caseinolíticas com comportamento, quanto à ação de inibidores específicos, ação colagenolítica e peso molecular, semelhante ao...

  7. Dermatose perfurante adquirida associada à insuficiência hepática em paciente transplantado de fígado

    OpenAIRE

    Daniela Badziak; Carolina Lenhardt; Barros,Michele F. de; Fernando Luiz Mandelli; Sérgio Zuñeda Serafini; Jesus Rodriguez Santamaria

    2007-01-01

    A dermatose perfurante adquirida é entidade clinicopatológica caracterizada por eliminação transepitelial de material dérmico degenerado, ocorrendo em muitas condições, entre elas diabetes mellitus, insuficiência renal crônica e colangite esclerosante. Relata-se o caso de paciente de 17 anos, com dermatose perfurante adquirida associada à insuficiência hepática crônica, conseqüente à complicação hepática de transplante de fígado para tratamento de sua doença de base, a glicogenose tipo I.Acqu...

  8. Discovery of Phytophthora infestans genes expressed in planta through mining of cDNA libraries.

    Directory of Open Access Journals (Sweden)

    Roberto Sierra

    Full Text Available BACKGROUND: Phytophthora infestans (Mont. de Bary causes late blight of potato and tomato, and has a broad host range within the Solanaceae family. Most studies of the Phytophthora--Solanum pathosystem have focused on gene expression in the host and have not analyzed pathogen gene expression in planta. METHODOLOGY/PRINCIPAL FINDINGS: We describe in detail an in silico approach to mine ESTs from inoculated host plants deposited in a database in order to identify particular pathogen sequences associated with disease. We identified candidate effector genes through mining of 22,795 ESTs corresponding to P. infestans cDNA libraries in compatible and incompatible interactions with hosts from the Solanaceae family. CONCLUSIONS/SIGNIFICANCE: We annotated genes of P. infestans expressed in planta associated with late blight using different approaches and assigned putative functions to 373 out of the 501 sequences found in the P. infestans genome draft, including putative secreted proteins, domains associated with pathogenicity and poorly characterized proteins ideal for further experimental studies. Our study provides a methodology for analyzing cDNA libraries and provides an understanding of the plant--oomycete pathosystems that is independent of the host, condition, or type of sample by identifying genes of the pathogen expressed in planta.

  9. Effect of Flumorph on F-Actin Dynamics in the Potato Late Blight Pathogen Phytophthora infestans.

    Science.gov (United States)

    Hua, Chenlei; Kots, Kiki; Ketelaar, Tijs; Govers, Francine; Meijer, Harold J G

    2015-04-01

    Oomycetes are fungal-like pathogens that cause notorious diseases. Protecting crops against oomycetes requires regular spraying with chemicals, many with an unknown mode of action. In the 1990s, flumorph was identified as a novel crop protection agent. It was shown to inhibit the growth of oomycete pathogens including Phytophthora spp., presumably by targeting actin. We recently generated transgenic Phytophthora infestans strains that express Lifeact-enhanced green fluorescent protein (eGFP), which enabled us to monitor the actin cytoskeleton during hyphal growth. For analyzing effects of oomicides on the actin cytoskeleton in vivo, the P. infestans Lifeact-eGFP strain is an excellent tool. Here, we confirm that flumorph is an oomicide with growth inhibitory activity. Microscopic analyses showed that low flumorph concentrations provoked hyphal tip swellings accompanied by accumulation of actin plaques in the apex, a feature reminiscent of tips of nongrowing hyphae. At higher concentrations, swelling was more pronounced and accompanied by an increase in hyphal bursting events. However, in hyphae that remained intact, actin filaments were indistinguishable from those in nontreated, nongrowing hyphae. In contrast, in hyphae treated with the actin depolymerizing drug latrunculin B, no hyphal bursting was observed but the actin filaments were completely disrupted. This difference demonstrates that actin is not the primary target of flumorph.

  10. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control.

    Science.gov (United States)

    Blaya, Josefa; Marhuenda, Frutos C; Pascual, Jose A; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

  11. Study on the Resistance Induced by Salicylic Acid Against Phytophthora capsici in Pepper (Capsicum annuum)

    Institute of Scientific and Technical Information of China (English)

    MAO Ai-jun; WANG Yong-jian; FENG Lan-xiang; GENG San-sheng; XU Yong

    2005-01-01

    Pepper Phytophthora blight caused by Phytophthora capsici L. is the most destructive disease for reducing pepper yields in the world. Building up varietal resistance and induced resistance to the disease are of agricultural importance. In this paper, the disease resistance induced by salicylic acid (SA) against P. capsici were studied by using four hot pepper lines with different resistant abilities and one P. capsici strain with middle pathogenicity. Results show that SA could induce significantly the resistance of pepper seedlings to P. capsici, but CaC12, KH2PO4 and VAM couldn't. SA at a relative low concentration from 0.15 to 0.3 g L-1 had no antifungal activity in vitro against P. capsici. That means the disease resistant enhancement of the plants treated with SA is due to the induction effect, but not the antifungal effect of SA. About 1 to 5 days internal between SA-treatment and challenge inoculation was sufficient to induce the disease resistance of hot pepper. The resistance could remain more than 20 days after treatment with SA.

  12. Vectors for fluorescent protein tagging in Phytophthora: tools for functional genomics and cell biology.

    Science.gov (United States)

    Ah-Fong, Audrey M V; Judelson, Howard S

    2011-09-01

    Fluorescent tagging has become the strategy of choice for examining the subcellular localisation of proteins. To develop a versatile community resource for this method in oomycetes, plasmids were constructed that allow the expression of either of four spectrally distinct proteins [cyan fluorescent protein (CFP), green fluorescent protein (GFP), yellow fluorescent protein (YFP), and mCherry], alone or fused at their N- or C-termini, to sequences of interest. Equivalent sets of plasmids were made using neomycin or hygromycin phosphotransferases (nptII, hpt) as selectable markers, to facilitate double-labelling and aid work in diverse species. The fluorescent proteins and drug-resistance markers were fused to transcriptional regulatory sequences from the oomycete Bremia lactucae, which are known to function in diverse oomycetes, although the promoter in the fluorescence cassette (ham34) can be replaced easily by a promoter of interest. The function of each plasmid was confirmed in Phytophthora infestans. Moreover, fusion proteins were generated using targeting sequences for the endoplasmic reticulum, Golgi, mitochondria, nuclei, and peroxisomes. Studies of the distribution of the fusions in mycelia and sporangia provided insight into cellular organisation at different stages of development. This toolbox of vectors should advance studies of gene function and cell biology in Phytophthora and other oomycetes. Copyright © 2011 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  14. Purification and characterization of elicitor protein from Phytophthora colocasiae and basic resistance in Colocasia esculenta.

    Science.gov (United States)

    Mishra, Ajay Kumar; Sharma, Kamal; Misra, Raj Shekhar

    2009-01-01

    An elicitor was identified in the fungus Phytophthora colocasiae. The molecular weight of the purified elicitor was estimated by means of gel filtration chromatography and SDS-PAGE and was estimated as 15kDa. Protease treatment severely reduced its activity, allowing the conclusion that the elicitor is proteinaceous. Infiltration of a few nanograms of this proteinaceous elicitor into taro leaves caused the formation of lesions that closely resemble hypersensitive response lesions. The elicitation of the cells was effective in the induction of the activity of lipoxygenase. Cellular damage, restricted to the infiltrated zone, occurred only several hours later, after the infiltration of the elicitor protein. After few days, systemic acquired resistance was also induced. Thus, taro plant cells that perceived the glycoprotein generated a cascade of signals acting at local, short, and long distances, and causing the coordinate expression of specific defence. The obtained results give important information regarding the plant-pathogen interactions, mainly as subsidy for taro improvement against Phytophthora leaf blight.

  15. Phytophthora capsici Epidemic Dispersion on Commercial Pepper Fields in Aguascalientes, Mexico

    Directory of Open Access Journals (Sweden)

    Adrián Zapata-Vázquez

    2012-01-01

    Full Text Available Chili pepper blight observed on pepper farms from north Aguascalientes was monitored for the presence of Phytophthora capsici during 2008–2010. Initially, ELISA tests were directed to plant samples from greenhouses and rustic nurseries, showing an 86% of positive samples. Later, samples of wilted plants from the farms during the first survey were tested with ELISA. The subsequent survey on soil samples included mycelia isolation and PCR amplification of a 560 bp fragment of ITS-specific DNA sequence of P. capsici. Data was analyzed according to four geographical areas defined by coordinates to ease the dispersal assessment. In general, one-third of the samples from surveyed fields contained P. capsici, inferring that this may be the pathogen responsible of the observed wilt. Nevertheless, only five sites from a total of 92 were consistently negative to P. capsici. The presence of this pathogen was detected through ELISA and confirmed through PCR. The other two-thirds of the negative samples may be attributable to Fusarium and Rhizoctonia, both isolated instead of Phytophthora in these areas. Due to these striking results, this information would be of interest for local plant protection committees and farmers to avoid further dispersal of pathogens to new lands.

  16. Phytophthora capsici epidemic dispersion on commercial pepper fields in Aguascalientes, Mexico.

    Science.gov (United States)

    Zapata-Vázquez, Adrián; Sánchez-Sánchez, Mario; del-Río-Robledo, Alicia; Silos-Espino, Héctor; Perales-Segovia, Catarino; Flores-Benítez, Silvia; González-Chavira, Mario Martín; Valera-Montero, Luis Lorenzo

    2012-01-01

    Chili pepper blight observed on pepper farms from north Aguascalientes was monitored for the presence of Phytophthora capsici during 2008-2010. Initially, ELISA tests were directed to plant samples from greenhouses and rustic nurseries, showing an 86% of positive samples. Later, samples of wilted plants from the farms during the first survey were tested with ELISA. The subsequent survey on soil samples included mycelia isolation and PCR amplification of a 560 bp fragment of ITS-specific DNA sequence of P. capsici. Data was analyzed according to four geographical areas defined by coordinates to ease the dispersal assessment. In general, one-third of the samples from surveyed fields contained P. capsici, inferring that this may be the pathogen responsible of the observed wilt. Nevertheless, only five sites from a total of 92 were consistently negative to P. capsici. The presence of this pathogen was detected through ELISA and confirmed through PCR. The other two-thirds of the negative samples may be attributable to Fusarium and Rhizoctonia, both isolated instead of Phytophthora in these areas. Due to these striking results, this information would be of interest for local plant protection committees and farmers to avoid further dispersal of pathogens to new lands.

  17. Resistance to Phytophthora infestans EC-1 clonal lineage in Solanum tuberosum by introducing the RB gene

    Directory of Open Access Journals (Sweden)

    María Lupe Román

    2015-04-01

    Full Text Available One of the most efficient options for the control of late blight disease in potato (Solanum tuberosum is the development of resistant varieties to Phytophthora infestans mediated by the direct transfer of resistance (R genes through genetic engineering. In the present work, we used Solanum bulbocastanum RB gene to confers broad spectrum resistance to P. infestans races. To that end, Agrobacterium - mediated genetic transformation was used to transform a susceptible potato variety, Desiree, with the binary vector pCIP68 harboring the RB gene. As a result, 19 transformed plants containing the RB gene were obtained. kanamycin resistance test and polymerase chain reaction (PCR assays confirmed the integration of the T-DNA in the potato genome. The 19 transformed plants, also called transgenic events were subjected to infection under biosafety greenhouse conditions. Phytophthora infestans isolate POX067 of the EC-1 clonal lineage, commonly find in Peru, was used for the infection. Three of the 19 plants ([RB]54, [RB]56 and [RB]70 show high resistance levels to isolate POX067 of P. infestans.

  18. Biocontrol Activity of Myxococcus sp. KYC 1126 against Phytophthora Blight on Hot Pepper

    Directory of Open Access Journals (Sweden)

    Sung Chul Yun

    2011-08-01

    Full Text Available Bacteriolytic myxobacteria have been known to secrete various antifungal metabolites against several soilborne phytopathogens including Phytophthora. Among the three isolates of Myxococcus spp., KYC 1126 and KYC 1136 perfectly inhibited the mycelial growth of Phytophtora capsici in vitro. In order to show the biocontrol activity on Phytophthora blight of hot pepper, we tried to find the best way of application of myxobacterial isolate. Although KYC 1126 fruiting body was easily grown on the colony of Escherichia coli as a nutrient source, it did not control the disease when it was pre-applied in soil. Before the bioassay of a liquid culture filtrate of KYC 1126 was conducted, its antifungal activity was confirmed on the seedlings applying with the mixture of the pathogen`s zoospore suspension and KYC 1126 filtrate. On greenhouse experiments with five and four replications, the control value of KYC 1126 on phyllosphere and rhizosphere was 88% and 36%, respectively. Whereas, the control value of dimetnomorph+propineb on phyllosphere was 100% and that of propamorcarb on rhizosphere was 44%. There was a phytotoxicity of the myxobacterial filtrate when seedlings were washed and soaked for 24 hours. Gummy materials were covered with roots. And stem and petiole were constricted, then a whole seedling was eventually blighted.

  19. Survey and analysis of microsatellites from transcript sequences in Phytophthora species: frequency, distribution, and potential as markers for the genus

    Directory of Open Access Journals (Sweden)

    Barreto Emiliano

    2006-09-01

    Full Text Available Abstract Background Members of the genus Phytophthora are notorious pathogens with world-wide distribution. The most devastating species include P. infestans, P. ramorum and P. sojae. In order to develop molecular methods for routinely characterizing their populations and to gain a better insight into the organization and evolution of their genomes, we used an in silico approach to survey and compare simple sequence repeats (SSRs in transcript sequences from these three species. We compared the occurrence, relative abundance, relative density and cross-species transferability of the SSRs in these oomycetes. Results The number of SSRs in oomycetes transcribed sequences is low and long SSRs are rare. The in silico transferability of SSRs among the Phytophthora species was analyzed for all sets generated, and primers were selected on the basis of similarity as possible candidates for transferability to other Phytophthora species. Sequences encoding putative pathogenicity factors from all three Phytophthora species were also surveyed for presence of SSRs. However, no correlation between gene function and SSR abundance was observed. The SSR survey results, and the primer pairs designed for all SSRs from the three species, were deposited in a public database. Conclusion In all cases the most common SSRs were trinucleotide repeat units with low repeat numbers. A proportion (7.5% of primers could be transferred with 90% similarity between at least two species of Phytophthora. This information represents a valuable source of molecular markers for use in population genetics, genetic mapping and strain fingerprinting studies of oomycetes, and illustrates how genomic databases can be exploited to generate data-mining filters for SSRs before experimental validation.

  20. 附子、肉桂、仙茅对正常大鼠药物代谢酶CYP3A和GST活性的影响%Effects of Aconiti Lateralis Radix Praeparata、 Cinnamomi Cortex Cassiae、 Curculiginis Rhizoma on the activities of drug metabolizing enzymes CYP3A and GST in rats

    Institute of Scientific and Technical Information of China (English)

    薛春苗; 张冰; 刘小青; 李连珍; 张倩

    2011-01-01

    目的:探讨辛热药附子、肉桂、仙茅对正常大鼠药物代谢酶细胞色素P4503A( CYP3A)和谷胱甘肽-S转移酶(GST)活性的影响,为辛热药性的科学阐释及临床安全合理用药提供依据.方法:SD雄性大鼠随机分为4组,空白组灌服自来水,其他各组分别灌胃附子(12g· kg-1·d-1)、肉桂(30g· kg-1·d-1)、仙茅(20g·kg-1·d-1)水煎液,连续7d后,检测肝、小肠微粒体CYP3A活性及肝微粒体和血浆GST活性.结果:与正常组比,附子、肉桂、仙茅组大鼠肝微粒体CYP3A和GST活性显著升高(P<0.01),而小肠微粒体CYP3A活性变化不明显,血浆GST活性有下降趋势.结论:附子、肉桂、仙茅能明显升高大鼠肝脏CYP3A和GST活性,可能是其辛热药性表达的生物学基础之一.%Objective: To discuss the effects of pungent-hot medicine Aconiti Lateralis Radix Preparata, Cinnamomi Cortex Cassiae and Curculiginis Rhizoma on the activities of drug metabolizing enzymes CYP3A and GST in rats. This would provide the experimental evidences for the research of pungent-hot medicine and clinical rational use. Methods: Male SD rats were randomly divided into four groups. Drinking water was .given ig to normal group rats. Radix Aconiti Lateralis Preparata (12g-kg -1-d-1), Cinnamomi Cortex Cassiae (30g-kg-1-d-1) and Curculiginis Rhizoma (20g-kg-1-d-1) water extracts were given ig to the other three groups rats for 7 consecutive days. The activities of CYP3A in liver and small intestinal microsomes were measured. The activities of GST in liver microsomes and plasma were determinated. Results: The activities of liver microsomes CYP3A and GST were increased in the rats treated with Aconiti Lateralis Radix Preparata, Cinnamomi Cortex Cassiae and Curculiginis Rhizomafor 7 days (P<0.01), no significantly changes of small intestinal microsomes CYP3A and plasma GST activities. Conclusions: Aconiti Lateralis Radix Preparata, Cortex Cinnamomi Cassiae and Curculiginis Rhizoma increased