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Sample records for plant pathogenic fungi

  1. Plant Pathogenic Fungi and Oomycetes

    NARCIS (Netherlands)

    Wit, de P.J.G.M.

    2015-01-01

    Fungi and Oomycetes are notorious plant pathogens and use similar strategies to infect plants. The majority of plants, however, is not infected by pathogens as they recognize pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors that mediate PAMP-triggered immunity (PTI) ,

  2. Plant Pathogenic Fungi and Oomycetes

    NARCIS (Netherlands)

    Wit, de P.J.G.M.

    2015-01-01

    Fungi and Oomycetes are notorious plant pathogens and use similar strategies to infect plants. The majority of plants, however, is not infected by pathogens as they recognize pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors that mediate PAMP-triggered immunity (PTI) ,

  3. Improving ITS sequence data for identification of plant pathogenic fungi

    Science.gov (United States)

    R. Henrik Nilsson; Kevin D. Hyde; Julia Pawłowska; Martin Ryberg; Leho Tedersoo; Anders Bjørnsgard Aas; Siti A. Alias; Artur Alves; Cajsa Lisa Anderson; Alexandre Antonelli; A. Elizabeth Arnold; Barbara Bahnmann; Mohammad Bahram; Johan Bengtsson-Palme; Anna Berlin; Sara Branco; Putarak Chomnunti; Asha Dissanayake; Rein Drenkhan; Hanna Friberg; Tobias Guldberg Frøslev; Bettina Halwachs; Martin Hartmann; Beatrice Henricot; Ruvishika Jayawardena; Ari Jumpponen; Håvard Kauserud; Sonja Koskela; Tomasz Kulik; Kare Liimatainen; Björn D. Lindahl; Daniel Lindner; Jian-Kui Liu; Sajeewa Maharachchikumbura; Dimuthu Manamgoda; Svante Martinsson; Maria Alice Neves; Tuula Niskanen; Stephan Nylinder; Olinto Liparini Pereira; Danilo Batista Pinho; Teresita M. Porter; Valentin Queloz; Taavi Riit; Marisol Sánchez-García; Filipe de Sousa; Emil Stefańczyk; Mariusz Tadych; Susumu Takamatsu; Qing Tian; Dhanushka Udayanga; Martin Unterseher; Zheng Wang; Saowanee Wikee; Jiye Yan; Ellen Larsson; Karl-Henrik Larsson; Urmas Kõljalg; Kessy Abarenkov

    2014-01-01

    Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours. These taxa often have complex and poorly understood life cycles, lack observable, discriminatory morphological characters, and may not be amenable to in vitro culturing. As a result, species identification is frequently difficult...

  4. Effects of alkyl parabens on plant pathogenic fungi.

    Science.gov (United States)

    Ito, Shinsaku; Yazawa, Satoru; Nakagawa, Yasutaka; Sasaki, Yasuyuki; Yajima, Shunsuke

    2015-04-15

    Alkyl parabens are used as antimicrobial preservatives in cosmetics, food, and pharmaceutical products. However, the mode of action of these chemicals has not been assessed thoroughly. In this study, we determined the effects of alkyl parabens on plant pathogenic fungi. All the fungi tested, were susceptible to parabens. The effect of linear alkyl parabens on plant pathogenic fungi was related to the length of the alkyl chain. In addition, the antifungal activity was correlated with the paraben-induced inhibition of oxygen consumption. The antifungal activity of linear alkyl parabens likely originates, at least in part, from their ability to inhibit the membrane respiratory chain, especially mitochondrial complex II. Additionally, we determined that some alkyl parabens inhibit Alternaria brassicicola infection of cabbage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Plant cell wall-degrading enzymes and their secretion in plant-pathogenic fungi.

    Science.gov (United States)

    Kubicek, Christian P; Starr, Trevor L; Glass, N Louise

    2014-01-01

    Approximately a tenth of all described fungal species can cause diseases in plants. A common feature of this process is the necessity to pass through the plant cell wall, an important barrier against pathogen attack. To this end, fungi possess a diverse array of secreted enzymes to depolymerize the main structural polysaccharide components of the plant cell wall, i.e., cellulose, hemicellulose, and pectin. Recent advances in genomic and systems-level studies have begun to unravel this diversity and have pinpointed cell wall-degrading enzyme (CWDE) families that are specifically present or enhanced in plant-pathogenic fungi. In this review, we discuss differences between the CWDE arsenal of plant-pathogenic and non-plant-pathogenic fungi, highlight the importance of individual enzyme families for pathogenesis, illustrate the secretory pathway that transports CWDEs out of the fungal cell, and report the transcriptional regulation of expression of CWDE genes in both saprophytic and phytopathogenic fungi.

  6. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Bergstrom Gary C

    2011-02-01

    Full Text Available Abstract Background The discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for the production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly cellulolytic and is a major industrial microbial source for commercial cellulases, xylanases and other cell wall degrading enzymes. However, enzyme-prospecting research continues to identify opportunities to enhance the activity of T. reesei enzyme preparations by supplementing with enzymatic diversity from other microbes. The goal of this study was to evaluate the enzymatic potential of a broad range of plant pathogenic and non-pathogenic fungi for their ability to degrade plant biomass and isolated polysaccharides. Results Large-scale screening identified a range of hydrolytic activities among 348 unique isolates representing 156 species of plant pathogenic and non-pathogenic fungi. Hierarchical clustering was used to identify groups of species with similar hydrolytic profiles. Among moderately and highly active species, plant pathogenic species were found to be more active than non-pathogens on six of eight substrates tested, with no significant difference seen on the other two substrates. Among the pathogenic fungi, greater hydrolysis was seen when they were tested on biomass and hemicellulose derived from their host plants (commelinoid monocot or dicot. Although T. reesei has a hydrolytic profile that is highly active on cellulose and pretreated biomass, it was less active than some natural isolates of fungi when tested on xylans and untreated biomass. Conclusions Several highly active isolates of plant pathogenic fungi were identified, particularly when tested on xylans and untreated biomass. There were statistically significant preferences for biomass type reflecting the monocot or dicot host preference of the

  7. Chemosensitization of plant pathogenic fungi to agricultural fungicides.

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    Vitaly eDzhavakhiya

    2012-03-01

    Full Text Available A common consequence of using agricultural fungicides is the development of resistance by fungal pathogens, which undermines reliability of fungicidal effectiveness. A potentially new strategy to aid in overcoming or minimizing this problem is enhancement of pathogen sensitivity to fungicides, or chemosensitization. Chemosensitization can be accomplished by combining a commercial fungicide with a certain non- or marginally fungicidal substance at levels where, alone, neither compound would be effective. Chemosensitization decreases the probability of the pathogen developing resistance, reduces the toxic impact on the environment by lowering effective dosage levels of toxic fungicides, and improves efficacy of antifungal agents. The present study shows that the antifungal activity of azole and strobilurin fungicides can be significantly enhanced through their co-application with certain natural or synthetic products against several economically important plant pathogenic fungi. Quadris (azoxystrobin combined with thymol at a non-fungitoxic concentration produced much higher growth inhibition of Bipolaris sorokiniana, Phoma glomerata, Alternaria sp. and Stagonospora nodorum than the fungicide alone. The effect of Dividend (difenoconazole applied with thymol significantly enhanced antifungal activity against B. sorokiniana and S. nodorum. Folicur (tebuconazole combined with 4-hydroxybenzaldehyde (4-HBA, 2,3-dihydroxybenzaldehyde or thymol significantly inhibited growth of A. alternata, at a much greater level than the fungicide alone. In addition, co-application of Folicur and 4-HBA resulted in a similar enhancement of antifungal activity against Fusarium culmorum. Lastly, we discovered that metabolites in the culture liquid of F. sambucinum biocontrol isolate FS-94 also had chemosensitizing activity, increasing S. nodorum sensitivity to Folicur and Dividend.

  8. Chemosensitization of plant pathogenic fungi to agricultural fungicides.

    Science.gov (United States)

    Dzhavakhiya, Vitaly; Shcherbakova, Larisa; Semina, Yulia; Zhemchuzhina, Natalia; Campbell, Bruce

    2012-01-01

    A common consequence of using agricultural fungicides is the development of resistance by fungal pathogens, which undermines reliability of fungicidal effectiveness. A potentially new strategy to aid in overcoming or minimizing this problem is enhancement of pathogen sensitivity to fungicides, or "chemosensitization." Chemosensitization can be accomplished by combining a commercial fungicide with a certain non- or marginally fungicidal substance at levels where, alone, neither compound would be effective. Chemosensitization decreases the probability of the pathogen developing resistance, reduces the toxic impact on the environment by lowering effective dosage levels of toxic fungicides, and improves efficacy of antifungal agents. The present study shows that the antifungal activity of azole and strobilurin fungicides can be significantly enhanced through their co-application with certain natural or synthetic products against several economically important plant pathogenic fungi. Quadris (azoxystrobin) combined with thymol at a non-fungitoxic concentration produced much higher growth inhibition of Bipolaris sorokiniana, Phoma glomerata, Alternaria sp. and Stagonospora nodorum than the fungicide alone. The effect of Dividend (difenoconazole) applied with thymol significantly enhanced antifungal activity against B. sorokiniana and S. nodorum. Folicur (tebuconazole) combined with 4-hydroxybenzaldehyde (4-HBA), 2,3-dihydroxybenzaldehyde or thymol significantly inhibited growth of Alternaria alternata, at a much greater level than the fungicide alone. In addition, co-application of Folicur and 4-HBA resulted in a similar enhancement of antifungal activity against Fusarium culmorum. Lastly, we discovered that metabolites in the culture liquid of Fusarium sambucinum biocontrol isolate FS-94 also had chemosensitizing activity, increasing S. nodorum sensitivity to Folicur and Dividend.

  9. Diaporthe: a genus of endophytic, saprobic and plant pathogenic fungi

    NARCIS (Netherlands)

    Gomes, R.R.; Glienke, C.; Videira, S.I.R.; Lombard, L.; Groenewald, J.Z.; Crous, P.W.

    2013-01-01

    Diaporthe (Phomopsis) species have often been reported as plant pathogens, non-pathogenic endophytes or saprobes, commonly isolated from a wide range of hosts. The primary aim of the present study was to resolve the taxonomy and phylogeny of a large collection of Diaporthe species occurring on diver

  10. Nutrient acquisition and secondary metabolites in plant pathogenic fungi

    DEFF Research Database (Denmark)

    Droce, Aida

    and infection processes of these two distinct phytopathogens are described with special attention on the importance of uptake and reallocation of nutrients. Nutrient uptake from host plant is crucial for fungi to grow and proliferate and during several developmental processes nutrient reallocation, a mechanism...... called autophagy, is crucial. In this ph.d project autophagy and dipeptide transport in Fg and Bgh is assessed with respect to pathology, developmental processes and mycotoxins production. Several techniques within molecular biology, bioinformatics, microbiology, analytical chemistry and plant pathology...

  11. The biotechnological use and potential of plant pathogenic smut fungi.

    Science.gov (United States)

    Feldbrügge, Michael; Kellner, Ronny; Schipper, Kerstin

    2013-04-01

    Plant pathogens of the family Ustilaginaceae parasitise mainly on grasses and cause smut disease. Among the best characterised members of this family are the covered smut fungus Ustilago hordei colonising barley and oat as well as the head smut Sporisorium reilianum and the corn smut Ustilago maydis, both infecting maize. Over the past years, U. maydis in particular has matured into a model system for diverse topics like plant-pathogen interaction, cellular transport processes or DNA repair. Consequently, a broad set of genetic, molecular and system biological methods has been established. This set currently serves as a strong foundation to improve existing and establish novel biotechnological applications. Here, we review four promising aspects covering different fields of applied science: (1) synthesis of secondary metabolites produced at fermenter level. (2) Lipases and other hydrolytic enzymes with potential roles in biocatalytic processes. (3) Degradation of ligno-cellulosic plant materials for biomass conversion. (4) Protein expression based on unconventional secretion, a novel approach inspired by basic research on mRNA transport. Thus, plant pathogenic Ustilaginaceae offer a great potential for future biotechnological applications by combining basic research and applied science.

  12. Foliar endophytic fungi as potential protectors from pathogens in myrmecophytic Acacia plants

    OpenAIRE

    González-Teuber, M.; Jimenez-Aleman, G.; W Boland

    2014-01-01

    In defensive ant-plant interactions myrmecophytic plants express reduced chemical defense in their leaves to protect themselves from pathogens, and it seems that mutualistic partners are required to make up for this lack of defensive function. Previously, we reported that mutualistic ants confer plants of Acacia hindsii protection from pathogens, and that the protection is given by the ant-associated bacteria. Here, we examined whether foliar endophytic fungi may potentially act as a new part...

  13. Foliar endophytic fungi as potential protectors from pathogens in myrmecophytic Acacia plants.

    Science.gov (United States)

    González-Teuber, Marcia; Jiménez-Alemán, Guillermo H; Boland, Wilhelm

    2014-10-01

    In defensive ant-plant interactions myrmecophytic plants express reduced chemical defense in their leaves to protect themselves from pathogens, and it seems that mutualistic partners are required to make up for this lack of defensive function. Previously, we reported that mutualistic ants confer plants of Acacia hindsii protection from pathogens, and that the protection is given by the ant-associated bacteria. Here, we examined whether foliar endophytic fungi may potentially act as a new partner, in addition to mutualistic ants and their bacteria inhabitants, involved in the protection from pathogens in myrmecophytic Acacia plants. Fungal endophytes were isolated from the asymptomatic leaves of A. hindsii plants for further molecular identification of 18S rRNA gene. Inhibitory effects of fungal endophytes were tested against Pseudomonas plant pathogens. Our findings support a potential role of fungal endophytes in pathogen the protection mechanisms against pathogens in myrmecophytic plants and provide the evidence of novel fungal endophytes capable of biosynthesizing bioactive metabolites.

  14. Antifungal Activities of Extracts from Selected Lebanese Wild Plants against Plant Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Y. Abou-Jawdah

    2004-12-01

    Full Text Available Extracts of nine plant species growing wild in Lebanon were tested for their efficacy against seven plant pathogenic fungi: Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, Rhizoctonia solani and Sphaerotheca cucurbitae. Extracts of three of the plants, Origanum syriacum, Micromeria nervosa and Plumbago maritima, showed the highest levels of in vitro activity against spore germination and mycelial growth of the fungi tested. Inula viscosa showed high activity against spore germination but only moderate activity against mycelial growth. The other five plant species tested Calamintha origanifolia, Micromeria juliana, Ruta sp., Sideritis pullulans and Urginea maritima showed only moderate to low activity against these fungi. Preventive sprays with extracts of O. syriacum, M. nervosa, P. maritima and I. viscosa, applied at concentrations ranging between 4 and 8% to squash and cucumber seedlings, gave efficient protection against gray mold caused by B. cinerea and powdery mildew caused by S. cucurbitae. However, these extracts did not control green mold of citrus fruits caused by Penicillium sp. Thin layer chromatography revealed three inhibitory bands in extracts of O. syriacum, two in I. viscosa and only one in each of the other plants tested: M. nervosa, P. maritima, C. origanifolia and Ruta sp.

  15. Ulvans induce resistance against plant pathogenic fungi independently of their sulfation degree.

    Science.gov (United States)

    de Freitas, Mateus B; Ferreira, Luciana G; Hawerroth, Caroline; Duarte, Maria Eugênia R; Noseda, Miguel D; Stadnik, Marciel J

    2015-11-20

    The present work aimed to evaluate the defense responses induced by chemically sulfated ulvans in Arabidopsis thaliana plants against the phytopathogenic fungi Alternaria brassicicola and Colletotrichum higginsianum. Derivatives with growing sulfate content (from 20.9 to 36.6%) were prepared with SO3-pyridine complex in formamide. NMR and FTIR spectroscopic analyses confirmed the increase of sulfate groups after the chemical sulfation process. The native sulfated polysaccharide (18.9% of sulfate) and its chemically sulfated derivatives similarly reduced the severity of both pathogenic fungi infections. Collectively, our results suggest that ulvans induce resistance against both fungal pathogens independently of its sulfation degree.

  16. Differential Communications between Fungi and Host Plants Revealed by Secretome Analysis of Phylogenetically Related Endophytic and Pathogenic Fungi.

    Science.gov (United States)

    Xu, Xihui; He, Qin; Chen, Chen; Zhang, Chulong

    During infection, both phytopathogenic and endophytic fungi form intimate contact with living plant cells, and need to resist or disable host defences and modify host metabolism to adapt to their host. Fungi can achieve these changes by secreting proteins and enzymes. A comprehensive comparison of the secretomes of both endophytic and pathogenic fungi can improve our understanding of the interactions between plants and fungi. Although Magnaporthe oryzae, Gaeumannomyces graminis, and M. poae are economically important fungal pathogens, and the related species Harpophora oryzae is an endophyte, they evolved from a common pathogenic ancestor. We used a pipeline analysis to predict the H. oryzae, M. oryzae, G. graminis, and M. poae secretomes and identified 1142, 1370, 1001, and 974 proteins, respectively. Orthologue gene analyses demonstrated that the M. oryzae secretome evolved more rapidly than those of the other three related species, resulting in many species-specific secreted protein-encoding genes, such as avirulence genes. Functional analyses highlighted the abundance of proteins involved in the breakdown of host plant cell walls and oxidation-reduction processes. We identified three novel motifs in the H. and M. oryzae secretomes, which may play key roles in the interaction between rice and H. oryzae. Furthermore, we found that expression of the H. oryzae secretome involved in plant cell wall degradation was downregulated, but the M. oryzae secretome was upregulated with many more upregulated genes involved in oxidation-reduction processes. The divergent in planta expression patterns of the H. and M. oryzae secretomes reveal differences that are associated with mutualistic and pathogenic interactions, respectively.

  17. In vitro antifungal activity of three geophytic plant extracts against three post-harvest pathogenic fungi.

    Science.gov (United States)

    Maswada, Hanafey F; Abdallah, Sabry A

    2013-12-01

    Plant extracts appear to be one of the most effective alternative methods of plant diseases control which are less harmful to human beings and environment. In vitro antifungal activity of methanolic extracts of three promising wild geophytic plants against three post-harvest pathogenic fungi using radial growth technique was conducted. These extracts included the shoot system (S) and underground parts (R) of Asparagus stipularis, Cyperus capitatus and Stipagrostis lanata. The tested fungi were Alternaria solani, Aspergillus niger and Rhizopus stolonifer. The results exhibited that, all plant extracts had antifungal activity against the tested fungi. The antifungal activity greatly varied depending on plant parts and/or plant species. R. stolonifer was the most susceptible fungus to the tested plant extracts followed by A. niger and then A. solani. On the other hand, the most effective plant extracts against tested fungi were S. lanata (S) and A. stipularis (R). The most effective plant extracts against R. stolonifer were S. lanata (R) and C. capitatus (S). While, the extracts of A. stipularis (R) and S. lanata (S) were the most effective against A. niger. The extracts of C. capitatus (S) and S. lanata (S) exhibited the highest antifungal activity against A. solani. The results demonstrated that, the methanolic extracts of A. stipularis, C. capitatus and S. lanata had potential antifungal activity against A. solani, A. niger and R. stolonifer.

  18. bryophyte extracts with activity against plant pathogenic fungi

    African Journals Online (AJOL)

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    evidenced on treated plants at 4 hours before the inoculation. However, plants treated by the same ... posing of toxicity dangers to the society in Western. Ethiopia have resulted in ...... of extinction due to deforestation and habitat degradation.

  19. Protecting Plants against Pests and Pathogens with Entomopathogenic Fungi

    DEFF Research Database (Denmark)

    Keyser, Chad Alton

    is an increasingly important area of research. Efforts to maximize agricultural output are significantly dependent on reliable means for pest suppression. Biological control, or the use of living organisms to suppress a pest population, is a leading alternative to traditional chemical-based pesticides for crop...... protection. The fungal genus Metarhizium is one of the most intensely researched groups of entomopathogenic fungi and several isolates have been successfully employed as biopesticides for crop protection; however, inconsistent field reliability has limited wider implementation. Research emphasizing...... of variability with in the species. The results of these studies further clarify the important role Metarhizium spp. play in the natural environment and highlight their vast potential to be implemented as biological control agents of important pest insects....

  20. Protecting Plants against Pests and Pathogens with Entomopathogenic Fungi

    DEFF Research Database (Denmark)

    Keyser, Chad Alton

    This thesis investigates the natural occurrence of the fungal genus Metarhizium in association with crop-roots in Denmark, and advances the current understanding of how these fungi interact with other root-associating organisms when applied as a biological control agent. Insect-pest management...... is an increasingly important area of research. Efforts to maximize agricultural output are significantly dependent on reliable means for pest suppression. Biological control, or the use of living organisms to suppress a pest population, is a leading alternative to traditional chemical-based pesticides for crop...... of variability with in the species. The results of these studies further clarify the important role Metarhizium spp. play in the natural environment and highlight their vast potential to be implemented as biological control agents of important pest insects....

  1. Synthesis and in vitro antifungal efficacy of oleoyl-chitosan nanoparticles against plant pathogenic fungi.

    Science.gov (United States)

    Xing, Ke; Shen, Xiaoqiang; Zhu, Xiao; Ju, Xiuyun; Miao, Xiangmin; Tian, Jun; Feng, Zhaozhong; Peng, Xue; Jiang, Jihong; Qin, Sheng

    2016-01-01

    An antifungal dispersion system was prepared by oleoyl-chitosan (O-chitosan) nanoparticles, and the antifungal activity against several plant pathogenic fungi was investigated. Under scanning electron microscopy, the nanoparticles formulation appeared to be uniform with almost spherical shape. The particle size of nanoparticles was around 296.962 nm. Transmission electron microscopy observation showed that nanoparticles could be well distributed in potato dextrose agar medium. Mycelium growth experiment demonstrated that Nigrospora sphaerica, Botryosphaeria dothidea, Nigrospora oryzae and Alternaria tenuissima were chitosan-sensitive, while Gibberella zeae and Fusarium culmorum were chitosan-resistant. The antifungal index was increased as the concentration of nanoparticles increased for chitosan-sensitive fungi. Fatty acid analyses revealed that plasma membranes of chitosan-sensitive fungi were shown to have lower levels of unsaturated fatty acid than chitosan-resistant fungi. Phylogenetic analysis based on ITS gene sequences indicated that two chitosan-resistant fungi had a near phylogenetic relationship. Results showed that O-chitosan nanoparticles could be a useful alternative for controlling pathogenic fungi in agriculture. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Antifungal Substances from Streptomyces sp. A3265 Antagonistic to Plant Pathogenic Fungi.

    Science.gov (United States)

    Van Minh, Nguyen; Woo, E-Eum; Kim, Ji-Yul; Kim, Dae-Won; Hwang, Byung Soon; Lee, Yoon-Ju; Lee, In-Kyoung; Yun, Bong-Sik

    2015-09-01

    In a previous study, we identified a Streptomyces sp., A3265, as exhibiting potent antifungal activity against various plant pathogenic fungi, including Botrytis cinerea, Colletotrichum gloeosporioides, and Rhizoctonia solani. This strain also exhibited a biocontrolling effect against ginseng root rot and damping-off disease, common diseases of ginseng and other crops. In this study, we isolated two antifungal substances responsible for this biocontrolling effect via Diaion HP-20 and Sephadex LH-20 column chromatography, medium pressure liquid chromatography, and high-performance liquid chromatography. These compounds were identified as guanidylfungin A and methyl guanidylfungin A by spectroscopic methods. These compounds exhibited potent antimicrobial activity against various plant pathogenic fungi as well as against bacteria.

  3. Identification of Plant-Pathogenic Fungi Using Fourier Transform Infrared Spectroscopy Combined with Chemometric Analyses

    Institute of Scientific and Technical Information of China (English)

    CHAI A-li; WANG Yi-kai; ZHU Fa-di; SHI Yan-xia; XIE Xue-wen; LI Bao-ju

    2016-01-01

    Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic exami-nation and can be influenced by the interpretation of the micro-morphological characters observed.The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic fungi by Fourier transform infrared (FTIR)spectroscopy.In this study,FTIR-attenuated total reflectance (ATR) spectroscopy was used in combination with chemometric analysis for identification of important pathogenic fun-gi of horticultural plants.Mixtures of mycelia and spores from 27 fungal strains belonging to nine different families were collected from liquid PD or solid PDA media cultures and subj ected to FTIR-ATR spectroscopy measurements.The FTIR-ATR spectra ranging from 4 000 to 400 cm-1 were obtained.To classify the FTIR-ATR spectra,cluster analysis was compared with canonical vitiate analysis (CVA)in the spectral regions of 3 050~2 800 and 1 800~900 cm-1 .Results showed that the identification accuracies achieved 97.53% and 9 9.1 8% for the cluster analysis and CVA analysis,respectively,demonstrating the high potential of this tech-nique for fungal strain identification.

  4. Fungal Control of Pathogenic Fungi Isolated From Some Wild Plants in Taif Governorate, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abou-Zeid, A. M.

    2008-01-01

    Full Text Available Twenty two plants were collected from Taif Governorate and identified as: Aerva lanata, Arnebia hispidissima, Artemisia judaica, Artemisia monosperma, Asphodelus aestives, Avena barbata, Capparis dcidua, Eucalyptus globulus, Euphorbia glomerifera, Foeniculum vulgare, Forsskaolea tenacissima, Juniperus procera, Launaea mucronata, Launaea sonchoides, Medicago sativa, Opuntia ficus, Phagnalon sinaicum, Prunus persica, Pulicaria crispa, Punica granatum, Rumex dentatus and Trichodesma calathiforme. Pathogenic fungi were isolated from some of these plants and identified as Alternaria alternata, Cephalosporium madurae, Cladosporium herbarum, Fusarium oxysporum, Humicola grisea, Penicillium chrysogenum and Ulocladium botrytis. Four antagonistic isolates were tested, 2 from Gliocladium fungus and 2 from Trichoderma fungus. We found that all the four antagonistic isolates (G. deliquescens, G. virens, T. viride and T. hamatum significantly inhibited the radial growth of the pathogenic fungi tested, with different ratios. The results indicated that the antibiotics produced by the antagonists were more effective than the fungus itself and differ with different fungi. Coating plant stems with antagonists or with antagonist extracts reduce the severity of the disease but not prevent it in all tested pathogens.

  5. Pseudogenization in pathogenic fungi with different host plants and lifestyles might reflect their evolutionary past.

    Science.gov (United States)

    van der Burgt, Ate; Karimi Jashni, Mansoor; Bahkali, Ali H; de Wit, Pierre J G M

    2014-02-01

    Pseudogenes are genes with significant homology to functional genes, but contain disruptive mutations (DMs) leading to the production of non- or partially functional proteins. Little is known about pseudogenization in pathogenic fungi with different lifestyles. Here, we report the identification of DMs causing pseudogenes in the genomes of the fungal plant pathogens Botrytis cinerea, Cladosporium fulvum, Dothistroma septosporum, Mycosphaerella fijiensis, Verticillium dahliae and Zymoseptoria tritici. In these fungi, we identified 1740 gene models containing 2795 DMs obtained by an alignment-based gene prediction method. The contribution of sequencing errors to DMs was minimized by analyses of resequenced genomes to obtain a refined dataset of 924 gene models containing 1666 true DMs. The frequency of pseudogenes varied from 1% to 5% in the gene catalogues of these fungi, being the highest in the asexually reproducing fungus C. fulvum (4.9%), followed by D. septosporum (2.4%) and V. dahliae (2.1%). The majority of pseudogenes do not represent recent gene duplications, but members of multi-gene families and unitary genes. In general, there was no bias for pseudogenization of specific genes in the six fungi. Single exceptions were those encoding secreted proteins, including proteases, which appeared more frequently pseudogenized in C. fulvum than in D. septosporum. Most pseudogenes present in these two phylogenetically closely related fungi are not shared, suggesting that they are related to adaptation to a different host (tomato versus pine) and lifestyle (biotroph versus hemibiotroph). © 2013 BSPP AND JOHN WILEY & SONS LTD.

  6. A survey on the pathogenic fungi in soil samples of potted plants from Sari hospitals, Iran.

    Science.gov (United States)

    Hedayati, M T; Mohseni-Bandpi, A; Moradi, S

    2004-09-01

    A total of 23 soil samples of potted plants was collected from hospitals in Sari, Iran. Each sample contained approximately 200 g soil, taken from a depth of 0-10 cm of the pots. Samples were analysed by two different methods. (1) Culture on Sabouraud's dextrose agar medium containing chloramphenicol (SC); cultured fungi were identified by macroscopic and microscopic characterization. (2) The hair-baiting technique (HBT) was used to isolate the keratinophilic fungi. After culture on SC medium, 100% of plates were positive for fungal growth, and in total 1150 colonies with 13 different types of fungi were isolated. Penicillium spp. (52%), Acremonium spp. (20%), Paecilomyces spp. (11.9%), Cladsporium spp. (3.7%) and Aspergillus spp. (3.1%) were the predominant fungal species. Rhizopus spp. (0.1%) were less frequent. Keratinophilic fungi such as Microsporum gypseum, Microsporum cookei and Chrysosporium spp. were isolated using HBT. The presence of pathogenic fungi such as Cladosporium spp, Aspergillus spp, M. gypseum, and M. cookei in potted plants in hospitals represents a potential source of nosocomial infection.

  7. Lifestyle transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses.

    Science.gov (United States)

    O'Connell, Richard J; Thon, Michael R; Hacquard, Stéphane; Amyotte, Stefan G; Kleemann, Jochen; Torres, Maria F; Damm, Ulrike; Buiate, Ester A; Epstein, Lynn; Alkan, Noam; Altmüller, Janine; Alvarado-Balderrama, Lucia; Bauser, Christopher A; Becker, Christian; Birren, Bruce W; Chen, Zehua; Choi, Jaeyoung; Crouch, Jo Anne; Duvick, Jonathan P; Farman, Mark A; Gan, Pamela; Heiman, David; Henrissat, Bernard; Howard, Richard J; Kabbage, Mehdi; Koch, Christian; Kracher, Barbara; Kubo, Yasuyuki; Law, Audrey D; Lebrun, Marc-Henri; Lee, Yong-Hwan; Miyara, Itay; Moore, Neil; Neumann, Ulla; Nordström, Karl; Panaccione, Daniel G; Panstruga, Ralph; Place, Michael; Proctor, Robert H; Prusky, Dov; Rech, Gabriel; Reinhardt, Richard; Rollins, Jeffrey A; Rounsley, Steve; Schardl, Christopher L; Schwartz, David C; Shenoy, Narmada; Shirasu, Ken; Sikhakolli, Usha R; Stüber, Kurt; Sukno, Serenella A; Sweigard, James A; Takano, Yoshitaka; Takahara, Hiroyuki; Trail, Frances; van der Does, H Charlotte; Voll, Lars M; Will, Isa; Young, Sarah; Zeng, Qiandong; Zhang, Jingze; Zhou, Shiguo; Dickman, Martin B; Schulze-Lefert, Paul; Ver Loren van Themaat, Emiel; Ma, Li-Jun; Vaillancourt, Lisa J

    2012-09-01

    Colletotrichum species are fungal pathogens that devastate crop plants worldwide. Host infection involves the differentiation of specialized cell types that are associated with penetration, growth inside living host cells (biotrophy) and tissue destruction (necrotrophy). We report here genome and transcriptome analyses of Colletotrichum higginsianum infecting Arabidopsis thaliana and Colletotrichum graminicola infecting maize. Comparative genomics showed that both fungi have large sets of pathogenicity-related genes, but families of genes encoding secreted effectors, pectin-degrading enzymes, secondary metabolism enzymes, transporters and peptidases are expanded in C. higginsianum. Genome-wide expression profiling revealed that these genes are transcribed in successive waves that are linked to pathogenic transitions: effectors and secondary metabolism enzymes are induced before penetration and during biotrophy, whereas most hydrolases and transporters are upregulated later, at the switch to necrotrophy. Our findings show that preinvasion perception of plant-derived signals substantially reprograms fungal gene expression and indicate previously unknown functions for particular fungal cell types.

  8. SCREENING OF FLUORESCENT RHIZOBACTERIA FOR THE BIOCONTROL OF SOILBORNE PLANT PATHOGENIC FUNGI

    Directory of Open Access Journals (Sweden)

    ANELISE DIAS

    2014-01-01

    Full Text Available The biocontrol of soilborne plant pathogens represents a promising approach from the environ- mental and practical points of view. Fluorescent pseudomonad rhizobacteria are well known by their antagonis- tic capacity towards several plant pathogens due to a diversity of antimicrobial metabolites they produce. This study was conceived to select and characterize rhizobacteria having antagonistic potential towards the patho- genic fungi Rhizoctonia solani and Sclerotium rolfsii. A total of 94 bacterial strains isolated from the rhizospheres of four vegetable species under organic cultivation were evaluated. Twenty-two strains which predominate in lettuce and rudbeckia rhizospheres showed identical biochemical profiles to Pseudomonas fluo- rescens, while in kale and parsley rhizospheres identical profiles to Pseudomonas putida (subgroups A and B strains prevailed. Two types of antagonism were verified in vitro and defined as competition and inhibition of mycelial growth. Sixty percent of the evaluated strains showed antagonistic potential and, among those, 24 strains expressed antagonism to both target fungi, with P. fluorescens being the most representative bacterial species. This work clearly identified a number of strains with potential for use as plant growth-promoting and biocontrol of the two soilborne fungal pathogens in vegetable crops production systems.

  9. Inhibition of polyamine biosynthesis and growth in plant pathogenic fungi in vitro.

    Science.gov (United States)

    Rajam, B; Rajam, M V

    1996-02-01

    Polyamine (PA) biosynthesis inhibitors, difluoromethylornithine (DFMO), difluoromethylarginine (DFMA), methylglyoxal bis-(guanylhydrazone) (MGBG) and bis-(cyclohexylammonium) sulphate (BCHA) have been tested for their effects on colony diameters at different intervals after inoculation of four plant pathogenic fungi (Helminthosporium oryzae, Curvularia lunata, Pythium aphanidermatum and Colletotrichum capsici). All these inhibitors, except DFMA had strongly retarded the growth of four fungi in a dose- and species-dependent fashion, and H. oryzae and C. lunata were found to be most sensitive to the effects of PA inhibitors. P. aphanidermatum and C. capsici were relatively insensitive and required rather high concentrations of inhibitors to get greater inhibition of mycelial growth, except DFMA which had stimulatory effect on the growth of these two fungi. However DFMA had greatly suppressed the growth of H. oryzae and C. lunata. The effect was generally more pronounced with MGBG than with DFMO and BCHA, and 1 mM Put completely prevented the inhibitory effects of 1 and 5 mM DFMO. Analysis of free and conjugated PAs in two sensitive fungi (H. oryzae and C. lunata) revealed that Put was present in highest concentrations followed by Spd and Spm and their levels were greatly reduced by DFMO application, and such inhibitions were totally reversed by exogenously supplied Put; in fact, PA titers were considerably increased by 1 mM Put alone and in combination with 1 mM DFMO. These results suggest that PA inhibitors, particularly DFMO and MGBG may be useful as target-specific fungicides in plants.

  10. Evaluation of antifungal potential of selected medicinal plants against human pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Hayat Sakander

    2015-01-01

    Full Text Available Context: Evaluation of medicinal plants used in traditional medicine lead to novel bioactive compounds with antifungal activity that could be exploited as therapeutic agents. Aims: The aim was to screen selected medicinal plants for antifungal activity against three important human pathogenic fungi and to identify the broad group of phytochemicals responsible for the activity. Materials and Methods: A total of 8 medicinal plants were screened for antifungal activity against three human pathogenic fungi. Aqueous and the solvent extracts of the plant materials were prepared by polarity based solvent extraction. Antifungal activity was tested by well and disc diffusion methods. Minimum inhibitory concentration (MIC of the active extract was determined by micro-broth dilution technique. Phytochemical analysis of the active extract was done. Statistical Analysis Used: The results were statistically analysed by One-Way analysis of variance with Post-hoc Tukey′s B test at P < 0.05 using the  Software SPSS version 20 (IBM Corp. Armonk, NY Released 2011. Results: Significant antifungal activity was observed in the aqueous extracts of the fruits of Terminalia chebula (47.75 mm against Microsporum gypseum and the mesocarp of Persea americana (40.5 mm against Microsporum canis. Candida albicans was inhibited by the ethyl acetate (20 mm and aqueous extracts (16 mm of T. chebula fruits and aqueous extract of the seeds of Syzygium jambos (16 mm. The aqueous extract of mesocarp of P. americana showed lowest MIC value (312.5 μg/ml against M. canis and M. gypseum. Phytochemical analysis of the active extracts revealed the presence of phenols, tannins, alkaloids and flavonoids. Conclusions: The study validates the use of the plants in the treatment of fungal infections and has provided important leads for the discovery of new plant-based antifungal agents.

  11. Diversity of Endophytic Fungi from Red Ginger (Zingiber officinale Rosc. Plant and Their Inhibitory Effect to Fusarium oxysporum Plant Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    SIHEGIKO KANAYA

    2013-09-01

    Full Text Available Indonesia has been known as a country with high medicinal plant diversity. One of the most common medicinal plant from Indonesia is red ginger (Zingiber officinale Rosc.. Nevertheless, limited studies of endophytic fungi associated with these medicinal plants are hitherto available. The objectives of this research were to study the diversity of endophytic fungi on red ginger and to analyze their potential as a source of antifungal agent. All parts of plant organs such as leaf, rhizome, root, and stem were subjected for isolation. Fungal identification was carried out by using a combination of morphological characteristic and molecular analysis of DNA sequence generated from ITS rDNA region. Thirty endophytic fungi were successfully isolated from leaf, rhizome, root, and stem of red ginger plant. Antagonistic activity was tested against Fusarium oxysporum, a pathogenic fungus on plants, using an antagonistic assay. Based on this approach, the fungi were assigned as Acremonium macroclavatum, Beltraniella sp., Cochliobolus geniculatus and its anamorphic stage Curvularia affinis, Fusarium solani, Glomerella cingulata, and its anamorphic stage Colletotrichum gloeosporoides, Lecanicillium kalimantanense, Myrothecium verrucaria, Neonectria punicea, Periconia macrospinosa, Rhizopycnis vagum, and Talaromyces assiutensis. R. vagum was found specifically on root whereas C. affinis, L. kalimantanense, and M. verrucaria were found on stem of red ginger plant. A. macroclavatum was found specifically in red ginger plant’s organ which located under the ground, whereas C. affinis was found from shoot or organ which located above the ground. The antagonistic activity of isolated endophytic fungi against F. oxysporum varied with the inhibition value range from 1.4 to 68.8%. C. affinis (JMbt7, F. solani (JMd14, and G. cingulata (JMr2 had significantly high antagonistic activity with the value above 65%; and R. vagum (JMa4 and C. geniculatus (JMbt9 had

  12. Antifungal activity of diketopiperazines and stilbenes against plant pathogenic fungi in vitro.

    Science.gov (United States)

    Kumar, S Nishanth; Nambisan, Bala

    2014-01-01

    The present study aimed to investigate antifungal activity of a stilbene and diketopiperazine compounds against plant pathogenic fungi, including Phytophthora capsici, P. colocasiae, Botrytis cinerea and Colletotrichum gloeosporioides. Minimal inhibition concentrations (MIC) and minimal fungicidal concentrations (MFC) of stilbenes and diketopiperazines for each fungus were determined using microplate method. Best activity was recorded by stilbenes against P. capsici and P. colocasiae. All four test compounds were effective in inhibiting different stages of the life cycle of test fungi. Stilbenes were more effective than diketopiperazines in inhibiting mycelial growth and inhibiting different stages of the life cycle of P. capsici and P. colocasiae. Rupture of released zoospores induced by stilbenes was reduced by addition of 100 mM glucose. The effects of stilbenes on mycelial growth and zoospore release, but not zoospore rupture, were reduced largely when pH value was above 7. In addition, stilbenes were investigated for its antifungal stability against Phytophthora sp. The results showed that stilbenes maintained strong fungistatic activity over a wide pH range (pH 4–9) and temperature range (70–120 °C). The compound stilbenes exhibited strong and stable broad-spectrum antifungal activity, and had a significant fungicidal effect on fungal cells. Results from prebiocontrol evaluations performed to date are probably useful in the search for alternative approaches to controlling serious plant pathogens.

  13. Tools to kill: genome of one of the most destructive plant pathogenic fungi Macrophomina phaseolina.

    Science.gov (United States)

    Islam, Md Shahidul; Haque, Md Samiul; Islam, Mohammad Moinul; Emdad, Emdadul Mannan; Halim, Abdul; Hossen, Quazi Md Mosaddeque; Hossain, Md Zakir; Ahmed, Borhan; Rahim, Sifatur; Rahman, Md Sharifur; Alam, Md Monjurul; Hou, Shaobin; Wan, Xuehua; Saito, Jennifer A; Alam, Maqsudul

    2012-09-19

    Macrophomina phaseolina is one of the most destructive necrotrophic fungal pathogens that infect more than 500 plant species throughout the world. It can grow rapidly in infected plants and subsequently produces a large amount of sclerotia that plugs the vessels, resulting in wilting of the plant. We sequenced and assembled ~49 Mb into 15 super-scaffolds covering 92.83% of the M. phaseolina genome. We predict 14,249 open reading frames (ORFs) of which 9,934 are validated by the transcriptome. This phytopathogen has an abundance of secreted oxidases, peroxidases, and hydrolytic enzymes for degrading cell wall polysaccharides and lignocelluloses to penetrate into the host tissue. To overcome the host plant defense response, M. phaseolina encodes a significant number of P450s, MFS type membrane transporters, glycosidases, transposases, and secondary metabolites in comparison to all sequenced ascomycete species. A strikingly distinct set of carbohydrate esterases (CE) are present in M. phaseolina, with the CE9 and CE10 families remarkably higher than any other fungi. The phenotypic microarray data indicates that M. phaseolina can adapt to a wide range of osmotic and pH environments. As a broad host range pathogen, M. phaseolina possesses a large number of pathogen-host interaction genes including those for adhesion, signal transduction, cell wall breakdown, purine biosynthesis, and potent mycotoxin patulin. The M. phaseolina genome provides a framework of the infection process at the cytological and molecular level which uses a diverse arsenal of enzymatic and toxin tools to destroy the host plants. Further understanding of the M. phaseolina genome-based plant-pathogen interactions will be instrumental in designing rational strategies for disease control, essential to ensuring global agricultural crop production and security.

  14. Tools to kill: Genome of one of the most destructive plant pathogenic fungi Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    Islam Md

    2012-09-01

    Full Text Available Abstract Background Macrophomina phaseolina is one of the most destructive necrotrophic fungal pathogens that infect more than 500 plant species throughout the world. It can grow rapidly in infected plants and subsequently produces a large amount of sclerotia that plugs the vessels, resulting in wilting of the plant. Results We sequenced and assembled ~49 Mb into 15 super-scaffolds covering 92.83% of the M. phaseolina genome. We predict 14,249 open reading frames (ORFs of which 9,934 are validated by the transcriptome. This phytopathogen has an abundance of secreted oxidases, peroxidases, and hydrolytic enzymes for degrading cell wall polysaccharides and lignocelluloses to penetrate into the host tissue. To overcome the host plant defense response, M. phaseolina encodes a significant number of P450s, MFS type membrane transporters, glycosidases, transposases, and secondary metabolites in comparison to all sequenced ascomycete species. A strikingly distinct set of carbohydrate esterases (CE are present in M. phaseolina, with the CE9 and CE10 families remarkably higher than any other fungi. The phenotypic microarray data indicates that M. phaseolina can adapt to a wide range of osmotic and pH environments. As a broad host range pathogen, M. phaseolina possesses a large number of pathogen-host interaction genes including those for adhesion, signal transduction, cell wall breakdown, purine biosynthesis, and potent mycotoxin patulin. Conclusions The M. phaseolina genome provides a framework of the infection process at the cytological and molecular level which uses a diverse arsenal of enzymatic and toxin tools to destroy the host plants. Further understanding of the M. phaseolina genome-based plant-pathogen interactions will be instrumental in designing rational strategies for disease control, essential to ensuring global agricultural crop production and security.

  15. Proteomic study of three component interactions:plant, pathogens and antagonistic fungi

    Institute of Scientific and Technical Information of China (English)

    Marra R; Turrà D; Scala F; Lorito M; Ambrosino P; Scala V; Romano C; Vinale F; Ferraioli S; Ruocco M; Carbone V; Woo S L

    2004-01-01

    @@ The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma,are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean,tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi ( Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The protcome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens,the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots In

  16. Plant biomass degradation by fungi.

    Science.gov (United States)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P

    2014-11-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the topic is highly relevant in the field of plant pathogenic fungi as they degrade plant biomass to either gain access to the plant or as carbon source, resulting in significant crop losses. Finally, fungi are the main degraders of plant biomass in nature and as such have an essential role in the global carbon cycle and ecology in general. In this review we provide a global view on the development of this research topic in saprobic ascomycetes and basidiomycetes and in plant pathogenic fungi and link this to the other papers of this special issue on plant biomass degradation by fungi. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. The effect of elevated atmospheric CO{sub 2} on interactions between plant roots, arbuscular-mycorrhizal and pathogenic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Rillig, M.C.; Klironomos, J.N.; Allen, M.F. [San Diego State Univ., CA (United States)] [and others

    1995-09-01

    Of all effects of elevated atmospheric CO{sub 2} on plants and ecosystems, the least is known about plant rhizosphere responses. Rhizosphere fungi are fed primarily by root-derived substrates, and fulfill functions such as immobilization, decomposition, pathogeneity, and improvement of plant nutrition. This study describes the effect of elevated CO{sub 2} on the interaction between the pathogen Fusarium solani and the AM fungus Glomus intraradices in the rhizosphere of Artemisia tridentata. We measured intraradical infection and extraradical growth by the two fungi under elevated and ambient CO{sub 2} concentrations. We found a strong interaction between the two fungi. Root infection by and extraradical hyphal length of solani did not differ significantly between CO{sub 2} treatments in the presence of G. intraradices. In the absence of G. intraradices, however, infection by F. solani and its extraradical hyphal length increased under elevated CO{sub 2}. Our results indicate that pathogenic fungi do respond to elevated CO{sub 2} by increased hyphal growth and root infection (potential response), but also show that mycorrhizal fungi can profit more from the new conditions and serve to suppress the pathogen.

  18. Identifying and naming plant-pathogenic fungi: past, present, and future

    NARCIS (Netherlands)

    Crous, P.W.; Hawksworth, D.L.; Wingfield, M.J.

    2015-01-01

    Scientific names are crucial in communicating knowledge about fungi. In plant pathology, they link information regarding the biology, host range, distribution, and potential risk. Our understanding of fungal biodiversity and fungal systematics has undergone an exponential leap, incorporating genomic

  19. The microscopic pathogenic fungi of the Łęczna-Włodawa Lake District. I. The occurrence of pathogenic fungi in plant communities and theirs phenology

    Directory of Open Access Journals (Sweden)

    Wiesław Mułenko

    2014-08-01

    Full Text Available The paper presents the results of the studies on tbe occurrence and phenology of puthogenic fungi in plant communities of the Łęczna-Włodawa Lake District in 1981-1984. The taxonomic list of collected fungi species will be published in another paper.

  20. Crossover fungal pathogens: the biology and pathogenesis of fungi capable of crossing kingdoms to infect plants and humans.

    Science.gov (United States)

    Gauthier, Gregory M; Keller, Nancy P

    2013-12-01

    The outbreak of fungal meningitis associated with contaminated methylprednisolone acetate has thrust the importance of fungal infections into the public consciousness. The predominant pathogen isolated from clinical specimens, Exserohilum rostratum (teleomorph: Setosphaeria rostrata), is a dematiaceous fungus that infects grasses and rarely humans. This outbreak highlights the potential for fungal pathogens to infect both plants and humans. Most crossover or trans-kingdom pathogens are soil saprophytes and include fungi in Ascomycota and Mucormycotina phyla. To establish infection, crossover fungi must overcome disparate, host-specific barriers, including protective surfaces (e.g. cuticle, skin), elevated temperature, and immune defenses. This review illuminates the underlying mechanisms used by crossover fungi to cause infection in plants and mammals, and highlights critical events that lead to human infection by these pathogens. Several genes including veA, laeA, and hapX are important in regulating biological processes in fungi important for both invasive plant and animal infections. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Effect of root exudates of various plants on composition of bacteria and fungi communities with special regard to pathogenic soil-borne fungi

    Directory of Open Access Journals (Sweden)

    Danuta Piętka

    2013-12-01

    Full Text Available The purpose of the studies conducted in the years 1996 - 1998 was to determine the composition of bacteria and fungi populations in the rhizosphere of winter wheat, spring wheat, soybean and potato, and in non-rhizosphere soil. Besides, the effect of root exudates of these plants on the formation of pathogenic fungi communities was established. The microbiological analysis showed that the greatest tolal number of bacteria was found in the rhizospheres of potato and soybean, and the lowest number in non-rhizosphere soil. The smallest total number of fungi was found in the rhizosphere of winter wheat, and the largest in the rhizosphere of soybean. Pathogenic fungi dominated in the rhizospheres of soybean and potato, while non-rhizosphere soil was the poorest in these microorganisms. Among the pathogenic fungi, Fusarium oxysporum, F.culmorum and F.solani were most frequently isolated. Soybean roots exudated the greatest amount of aminoacids, and acidic aminoacids, which have a positive effect on the development of phytopathogens, dominated in their content. On the other hand, the best quantitative and qualitative composition of aminoacids was found out in the root exudates of winter wheat, since they conlained big amounts of alkaline and aromatic aminoacids.

  2. The rising threat of fungicide resistance in plant pathogenic fungi: Botrytis as a case study.

    Science.gov (United States)

    Hahn, Matthias

    2014-10-01

    The introduction of site-specific fungicides almost 50 years ago has revolutionized chemical plant protection, providing highly efficient, low toxicity compounds for control of fungal diseases. However, it was soon discovered that plant pathogenic fungi can adapt to fungicide treatments by mutations leading to resistance and loss of fungicide efficacy. The grey mould fungus Botrytis cinerea, a major cause of pre- and post-harvest losses in fruit and vegetable production, is notorious as a 'high risk' organism for rapid resistance development. In this review, the mechanisms and the history of fungicide resistance in Botrytis are outlined. The introduction of new fungicide classes for grey mould control was always followed by the appearance of resistance in field populations. In addition to target site resistance, B. cinerea has also developed a resistance mechanism based on drug efflux transport. Excessive spraying programmes have resulted in the selection of multiresistant strains in several countries, in particular in strawberry fields. The rapid erosion of fungicide activity against these strains represents a major challenge for the future of fungicides against Botrytis. To maintain adequate protection of intensive cultures against grey mould, strict implementation of resistance management measures are required as well as alternative strategies with non-chemical products.

  3. Diversity of Endophytic Fungi from Red Ginger (Zingiber officinale Rosc.) Plant and Their Inhibitory Effect to Fusarium oxysporum Plant Pathogenic Fungi

    OpenAIRE

    SIHEGIKO KANAYA; LATIFAH KOSIM DARUSMAN; NAMPIAH SUKARNO; UTUT WIDYASTUTI; ROHANI CINTA BADIA GINTING

    2013-01-01

    Indonesia has been known as a country with high medicinal plant diversity. One of the most common medicinal plant from Indonesia is red ginger (Zingiber officinale Rosc.). Nevertheless, limited studies of endophytic fungi associated with these medicinal plants are hitherto available. The objectives of this research were to study the diversity of endophytic fungi on red ginger and to analyze their potential as a source of antifungal agent. All parts of plant organs such as leaf, rhizome, root,...

  4. Lifestyle transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses

    NARCIS (Netherlands)

    O'Connell, R.J.; Thon, M.R.; Hacquard, S.; Amyotte, S.G.; Kleemann, J.; Torres, M.F.; Damm, U.; Buiate, E.A.; Epstein, L.; Alkan, N.; Altmuller, J.; Alvarado-Balderrama, L.; Bauser, C.A.; Becker, C.; Birren, B.W.; Chen, Z.; Choi, J.; Crouch, J.A.; Duvick, J.P.; Farman, M.A.; Gan, P.; Heiman, D.; Henrissat, B.; Howard, R.J.; Kabbage, M.; Koch, C.; Kracher, B.; Kubo, Y.; Law, A.D.; Lebrun, M.-H.; Lee, Y.-H.; Miyara, I.; Moore, N.; Neumann, U.; Nordstrom, K.; Panaccione, D.G.; Panstruga, R.; Place, M.; Proctor, R.H.; Prusky, D.; Rech, G.; Reinhardt, R.; Rollins, J.A.; Rounsley, S.; Schardl, C.L.; Schwartz, D.C.; Shenoy, N.; Shirasu, K.; Sikhakolli, U.R.; Stuber, K.; Sukno, S.A.; Sweigard, J.A.; Takano, Y.; Takahara, H.; Trail, F.; Does, H.C.; Voll, L.M.; Will, I.; Young, S.; Zeng, Q.; Zhang, Jingze; Zhou, S.; Dickman, M.B.; Schulze-Lefert, P.; Verloren van Themaat, E.; Ma, L.-J.; Vaillancourt, L.J.

    2012-01-01

    Colletotrichum species are fungal pathogens that devastate crop plants worldwide. Host infection involves the differentiation of specialized cell types that are associated with penetration, growth inside living host cells (biotrophy) and tissue destruction (necrotrophy). We report here genome and

  5. Lifestyle transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses

    NARCIS (Netherlands)

    O'Connell, R.J.; Thon, M.R.; Hacquard, S.; Amyotte, S.G.; Kleemann, J.; Torres, M.F.; Damm, U.; Buiate, E.A.; Epstein, L.; Alkan, N.; Altmuller, J.; Alvarado-Balderrama, L.; Bauser, C.A.; Becker, C.; Birren, B.W.; Chen, Z.; Choi, J.; Crouch, J.A.; Duvick, J.P.; Farman, M.A.; Gan, P.; Heiman, D.; Henrissat, B.; Howard, R.J.; Kabbage, M.; Koch, C.; Kracher, B.; Kubo, Y.; Law, A.D.; Lebrun, M.-H.; Lee, Y.-H.; Miyara, I.; Moore, N.; Neumann, U.; Nordstrom, K.; Panaccione, D.G.; Panstruga, R.; Place, M.; Proctor, R.H.; Prusky, D.; Rech, G.; Reinhardt, R.; Rollins, J.A.; Rounsley, S.; Schardl, C.L.; Schwartz, D.C.; Shenoy, N.; Shirasu, K.; Sikhakolli, U.R.; Stuber, K.; Sukno, S.A.; Sweigard, J.A.; Takano, Y.; Takahara, H.; Trail, F.; Does, H.C.; Voll, L.M.; Will, I.; Young, S.; Zeng, Q.; Zhang, Jingze; Zhou, S.; Dickman, M.B.; Schulze-Lefert, P.; Verloren van Themaat, E.; Ma, L.-J.; Vaillancourt, L.J.

    2012-01-01

    Colletotrichum species are fungal pathogens that devastate crop plants worldwide. Host infection involves the differentiation of specialized cell types that are associated with penetration, growth inside living host cells (biotrophy) and tissue destruction (necrotrophy). We report here genome and tr

  6. Fungi with multifunctional lifestyles: endophytic insect pathogenic fungi.

    Science.gov (United States)

    Barelli, Larissa; Moonjely, Soumya; Behie, Scott W; Bidochka, Michael J

    2016-04-01

    This review examines the symbiotic, evolutionary, proteomic and genetic basis for a group of fungi that occupy a specialized niche as insect pathogens as well as endophytes. We focus primarily on species in the genera Metarhizium and Beauveria, traditionally recognized as insect pathogenic fungi but are also found as plant symbionts. Phylogenetic evidence suggests that these fungi are more closely related to grass endophytes and diverged from that lineage ca. 100 MYA. We explore how the dual life cycles of these fungi as insect pathogens and endophytes are coupled. We discuss the evolution of insect pathogenesis while maintaining an endophytic lifestyle and provide examples of genes that may be involved in the transition toward insect pathogenicity. That is, some genes for insect pathogenesis may have been co-opted from genes involved in endophytic colonization. Other genes may be multifunctional and serve in both lifestyle capacities. We suggest that their evolution as insect pathogens allowed them to effectively barter a specialized nitrogen source (i.e. insects) with host plants for photosynthate. These ubiquitous fungi may play an important role as plant growth promoters and have a potential reservoir of secondary metabolites.

  7. The Herbivore-Induced Plant Volatiles Methyl Salicylate and Menthol Positively affect Growth and Pathogenicity of Entomopathogenic Fungi

    Science.gov (United States)

    Lin, Yongwen; Qasim, Muhammad; Hussain, Mubasher; Akutse, Komivi Senyo; Avery, Pasco Bruce; Dash, Chandra Kanta; Wang, Liande

    2017-01-01

    Some herbivore-induced-plant volatiles (HIPVs) compounds are vital for the functioning of an ecosystem, by triggering multi-trophic interactions for natural enemies, plants and herbivores. However, the effect of these chemicals, which play a crucial role in regulating the multi-trophic interactions between plant-herbivore-entomopathogenic fungi, is still unknown. To fill this scientific gap, we therefore investigated how these chemicals influence the entomopathogenic fungi growth and efficacy. In this study, Lipaphis erysimi induced Arabidopsis thaliana HIPVs were collected using headspace system and detected with GC-MS, and then analyzed the effects of these HIPVs chemicals on Lecanicillium lecanii strain V3450. We found that the HIPVs menthol and methyl salicylate at 1 and 10 nmol·ml−1 improved many performance aspects of the fungus, such as germination, sporulation, appressorial formation as well as its pathogenicity and virulence. These findings are not only important for understanding the multi-trophic interactions in an ecosystem, but also would contribute for developing new and easier procedures for conidial mass production as well as improve the pathogenicity and virulence of entomopathogenic fungi in biological pest management strategies. PMID:28079180

  8. The Herbivore-Induced Plant Volatiles Methyl Salicylate and Menthol Positively affect Growth and Pathogenicity of Entomopathogenic Fungi

    Science.gov (United States)

    Lin, Yongwen; Qasim, Muhammad; Hussain, Mubasher; Akutse, Komivi Senyo; Avery, Pasco Bruce; Dash, Chandra Kanta; Wang, Liande

    2017-01-01

    Some herbivore-induced-plant volatiles (HIPVs) compounds are vital for the functioning of an ecosystem, by triggering multi-trophic interactions for natural enemies, plants and herbivores. However, the effect of these chemicals, which play a crucial role in regulating the multi-trophic interactions between plant-herbivore-entomopathogenic fungi, is still unknown. To fill this scientific gap, we therefore investigated how these chemicals influence the entomopathogenic fungi growth and efficacy. In this study, Lipaphis erysimi induced Arabidopsis thaliana HIPVs were collected using headspace system and detected with GC-MS, and then analyzed the effects of these HIPVs chemicals on Lecanicillium lecanii strain V3450. We found that the HIPVs menthol and methyl salicylate at 1 and 10 nmol·ml-1 improved many performance aspects of the fungus, such as germination, sporulation, appressorial formation as well as its pathogenicity and virulence. These findings are not only important for understanding the multi-trophic interactions in an ecosystem, but also would contribute for developing new and easier procedures for conidial mass production as well as improve the pathogenicity and virulence of entomopathogenic fungi in biological pest management strategies.

  9. Chemical constituents from Melodorum fruticosum Lour. flowers against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Rachsawan Mongkol

    2016-07-01

    Full Text Available The antifungal activity of hexane, dichloromethane and methanol extracts of 45 Thai plants were in vitro screened against plant phytopathogenic fungi (Alternaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora parasitica. Seven extracts strongly inhibited the mycelial growth of fungi. The plant extracts with highest antifungal activity were Limnophila aromatic, Eupatorium odoratum, Melodorum fruticosum and Alpinia galanga with 70%, 58%, 74% and 100% inhibition, respectively. The potent dichloromethane extract from M. fruticosum flowers was separated using bioassay guided against P. parasitica. Eight compounds: 1-hexacosanol (1, 5-hydroxy-7-methoxyflavone (2, β-sitosterol (3, melodorinone B (4, benzoic acid (5, chrysin (6, melodorinol (7 and melodorinone A (8 could be isolated. Among the isolated compounds, benzoic acid (5 and melodorinol (7 exhibited strong activity against mycelial growth of P. parasitica at 100% and 93% inhibition with the half maximal inhibitory concentration (IC50 values of 108 μg/mL and 130 μg/mL, respectively. This plant could be exploited for eco-friendly management control of plant diseases.

  10. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Science.gov (United States)

    Discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly c...

  11. Insights on the susceptibility of plant pathogenic fungi to phenazine-1-carboxylic acid and its chemical derivatives.

    Science.gov (United States)

    Puopolo, Gerardo; Masi, Marco; Raio, Aida; Andolfi, Anna; Zoina, Astolfo; Cimmino, Alessio; Evidente, Antonio

    2013-01-01

    Pseudomonas chlororaphis subsp. aureofaciens strain M71 produced two phenazine compounds as main secondary metabolites. These metabolites were identified as phenazine-1-carboxylic acid (PCA) and 2-hydroxyphenazine (2-OH P). In this study, the spectrum of the activity of PCA and 2-OH P was evaluated against a group of crop and forestal plant pathogenic fungi by an agar plate bioassay. PCA was active against most of the tested plant pathogens, while 2-OH P slightly inhibited a few fungal species. Furthermore, four semisynthesised derivatives of PCA (phenazine-1-carboxymethyl, phenazine-1-carboxamide, phenazine-1-hydroxymethyl and phenazine-1-acetoxymethyl) were assayed for their antifungal activity against 11 phytopathogenic species. Results showed that the carboxyl group is a structural feature important for the antifungal activity of PCA. Since the activity of phenazine-1-carboxymethyl and phenazine-1-carboxamide, the two more lipophilic and reversible PCA derivatives remained substantially unaltered compared with PCA.

  12. Effect of rare earth application on the growth of Trichoderma spp.and several plant pathogenic fungi

    Institute of Scientific and Technical Information of China (English)

    d'Aquino L; Carboni M; Woo S L; Morgana M; Nardi L; Lorito M

    2004-01-01

    @@ Rare earth elements (REEs) enriched fertilisers are currently used in China for soil and foliar applications to crops, but little is known about the effect of REEs applications on the growth of beneficial and detrimental soilborne microorganisms. The growth of biological control agents Trichoderma atroviride strain P1, Trichoderma harzianum strain A6 and strain T22, plant pathogens Botrytis cinerea, Alternaria alternata, Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum was investigated in the presence of REEs. An in vitro assays was used to monitor the effect of different concentration levels of either a mix of REEs (La, Ce, Pr, Nd) nitrates or lanthanum alone in comparison to treatments conducted with potassium nitrate and water. Although all fungi were affected when the REEs mix or lanthanum were present at concentrations higher than 100 mM, the growth inhibition depended mainly upon the combination of compounds, the dose and the fungal species or strains tested. Trichoderma strains and B. cinerea were more sensitive than A.alternata, F. solani, R. solani or at higher concentrations. Differing growth responses of some fungi to treatments with REEs mix vs. lanthanum alone indicated that in given situations the effect of the REEs compounds may be caused by elements other than lanthanum or by element mixtures.Further investigations are in progress to determine the effect of REEs on important interactions in the soil community between beneficial fungi, pathogenic fungi and/or the plant. REEs are naturally present in the environment and in biological systems but accumulation in soil can take place following successive applications. Therefore, it would be useful to achieve a better understanding of the effect of REEs accumulation on the activity of rhizosphere microorganisms given the widespread use in some regions of rare earths as fertilizers and their presence as fertilizer contaminants.

  13. [Plants and pathogenic agents, a refined and dangerous relationship: the example of fungi].

    Science.gov (United States)

    Esquerré-Tugayé, M T

    2001-10-01

    Plant-fungus interactions are highly diverse, either being beneficial to the host plant such as those leading to mycorhizal symbiosis, or very detrimental when leading to severe diseases. Since the beginning of agriculture, improvement of plant resistance to pathogens has remained a major challenge. Breeding for resistance, first conducted empirically in the past centuries, was then performed on a more theoretical basis after the statement of heredity laws by Mendel at the end of the XIXth century. As a result, most cultivated species contain various cultivars whose resistance or susceptibility to a given pathogen species depend on their interaction with various races of that pathogen. Such highly specific race-cultivar systems are particularly suited for understanding the molecular dialogue which underlies compatible (host susceptible/pathogen virulent) or incompatible (host resistant/pathogen avirulent) interactions. During the twentieth century, one of the major events that paved the way for future research was the statement by Flor [1946, 1947] of the gene-for-gene concept. Studying inheritance of the disease phenotype in the interaction between flax and Melampsora lini he showed that resistance in the host and avirulence in the pathogen are dictated by single dominant genes which correspond one to one, i.e. one resistance gene for one avirulence gene. The fact that incompatibility may depend on the presence of only one resistance (R) gene in the host and one avirulence (Avr) gene in the pathogen was fully confirmed about 40 years later. Molecular genetics and complementation experiments have allowed to isolate numerous R and Avr genes from various plant-pathogen systems, and to verify the gene-for-gene concept. These studies have enlightened the elicitor/receptor concept, formerly introduced to account for the specificity of the compatible and incompatible interactions. The present knowledge of R and Avr genes also allows to predict how such genes have evolved

  14. Interactions of Neotyphodium gansuense, Achnatherum inebrians, and plant-pathogenic fungi.

    Science.gov (United States)

    Li, Chun-jie; Gao, Jia-hui; Nan, Zhi-biao

    2007-10-01

    Interactions of Neotyphodium gansuense, Achnatherum inebrians, and nine fungal pathogens were studied by tests of inhibition of four fungal pathogens by Neotyphodium endophytes in vitro and by inoculation of nine fungal pathogens on detached leaves of endophyte-infected (E+) and endophyte-free (E-) plants. Compared with the controls, most isolates of N. gansuense significantly inhibited the growth in vitro of, in decreasing order of inhibition, Bipolaris sorokiniana, Curvularia lunata, Fusarium acuminatum, and Alternaria alternata. Inhibition zones appeared between pathogens and some isolates of N. gansuense. Some isolates of N. gansuense significantly inhibited sporulation of B. sorokiniana, A. alternata, and C. lunata. However, there was no significant inhibition of F. acuminatum and a few isolates significantly increased sporulation. The leaf inoculation trial indicated that almost all fungal pathogens were able to cause lesions on detached leaves regardless of endophyte status. Both the number and size of disease lesions on E+A. inebrians leaves caused by A. alternata, F. chlamydosporum, F. oxysporum, and F. solani were reduced compared with those on E- leaves. Only lesion numbers (not size) of Ascochyta leptospora leaf spots were significantly reduced on E+ leaves compared with E- leaves. Conversely, only the length of Ascochyta leptospora leaf spots were significantly smaller on E+ leaves than on E- leaves; numbers of lesions were not significantly affected. C. lunata was strongly pathogenic to both E+ and E- leaves and numerous lesions developed and merged into patches, the leaf surface was covered and the leaf rotted away.

  15. Comparative analysis of plant-produced, recombinant dimeric IgA against cell wall β-glucan of pathogenic fungi.

    Science.gov (United States)

    Capodicasa, Cristina; Catellani, Marcello; Moscetti, Ilaria; Bromuro, Carla; Chiani, Paola; Torosantucci, Antonella; Benvenuto, Eugenio

    2017-08-19

    Immunoglobulins A (IgA) are crucially involved in protection of human mucosal surfaces from microbial pathogens. In this work, we devised and expressed in plants recombinant chimeric antifungal antibodies (Abs) of isotype A (IgA1, IgA2, and scFvFcA1), derived from a murine mAb directed to the fungal cell wall polysaccharide β-glucan which had proven able to confer protection against multiple pathogenic fungi. All recombinant IgA (rIgA) were expressed and correctly assembled in dimeric form in plants and evaluated for yield, antigen-binding efficiency and antifungal properties in vitro, in comparison with a chimeric IgG1 version. Production yields and binding efficiency to purified β-glucans showed significant variations not only between Abs of different isotypes but also between the different IgA formats. Moreover, only the dimeric IgA1 was able to strongly bind cells of the fungal pathogen Candida albicans and to restrain its adhesion to human epithelial cells. Our data indicate that IgG to IgA switch and differences in molecular structure among different rIgA formats can impact expression in plant and biological activity of anti-β-glucans Abs and provide new insights for the design of recombinant IgA as anti-infective immunotherapeutics, whose potential is still poorly investigated. © 2017 Wiley Periodicals, Inc.

  16. Lectins in human pathogenic fungi.

    Science.gov (United States)

    Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

    2014-01-01

    Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  17. Comparative Genomics Including the Early-Diverging Smut Fungus Ceraceosorus bombacis Reveals Signatures of Parallel Evolution within Plant and Animal Pathogens of Fungi and Oomycetes.

    Science.gov (United States)

    Sharma, Rahul; Xia, Xiaojuan; Riess, Kai; Bauer, Robert; Thines, Marco

    2015-08-27

    Ceraceosorus bombacis is an early-diverging lineage of smut fungi and a pathogen of cotton trees (Bombax ceiba). To study the evolutionary genomics of smut fungi in comparison with other fungal and oomycete pathogens, the genome of C. bombacis was sequenced and comparative genomic analyses were performed. The genome of 26.09 Mb encodes for 8,024 proteins, of which 576 are putative-secreted effector proteins (PSEPs). Orthology analysis revealed 30 ortholog PSEPs among six Ustilaginomycotina genomes, the largest groups of which are lytic enzymes, such as aspartic peptidase and glycoside hydrolase. Positive selection analyses revealed the highest percentage of positively selected PSEPs in C. bombacis compared with other Ustilaginomycotina genomes. Metabolic pathway analyses revealed the absence of genes encoding for nitrite and nitrate reductase in the genome of the human skin pathogen Malassezia globosa, but these enzymes are present in the sequenced plant pathogens in smut fungi. Interestingly, these genes are also absent in cultivable oomycete animal pathogens, while nitrate reductase has been lost in cultivable oomycete plant pathogens. Similar patterns were also observed for obligate biotrophic and hemi-biotrophic fungal and oomycete pathogens. Furthermore, it was found that both fungal and oomycete animal pathogen genomes are lacking cutinases and pectinesterases. Overall, these findings highlight the parallel evolution of certain genomic traits, revealing potential common evolutionary trajectories among fungal and oomycete pathogens, shaping the pathogen genomes according to their lifestyle.

  18. Flexible gateway constructs for functional analyses of genes in plant pathogenic fungi

    NARCIS (Netherlands)

    Mehrabi, Rahim; Mirzadi Gohari, Amir; Silva, da Gilvan Ferreira; Steinberg, Gero; Kema, Gert H.J.; Wit, de Pierre J.G.M.

    2015-01-01

    Genetic manipulation of fungi requires quick, low-cost, efficient, high-throughput and molecular tools. In this paper, we report 22 entry constructs as new molecular tools based on the Gateway technology facilitating rapid construction of binary vectors that can be used for functional analysis of

  19. Antifungal activity of nettle (Urtica dioica L.), colocynth (Citrullus colocynthis L. Schrad), oleander (Nerium oleander L.) and konar (Ziziphus spina-christi L.) extracts on plants pathogenic fungi.

    Science.gov (United States)

    Hadizadeh, I; Peivastegan, B; Kolahi, M

    2009-01-01

    Anti-mycotic activity of the ethanol extracts from Nettle (Urtica dioica L.), Colocynth (Citrullus colocynthis L. Schrad), Konar (Ziziphus spina-christi L.) and Oleander (Nerium oleander L.) floral parts were screened in vitro against four important plant pathogenic fungi viz.; Alternaria alternate, Fusarium oxysporum, Fusarium solani and Rizoctonia solani using agar dilution bioassay. Extracts showed antifungal activity against all the tested fungi. Among the plants, Nettle and Colocynth were the most effective against A. alternate and R. solani while Oleander possesses the best inhibition on F. oxysporum and F. solani. Konar was the most effective extract by reducing the growth of Rizoctonia solani than other fungi. These results showed that extracts could be considered suitable alternatives to chemical additives for the control of fungal diseases in plants.

  20. THE EFFECT OF LOW INDUCTIVITY STATIC MAGNETIC FIELD ON SOME PLANT PATHOGEN FUNGI

    Directory of Open Access Journals (Sweden)

    Pál NAGY

    2006-02-01

    Full Text Available Growth and sporulation of phytopathogen microscopic fungi were studied under a static magnetic fi eld. The applied flux densities were 0,1, 0,5 and 1 mT. As a result of our experiments, the magnetic fi eld decreased the growth of colonies by 10 % using this fl ux density region. At the same time, the number of the developed conidia of Alternaria alternata and Curvularia inaequalis increased by 68-133 percent, but the number of Fusarium oxysporum conidia decreased by 79-83 percent.

  1. The cAMP Signaling and MAP Kinase Pathways in Plant Pathogenic Fungi

    NARCIS (Netherlands)

    Mehrabi, R.; Zhao, X.; Kim, Y.; Xu, J.R.

    2009-01-01

    The key components of the well conserved cyclic AMP signaling and MAP kinase pathways have been functionally characterized in the corn smut Ustilago maydis, rice blast fungus Magnaporthe grisea, and a few other fungal pathogens. In general, the cAMP signaling and the MAP kinase cascade homologous to

  2. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    K. Al-Mughrabi

    2003-12-01

    Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

  3. Application of Biosynthesized Silver Nanoparticles for the Control of Land Snail Eobania vermiculata and Some Plant Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Safaa M. Ali

    2015-01-01

    Full Text Available The land snail Eobania vermiculata is an important crop pest causing considerable damage in agriculture. The aim of the present work is to evaluate the possibilities of using silver nanoparticles (AgNPs to control the land snail. The AgNPs have been synthesized biologically using white radish (Raphanus sativus var. aegyptiacus. The biosynthesis was regularly monitored by UV-Vis spectroscopy. X-ray diffraction spectra revealed peaks of crystalline nature of AgNPs and the transmission electron micrographs further confirmed the size of the synthesized nanoparticles ranging from 6 to 38 nm. The exposure of the snails and soil matrix to AgNPs in a laboratory experiment reduced the activity and the viability of the land snail (20% of AgNPs treated snails died as well as the frequency of fungal population in the surrounding soil. Moreover histology and ultrastructure alterations have been found in both kidney and the digestive gland of AgNPs treated land snails. The synergistic effect of synthesized AgNPs as antifungal was evaluated and clearly revealed that AgNPs can be effectively used against various plant pathogenic fungi. The present study results may open a new avenue to use the snail as bioindicator organism of environmental pollution.

  4. A rapid method for isolation of total DNA from pathogenic filamentous plant fungi.

    Science.gov (United States)

    González-Mendoza, D; Argumedo-Delira, R; Morales-Trejo, A; Pulido-Herrera, A; Cervantes-Díaz, L; Grimaldo-Juarez, O; Alarcón, A

    2010-02-02

    DNA isolation from some fungal organisms of agronomic importance is difficult because they have cell walls or capsules that are relatively unsusceptible to lysis. We have developed a fast DNA isolation protocol for Fusarium oxysporum, which causes fusarium wilt disease in more than 100 plant species, and for Pyrenochaeta terrestris, which causes pink root in onions. This protocol was based on the sodium dodecyl sulfate/phenol method, without beta-mercaptoethanol and without maceration in liquid nitrogen; it uses phenol/chloroform extraction to remove proteins and co-precipitated polysaccharides. The A(260/280) absorbance ratios of isolated DNA were around 1.9, suggesting that the DNA fraction was pure and may be used for further analysis. Additionally, the A(260/230) values were higher than 1.8, suggesting negligible contamination by polysaccharides. The DNA isolated by this protocol is of sufficient quality for molecular applications; this technique could be applied to other organisms that have similar substances that hinder DNA extraction.

  5. QUALITATIVE PHYTOCHEMICAL SCREENING AND ANTIFUNGAL ACTIVITY OF CARICA PAPAYA LEAF EXTRACT AGAINST HUMAN AND PLANT PATHOGENIC FUNGI

    Directory of Open Access Journals (Sweden)

    Sikandar Khan Sherwani

    2013-07-01

    Full Text Available Plants have been explored extensively all over the globe in quest of a novel bioactive compound that could a good therapeutic candidate treating infectious diseases especially against drug resistant microbes. Qualitative phytochemical analyses of Carica papaya leaf extract reveal that except steroids and tannins all the possible phytochemical constituents including carbohydrates, proteins, anthraquinones, flavonoids, saponins, cardiac glycosides and alkaloids were present. Two ways of Carica papaya leaf extract preparations i.e crushed and boiled were tested for their antifungal activity against 6 saprophytic fungi Penicillium sp, Aspergilus flavus, Aspergillus niger, Fusarium sp, Rhizopus and Helminthosporum, 5 dermatophytic fungi Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans and 6 yeasts including Candida albicans, Candida albicans ATCC 0383, Saccharomyces cerevisiae, Candida galbrata, Candida tropicalis, Candida kruzei. The activity was found against majority of fungi but was much better in case of crushed leaf extract.

  6. Ubiquity of insect-derived nitrogen transfer to plants by endophytic insect-pathogenic fungi: an additional branch of the soil nitrogen cycle.

    Science.gov (United States)

    Behie, Scott W; Bidochka, Michael J

    2014-03-01

    The study of symbiotic nitrogen transfer in soil has largely focused on nitrogen-fixing bacteria. Vascular plants can lose a substantial amount of their nitrogen through insect herbivory. Previously, we showed that plants were able to reacquire nitrogen from insects through a partnership with the endophytic, insect-pathogenic fungus Metarhizium robertsii. That is, the endophytic capability and insect pathogenicity of M. robertsii are coupled so that the fungus acts as a conduit to provide insect-derived nitrogen to plant hosts. Here, we assess the ubiquity of this nitrogen transfer in five Metarhizium species representing those with broad (M. robertsii, M. brunneum, and M. guizhouense) and narrower insect host ranges (M. acridum and M. flavoviride), as well as the insect-pathogenic fungi Beauveria bassiana and Lecanicillium lecanii. Insects were injected with (15)N-labeled nitrogen, and we tracked the incorporation of (15)N into two dicots, haricot bean (Phaseolus vulgaris) and soybean (Glycine max), and two monocots, switchgrass (Panicum virgatum) and wheat (Triticum aestivum), in the presence of these fungi in soil microcosms. All Metarhizium species and B. bassiana but not L. lecanii showed the capacity to transfer nitrogen to plants, although to various degrees. Endophytic association by these fungi increased overall plant productivity. We also showed that in the field, where microbial competition is potentially high, M. robertsii was able to transfer insect-derived nitrogen to plants. Metarhizium spp. and B. bassiana have a worldwide distribution with high soil abundance and may play an important role in the ecological cycling of insect nitrogen back to plant communities.

  7. Mannitol in Plants, Fungi, and Plant-Fungal Interactions.

    Science.gov (United States)

    Patel, Takshay K; Williamson, John D

    2016-06-01

    Although the presence of mannitol in organisms as diverse as plants and fungi clearly suggests that this compound has important roles, our understanding of fungal mannitol metabolism and its interaction with mannitol metabolism in plants is far from complete. Despite recent inroads into understanding the importance of mannitol and its metabolic roles in salt, osmotic, and oxidative stress tolerance in plants and fungi, our current understanding of exactly how mannitol protects against reactive oxygen is also still incomplete. In this opinion, we propose a new model of the interface between mannitol metabolism in plants and fungi and how it impacts plant-pathogen interactions.

  8. Stepwise screening of microorganisms for commercial use in biological control of plant pathogenic fungi and bacteria. Biological Control

    NARCIS (Netherlands)

    Köhl, J.; Postma, J.; Nicot, P.; Ruocco, M.

    2011-01-01

    The development of new biocontrol products against plant diseases requires screening of high numbers of candidate antagonists. Antagonists for commercial use have to fulfill many different requirements. Besides being active against the specific targeted plant pathogens they must be safe and cost-eff

  9. Pathogenic seed-borne fungi of triticale

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available The occurrence of pathogenic fungi on 86 triticale seed samples was studied during the years 1992-1994. From each samples 400 seeds were tested using the blotter method with prefreezing and keeping under lights. In the greenhouse experiment pathogenicity of isolated fungi was evaluated. It was found that 20% of tested kernels were transmitting pathogenic fungi. Species of the genus Fusarium (including Microdochium nivale were isolated from 9,7 % of tested kernels, Drechslera tritici-repentis from 4,6 %, Stagonospora nodorum from 4,2 %, Bipolaris sorokiniana from 1,2%, Botryris cinerea from 0,9% and Drechslera dematioidea was noted sporadically.

  10. Plant biomass degradation by fungi

    NARCIS (Netherlands)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the

  11. Plant biomass degradation by fungi

    NARCIS (Netherlands)

    Mäkelä, Miia R; Donofrio, Nicole; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    Plant biomass degradation by fungi has implications for several fields of science. The enzyme systems employed by fungi for this are broadly used in various industrial sectors such as food & feed, pulp & paper, detergents, textile, wine, and more recently biofuels and biochemicals. In addition, the

  12. Exploring Antagonistic Candidate Fungi for Controling Pathogenic Fungi (Colletotricum gloeosporioides Causing Anthracnose Disease in Kintamani Siam Orange Plants (Citrus Nobillis Lour Var. Hass

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Darsini

    2017-02-01

    Full Text Available Orange plantation center in Bali are located in Bangli Regency, Kintamani District. Kintamani orange plantations cultivated three types of oranges: tangerine, selayer, and mandarin oranges. The famous orange in Bali today is Kintamani orange,  tangerine type.  The typical flavor and aroma of Kintamani tangerine make it is favored by consumers from various regions. Based on the information from Bangli District Agriculture Office and the results of field surveys in the last two years (in 2013 and 2014, cultivation of orange in Kintamani has been infected with anthracnose disease. The disease is characterized by symptoms whereby brown twigs spread to the leaves and fruit, and the fruits which are about to be harvested rot simultaneously and eventually fall due to decay. This condition causes farmers to suffer significant losses. The cause of anthracnose on Kintamani orange is Colletotrichum gloeosporioides .  The Control of these diseases has been carried out by farmers with various synthetic fungicides but the disease is still widespread.   It is feared that the uncontrolled use of synthetic pesticides can harm the environment, cause resistance to C. gloeosporioides fungi, and kill non-target beneficial micro-organism. It is necessary to conduct research that aims to control anthracnose biologically to maintain the ecological balance and environmental safety. Based on the results of this research by exploring the fungi on healthy plants around orange trees infected with anthracnose diseases, nine isolates of antagonist candidate fungus were obtained based on colony color of fungal hyphae (IS1, IS2, IS3, IS4, IS5. IS6, IS7, IS8, IS9.   Based on the test results of the in vitro dual culture, two candidates of antagonistic fungal isolates were selected,  the isolates IS4 and IS7. It was because on day 7 after the second dual culture, these two isolates had the highest percentage of inhibition,  89.22% and 85.11 % respectively. Based on the

  13. The effect of chitosan on limitation of growth and development of some pathogenic fungi for ornamental plants

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    Alicja Saniewska

    2013-12-01

    Full Text Available The inhibitory effect of crab-shell chitosan, medium (200-800 cps and high molecular weight ( 800-2000 cps (purchased from Sigma-Aldrich Chemicals toward Alternaria alternata, Botrytis tulipae, Fiisarium oxysporum f. sp. callistephi, Fusarium oxysporum f. sp. tulipae, Phoma narcissi and Phoma poolensis was evaluated in vitro and in vivo. The chitosan evidently inhibited in vitro growth of all tested pathogens, with a marked effect at higher concentrations above 200 μg/cm3. Chitosan at a concentration of 1,25; 2,5 and 5,0 mg/cm3 didn't have inhibitory action in appearance of fungi growth on naturally contaminated Callistephus chinensis seeds. At the same concentrations, chitosan applied as bulb scales dressing of Hymenocallis narcissiflora bulbs, before inoculation or after inoculation with Phoma narcissi, inhibited the development of necrotic spots on scales. Chitosan used preventively or curatively at a concentrations of 1,25; 2,5 and 5,0 mg/cm3 indicated inhibitory effect on development of Fusarium oxysporum f. sp. tulipae on tulip bulbs. Chitosan at a concentration of 10 mg/cm3 applied preventively (first spray 12th June was very effective in the control of Puccinia antirrhini on snapdragon in the field. The strongest inhibitory effect was observed on snapdragon treated 8 times at week intervals.

  14. Evolutionary interaction networks of insect pathogenic fungi.

    Science.gov (United States)

    Boomsma, Jacobus J; Jensen, Annette B; Meyling, Nicolai V; Eilenberg, Jørgen

    2014-01-01

    Lineages of insect pathogenic fungi are concentrated in three major clades: Hypocreales (several genera), Entomophthoromycota (orders Entomophthorales and Neozygitales), and Onygenales (genus Ascosphaera). Our review focuses on aspects of the evolutionary biology of these fungi that have remained underemphasized in previous reviews. To ensure integration with the better-known domains of insect pathology research, we followed a conceptual framework formulated by Tinbergen, asking complementary questions on mechanism, ontogeny, phylogeny, and adaptation. We aim to provide an introduction to the merits of evolutionary approaches for readers with a background in invertebrate pathology research and to make the insect pathogenic fungi more accessible as model systems for evolutionary biologists. We identify a number of questions in which fundamental research can offer novel insights into the evolutionary forces that have shaped host specialization and life-history traits such as spore number and size, somatic growth rate, toxin production, and interactions with host immune systems.

  15. Nine Pathogenic Fungi of Waterhyacinth Isolated in China

    Institute of Scientific and Technical Information of China (English)

    DING Yi; ZHAO Nan; CHU Jian-jun

    2008-01-01

    The native pathogens of waterhyacinth in China, were studied and compared on pathogenicity by Koch's postulate. Nine pathogenic fungi, YBH, YBB, YB, YYX, YY, YBA1, YBA2, YBA3 and YYB12, were isolated from diseased waterhyacinth plants, and collected from Zhejiang province and Shanghai. According to cultural characteristics, the nine isolates were preliminarily identified. Isolates YBH and YBB were Collectotrichum sp.:YB, YYX and YY were placed in fungi imperfecti:the isolates YBA1, YBA2, YBA3 and YYB12 were Alternaria sp. The isolate YBH was the highly virulent with a disease index (DI) of 65.28% after one month inoculation. The isolate YBA3 was equily virulent, with the disease index of 67% after 7 day introduction. These two pathogens appear to have the potential as biocontrol agents and they deserve further study.

  16. Dung-inhabiting fungi: a potential reservoir of novel secondary metabolites for the control of plant pathogens.

    Science.gov (United States)

    Sarrocco, Sabrina

    2016-04-01

    Coprophilous fungi are a large group of saprotrophic fungi mostly found in herbivore dung. The number of these fungi undergoing investigation is continually increasing, and new species and genera continue to be described. Dung-inhabiting fungi play an important ecological role in decomposing and recycling nutrients from animal dung. They produce a large array of bioactive secondary metabolites and have a potent enzymatic arsenal able to utilise even complex molecules. Bioactive secondary metabolites are actively involved in interaction with and defence against other organisms whose growth can be inhibited, resulting in an enhanced ecological fitness of producer strains. Currently, these antibiotics and bioactive secondary metabolites are of interest in medicine in particular, while very little information is available concerning their potential use in agriculture. This review introduces the ecology of dung-inhabiting fungi, with particular emphasis on the production of antibiotic compounds as a means to compete with other microorganisms. Owing to the fast pace of technological progress, new approaches to predicting the biosynthesis of bioactive metabolites are proposed. Coprophilous fungi should be considered as elite candidate organisms for the discovery of novel antifungal compounds, above all in view of their exploitation for crop protection. © 2015 Society of Chemical Industry.

  17. Auxin-mediated relationships between apple plants and root inhabiting fungi: impact on root pathogens and potentialities of growth-promoting populations

    Science.gov (United States)

    Studies were conducted to examine the symbiotic relationship between plant hosts and endophytic fungi recovered in multi-generation replanted apple orchard soils. Based upon results obtained, subsequent studies were oriented toward investigating fungal populations showing a mutualistic symbiotic rel...

  18. Pathogen Phytosensing: Plants to Report Plant Pathogens

    Directory of Open Access Journals (Sweden)

    C. Neal Stewart

    2008-04-01

    Full Text Available Real-time systems that provide evidence of pathogen contamination in crops can be an important new line of early defense in agricultural centers. Plants possess defense mechanisms to protect against pathogen attack. Inducible plant defense is controlled by signal transduction pathways, inducible promoters and cis-regulatory elements corresponding to key genes involved in defense, and pathogen-specific responses. Identified inducible promoters and cis-acting elements could be utilized in plant sentinels, or ‘phytosensors’, by fusing these to reporter genes to produce plants with altered phenotypes in response to the presence of pathogens. Here, we have employed cis-acting elements from promoter regions of pathogen inducible genes as well as those responsive to the plant defense signal molecules salicylic acid, jasmonic acid, and ethylene. Synthetic promoters were constructed by combining various regulatory elements supplemented with the enhancer elements from the Cauliflower mosaic virus (CaMV 35S promoter to increase basal level of the GUS expression. The inducibility of each synthetic promoter was first assessed in transient expression assays using Arabidopsis thaliana protoplasts and then examined for efficacy in stably transgenic Arabidopsis and tobacco plants. Histochemical and fluorometric GUS expression analyses showed that both transgenic Arabidopsis and tobacco plants responded to elicitor and phytohormone treatments with increased GUS expression when compared to untreated plants. Pathogen-inducible phytosensor studies were initiated by analyzing the sensitivity of the synthetic promoters against virus infection. Transgenic tobacco plants infected with Alfalfa mosaic virus showed an increase in GUS expression when compared to mock-inoculated control plants, whereas Tobacco mosaic virus infection caused no changes in GUS expression. Further research, using these transgenic plants against a range of different

  19. Oomycetes and fungi: similar weaponry to attack plants

    NARCIS (Netherlands)

    Latijnhouwers, M.; Wit, de P.J.G.M.; Govers, F.

    2003-01-01

    Fungi and Oomycetes are the two most important groups of eukaryotic plant pathogens. Fungi form a separate kingdom and are evolutionarily related to animals. Oomycetes are classified in the kingdom Protoctista and are related to heterokont, biflagellate, golden-brown algae. Fundamental differences

  20. Oomycetes and fungi: similar weaponry to attack plants

    NARCIS (Netherlands)

    Latijnhouwers, M.; Wit, de P.J.G.M.; Govers, F.

    2003-01-01

    Fungi and Oomycetes are the two most important groups of eukaryotic plant pathogens. Fungi form a separate kingdom and are evolutionarily related to animals. Oomycetes are classified in the kingdom Protoctista and are related to heterokont, biflagellate, golden-brown algae. Fundamental differences i

  1. Screening extracts of Achyranthes japonica and Rumex crispus for activity against various plant pathogenic fungi and control of powdery mildew.

    Science.gov (United States)

    Kim, Jin-Cheol; Choi, Gyung Ja; Lee, Seon-Woo; Kim, Jin-Seog; Chung, Kyu Young; Cho, Kwang Yun

    2004-08-01

    Methanol extracts of fresh materials of 183 plants were screened for in vivo antifungal activity against Magnaporthe grisea, Corticium sasaki, Botrytis cinerea, Phytophthora infestans, Puccinia recondita and Erysiphe graminis f sp hordei. Among them, 33 plant extracts showed disease-control efficacy of more than 90% against at least one of six plant diseases. The methanol extracts of Achyranthes japonica (whole plant) and Rumex crispus (roots) at concentrations greater than 11 g fresh weight of plant tissue per litre of aqueous Tween 20 solution effectively controlled the development of barley powdery mildew caused by E graminis f sp hordei in an in vivo assay using plant seedlings. At a concentration of 300 g fresh weight of plant tissue per litre of Tween 20 solution, the two extracts were as efficient as the fungicide fenarimol (30 mg litre(-1)) and more active than the fungicide polyoxin B (100 and 33 mg litre(-1)) against Sphaerotheca fuliginea on cucumber plants in glasshouse trials.

  2. Inhibition of plant-pathogenic fungi by the barley cystatin Hv-CPI (gene Icy) is not associated with its cysteine-proteinase inhibitory properties.

    Science.gov (United States)

    Martínez, M; López-Solanilla, E; Rodríguez-Palenzuela, P; Carbonero, P; Díaz, I

    2003-10-01

    The recombinant barley cystatin Hv-CPI inhibited the growth of three phytopathogenic fungi (Botrytis cinerea, Colletotrichum graminicola, and Plectosphaerella cucumerina) and the saprotrophic fungus Trichoderma viride. Several mutants of barley cystatin were generated by polymerase chain reaction approaches and both their antifungal and their cysteine-proteinase inhibitory properties investigated. Point mutants R38-->G, Q63-->L, and Q63-->P diminished their capacity for inhibiting papain and cathepsin B, retaining their antifungal properties. However, mutant C68-->G was more active for papain and cathepsin B than the wild type. These results indicate that in addition to the consensus cystatin-reactive site, Q63-V64-V65-A66-G67, the A37-R38-F39-A40-V41 region, common to all cereal cystatins, and the C68 residue are important for barley cystatin activity. On the other hand, the K92-->P mutant is inactive as a fungicide, but still retains measurable inhibitory activity for papain and cathepsin B. Against B. cinerea, the antifungal effect of Hv-CPI and of its derived mutants does not always correlate with their activities as proteinase inhibitors, because the Q63-->P mutant is inactive as a cystatin, while still inhibiting fungal growth, and the K92-->P mutant shows the reciprocal effects. These data indicate that inhibition of plant-pathogenic fungi by barley cystatin is not associated with its cysteine-proteinase inhibitory activity. Moreover, these results are corroborated by the absence of inhibition of intra- and extramycelia-proteinase activities by barley cystatin and by other well-known inhibitors of cysteine-proteinase activity in the fungal zymograms of B. cinerea.

  3. Conditionally pathogenic fungi in recreational waters

    Directory of Open Access Journals (Sweden)

    Matavulj Milan N.

    2005-01-01

    Full Text Available The improvement of health and life conditions depends on various environmental factors. The exposition to organic and inorganic pollutants, as well as to the broad spectar of microorganisms is one of these factors. Medically important fungi have been increasing their number recently especially in urban and in recreational zones. Some of them, first of all molds and yeasts, are involved by different means in causing more or less serious diseases of man and animals. Frequency of alergic symptoms and human mycotic lesions increased significantly during last decades. Such phenomena have provoked more scientific attention recently. According to the available literature data, micro-fungi, causing mycoses and "environmental" fungi too could be considered as an important factor of health risk, being neglected and underestimated so far, especially in analyses of safe use of recreational waters and surrounding areas, among them swimming pools, river and sea beaches. On the basis of such statement there arises conclusion that water and ground of recreational zones could serve as vectors in transmission pathways of potentially or conditionally pathogenic fungi, being dangerous especially for immunocompromised individuals, which suggests inclusion of qualitative and quantitative composition of fungal community into a continual monitoring of hygienic status of recreational zones.

  4. Functional analysis of the conserved transcriptional regulator CfWor1 in Cladosporium fulvum reveals diverse roles in the virulence of plant pathogenic fungi.

    Science.gov (United States)

    Okmen, Bilal; Collemare, Jérôme; Griffiths, Scott; van der Burgt, Ate; Cox, Russell; de Wit, Pierre J G M

    2014-04-01

    Fungal Wor1-like proteins are conserved transcriptional regulators that are reported to regulate the virulence of several plant pathogenic fungi by affecting the expression of virulence genes. Here, we report the functional analysis of CfWor1, the homologue of Wor1 in Cladosporium fulvum. Δcfwor1 mutants produce sclerotium-like structures and rough hyphae, which are covered with a black extracellular matrix. These mutants do not sporulate and are no longer virulent on tomato. A CE.CfWor1 transformant that constitutively expresses CfWor1 produces fewer spores with altered morphology and is also reduced in virulence. RNA-seq and RT-qrtPCR analyses suggest that reduced virulence of Δcfwor1 mutants is due to global downregulation of transcription, translation and mitochondrial respiratory chain. The reduced virulence of the CE.CfWor1 transformant is likely due to downregulation of effector genes. Complementation of a non-virulent Δfosge1 (Wor1-homologue) mutant of Fusarium oxysporum f. sp. lycopersici with CfWor1 restored expression of the SIX effector genes in this fungus, but not its virulence. Chimeric proteins of CfWor1/FoSge1 also only partially restored defects of the Δfosge1 mutant, suggesting that these transcriptional regulators have functionally diverged. Altogether, our results suggest that CfWor1 primarily regulates development of C. fulvum, which indirectly affects the expression of a subset of virulence genes.

  5. The RAM network in pathogenic fungi.

    Science.gov (United States)

    Saputo, Sarah; Chabrier-Rosello, Yeissa; Luca, Francis C; Kumar, Anuj; Krysan, Damian J

    2012-06-01

    The regulation of Ace2 and morphogenesis (RAM) network is a protein kinase signaling pathway conserved among eukaryotes from yeasts to humans. Among fungi, the RAM network has been most extensively studied in the model yeast Saccharomyces cerevisiae and has been shown to regulate a range of cellular processes, including daughter cell-specific gene expression, cell cycle regulation, cell separation, mating, polarized growth, maintenance of cell wall integrity, and stress signaling. Increasing numbers of recent studies on the role of the RAM network in pathogenic fungal species have revealed that this network also plays an important role in the biology and pathogenesis of these organisms. In addition to providing a brief overview of the RAM network in S. cerevisiae, we summarize recent developments in the understanding of RAM network function in the human fungal pathogens Candida albicans, Candida glabrata, Cryptococcus neoformans, Aspergillus fumigatus, and Pneumocystis spp.

  6. Screening of plant pathogenic fungi by ginsenoside compound K production%人参皂苷compound K转化菌株的筛选

    Institute of Scientific and Technical Information of China (English)

    杨元超; 王英平; 闫梅霞; 孙成贺; 郑培和

    2011-01-01

    目的:筛选具有人参皂苷转化能力的真菌菌株,用于生产稀有人参皂苷compound K.方法:通过液态发酵,以三七茎叶总皂苷为底物,采用TLC和HPLC-ELSD检测转化产物,从12株植物病原真菌中筛选能够转化产生人参皂苷compoundK的最佳菌株.结果:获得一株高效人参皂苷转化真菌,可以转化产生人参皂苷compound K,该菌株为镰刀属真菌串珠镰孢Fusarium moniliforme.结论:串珠镰孢对三七茎叶总皂苷具有较高的转化效率,有望用于生产制备compound K等低含量高活性的稀有人参皂苷.%Objective:To screen a new strain which can transform panaxadiol saponins into the rare ginsenoside compound K.Method:The total saponins in stems and leaves of Panax notoginseng was used as a substrate in the liquid state fermentation process.and the results were detected by TCL and HPLC-ELSD to screen a strain from twelve plant pathogenic fungi which can produce ginsenoside compound K.Result:Fusarium moniliforme was found to transform the total saponins to ginsenoside compound K efficiently in the all twelve fungal strains.In the fermentation process, ginsenoside Rb1 was transformed almost completely,and the content of ginsenoside Rd was decreasing evidently.Conclusion:F.moniliforme is selected as a new high-yield strain.It is expected to be used to produce the high activity infrequent ginsenoside compound K and to improve the content of active principles in medicinal plants.

  7. Plant pathogen resistance

    Science.gov (United States)

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  8. Plant pathogen resistance

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Jean T.; Jung, Ho Won; Tschaplinski, Timothy

    2015-10-20

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  9. CHARACTERIZATION OF PATHOGENIC FUNGI GENOMES USING PULSED FIELD GEL ELECTROPHORESIS

    Institute of Scientific and Technical Information of China (English)

    吴绍熙; 郭宁如; 殷正男; 柴建华

    1996-01-01

    Pulsed field gel eleetrophoresis (PFGE) has been firstly introdueed in characterization of the pathogenic fungi Pericillium marneffei and Exophiata dermatitidis genomes. The numbers and sizes of their chromosomes have been detected. Polymorphism was identified on the smallest chromosome of E.derntatitidis. The result shows that PFGE for characterization of large molecular DNA pathogenic fungi is very suitable, it is more simple and more efficacy. The result also shows the diversity of pathogenic fungi is relative common even in rare occurred pathogeafie fungi such as E. dermatitidis.

  10. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

  11. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

  12. In situ hybridization for the detection of rust fungi in paraffin embedded plant tissue sections

    Science.gov (United States)

    Rust fungi infect a wide range of plant species making them of particular interest to plant pathologists. In order to study the interactions between these important pathogenic fungi and their host plants it is useful to be able to differentiate fungal tissue from plant tissue. This can be accomplish...

  13. Production of cross-kingdom oxylipins by pathogenic fungi: An update on their role in development and pathogenicity.

    Science.gov (United States)

    Fischer, Gregory J; Keller, Nancy P

    2016-03-01

    Oxylipins are a class of molecules derived from the incorporation of oxygen into polyunsaturated fatty acid substrates through the action of oxygenases. While extensively investigated in the context of mammalian immune responses, over the last decade it has become apparent that oxylipins are a common means of communication among and between plants, animals, and fungi to control development and alter host-microbe interactions. In fungi, some oxylipins are derived nonenzymatically while others are produced by lipoxygenases, cyclooxygenases, and monooxygenases with homology to plant and human enzymes. Recent investigations of numerous plant and human fungal pathogens have revealed oxylipins to be involved in the establishment and progression of disease. This review highlights oxylipin production by pathogenic fungi and their role in fungal development and pathogen/host interactions.

  14. Pathogenicity determinants in smut fungi revealed by genome comparison.

    Science.gov (United States)

    Schirawski, Jan; Mannhaupt, Gertrud; Münch, Karin; Brefort, Thomas; Schipper, Kerstin; Doehlemann, Gunther; Di Stasio, Maurizio; Rössel, Nicole; Mendoza-Mendoza, Artemio; Pester, Doris; Müller, Olaf; Winterberg, Britta; Meyer, Elmar; Ghareeb, Hassan; Wollenberg, Theresa; Münsterkötter, Martin; Wong, Philip; Walter, Mathias; Stukenbrock, Eva; Güldener, Ulrich; Kahmann, Regine

    2010-12-10

    Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.

  15. Plant Fungal Pathogens: Methods and Protocols

    NARCIS (Netherlands)

    Bolton, M.D.; Thomma, B.P.H.J.

    2012-01-01

    Over the course of evolution, fungi have adapted to occupy specific niches, from symbiotically inhabiting the flora of the intestinal tract of mammals to saprophytic growth on leaf litter resting on the forest floor. In Plant Fungal Pathogens: Methods and Protocols, expert researchers in the field d

  16. Fungi of the genus Fusarium as pathogens of soybean seedlings

    Directory of Open Access Journals (Sweden)

    Joanna Marcinkowska

    2013-12-01

    Full Text Available Twenty isolates of fungi of the genus Fusarium collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species F. culmorum was most numerously represented among the isolated (4 of 8 pathogens. Isolates of F. sambucinum were also pathogenic (2 of 4 and those of F. soloni (1 of 3, too. The only isolate of F. avenaceum also caused seedling blight. Two isolates of F. oxysporum and two of F. arthrosporioides were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

  17. Dispersal of arbuscular mycorrhizal fungi and plants during succession

    Science.gov (United States)

    García de León, David; Moora, Mari; Öpik, Maarja; Jairus, Teele; Neuenkamp, Lena; Vasar, Martti; Bueno, C. Guillermo; Gerz, Maret; Davison, John; Zobel, Martin

    2016-11-01

    Arbuscular mycorrhizal (AM) fungi are important root symbionts that enhance plant nutrient uptake and tolerance to pathogens and drought. While the role of plant dispersal in shaping successional vegetation is well studied, there is very little information about the dispersal abilities of AM fungi. We conducted a trap-box experiment in a recently abandoned quarry at 10 different distances from the quarry edge (i.e. the potential propagule source) over eleven months to assess the short term, within-year, arrival of plant and AM fungal assemblages and hence their dispersal abilities. Using DNA based techniques we identified AM fungal taxa and analyzed their phylogenetic diversity. Plant diversity was determined by transporting trap soil to a greenhouse and identifying emerging seedlings. We recorded 30 AM fungal taxa. These contained a high proportion of ruderal AM fungi (30% of taxa, 79% of sequences) but the richness and abundance of AM fungi were not related to the distance from the presumed propagule source. The number of sequences of AM fungi decreased over time. Twenty seven plant species (30% of them ruderal) were recorded from the soil seed traps. Plant diversity decreased with distance from the propagule source and increased over time. Our data show that AM fungi with ruderal traits can be fast colonizers of early successional habitats.

  18. Epiparasitic plants specialized on arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Bidartondo, Martin I; Redecker, Dirk; Hijri, Isabelle; Wiemken, Andres; Bruns, Thomas D; Domínguez, Laura; Sérsic, Alicia; Leake, Jonathan R; Read, David J

    2002-09-26

    Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature.

  19. Comparative analysis of twelve Dothideomycete plant pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin; Aerts, Andrea; Salamov, Asaf; Goodwin, Stephen B.; Grigoriev, Igor

    2011-03-11

    The Dothideomycetes are one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops grown for biofuel, food or feed. Most Dothideomycetes have only a single host and related Dothideomycete species can have very diverse host plants. Twelve Dothideomycete genomes have currently been sequenced by the Joint Genome Institute and other sequencing centers. They can be accessed via Mycocosm which has tools for comparative analysis

  20. Evaluation of Risk of Resistance in Plant Pathogenous Fungi to Fungicides%植物病原菌对杀菌剂抗性风险评估

    Institute of Scientific and Technical Information of China (English)

    王文桥; 马志强; 张小风; 张文吉

    2001-01-01

    植物病原菌对杀菌剂的抗性风险由基本风险和治理风险组成。杀菌剂使用之前或之初可根据人工诱变、药剂选择或驯化实验、田间野生敏感菌株敏感性变异、抗药菌株的生物及遗传特征、杀菌剂作用方式等进行基本抗药风险预测;杀菌剂使用数年之后可根据人工诱变、药剂选择或驯化、田间药效与抗药性发生、抗药菌株的生物及遗传特征、杀菌剂作用方式与使用对策等已有资料进行抗药风险评估。目前已有4种方法用于抗药风险评估。由杀菌剂与病害共同决定的基本抗药风险可分成低、中和高度。基本抗性风险高的药剂合理使用可延缓田间抗药性发生,中度基本抗性风险药剂不合理使用也可引发田间抗药性发生和药效明显降低。%Risk of resistance in plant pathogenous fungi to fungicides is composed of inherent risk and management risk. At the beginning of the application of target fungicide, inherent risk of resistance can be predicted by artificial induction or fungicide selection, sensitivity variation of wild-type sensitive strains, biological and genetic characteristics of resistant strains and mode of action of target fungicide. Several years after application of target fungicide, risk of resistance can be assessed according to the known experimental data, such as artificial induction or fungicide selection, efficacy appearance and resistance occurrence in field, biological and genetic characteristics of resistant strains, mode of action and application strategies of target fungicide. Currently, 4 methods have been adopted to evaluate risk of resistance. Inherent risk of resistance caused by diseases and fungicides can be divided into low, intermediate, and high level. High risk of resistance to phenylamide fungicides and lower risk of resistance to cymoxanil have been assessed in Phytophthora infestans and Plasmopara viticola. Low or intermediate risk of

  1. Antibody-based resistance to plant pathogens.

    Science.gov (United States)

    Schillberg, S; Zimmermann, S; Zhang, M Y; Fischer, R

    2001-01-01

    Plant diseases are a major threat to the world food supply, as up to 15% of production is lost to pathogens. In the past, disease control and the generation of resistant plant lines protected against viral, bacterial or fungal pathogens, was achieved using conventional breeding based on crossings, mutant screenings and backcrossing. Many approaches in this field have failed or the resistance obtained has been rapidly broken by the pathogens. Recent advances in molecular biotechnology have made it possible to obtain and to modify genes that are useful for generating disease resistant crops. Several strategies, including expression of pathogen-derived sequences or anti-pathogenic agents, have been developed to engineer improved pathogen resistance in transgenic plants. Antibody-based resistance is a novel strategy for generating transgenic plants resistant to pathogens. Decades ago it was shown that polyclonal and monoclonal antibodies can neutralize viruses, bacteria and selected fungi. This approach has been improved recently by the development of recombinant antibodies (rAbs). Crop resistance can be engineered by the expression of pathogen-specific antibodies, antibody fragments or antibody fusion proteins. The advantages of this approach are that rAbs can be engineered against almost any target molecule, and it has been demonstrated that expression of functional pathogen-specific rAbs in plants confers effective pathogen protection. The efficacy of antibody-based resistance was first shown for plant viruses and its application to other plant pathogens is becoming more established. However, successful use of antibodies to generate plant pathogen resistance relies on appropriate target selection, careful antibody design, efficient antibody expression, stability and targeting to appropriate cellular compartments.

  2. Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Daniel Cook

    2017-06-01

    Full Text Available Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnK gene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable swainsonine, then complementing the mutant with the wild-type gene to restore swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete’s foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of swainsonine producers to at least four orders of Ascomycota, and suggest that swainsonine has roles in mutualistic symbioses and diseases of plants and animals.

  3. The possible usage of mycoviruses in biological control against tree pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Ayşe Gülden Aday Kaya

    2015-01-01

    Full Text Available Mycoviruses in many organism including plant pathogenic fungi. They are mostly spread intracellularly via asexual and sexual reproduction of the fungi and cause some changes on them. Although many mycoviruses have no clear effect on their hosts, there are also many reports that they cause some phenotypic chances. Especially, they have effect on plant pathogenic fungi by increasing or decreasing their virulence. When they reduce the virulence of the host like in Chestnut canker sample, it is possible to use them in biological control. In this review, mycoviruses detected on some important fungal pathogens of forest trees both in our country and world were introduced and the studies carried out were summarized.

  4. Rapid identification and detection of pathogenic Fungi by padlock probes

    NARCIS (Netherlands)

    Tsui, C.K.M.; Wang, B.; Schoen, C.D.; Hamelin, R.C.

    2013-01-01

    Fungi are important pathogens of human diseases, as well as to agricultural crop and trees. Molecular diagnostics can detect diseases early, and improve identification accuracy and follow-up disease management. The use of padlock probe is effective to facilitate these detections and pathogen identif

  5. GROWTH INHIBITION OF PATHOGENIC ROOT FUNGI BY EXTRACTS OF ECTOMYCORRHIZAL FUNGI OR Picea glehnii INOCULATED WITH ECTOMYCORRHIZAL FUNGI

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    MARIA CATARINA MEGUMI KASUYA

    1996-01-01

    Full Text Available This work sought to verify the presence of compounds with antimicrobial properties in extracts of ectomycorrhizal fungi or in Picea glehnii inoculated with ectomycorrhizal fungi. Extracts from Pisolithus tinctorius, Scleroderma flavidum, Amanita pantherina and Paxillus sp., grown in liquid culture media, and from P. glehnii seedlings inoculated or not with the above ectomycorrhizal fungi and cultivated in in vitro condition, were processed to obtain two fractions, water and ethyl acetate solubles. These fractions were tested for the presence of inhibitory constituents against Fusarium roseum, Pythium sp. and Rhizoctonia solani. Direct bioautography technique on TLC or paper disc technique was used, depending on the extract and pathogenic fungi tested. The results showed the production on inhibitory components, not only by ectomycorrhizal fungi, but also by P. glehnii inoculated or not with ectomycorrhizal fungi. The sensitivity varied considerably according to the type of fungus or extract.

  6. On the relationships between nematodes, mycorrhizal fungi and plants: functional composition of species and plant performance

    NARCIS (Netherlands)

    Brussaard, L.; Kuyper, T.W.; Goede, de R.G.M.

    2001-01-01

    We analysed data from descriptive and experimental studies on the possible relationships between plants, nematodes and mycorrhizal fungi in (successional) plant communities in The Netherlands. A key role for pathogenic nematodes in cyclic succession in grazed grassland confirmed similar results in

  7. 火棘抑菌内生真菌的筛选与拮抗植物病原菌作用研究%Screening of Pyracantha fortuneana Endophytic Fungus and Function Examination of Antagonism to Plant Pathogenic Fungi

    Institute of Scientific and Technical Information of China (English)

    田小曼; 陈阿敏

    2012-01-01

    采用常规分离方法从火棘的茎、叶、果实中分离得到15株内生真菌,以小麦根腐病菌、小麦赤霉病菌、番茄早疫病菌等9种病原真菌作靶标菌,筛选出了一株具有较高抑菌活性的菌株-J4,采用形态学观察和ITS序列测定相结合的方法对J4进行鉴定.结果表明,J4菌株为子囊菌亚门间座壳属(Dia porthe)真菌.%Fifteen endophytic fungi were screened from the stems, leaves, and fruits of Pyracantha fortuneana. The antifungal activities of the fungi to 9 plant pathogenic fungi (including Bipolaris sorokiniana , Gibberella zeae ,and Alternaria solani and so on) were selected. One strain, J4 with high antifungal activity was screened and obtained. Morphological observations and ITS sequence of strain J4 were conducted. The results showed that the strain belonged to ascomycetes Diaporthe genus.

  8. Histone Acetylation in Fungal Pathogens of Plants

    Directory of Open Access Journals (Sweden)

    Junhyun Jeon

    2014-03-01

    Full Text Available Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.

  9. Amoeba provide insight into the origin of virulence in pathogenic fungi.

    Science.gov (United States)

    Casadevall, Arturo

    2012-01-01

    Why are some fungi pathogenic while the majority poses no threat to humans or other hosts? Of the more than 1.5 million fungal species only about 150-300 are pathogenic for humans, and of these, only 10-15 are relatively common pathogens. In contrast, fungi are major pathogens for plants and insects. These facts pose several fundamental questions including the mechanisms responsible for the origin of virulence among the few pathogenic species and the high resistance of mammals to fungal diseases. This essay explores the origin of virulences among environmental fungi with no obvious requirement for animal association and proposes that selection pressures by amoeboid predators led to the emergence of traits that can also promote survival in mammalian hosts. In this regard, analysis of the interactions between the human pathogenic funges Cryptococcus neoformans and amoeba have shown a remarkable similarity with the interaction of this fungus with macrophages. Hence the virulence of environmental pathogenic fungi is proposed to originate from a combination of selection by amoeboid predators and perhaps other soil organism with thermal tolerance sufficient to allow survival in mammalian hosts.

  10. In Vitro Assessment of Extracts of the Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Higher Basidiomycetes) Against Different Plant Pathogenic Fungi.

    Science.gov (United States)

    Baig, Mirza Nabeel; Shahid, Ahmad Ali; Ali, Muhammad

    2015-01-01

    Five isolates of the lingzhi or reishi medicinal mushroom Ganoderma lucidum (GL-1, GL-2, GL-3, GL-4, GL-5) were collected from different locations within and surrounding Lahore, Pakistan, to study the antifungal potential of their bioactive compounds. After studying morphology, different concentrations of the extracts were prepared in methanol and water using a Soxhlet extractor. Different cultures of fungal pathogens were acquired from the First Fungal Culture Bank of Pakistan, University of the Punjab, Lahore. The antimicrobial potential of 5 G. lucidum samples against 5 fungal pathogens (Fusarium oxysporum, Aspergillus niger, A. flavus, Penicillium sp., and Alternaria alternata) was observed. The lowest biomass reduction (7%) was observed in 1% and 2% concentrations of a methanolic extract and 6% in the case of a water extract. Major inhibition was observed using higher concentrations of the methanolic extract (3% and 4%). These extracts significantly suppressed fungal biomass up to 38% and 56% in A. niger, 47% in A. flavus, 58% in ,i>Penicillium sp., 46% in A. alternaria, and 45% in F. oxysporum compared with the control. It was concluded from these studies that methanolic extracts of G. lucidum showed better activity against all plant fungal pathogens when compared with the water extracts.

  11. Fungi in the cystic fibrosis lung: bystanders or pathogens?

    Science.gov (United States)

    Chotirmall, Sanjay H; McElvaney, Noel G

    2014-07-01

    Improvement to the life expectancy of people with cystic fibrosis (PWCF) brings about novel challenges including the need for evaluation of the role of fungi in the cystic fibrosis (CF) lung. To determine if such organisms represent bystanders or pathogens affecting clinical outcomes we review the existing knowledge from a clinical, biochemical, inflammatory and immunological perspective. The prevalence and importance of fungi in the CF airway has likely been underestimated with the most frequently isolated filamentous fungi being Aspergillus fumigatus and Scedosporium apiospermum and the major yeast Candida albicans. Developing non-culture based microbiological methods for fungal detection has improved both our classification and understanding of their clinical consequences including localized, allergic and systemic infections. Cross-kingdom interaction between bacteria and fungi are discussed as is the role of biofilms further affecting clinical outcome. A combination of host and pathogen-derived factors determines if a particular fungus represents a commensal, colonizer or pathogen in the setting of CF. The underlying immune state, disease severity and treatment burden represent key host variables whilst fungal type, form, chronicity and virulence including the ability to evade immune recognition determines the pathogenic potential of a specific fungus at a particular point in time. Further research in this emerging field is warranted to fully elucidate the spectrum of disease conferred by the presence of fungi in the CF airway and the indications for therapeutic interventions. Copyright © 2014. Published by Elsevier Ltd.

  12. Response of root fungi in Pisum sativum to plant and soil environmental factors

    DEFF Research Database (Denmark)

    Yu, Lingling

    Plant roots harbor a large number of fungi that play an important role both in agroecosystems and natural ecosystems. These fungi can be plant pathogenic, parasitic, saprotrophic or mutualistic. The root-associated fungi are involved in various ecological processes in root ecosystems......, such as improving plant nutrient uptake, cycling organic carbon, suppressing plant diseases and enhancing plant tolerance to biotic and abiotic stress. In turn, the community and structure of root-associated fungi maybe influenced by rhizosphere conditions such as plant health status, plant growth stage...... and nutritional status of the plant and soil environments. However, limited information is available about the richness and composition of most of these root-associated fungi as studies of fungal communities remain a challenge because of below-ground high taxonomic and ecological diversity. In the present study...

  13. Response of root fungi in Pisum sativum to plant and soil environmental factors

    DEFF Research Database (Denmark)

    Yu, Lingling

    Plant roots harbor a large number of fungi that play an important role both in agroecosystems and natural ecosystems. These fungi can be plant pathogenic, parasitic, saprotrophic or mutualistic. The root-associated fungi are involved in various ecological processes in root ecosystems, such as imp......Plant roots harbor a large number of fungi that play an important role both in agroecosystems and natural ecosystems. These fungi can be plant pathogenic, parasitic, saprotrophic or mutualistic. The root-associated fungi are involved in various ecological processes in root ecosystems......, such as improving plant nutrient uptake, cycling organic carbon, suppressing plant diseases and enhancing plant tolerance to biotic and abiotic stress. In turn, the community and structure of root-associated fungi maybe influenced by rhizosphere conditions such as plant health status, plant growth stage...... and nutritional status of the plant and soil environments. However, limited information is available about the richness and composition of most of these root-associated fungi as studies of fungal communities remain a challenge because of below-ground high taxonomic and ecological diversity. In the present study...

  14. Sandpits as a reservoir of potentially pathogenic fungi for children.

    Science.gov (United States)

    Wójcik, Anna; Błaszkowska, Joanna; Kurnatowski, Piotr; Góralska, Katarzyna

    2016-12-23

    Fungi belonging to various physiological and morphological groups present in the environment are potential human pathogens. Some of them are considered as emerging pathogens. Therefore, their presence in children's playgrounds should be regarded as health risk factor. Sixty-eight samples of sand collected from 17 sandpits of different localities in Łódź, Poland, in autumn 2010 and 2011, and in spring 2011 and 2012 were evaluated. The fungi were isolated with classical mycological methods and identified on the basis of morphological and biochemical features. The prevalence of fungi in spring was 94.1% of sandpits in both layers of sand (depth 0-3 cm and 10-15 cm) and in one kindergarten sandpit, but only in a deeper layer. In autumn, fungi occurred in both layers in all sandpits (100%). The fungal concentration (CFU/g of sand) varied considerably (range 0 - uncountable) in both layers. A total of 352 isolates belonging to 80 species were found. There were 69 yeasts and yeast-like fungi isolates from 12 species (9 species in each season), and 283 filamentous fungi from 68 species: 35 species in spring and 55 in autumn, with 4 keratinolytic species. There were important causes of allergies, among them Cladosporium herbarum and Alternaria alternata, as well as of opportunistic mycoses: Cryptococcus neoformans, Aspergillus fumigatus and new and 'emerging' fungal pathogens e.g., Trichosporon, Rhodotorula, Fusarium and Scedosporium species. Potentially pathogenic fungi are present in the sand taken from sandpits in Łódź. This fact poses a significant threat to child health and therefore proper maintenance and periodic checking of sandpits are of great importance.

  15. Glycyrrhiza glabra extract protects plants against important phytopathogenic fungi.

    Science.gov (United States)

    Schuster, C; Konstantinidou-Doltsinis, S; Schmitt, A

    2010-01-01

    In previous investigations an ethanolic plant extract from Glycyrrhiza glabra (2.5% w/v) showed 100% efficacy against late blight (Phytophthora infestans) on detached tomato leaves. Based on these findings, the objective of this work was to investigate the effect of this extract against different important plant pathogenic fungi. Tests were carried out on potted plants. Against P. infestans, efficacies of 75% and 58% were achieved on tomato and potato plants with 5% extract concentration, respectively. Against another Oomycete, Pseudoperonospora cubensis, on cucumber, application of a 2.5% extract led to an efficacy of above 90%. The EC50-value was calculated to be 0.5% In a trial on beans against bean rust (Uromyces appendiculatus), G. glabra extract (5% concentration) showed 92% efficacy. In contrast, against powdery mildew on cucumber (Podosphaera xanthii), no disease reduction was found. Overall, the results indicate a high potential for the extract of G. glabra to control a number of important plant pathogens.

  16. Genomic transition to pathogenicity in chytrid fungi.

    Directory of Open Access Journals (Sweden)

    Suzanne Joneson

    2011-11-01

    Full Text Available Understanding the molecular mechanisms of pathogen emergence is central to mitigating the impacts of novel infectious disease agents. The chytrid fungus Batrachochytrium dendrobatidis (Bd is an emerging pathogen of amphibians that has been implicated in amphibian declines worldwide. Bd is the only member of its clade known to attack vertebrates. However, little is known about the molecular determinants of - or evolutionary transition to - pathogenicity in Bd. Here we sequence the genome of Bd's closest known relative - a non-pathogenic chytrid Homolaphlyctis polyrhiza (Hp. We first describe the genome of Hp, which is comparable to other chytrid genomes in size and number of predicted proteins. We then compare the genomes of Hp, Bd, and 19 additional fungal genomes to identify unique or recent evolutionary elements in the Bd genome. We identified 1,974 Bd-specific genes, a gene set that is enriched for protease, lipase, and microbial effector Gene Ontology terms. We describe significant lineage-specific expansions in three Bd protease families (metallo-, serine-type, and aspartyl proteases. We show that these protease gene family expansions occurred after the divergence of Bd and Hp from their common ancestor and thus are localized to the Bd branch. Finally, we demonstrate that the timing of the protease gene family expansions predates the emergence of Bd as a globally important amphibian pathogen.

  17. Swainsonine biosynthesis genes in diverse symbiotic and pathogenic fungi

    Science.gov (United States)

    Swainsonine, a cytotoxic fungal alkaloid and a potential cancer therapy drug, is produced by the insect pathogen and plant symbiont, Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glo...

  18. Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

    Directory of Open Access Journals (Sweden)

    You-Kun Zheng

    2017-07-01

    Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

  19. Comparative analysis of fungal genomes reveals different plant cell wall degrading capacity in fungi

    Science.gov (United States)

    2013-01-01

    Background Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported. Results In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 103 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed. Importantly, cellulases of some GH families are present in fungi that are not known to have cellulose-degrading ability. In addition, our results also showed that in general, plant pathogenic fungi have the highest number of CAZymes. Biotrophic fungi tend to have fewer CAZymes than necrotrophic and hemibiotrophic fungi. Pathogens of dicots often contain more pectinases than fungi infecting monocots. Interestingly, besides yeasts, many saprophytic fungi that are highly active in degrading plant biomass contain fewer CAZymes than plant pathogenic fungi. Furthermore, analysis of the gene expression profile of the wheat scab fungus Fusarium graminearum revealed that most of the CAZyme genes related to cell wall degradation were up-regulated during plant infection. Phylogenetic analysis also

  20. Parallels in amphibian and bat declines from pathogenic fungi.

    Science.gov (United States)

    Eskew, Evan A; Todd, Brian D

    2013-03-01

    Pathogenic fungi have substantial effects on global biodiversity, and 2 emerging pathogenic species-the chytridiomycete Batrachochytrium dendrobatidis, which causes chytridiomycosis in amphibians, and the ascomycete Geomyces destructans, which causes white-nose syndrome in hibernating bats-are implicated in the widespread decline of their vertebrate hosts. We synthesized current knowledge for chytridiomycosis and white-nose syndrome regarding disease emergence, environmental reservoirs, life history characteristics of the host, and host-pathogen interactions. We found striking similarities between these aspects of chytridiomycosis and white-nose syndrome, and the research that we review and propose should help guide management of future emerging fungal diseases.

  1. Interactions between plants and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Hata, Shingo; Kobae, Yoshihiro; Banba, Mari

    2010-01-01

    Arbuscular mycorrhizal (AM) fungi inhabit the root cortical cells of most plants and obtain photosynthates from the host plants while they transfer mineral nutrients from the soil to the hosts. In this review, we first summarize recent progress regarding signal molecules involved in the recognition of each symbiont, the signaling pathways in the host plants, and the characteristics of AM-inducible nutrient transporters, which were elucidated mainly using model legumes. Then, we summarize studies on the colonization by AM fungi of lower plants and of the roots of major crops. There are not only "AM-responsive" crops like maize, sorghum, and soybean but also "AM-nonresponsive" ones like wheat, barley, and rice. Finally, we mention the worldwide problems of limited and biased agricultural resources and discuss future directions as to how we can make use of AM symbiosis for improving crop production and establishing sustainable agriculture.

  2. [Interactions between invasive plants and arbuscular mycorrhizal fungi: a review].

    Science.gov (United States)

    Bai, Yan-fang; Guo, Shao-xia; Li, Min

    2011-09-01

    The invasion of invasive plants changes the biological community structure in their invaded lands, leading to the biodiversity loss. As an important component of soil microorganisms in terrestrial ecosystem, arbuscular mycorrhizal (AM) fungi can affect the growth performance of invasive plants. This kind of specific relations between AM fungi and invasive plants also implies that AM fungi can affect plant invasion. On the other hand, the invasion of invasive plants can affect the community structure and function of AM fungi. This paper summarized the species and harms of invasive plants in China, and discussed the relationships between AM fungi and invasive plants invasion, including the roles of AM fungi in the processes of invasive plants invasion, the effects of the invasion on AM fungi, and the interactive mechanisms between the invasion and AM fungi.

  3. Fungal life-styles and ecosystem dynamics: biological aspects of plant pathogens, plant endophytes and saprophytes

    Science.gov (United States)

    Rodriguez, R.J.; Redman, R.S.

    1997-01-01

    This chapter discusses various biochemical, genetic, ecological, and evolutionary aspects of fungi that express either symbiotic or saprophytic life-styles. An enormous pool of potential pathogens exists in both agricultural and natural ecosystems, and virtually all plant species are susceptible to one or more fungal pathogens. Fungal pathogens have the potential to impact on the genetic structure of populations of individual plant species, the composition of plant communities and the process of plant succession. Endophytic fungi exist for at least part of their life cycles within the tissues of a plant host. This group of fungi is distinguished from plant pathogens because they do not elicit significant disease symptoms. However, endophytes do maintain the genetic and biochemical mechanisms required for infection and colonization of plant hosts. Fungi that obtain chemical nutrients from dead organic matter are known as saprophytes and are critical to the dynamics and resilience of ecosystems. There are two modes of saprophytic growth: one in which biomolecules that are amenable to transport across cell walls and membranes are directly absorbed, and another in which fungi must actively convert complex biopolymers into subunit forms amenable to transportation into cells. Regardless of life-style, fungi employ similar biochemical mechanisms for the acquisition and conversion of nutrients into complex biomolecules that are necessary for vegetative growth, production and dissemination of progeny, organismal competition, and survival during periods of nutrient deprivation or environmental inclemency.

  4. Acquisition, transport, and storage of iron by pathogenic fungi.

    Science.gov (United States)

    Howard, D H

    1999-07-01

    Iron is required by most living systems. A great variety of means of acquisition, avenues of uptake, and methods of storage are used by pathogenic fungi to ensure a supply of the essential metal. Solubilization of insoluble iron polymers is the first step in iron assimilation. The two methods most commonly used by microorganisms for solubilization of iron are reduction and chelation. Reduction of ferric iron to ferrous iron by enzymatic or nonenzymatic means is a common mechanism among pathogenic yeasts. Under conditions of iron starvation, many fungi synthesize iron chelators known as siderophores. Two classes of compounds that function in iron gathering are commonly observed: hydroxamates and polycarboxylates. Two major responses to iron stress in fungi are a high-affinity ferric iron reductase and siderophore synthesis. Regulation of these two mechanisms at the molecular level has received attention. Uptake of siderophores is a diverse process, which varies among the different classes of compounds. Since free iron is toxic, it must be stored for further metabolic use. Polyphosphates, ferritins, and siderophores themselves have been described as storage molecules. The iron-gathering mechanisms used by a pathogen in an infected host are largely unknown and can only be posited on the basis of in vitro studies at present.

  5. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Doethideomycetes Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabien; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; de Wit, Pierre J. G. M.; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-03-13

    The class of Dothideomycetes is one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops grown for biofuel, food or feed. Most Dothideomycetes have only a single host and related species can have very diverse host plants. Eighteen genomes of Dothideomycetes have currently been sequenced by the Joint Genome Institute and other sequencing centers. Here we describe the results of comparative analyses of the fungi in this group.

  6. The Zinc Transport Systems and Their Regulation in Pathogenic Fungi.

    Science.gov (United States)

    Jung, Won Hee

    2015-09-01

    Zinc is an essential micronutrient required for many enzymes that play essential roles in a cell. It was estimated that approximately 3% of the total cellular proteins are required for zinc for their functions. Zinc has long been considered as one of the key players in host-pathogen interactions. The host sequesters intracellular zinc by utilizing multiple cellular zinc importers and exporters as a means of nutritional immunity. To overcome extreme zinc limitation within the host environment, pathogenic microbes have successfully evolved a number of mechanisms to secure sufficient concentrations of zinc for their survival and pathogenesis. In this review, we briefly discuss the zinc uptake systems and their regulation in the model fungus Saccharomyces cerevisiae and in major human pathogenic fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus gattii.

  7. Evolution and genome architecture in fungal plant pathogens.

    Science.gov (United States)

    Möller, Mareike; Stukenbrock, Eva H

    2017-08-07

    The fungal kingdom comprises some of the most devastating plant pathogens. Sequencing the genomes of fungal pathogens has shown a remarkable variability in genome size and architecture. Population genomic data enable us to understand the mechanisms and the history of changes in genome size and adaptive evolution in plant pathogens. Although transposable elements predominantly have negative effects on their host, fungal pathogens provide prominent examples of advantageous associations between rapidly evolving transposable elements and virulence genes that cause variation in virulence phenotypes. By providing homogeneous environments at large regional scales, managed ecosystems, such as modern agriculture, can be conducive for the rapid evolution and dispersal of pathogens. In this Review, we summarize key examples from fungal plant pathogen genomics and discuss evolutionary processes in pathogenic fungi in the context of molecular evolution, population genomics and agriculture.

  8. Paleogene radiation of a plant pathogenic mushroom.

    Directory of Open Access Journals (Sweden)

    Martin P A Coetzee

    Full Text Available BACKGROUND: The global movement and speciation of fungal plant pathogens is important, especially because of the economic losses they cause and the ease with which they are able to spread across large areas. Understanding the biogeography and origin of these plant pathogens can provide insights regarding their dispersal and current day distribution. We tested the hypothesis of a Gondwanan origin of the plant pathogenic mushroom genus Armillaria and the currently accepted premise that vicariance accounts for the extant distribution of the species. METHODS: The phylogeny of a selection of Armillaria species was reconstructed based on Maximum Parsimony (MP, Maximum Likelihood (ML and Bayesian Inference (BI. A timeline was then placed on the divergence of lineages using a Bayesian relaxed molecular clock approach. RESULTS: Phylogenetic analyses of sequenced data for three combined nuclear regions provided strong support for three major geographically defined clades: Holarctic, South American-Australasian and African. Molecular dating placed the initial radiation of the genus at 54 million years ago within the Early Paleogene, postdating the tectonic break-up of Gondwana. CONCLUSIONS: The distribution of extant Armillaria species is the result of ancient long-distance dispersal rather than vicariance due to continental drift. As these finding are contrary to most prior vicariance hypotheses for fungi, our results highlight the important role of long-distance dispersal in the radiation of fungal pathogens from the Southern Hemisphere.

  9. Succession of root-associated fungi in Pisum sativum during a plant growth cycle as examined by 454 pyrosequencing

    DEFF Research Database (Denmark)

    Yu, L.; Nicolaisen, M.; Larsen, J.

    2012-01-01

    was to examine succession patterns of root-associated fungi in pea during a full plant growth cycle. Methods Plants were grown in pots with field soil in a growth chamber under controlled conditions. Fungal communities in pea roots were analyzed at different plant growth stages including the vegetative growth......Purpose Roots are inhabited by a broad range of fungi, including pathogens and mycorrhizal fungi, with functional traits related to plant health and nutrition. Management of these fungi in agroecosystems requires profound knowledge about their ecology. The main objective of this study......, flowering and senescence, using 454 pyrosequencing. Results One hundred and twenty one non-singleton operational taxonomic units (OTUs) representing fungal species were detected. Pathogenic and arbuscular mycorrhizal fungi dominated during the vegetative growth stage, whereas saprotrophic fungi dominated...

  10. Entomopathogenic Fungi: New Insights into Host-Pathogen Interactions.

    Science.gov (United States)

    Butt, T M; Coates, C J; Dubovskiy, I M; Ratcliffe, N A

    2016-01-01

    Although many insects successfully live in dangerous environments exposed to diverse communities of microbes, they are often exploited and killed by specialist pathogens. Studies of host-pathogen interactions (HPI) provide valuable insights into the dynamics of the highly aggressive coevolutionary arms race between entomopathogenic fungi (EPF) and their arthropod hosts. The host defenses are designed to exclude the pathogen or mitigate the damage inflicted while the pathogen responds with immune evasion and utilization of host resources. EPF neutralize their immediate surroundings on the insect integument and benefit from the physiochemical properties of the cuticle and its compounds that exclude competing microbes. EPF also exhibit adaptations aimed at minimizing trauma that can be deleterious to both host and pathogen (eg, melanization of hemolymph), form narrow penetration pegs that alleviate host dehydration and produce blastospores that lack immunogenic sugars/enzymes but facilitate rapid assimilation of hemolymph nutrients. In response, insects deploy an extensive armory of hemocytes and macromolecules, such as lectins and phenoloxidase, that repel, immobilize, and kill EPF. New evidence suggests that immune bioactives work synergistically (eg, lysozyme with antimicrobial peptides) to combat infections. Some proteins, including transferrin and apolipophorin III, also demonstrate multifunctional properties, participating in metabolism, homeostasis, and pathogen recognition. This review discusses the molecular intricacies of these HPI, highlighting the interplay between immunity, stress management, and metabolism. Increased knowledge in this area could enhance the efficacy of EPF, ensuring their future in integrated pest management programs.

  11. Calcium homeostasis and signaling in fungi and their relevance for pathogenicity of yeasts and filamentous fungi

    Directory of Open Access Journals (Sweden)

    Renata Tisi

    2016-09-01

    Full Text Available Though fungi show peculiarities in the purposes and specific traits of calcium signaling pathways, the general scheme and the most important players are well conserved if compared to higher eukaryotes. This provides a powerful opportunity either to investigate shared features using yeast as a model or to exploit fungal specificities as potential targets for antifungal therapies. The sequenced genomes from yeast Saccharomyces cerevisiae, Schizosaccharomyces pombe and the filamentous fungus Neurospora crassa were already published more than ten years ago. More recently the genome sequences of filamentous fungi of Aspergillus genus, some of which threatening pathogens, and dimorphic fungi Ustilago maydis were published, giving the chance to identify several proteins involved in calcium signaling based on their homology to yeast or mammalian counterparts. Nonetheless, unidentified calcium transporters are still present in these organisms which await to be molecularly characterized. Despite the relative simplicity in yeast calcium machinery and the availability of sophisticated molecular tools, in the last years, a number of new actors have been identified, albeit not yet fully characterized. This review will try to describe the state of the art in calcium channels and calcium signaling knowledge in yeast, with particular attention to the relevance of this knowledge with respect to pathological fungi.

  12. Can insects develop resistance to insect pathogenic fungi?

    Directory of Open Access Journals (Sweden)

    Ivan M Dubovskiy

    Full Text Available Microevolutionary adaptations and mechanisms of fungal pathogen resistance were explored in a melanic population of the Greater wax moth, Galleria mellonella. Under constant selective pressure from the insect pathogenic fungus Beauveria bassiana, 25(th generation larvae exhibited significantly enhanced resistance, which was specific to this pathogen and not to another insect pathogenic fungus, Metarhizium anisopliae. Defense and stress management strategies of selected (resistant and non-selected (susceptible insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies. We hypothesize that the insects developed a transgenerationally primed resistance to the fungus B. bassiana, a costly trait that was achieved not by compromising life-history traits but rather by prioritizing and re-allocating pathogen-species-specific augmentations to integumental front-line defenses that are most likely to be encountered by invading fungi. Specifically during B. bassiana infection, systemic immune defenses are suppressed in favour of a more limited but targeted repertoire of enhanced responses in the cuticle and epidermis of the integument (e.g. expression of the fungal enzyme inhibitor IMPI, and cuticular phenoloxidase activity. A range of putative stress-management factors (e.g. antioxidants is also activated during the specific response of selected insects to B. bassiana but not M. anisopliae. This too occurs primarily in the integument, and probably contributes to antifungal defense and/or helps ameliorate the damage inflicted by the fungus or the host's own immune responses.

  13. Can insects develop resistance to insect pathogenic fungi?

    Science.gov (United States)

    Dubovskiy, Ivan M; Whitten, Miranda M A; Yaroslavtseva, Olga N; Greig, Carolyn; Kryukov, Vadim Y; Grizanova, Ekaterina V; Mukherjee, Krishnendu; Vilcinskas, Andreas; Glupov, Viktor V; Butt, Tariq M

    2013-01-01

    Microevolutionary adaptations and mechanisms of fungal pathogen resistance were explored in a melanic population of the Greater wax moth, Galleria mellonella. Under constant selective pressure from the insect pathogenic fungus Beauveria bassiana, 25(th) generation larvae exhibited significantly enhanced resistance, which was specific to this pathogen and not to another insect pathogenic fungus, Metarhizium anisopliae. Defense and stress management strategies of selected (resistant) and non-selected (susceptible) insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies. We hypothesize that the insects developed a transgenerationally primed resistance to the fungus B. bassiana, a costly trait that was achieved not by compromising life-history traits but rather by prioritizing and re-allocating pathogen-species-specific augmentations to integumental front-line defenses that are most likely to be encountered by invading fungi. Specifically during B. bassiana infection, systemic immune defenses are suppressed in favour of a more limited but targeted repertoire of enhanced responses in the cuticle and epidermis of the integument (e.g. expression of the fungal enzyme inhibitor IMPI, and cuticular phenoloxidase activity). A range of putative stress-management factors (e.g. antioxidants) is also activated during the specific response of selected insects to B. bassiana but not M. anisopliae. This too occurs primarily in the integument, and probably contributes to antifungal defense and/or helps ameliorate the damage inflicted by the fungus or the host's own immune responses.

  14. Morphological characteristics and pathogenicity of fungi associated with Roselle (Hibiscus Sabdariffa) diseases in Penang, Malaysia.

    Science.gov (United States)

    Eslaminejad, Touba; Zakaria, Maziah

    2011-11-01

    Roselle, or Jamaica sorrel (Hibiscus sabdariffa) is a popular vegetable in many tropical regions, cultivated for its leaves, seeds, stems and calyces which, the dried calyces are used to prepare tea, syrup, jams and jellies and as beverages. The main objectives of this study were to identify and characterise fungal pathogens associated with Roselle diseases based on their morphological and cultural characteristics and to determine the pathogenicity of four fungi infecting Roselle seedlings, namely Phoma exigua, Fusarium nygamai, Fusarium tgcq and Rhizoctonia solani in Penang. A total of 200 fungal isolates were obtained from 90 samples of symptomatic Roselle tissues. The isolates were identified based on cultural and morphological characteristics, as well as their pathogenicity. The fungal pathogen most frequently isolated was P. exigua (present in 45% of the samples), followed by F. nygamai (25%), Rhizoctonia solani (19%) and F. camptoceras (11%). Pathogenicity tests showed that P. exigua, F. nygamai, F. camptoceras and R. solani were able to infect both wounded and unwounded seedlings with different degrees of severity as indicated by the Disease severity (DS). R. solani was the most pathogenic fungus affecting both wounded and unwounded Roselle seedlings, followed by P. exigua that was highly pathogenic on wounded seedlings. F. nygamai was less pathogenic while the least pathogenic fungus was F. camptoceras, infecting only the unwounded seedlings but, surprisingly, not the wounded plants.

  15. Linking plants, fungi and soil mechanics

    Science.gov (United States)

    Yildiz, Anil; Graf, Frank

    2017-04-01

    Plants provide important functions in respect soil strength and are increasingly considered for slope stabilisation within eco-engineering methods, particularly to prevent superficial soil failure. The protective functions include hydrological regulation through interception and evapo-transpiration as well as mechanical stabilisation through root reinforcement and, to a certain extent, chemical stabilisation through sticky metabolites. The ever-growing application of plants in slope stabilisation demanded more precise information of the vegetation effects and, concomitant, led the models for quantifying the reinforcement shoot up like mushrooms. However, so far, the framework and interrelationships for both the role of plants and the quantification concepts have not been thoroughly analysed and comprehensively considered, respectively, often resulting in unsatisfactory results. Although it seems obvious and is implicitly presupposed that the plant specific functions related to slope stability require growth and development, this is anything but given, particularly under the often hostile conditions dominating on bare and steep slopes. There, the superficial soil layer is often characterised by a lack of fines and missing medium-sized and fine pores due to an unstable soil matrix, predominantly formed by coarse grains. Low water retention capacity and substantial leaching of nutrients are the adverse consequences. Given this general set-up, sustainable plant growth and, particularly, root development is virtually unachievable. At exactly this point mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, come into play. Though, they are probably well-known within the eco-engineering community, mycorrhizal fungi lead a humble existence. This is in spite of the fact that they supply their hosts with water and nutrients, improving the plant's ability to master otherwise unbridgeable environmental conditions. However, in order to support

  16. Identification of diverse mycoviruses through metatranscriptomics characterization of the viromes of five major fungal plant pathogens

    Science.gov (United States)

    Infection of plant pathogenic fungi by mycoviruses can attenuate their virulence on plants and vigor in culture. In this study, we described the viromes of 275 isolates of five widely dispersed plant pathogenic fungal species (Colletotrichum truncatum, Macrophomina phaseolina, Phomopsis longicolla, ...

  17. Identification and analysis of cation channel homologues in human pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    David L Prole

    Full Text Available Fungi are major causes of human, animal and plant disease. Human fungal infections can be fatal, but there are limited options for therapy, and resistance to commonly used anti-fungal drugs is widespread. The genomes of many fungi have recently been sequenced, allowing identification of proteins that may become targets for novel therapies. We examined the genomes of human fungal pathogens for genes encoding homologues of cation channels, which are prominent drug targets. Many of the fungal genomes examined contain genes encoding homologues of potassium (K(+, calcium (Ca(2+ and transient receptor potential (Trp channels, but not sodium (Na(+ channels or ligand-gated channels. Some fungal genomes contain multiple genes encoding homologues of K(+ and Trp channel subunits, and genes encoding novel homologues of voltage-gated K(v channel subunits are found in Cryptococcus spp. Only a single gene encoding a homologue of a plasma membrane Ca(2+ channel was identified in the genome of each pathogenic fungus examined. These homologues are similar to the Cch1 Ca(2+ channel of Saccharomyces cerevisiae. The genomes of Aspergillus spp. and Cryptococcus spp., but not those of S. cerevisiae or the other pathogenic fungi examined, also encode homologues of the mitochondrial Ca(2+ uniporter (MCU. In contrast to humans, which express many K(+, Ca(2+ and Trp channels, the genomes of pathogenic fungi encode only very small numbers of K(+, Ca(2+ and Trp channel homologues. Furthermore, the sequences of fungal K(+, Ca(2+, Trp and MCU channels differ from those of human channels in regions that suggest differences in regulation and susceptibility to drugs.

  18. THE USE OF PLANTS TO PROTECT PLANTS AND FOOD AGAINST FUNGAL PATHOGENS: A REVIEW.

    Science.gov (United States)

    Shuping, D S S; Eloff, J N

    2017-01-01

    Plant fungal pathogens play a crucial role in the profitability, quality and quantity of plant production. These phytopathogens are persistent in avoiding plant defences causing diseases and quality losses around the world that amount to billions of US dollars annually. To control the scourge of plant fungal diseases, farmers have used fungicides to manage the damage of plant pathogenic fungi. Drawbacks such as development of resistance and environmental toxicity associated with these chemicals have motivated researchers and cultivators to investigate other possibilities. Several databases were accessed to determine work done on protecting plants against plant fungal pathogens with plant extracts using search terms "plant fungal pathogen", "plant extracts" and "phytopathogens". Proposals are made on the best extractants and bioassay techniques to be used. In addition to chemical fungicides, biological agents have been used to deal with plant fungal diseases. There are many examples where plant extracts or plant derived compounds have been used as commercial deterrents of fungi on a large scale in agricultural and horticultural setups. One advantage of this approach is that plant extracts usually contain more than one antifungal compound. Consequently the development of resistance of pathogens may be lower if the different compounds affect a different metabolic process. Plants cultivated using plants extracts may also be marketed as organically produced. Many papers have been published on effective antimicrobial compounds present in plant extracts focusing on applications in human health. More research is required to develop suitable, sustainable, effective, cheaper botanical products that can be used to help overcome the scourge of plant fungal diseases. Scientists who have worked only on using plants to control human and animal fungal pathogens should consider the advantages of focusing on plant fungal pathogens. This approach could not only potentially increase

  19. Arbuscular mycorrhizal fungi counteract the Janzen-Connell effect of soil pathogens

    NARCIS (Netherlands)

    Liang, Minxia; Liu, Xubing; Etienne, Rampal S; Huang, Fengmin; Wang, Yongfan; Yu, Shixiao

    2015-01-01

    Soilborne pathogens can contribute to diversity maintenance in tree communities through the Janzen-Connell effect, whereby the pathogenic reduction of seedling performance attenuates with distance from conspecifics. By contrast, arbuscular mycorrhizal fungi (AMF) have been reported to promote seedli

  20. Streptomyces sp.(S -msu2)菌株对几种树木病原拮抗效应的研究%Antagonistic Effects of Streptomyces sp.(S-msu2) on Fungi of Several Plant Pathogenic

    Institute of Scientific and Technical Information of China (English)

    庞丽杰; 王文革

    2015-01-01

    In order to find biological control strains for preventing and controlling plant diseases,antagonistic effect of Streptomyces sp.(S-msu2 )on pathogenic fungi of trees was studied by culturing face to face on a plate and growth rate method.Streptomyces sp.(S-msu2)have different degree of inhibition on six pathogenic fungi (Dothis-troma pini ,Valsa sordida ,Diplodia pinea ,Mycosphaerella laricileptolepis ,Botryosphaeria laricina & Cladospo-rium tenuissimum ).The average width of inhibitive zones on plate ranged from 4.5 mm to 13.4 mm.The fermenta-tion product of Streptomyces sp.could inhibit the growth of hyphal and germination of spore;inhibition effects of Streptomyces sp.on D .pinea is the optimal.The hyphal growth inhibition rate is up to 70.6%;relative inhibition rate of spore germination reach 75.7%.It could also lead to the distortion of germ tube which was used for spore germination.Result shows that the fungus Streptomyces sp.(S-msu2)have certain potential application of biologi-cal control for Pinus Sylvestris var.mongolica shoot blight and Valsa sordida .%采用平板对峙培养法和生长速率法研究了 Streptomyces sp.(S-msu2)菌株对几种树木病原真菌的拮抗效应,旨在挖掘对树木病害防治有效的生防菌株。Streptomyces sp.(S -msu2)菌株对 Dothistroma pini 、Valsa sordida 、Diplodia pinea 、Mycosphaerella laricileptolepis 、Botryosphaeria laricina 、Cladosporium tenuissimum 6种树木病原真菌均有不同程度的抑制作用,平均抑菌带宽度在4.5~13.4 mm 范围内。Streptomyces sp.菌株发酵产物对病原菌菌丝的生长及孢子的萌发也具有一定的抑制效果,对 D .pinea 抑制效果最好,菌丝生长抑制率高达70.6%,孢子萌发相对抑制率高达75.7%,并使萌发孢子的芽管发生畸变。Streptomyces sp.(S-msu2)菌株作为樟子松枯梢病和杨树烂皮病的生防菌株具有一定的应用潜力。

  1. Mycorrhizal fungi and parasitic plants: Reply.

    Science.gov (United States)

    de Vega, Clara; Arista, Montserrat; Ortiz, Pedro L; Talavera, Salvador

    2011-04-01

    In a recent study (American Journal of Botany 97: 730-737), we described the first case of a tripartite association in natural conditions among a holoparasitic plant (Cytinus), its host Cistaceae species, and mycorrhizal fungi at an anatomical level. In a letter to the editor, Brundrett (American Journal of Botany 98: 595-596) commented on our manuscript and questioned our conclusions, arguing that they are not adequately supported by the data. We reject this point of view and believe that the controversy has arisen because of the parasitic way of life of Cytinus. We maintain and demonstrate that there is enough evidence in the data that we presented to confirm the existence of mycorrhizal associations in the Cytinus-Cistaceae complex, supporting the functionality of the tripartite association. Most holoparasitic plants have been considered as nonmycorrhizal. However, it is not advisable to be categorical in drawing conclusions about the mycorrhizal status of a group of plants that has not been fully studied.

  2. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi

    NARCIS (Netherlands)

    Ohm, R.A.; Feau, N.; Henrissat, B.; Schoch, C.L.; Horwitz, B.A.; Barry, K.W.; Condon, B.J.; Copeland, A.C.; Dhillon, B.; Glaser, F.; Hesse, C.N.; Kosti, I.; LaButti, K.; Lindquist, E.A.; Lucas, S.; Salamov, A.A.; Bradshaw, R.E.; Ciuffetti, L.; Hamelin, R.C.; Kema, G.H.J.; Lawrence, C.; Scott, J.A.; Spatafora, J.W.; Turgeon, B.G.; Wit, de P.J.G.M.; Zhong, S.; Goodwin, S.B.; Grigoriev, I.V.

    2012-01-01

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to

  3. Adult trees cause density-dependent mortality in conspecific seedlings by regulating the frequency of pathogenic soil fungi.

    Science.gov (United States)

    Liang, Minxia; Liu, Xubing; Gilbert, Gregory S; Zheng, Yi; Luo, Shan; Huang, Fengmin; Yu, Shixiao

    2016-12-01

    Negative density-dependent seedling mortality has been widely detected in tropical, subtropical and temperate forests, with soil pathogens as a major driver. Here we investigated how host density affects the composition of soil pathogen communities and consequently influences the strength of plant-soil feedbacks. In field censuses of six 1-ha permanent plots, we found that survival was much lower for newly germinated seedlings that were surrounded by more conspecific adults. The relative abundance of pathogenic fungi in soil increased with increasing conspecific tree density for five of nine tree species; more soil pathogens accumulated around roots where adult tree density was higher, and this greater pathogen frequency was associated with lower seedling survival. Our findings show how tree density influences populations of soil pathogens, which creates plant-soil feedbacks that contribute to community-level and population-level compensatory trends in seedling survival.

  4. 拮抗多种植物病原真菌 Streptomyces triostinicus C2的分离与鉴定%Isolation and Identification of Streptomyces triostinicus C2 Antagonizing on a Variety of Plant Pathogenic Fungi

    Institute of Scientific and Technical Information of China (English)

    彭卫福; 吴志明; 陈未; 曾勇军; 李昆太

    2016-01-01

    The research purposes of this work are to isolate and screen a strain against phytopathogenic fungi. The antagonistic strain was isolated and screened using plate confrontation culture with Rhizoctonia solani as indicator,and was further identified on the basis of morphological characteristics,physiological and biochemical characterization,and 16S rDNA sequence analysis. From 18 soil samples collected from Yunnan,Guangdong,Anhui,Hubei,and Jiangxi Provinces of China,the isolated actinomycete strain C2 presented a strong inhibitory effect on R. solani,and it was preliminarily identified as Streptomyces triostinicus,designated as Streptomyces strain C2 here. The bioassay results showed that Streptomyces strain C2 possessed a broad-spectrum inhibitory effect on a range of plant fungi such as R. solani,Pyricularia grisea,Colletotrichum gloeosporioides,Fusarium oxysporum f. sp. niveum,and Penicillium citrinum,and the inhibition percentage was 49.78%,56.62%,80.96%,18.59%,and 94.10%,respectively. Conclusively,Streptomyces strain C2 was an antagonistic strain with broad-spectrum in suppressing the growth of various plant fungal pathogens.%旨在分离筛选获得对植物病原真菌具有抑制作用的拮抗菌。以水稻纹枯病菌为指示菌,采用平板对峙培养法进行拮抗菌的分离筛选;根据菌体形态学观察、生理生化特征以及16S rDNA 序列分析,对拮抗菌进行菌种鉴定。结果显示,从采集自云南、广东、安徽、湖北、江西等地的18个土样中分离筛选到一株对水稻纹枯病菌具有良好抑制效果的菌株 C2,该菌株初步鉴定为 Streptomyces triostinicus,并暂命名为链霉菌 C2;进一步测定链霉菌 C2的抗菌谱发现,它对水稻纹枯病菌、水稻稻瘟病菌、葡萄炭疽病菌、西瓜枯萎病菌和橘青霉等多种植物病原真菌均具有良好的抑制作用,其抑菌率分别为49.78%、56.62%、80.96%、18.59%和94.10%。链霉菌 C2是一株植物病原真菌广谱拮抗菌。

  5. Fungi colonizing the soil and roots of tomato (Lycopersicum esculentum Mill. plants treated with biological control agents

    Directory of Open Access Journals (Sweden)

    Bożena Cwalina-Ambroziak

    2012-12-01

    Full Text Available Tomato plants, cv. Rumba Ożarowska, grown in the greenhouse of the University of Warmia and Mazury, were protected in the form of alternate spraying (twice and watering (twice with 5% aqueous extracts of the following plant species: Aloe vulgaris Lam., Achillea millefolium L., Mentha piperita L., Polygonum aviculare L., Equisetum arvense L., Juglans regia L. and Urtica dioica L. Plants not treated with the extracts served as control. After fruit harvest, samples of roots and soil were collected. The roots were disinfected and next placed on PDA medium. Soil-colonizing fungi were cultured on Martin medium. Fungi were identified microscopically after incubation. Pathogenic fungal species, Colletotrichum coccodes, Fusarium equiseti, F. oxysporum and F. poae, accounted for over 60% of all isolates obtained from the roots of tomato plants. The soil fungal community was dominated by yeast-like fungi (75.4%, whereas pathogenic fungi were present in low numbers. The applied 5% aqueous plant extracts effectively reduced the abundance of fungi, including pathogenic species, colonizing tomato plants and soil. The extract from P. aviculare showed the highest efficacy, while the extract from J. regia was least effective. Fungi showing antagonistic activity against pathogens (Paecilomyces roseum and species of the genus Trichoderma were isolated in greatest abundance from the soil and the roots of tomato plants treated with A. millefolium, M. piperita and U. dioica extracts.

  6. Succession of root-associated fungi in Pisum sativum during a plant growth cycle as examined by 454 pyrosequencing

    DEFF Research Database (Denmark)

    Yu, L.; Nicolaisen, M.; Larsen, J.;

    2012-01-01

    Purpose Roots are inhabited by a broad range of fungi, including pathogens and mycorrhizal fungi, with functional traits related to plant health and nutrition. Management of these fungi in agroecosystems requires profound knowledge about their ecology. The main objective of this study was to exam...

  7. A review on the inhibitory potential of Nigella sativa against pathogenic and toxigenic fungi.

    Science.gov (United States)

    Shokri, Hojjatollah

    2016-01-01

    Nigella sativa (N. sativa) grows in various parts of the world, particularly in Iran. It has been traditionally used as a folk remedy to treat a number of diseases. The seeds of this plant contain moisture, proteins, carbohydrates, crude fiber, alkaloids, saponins, ash, fixed oils and essential oil. The major components of the essential oil are thymoquinone, p-cymene, trans-anethole, 2-methyl-5(1-methyl ethyl)-Bicyclo[3.1.0]hex-2-en and γ-terpinene. So far, several pharmacological effects such as anti-oxidant, anti-inflammatory, anti-cancer and anti-microbial have been reported for N. sativa or its active compounds. Thymoquinone, thymohydroquinone and thymol are the most active constituents which have different beneficial properties. The oil, extracts and some of N. sativa active components possessed moderate in vitro and in vivo inhibitory activity against pathogenic yeasts, dermatophytes, non-dermatophytic filamentous fungi and aflatoxin-producing fungi. The main morphological changes of pathogenic and toxigenic fungi treated with N. sativa oil were observed in the cell wall, plasma membrane and membranous organelles, particularly in the nuclei and mitochondria. Although this review represents first step in the search for a new anti-fungal drug, the full potential of N. sativa as a fungitoxic agent has not been exploited and necessitates further investigations.

  8. A review on the inhibitory potential of Nigella sativa against pathogenic and toxigenic fungi

    Directory of Open Access Journals (Sweden)

    Hojjatollah Shokri

    2016-01-01

    Full Text Available Nigella sativa (N. sativa grows in various parts of the world, particularly in Iran. It has been traditionally used as a folk remedy to treat a number of diseases. The seeds of this plant contain moisture, proteins, carbohydrates, crude fiber, alkaloids, saponins, ash, fixed oils and essential oil. The major components of the essential oil are thymoquinone, p-cymene, trans-anethole, 2-methyl-5(1-methyl ethyl-Bicyclo[3.1.0]hex-2-en and γ-terpinene. So far, several pharmacological effects such as anti-oxidant, anti-inflammatory, anti-cancer and anti-microbial have been reported for N. sativa or its active compounds. Thymoquinone, thymohydroquinone and thymol are the most active constituents which have different beneficial properties. The oil, extracts and some of N. sativa active components possessed moderate in vitro and in vivo inhibitory activity against pathogenic yeasts, dermatophytes, non-dermatophytic filamentous fungi and aflatoxin-producing fungi. The main morphological changes of pathogenic and toxigenic fungi treated with N. sativa oil were observed in the cell wall, plasma membrane and membranous organelles, particularly in the nuclei and mitochondria. Although this review represents first step in the search for a new anti-fungal drug, the full potential of N. sativa as a fungitoxic agent has not been exploited and necessitates further investigations.

  9. Comparative genomics and the evolution of pathogenicity in human pathogenic fungi.

    LENUS (Irish Health Repository)

    Moran, Gary P

    2011-01-01

    Because most fungi have evolved to be free-living in the environment and because the infections they cause are usually opportunistic in nature, it is often difficult to identify specific traits that contribute to fungal pathogenesis. In recent years, there has been a surge in the number of sequenced genomes of human fungal pathogens, and comparison of these sequences has proved to be an excellent resource for exploring commonalities and differences in how these species interact with their hosts. In order to survive in the human body, fungi must be able to adapt to new nutrient sources and environmental stresses. Therefore, genes involved in carbohydrate and amino acid metabolism and transport and genes encoding secondary metabolites tend to be overrepresented in pathogenic species (e.g., Aspergillus fumigatus). However, it is clear that human commensal yeast species such as Candida albicans have also evolved a range of specific factors that facilitate direct interaction with host tissues. The evolution of virulence across the human pathogenic fungi has occurred largely through very similar mechanisms. One of the most important mechanisms is gene duplication and the expansion of gene families, particularly in subtelomeric regions. Unlike the case for prokaryotic pathogens, horizontal transfer of genes between species and other genera does not seem to have played a significant role in the evolution of fungal virulence. New sequencing technologies promise the prospect of even greater numbers of genome sequences, facilitating the sequencing of multiple genomes and transcriptomes within individual species, and will undoubtedly contribute to a deeper insight into fungal pathogenesis.

  10. Antifungal Activity of The Extraction of Hopea chinensis Stem and Leaves Against Plant Pathogenic Fungi%狭叶坡垒枝叶粗提物抑菌活性研究

    Institute of Scientific and Technical Information of China (English)

    熊婷; 许亚楠; 周明晓晗; 苏坚; 王忠文; 唐文伟

    2016-01-01

    With the growth rate method,15 kinds of plant materies were selected for their antifungal activity against Fusarium oxysporum Schl. f. sp. cucumerirum Owen,Alternaria longipes( Ell. et Eu) Tisdale et Wadk,Curvularia lunata (Wakker) Boedijin,Botrytis cinerea Pers,and Rhizoctonia solani Kuhn.The results were as follows.Hopea chinensis Hand.Mass,Solanum touvum swartz together and other five materials showed inhibitory activity,H. chinensis showed the strongest inhibition.Further experiment on the antifungal activity of the petro⁃leum,ethyl acetate and water extracts of H. chinensisi stem and leaves with against 21 plant pathogenic fungi such as Helminthosporium turcicum Pass,Helminthosporium oryzae Breda de Haan,Fusarium oxysporum Schl. f. sp and other 21 plant was determined.The results showed that the ethyl acetate extract of H. chinensis had high antifungal activity against 18 plant pathogenic fungi such as Gibberella fujikuroi ( Saw) Wollenw, Mycosphaere⁃lla fijiensis Mareletto,Cercospora musae Zimm. Their antifungal activity against Phytophthora nicotianae Breda was the strongest whose inhibiting rate was 100%,flowed by that against Alternaria musae Bour. et Bat,Curv⁃alaria lunata(Wakker) Boedijin,Ceratocystis paradoxa(Dade)Moreau,Alternaria brassicola(Schw.)Wiltshire, Rhizoctonia solani Kuhn,whose inhibiting rates were 89.00%,94.12%,90.35%,89.93% and 95.13%,respective⁃ly,and whose EC50 were 0.475 8mg/mL,2.642 9 mg/mL,0.614 7 mg/mL,0.467 4 mg/mL,0.977 7 mg/mL and 3.463 7 mg/mL,respectively.The spore germination experiment was conducted on C. paradoxa and A.brassicola using ethyl acetate extract of H. chinensis and the EC50 of each were 0. 716 6 mg/mL and 1. 784 4 mg/mL, respectively.The results lay the foundation for further investigation on the active antifungal components in Hopea chinensis.%采用菌丝生长速率法,以西瓜枯萎菌( Fusarium oxysporum Schl. f. sp. cucumerirum Owen)、烟草赤星菌[ Al⁃ternaria longipes(Ell. et

  11. EFEITO DO EXTRATO DE SUCUPIRA (Pterodon emarginatus Vog. SOBRE O DESENVOLVIMENTO DE FUNGOS E BACTÉRIAS FITOPATOGÊNICOS EFFECT OF THE SUCUPIRA (Pterodon emarginatus Vog. EXTRACT ON THE DEVELOPMENT OF PLANT PATHOGENIC FUNGI AND BACTERIA

    Directory of Open Access Journals (Sweden)

    Marcos Gomes da Cunha

    2007-09-01

    Full Text Available

    O objetivo deste trabalho foi avaliar o efeito do extrato de favas de sucupira (Pterodon emarginatus sobre o desenvolvimento de fungos e bactérias fitopatogênicos. Na avaliação sobre o desenvolvimento micelial de fungos, o extrato de sucupira e o fungicida tebuconazole reduziram significativamente o crescimento micelial de Alternaria brassicae, Fusarium oxysporum, Rhizoctonia solani e Ceratocystis fimbriata. Entretanto, tebuconazole foi significativamente superior ao extrato de sucupira, exceto para o fungo A. brassicae. O índice de eficácia do extrato de sucupira foi de 70%, 74%, 62% e 82% para os fungos A. brassicae, F. oxysporum, R. solani, C. fimbriata, respectivamente. A eficácia do tebuconazole foi de 93,6% para A. brassicae e 100% para os outros fungos. Na avaliação sobre o crescimento de colônias bacterianas, à medida que se aumentou à concentração do extrato de sucupira, a eficiência foi gradativamente aumentada. Contudo, houve inversão do efeito sobre o halo de inibição das colônias no tratamento com 100% do extrato. A alta viscosidade do extrato pode ter afetado negativamente a sua dispersão no meio de cultura (BDA e, conseqüentemente, produzido menor halo de inibição. O extrato de sucupira a 10% foi significativamente o melhor tratamento; entretanto, o mesmo extrato, nas concentrações de 1% e 100%, apresentou redução significativa do desenvolvimento das colônias de Clavibacter michiganensis subsp. michiganensis, Xhantomonas campestris pv. campestris e Pseudomonas syringae, em relação à testemunha.

    PALAVRAS-CHAVE: Sucupira; crescimento micelial; fungicida.

    The objective of this work is to evaluate the effect ";in vitro"; of the sucupira extract (Pterodon emarginatus on plant pathogenic fungi and bacteria. The sucupira extract was

  12. Plant expansins in bacteria and fungi: evolution by horizontal gene transfer and independent domain fusion.

    Science.gov (United States)

    Nikolaidis, Nikolas; Doran, Nicole; Cosgrove, Daniel J

    2014-02-01

    Horizontal gene transfer (HGT) has been described as a common mechanism of transferring genetic material between prokaryotes, whereas genetic transfers from eukaryotes to prokaryotes have been rarely documented. Here we report a rare case of HGT in which plant expansin genes that code for plant cell-wall loosening proteins were transferred from plants to bacteria, fungi, and amoebozoa. In several cases, the species in which the expansin gene was found is either in intimate association with plants or is a known plant pathogen. Our analyses suggest that at least two independent genetic transfers occurred from plants to bacteria and fungi. These events were followed by multiple HGT events within bacteria and fungi. We have also observed that in bacteria expansin genes have been independently fused to DNA fragments that code for an endoglucanase domain or for a carbohydrate binding module, pointing to functional convergence at the molecular level. Furthermore, the functional similarities between microbial expansins and their plant xenologs suggest that these proteins mediate microbial-plant interactions by altering the plant cell wall and therefore may provide adaptive advantages to these species. The evolution of these nonplant expansins represents a unique case in which bacteria and fungi have found innovative and adaptive ways to interact with and infect plants by acquiring genes from their host. This evolutionary paradigm suggests that despite their low frequency such HGT events may have significantly contributed to the evolution of prokaryotic and eukaryotic species.

  13. Mysterious Mycorrhizae? A Field Trip & Classroom Experiment to Demystify the Symbioses Formed between Plants & Fungi

    Science.gov (United States)

    Johnson, Nancy C.; Chaudhary, V. Bala; Hoeksema, Jason D.; Moore, John C.; Pringle, Anne; Umbanhowar, James A.; Wilson, Gail W. T.

    2009-01-01

    Biology curricula cover fungi in units on bacteria, protists, and primitive plants, but fungi are more closely related to animals than to bacteria or plants. Like animals, fungi are heterotrophs and cannot create their own food; but, like plants, fungi have cell walls, and are for the most part immobile. Most species of fungi have a filamentous…

  14. Mysterious Mycorrhizae? A Field Trip & Classroom Experiment to Demystify the Symbioses Formed between Plants & Fungi

    Science.gov (United States)

    Johnson, Nancy C.; Chaudhary, V. Bala; Hoeksema, Jason D.; Moore, John C.; Pringle, Anne; Umbanhowar, James A.; Wilson, Gail W. T.

    2009-01-01

    Biology curricula cover fungi in units on bacteria, protists, and primitive plants, but fungi are more closely related to animals than to bacteria or plants. Like animals, fungi are heterotrophs and cannot create their own food; but, like plants, fungi have cell walls, and are for the most part immobile. Most species of fungi have a filamentous…

  15. Parasitic fungi of ornamental plants and herbs of Szczecin

    Directory of Open Access Journals (Sweden)

    Iwona Adamska

    2013-12-01

    Full Text Available In the years 2000-2001, the occurrence of fungi parasitizing on ornamental plants and herbs cultivated in the Vegetative Hall of the Agricultural University in Szczecin was investigated. The plants represented ca. 200 species. Disease and etiological symptoms were found in 37% of plant species. Most diseased plants came from the family Asteraceae. The plant species most frequently affected was Melisa officinalis. In the laboratory, 35 fungal species were recognized. Most fungi came from the phylum Ascomycota (13 species, and least from the phylum Oomycota (3 species. The phylum Ascomycota was represented only by species of the order Erysiphales. Other relatively frequently found fungi also were members of the phylum Basidiomycota (11 species. Of the fungi recognized, 31 species were earlier frequently recorded in Poland, and three rarely. Erysiphe flexuosa parasitizing Aesculus hippocastanum was not recorded in Poland to date; in Europe this fungus was recognized only in Germany and Switzerland.

  16. Evolution of filamentous plant pathogens: gene exchange across eukaryotic kingdoms.

    Science.gov (United States)

    Richards, Thomas A; Dacks, Joel B; Jenkinson, Joanna M; Thornton, Christopher R; Talbot, Nicholas J

    2006-09-19

    Filamentous fungi and oomycetes are eukaryotic microorganisms that grow by producing networks of thread-like hyphae, which secrete enzymes to break down complex nutrients, such as wood and plant material, and recover the resulting simple sugars and amino acids by osmotrophy. These organisms are extremely similar in both appearance and lifestyle and include some of the most economically important plant pathogens . However, the morphological similarity of fungi and oomycetes is misleading because they represent some of the most distantly related eukaryote evolutionary groupings, and their shared osmotrophic growth habit is interpreted as being the result of convergent evolution . The fungi branch with the animals, whereas the oomycetes branch with photosynthetic algae as part of the Chromalveolata . In this report, we provide strong phylogenetic evidence that multiple horizontal gene transfers (HGT) have occurred from filamentous ascomycete fungi to the distantly related oomycetes. We also present evidence that a subset of the associated gene families was initially the product of prokaryote-to-fungi HGT. The predicted functions of the gene products associated with fungi-to-oomycete HGT suggest that this process has played a significant role in the evolution of the osmotrophic, filamentous lifestyle on two separate branches of the eukaryote tree.

  17. Poly(lactic-co-glycolic) acid nanoparticles uptake by Vitis vinifera and grapevine-pathogenic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Valletta, Alessio [“Sapienza” University of Rome, Department of Environmental Biology (Italy); Chronopoulou, Laura; Palocci, Cleofe, E-mail: cleofe.palocci@uniroma1.it [“Sapienza” University of Rome, Department of Chemistry (Italy); Baldan, Barbara [University of Padua, Department of Biology (Italy); Donati, Livia; Pasqua, Gabriella [“Sapienza” University of Rome, Department of Environmental Biology (Italy)

    2014-12-15

    Poly(lactic-co-glycolic) acid (PLGA)-based NPs are currently considered among the most promising drug carriers, nevertheless their use in plants has never been investigated. In this work, for the first time, we demonstrated the ability of PLGA NPs to cross the plant cell wall and membrane of Vitis vinifera cell cultures and grapevine-pathogenic fungi. By means of fluorescence microscopy, we established that PLGA NPs can enter in grapevine leaf tissues through stomata openings and that they can be absorbed by the roots and transported to the shoot through vascular tissues. TEM analysis on cultured cells showed that NPs ≤ 50 nm could enter cells, while bigger ones remained attached to the cell wall. Viability tests demonstrated that PLGA NPs were not cytotoxic for V. vinifera-cultured cells. The cellular uptake of PLGA NPs by some important grapevine-pathogenic fungi has also been observed, thus suggesting that PLGA NPs could be used to deliver antifungal compounds within fungal cells. Overall the results reported suggest that such NPs may play a key role in future developments of agrobiotechnologies, as it is currently happening in biomedicine.

  18. Mycorrhiza: The Oldest Association Between Plant and Fungi

    Indian Academy of Sciences (India)

    Jagnaseni Barman; Aveek Samanta; Babita Saha; Siraj Datta

    2016-12-01

    The symbiotic association between plant and fungi (mycorrhizalassociation) is an amazing phenomenon observed innature. The mycorrhizal association is one of nature’s boonsfor sustainable agriculture. In today’s changing environment,indiscriminate use of pesticides and chemicals pose a greatthreat to the existence of mycorrhizal species. There is a needto spread awareness in order to save mycorrhizal fungi fromextinction.

  19. Nitrogen isotopes link mycorrhizal fungi and plants to nitrogen dynamics.

    Science.gov (United States)

    Hobbie, Erik A; Högberg, Peter

    2012-10-01

    In this review, we synthesize field and culture studies of the 15N/14N (expressed as δ15N) of autotrophic plants, mycoheterotrophic plants, parasitic plants, soil, and mycorrhizal fungi to assess the major controls of isotopic patterns. One major control for plants and fungi is the partitioning of nitrogen (N) into either 15N-depleted chitin, ammonia, or transfer compounds or 15N-enriched proteinaceous N. For example, parasitic plants and autotrophic hosts are similar in δ15N (with no partitioning between chitin and protein), mycoheterotrophic plants are higher in δ15 N than their fungal hosts, presumably with preferential assimilation of fungal protein, and autotrophic, mycorrhizal plants are lower in 15N than their fungal symbionts, with saprotrophic fungi intermediate, because mycorrhizal fungi transfer 15N-depleted ammonia or amino acids to plants. Similarly, nodules of N2-fixing bacteria transferring ammonia are often higher in δ15N than their plant hosts. N losses via denitrification greatly influence bulk soil δ15N, whereas δ15N patterns within soil profiles are influenced both by vertical patterns of N losses and by N transfers within the soil-plant system. Climate correlates poorly with soil δ15N; climate may primarily influence δ15N patterns in soils and plants by determining the primary loss mechanisms and which types of mycorrhizal fungi and associated vegetation dominate across climatic gradients.

  20. Phytocystatins and their potential to control plant diseases caused by fungi.

    Science.gov (United States)

    Lima, Aline M; dos Reis, Savio P; de Souza, Claudia R B

    2015-01-01

    Plant cystatins, also called phytocystatins, constitute a family of specific cysteine protease inhibitors found in several monocots and dicots, where they can be involved in the regulation of several endogenous processes and in defense against pests and pathogens, as well as in response to abiotic stress. In this mini-review we aimed to present isolated and characterized phytocystatins with potential use in control of plant disease caused by fungi.

  1. Effects of two AM fungi on phytoplasma infection in the model plant Chrysanthemum carinatum

    Directory of Open Access Journals (Sweden)

    Simonetta Sampò

    2012-03-01

    Full Text Available Phytoplasmas are plant pathogenic bacteria, naturally transmitted by insects and confined in the phloem of the host plant, where they take up nutrients and eventually cause plant death. Their control is mainly based on insecticide treatments. The aim of this work was to study the effect of two AM fungi in modifying plant response to chrysanthemum yellows phytoplasma (CY infection in chrysanthemum plants. Inoculation of Glomus intraradices BB-E and G. mosseae BEG12 reduced the damage caused by this plant pathogen in the aerial part of the plant, increased plant tolerance to the infection and reduced the severity of symptom expression, probably in a systemic way. Inoculation with G. mosseae did not alter CY multiplication and viability in young leaves, whilst the morphology of CY mature leaves was typical of senescent cells. Possible mechanisms involved are discussed.

  2. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    B. Knegt; J. Jansa; O. Franken; D.J.P. Engelmoer; G.D.A. Werner; H. Bücking; E.T. Kiers

    2014-01-01

    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  3. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    Knegt, B.; Jansa, J.; Franken, O.; Engelmoer, D.J.P.; Werner, G.D.A.; Bücking, H.; Kiers, E.T.

    2016-01-01

    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  4. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    Knegt, B.; Jansa, J.; Franken, O.; Engelmoer, D.J.P.; Werner, G.D.A.; Bücking, H.; Kiers, E.T.

    2016-01-01

    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  5. Plants versus fungi and oomycetes: pathogenesis, defense and counter-defense in the proteomics era.

    Science.gov (United States)

    El Hadrami, Abdelbasset; El-Bebany, Ahmed F; Yao, Zhen; Adam, Lorne R; El Hadrami, Ismailx; Daayf, Fouad

    2012-01-01

    Plant-fungi and plant-oomycete interactions have been studied at the proteomic level for many decades. However, it is only in the last few years, with the development of new approaches, combined with bioinformatics data mining tools, gel staining, and analytical instruments, such as 2D-PAGE/nanoflow-LC-MS/MS, that proteomic approaches thrived. They allow screening and analysis, at the sub-cellular level, of peptides and proteins resulting from plants, pathogens, and their interactions. They also highlight post-translational modifications to proteins, e.g., glycosylation, phosphorylation or cleavage. However, many challenges are encountered during in planta studies aimed at stressing details of host defenses and fungal and oomycete pathogenicity determinants during interactions. Dissecting the mechanisms of such host-pathogen systems, including pathogen counter-defenses, will ensure a step ahead towards understanding current outcomes of interactions from a co-evolutionary point of view, and eventually move a step forward in building more durable strategies for management of diseases caused by fungi and oomycetes. Unraveling intricacies of more complex proteomic interactions that involve additional microbes, i.e., PGPRs and symbiotic fungi, which strengthen plant defenses will generate valuable information on how pathosystems actually function in nature, and thereby provide clues to solving disease problems that engender major losses in crops every year.

  6. The dawn of symbiosis between plants and fungi

    Science.gov (United States)

    Bidartondo, Martin I.; Read, David J.; Trappe, James M.; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G.

    2011-01-01

    The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists. PMID:21389014

  7. The dawn of symbiosis between plants and fungi.

    Science.gov (United States)

    Bidartondo, Martin I; Read, David J; Trappe, James M; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G

    2011-08-23

    The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists.

  8. Plant-derived bioactive compounds produced by endophytic fungi.

    Science.gov (United States)

    Zhao, J; Shan, T; Mou, Y; Zhou, L

    2011-02-01

    Plant endophytic fungi are an important and novel resource of natural bioactive compounds with their potential applications in agriculture, medicine and food industry. In the past two decades, many valuable bioactive compounds with antimicrobial, insecticidal, cytotoxic, and anticancer activities have been successfully discovered from endophytic fungi. During the long period of co-evolution, a friendly relationship was formed between each endophyte and its host plant. Some endophytes have the ability to produce the same or similar bioactive compounds as those originated from their host plants. This review mainly deals with the research progress on endophytic fungi for producing plant-derived bioactive compounds such as paclitaxel, podophyllotoxin, camptothecine, vinblastine, hypericin, and diosgenin. The relations between endophytic fungi and their host plants, biological activities and action mechanisms of these compounds from endophytic fungi, some available strategies for efficiently promoting production of these bioactive compounds, as well as their potential applications in the future will also be discussed. It is beneficial for us to better understand and take advantage of plant endophytic fungi.

  9. Aruscular mycorhizal fungi alter plant allometry and biomass - density relationships

    DEFF Research Database (Denmark)

    Zhang, Qian; Zhang, Lu; Weiner, Jacob;

    2011-01-01

    fungi (AMF) can promote plant growth and affect plant form. Here experiments were carried out to test whether AMF affect plant allometry and the self-thinning trajectory. Methods Two experiments were conducted on Medicago sativa L., a leguminous species known to be highly dependent on mycorrhiza. Two...

  10. Do plants drive podzolization via rock-eating mycorrhizal fungi?

    NARCIS (Netherlands)

    Breemen, van N.; Lundstr"m, U.S.; Jongmans, A.G.

    2000-01-01

    Weathering and supply of nutrients derived from minerals to plants is known to be stimulated by plant symbiotic mycorrhizal fungi. Nutrients are generally thought to pass the bulk soil solution before plant uptake. Jongmans et al. [Jongmans, A.G., van Breemen, N., Lundstrom, U.S., van Hees, P.A.W.,

  11. Ant-plants and fungi: a new threeway symbiosis.

    Science.gov (United States)

    Defossez, Emmanuel; Selosse, Marc-André; Dubois, Marie-Pierre; Mondolot, Laurence; Faccio, Antonella; Djieto-Lordon, Champlain; McKey, Doyle; Blatrix, Rumsaïs

    2009-06-01

    Symbioses between plants and fungi, fungi and ants, and ants and plants all play important roles in ecosystems. Symbioses involving all three partners appear to be rare. Here, we describe a novel tripartite symbiosis in which ants and a fungus inhabit domatia of an ant-plant, and present evidence that such interactions are widespread. We investigated 139 individuals of the African ant-plant Leonardoxa africana for occurrence of fungus. Behaviour of mutualist ants toward the fungus within domatia was observed using a video camera fitted with an endoscope. Fungi were identified by sequencing a fragment of their ribosomal DNA. Fungi were always present in domatia occupied by mutualist ants but never in domatia occupied by opportunistic or parasitic ants. Ants appear to favour the propagation, removal and maintenance of the fungus. Similar fungi were associated with other ant-plants in Cameroon. All belong to the ascomycete order Chaetothyriales; those from L. africana formed a monophyletic clade. These new plant-ant-fungus associations seem to be specific, as demonstrated within Leonardoxa and as suggested by fungal phyletic identities. Such tripartite associations are widespread in African ant-plants but have long been overlooked. Taking fungal partners into account will greatly enhance our understanding of symbiotic ant-plant mutualisms.

  12. [Isolation of endophytic fungi from medicinal plant Brucea javanica and their microbial inhibition activity].

    Science.gov (United States)

    Liang, Zi-Ning; Zhu, Hua; Lai, Kai-Ping; Chen, Long

    2014-04-01

    To isolate and identify endophytic fungi from Brucea javanica, and to detect the antimicrobial activity of these strains. Endophytic fungi were isolated by tissue inoculation culture and identified by conventional morphological characteristic method. Seven kinds of pathogenic fungi and three kinds of bacteria were used as targeting microbes to test microbial inhibition activities by agar plate antagonistic action and modified agar gel diffusion methods, respectively. A total of 83 endophytic fungi strains were isolated from the root, stem, leaf and fruit of Brucea javanica. 34 strains were obtained from the stem, 32 strains were obtained from the leaf, 15 strains were isolated from the root and 2 strains came from the fruit. These 73 strains which had been identified attribute to 5 orders, 6 families and 12 genera. For the isolated strains, 14 strains had antifungal activities against at least one pathogenic fungi, 9 strains showed antibacterial activities against one or more bacteria. Especially, the strain YJ-17 which belonged to Phomopsis genus showed the best inhibitory effect on the targeting microbes. The endophytic fungi from Brucea javanica show diversity and microbial inhibition activity, and are worthy for further study on plant disease controlling.

  13. 农抗702对植物病原真菌的抑制效果及抑菌机理%Inhibition effect of Ag-antibiotic 702 on plant pathogenic fungi and related mechanisms

    Institute of Scientific and Technical Information of China (English)

    魏赛金; 杜亚楠; 倪国荣; 张慧雯; 涂国全; 潘晓华

    2012-01-01

    To explore the practical application value and action mechanisms of Ag-antibiotic 702 against pathogenic fungi, the inhibition spectrum of Ag-antibiotic 702 was studied by measuring the mycelium growth rate of pathogenic fungi, and the effects of Ag-antibiotic 702 on the membrane permeability of Rhizoctonia solani, a typical pathogenic fungus, were investigated, with the variations of mycelium electrolyte leakage and protein, nucleic acid, and Mg2+ and K+ contents under the action of Ag-antibiotic 702 determined, and the effects of Ag-antibiotic 702 on the cell membrane ergosterol biosynthesis and ultramicrostructure observed. The results showed that the active products of Ag-antibiotic 702 had stronger inhibition effect on 13 test pathogens, among which, Sclerotinia sclerotiorum was most sensitive, with the EC50 being 0. 23 μg·ml-1. As compared with the control, the relative electric conductivity of R. solani treated with Ag-antibiotic 702 was increased by 72. 2% , the contents of protein, nucleic acid, and Mg2+ and K+ leaked from the R. solani cells were all increased, while the ergosterol content was decreased by 92.0%. The cell membrane outline was not clear, organelles were badly damaged, and vacuole appeared. It was suggested that the inhibition of ergosterol biosynthesis and the increase of membrane permeability could be the main action mechanisms of Ag-antibiotic 702 against pathogenic fungi.%为探索农抗702在植物病害生物防治中的实际应用价值及对病原真菌的作用机理,采用生长速率法测定其抑菌谱,并以水稻纹枯病菌为研究对象,测定其作用下菌丝的电解质渗漏、蛋白质、核酸、Mg2+、K+含量的变化,及其对细胞膜麦角甾醇生物合成和水稻纹枯病菌超显微结构的影响.结果表明:农抗702对供试13种病原真菌均有较强的抑制作用,其中对油菜菌核病菌的作用最强,EC50为0.23 μg·mL-1;农抗702作用水稻纹枯病菌菌体后相对电导率增加72.2

  14. Anti-biotic Effect of Slightly Acidic Electrolyzed Water on Plant Bacterial / Fungal Pathogen

    OpenAIRE

    津野, 和宣; 中村, 悌一

    2012-01-01

    The anti-biotic effect of slightly acidic electrolyzed water on plant pathogen was determined. The spores of 4 kinds of fungal pathogen and 17 kinds of plant pathogenic bacteria were applied at different concentration.###Slightly acidic electrolyzed water showed strong growth inhibition in germination of fungi spores tested. In addition, by the treatment with slightly acidic electrolyzed water for 30 sec., all kinds of bacteria tested were inhibited to grow on the medium.###The anti-biotic ef...

  15. Pathogenicity of three entomopathogenic fungi to Matsucoccus matsumurae.

    Directory of Open Access Journals (Sweden)

    Weimin Liu

    Full Text Available Matsucoccus matsumurae (Kuwana (Hemiptera: Coccoidea: Matsucoccidae is an invasive alien species and a destructive pest of two native Chinese pines, Pinus tabulaeformis Carr. and P. massoniana Lamb., throughout the eastern regions of China. The pathogenicity of three entomopathogenic fungi, Lecanicillium lecanii strain V3.4504 and V3.4505, Fusarium incarnatum-equiseti strain HEB01 and Lecanicillium fungicola strain HEB02, against M. matsumurae was tested in four instars, to evaluate their potential as a biological control agent. The results showed that the four strains caused disease and death of the scale insect, among which the L. lecanii strains V3.4504 and V3.4505 displayed stronger virulence than the F. incarnatum-equiseti strains HEB01 and L. fungicola strain HEB02 to M. matsumurae in the 2nd-instar nymphs and the adult females. Furthermore, L. lecanii V3.4505 was most virulent to M. matsumurae. The adult females and the male 3rd-instar nymphs of M. matsumurae were susceptible to L. lecanii V3.4505; the adult females were more susceptible at LT50 = 1.96 than the 3rd-instar nymphs at LT50 = 5.67. The body surface structure, cuticle thickness and wax secretions of M. matsumurae impacted the fungal infection. L. lecanii is a promising biocontrol agent, and newly emerged male 3rd-instar nymphs and adult females are a crucial period of the insect's life cycle for M. matsumurae biocontrol.

  16. Pathogenicity of three entomopathogenic fungi to Matsucoccus matsumurae.

    Science.gov (United States)

    Liu, Weimin; Xie, Yingping; Dong, Jing; Xue, Jiaoliang; Zhang, Yanfeng; Lu, Yaobin; Wu, Jun

    2014-01-01

    Matsucoccus matsumurae (Kuwana) (Hemiptera: Coccoidea: Matsucoccidae) is an invasive alien species and a destructive pest of two native Chinese pines, Pinus tabulaeformis Carr. and P. massoniana Lamb., throughout the eastern regions of China. The pathogenicity of three entomopathogenic fungi, Lecanicillium lecanii strain V3.4504 and V3.4505, Fusarium incarnatum-equiseti strain HEB01 and Lecanicillium fungicola strain HEB02, against M. matsumurae was tested in four instars, to evaluate their potential as a biological control agent. The results showed that the four strains caused disease and death of the scale insect, among which the L. lecanii strains V3.4504 and V3.4505 displayed stronger virulence than the F. incarnatum-equiseti strains HEB01 and L. fungicola strain HEB02 to M. matsumurae in the 2nd-instar nymphs and the adult females. Furthermore, L. lecanii V3.4505 was most virulent to M. matsumurae. The adult females and the male 3rd-instar nymphs of M. matsumurae were susceptible to L. lecanii V3.4505; the adult females were more susceptible at LT50 = 1.96 than the 3rd-instar nymphs at LT50 = 5.67. The body surface structure, cuticle thickness and wax secretions of M. matsumurae impacted the fungal infection. L. lecanii is a promising biocontrol agent, and newly emerged male 3rd-instar nymphs and adult females are a crucial period of the insect's life cycle for M. matsumurae biocontrol.

  17. Friend or foe: differential responses of rice to invasion by mutualistic or pathogenic fungi revealed by RNAseq and metabolite profiling.

    Science.gov (United States)

    Xu, Xi-Hui; Wang, Chen; Li, Shu-Xian; Su, Zhen-Zhu; Zhou, Hui-Na; Mao, Li-Juan; Feng, Xiao-Xiao; Liu, Ping-Ping; Chen, Xia; Hugh Snyder, John; Kubicek, Christian P; Zhang, Chu-Long; Lin, Fu-Cheng

    2015-09-08

    The rice endophyte Harpophora oryzae shares a common pathogenic ancestor with the rice blast fungus Magnaporthe oryzae. Direct comparison of the interactions between a single plant species and two closely-related (1) pathogenic and (2) mutualistic fungi species can improve our understanding of the evolution of the interactions between plants and fungi that lead to either mutualistic or pathogenic interactions. Differences in the metabolome and transcriptome of rice in response to challenge by H. or M. oryzae were investigated with GC-MS, RNA-seq, and qRT-PCR. Levels of metabolites of the shikimate and lignin biosynthesis pathways increased continuously in the M. oryzae-challenged rice roots (Mo-roots); these pathways were initially induced, but then suppressed, in the H. oryzae-challenged rice roots (Ho-roots). Compared to control samples, concentrations of sucrose and maltose were reduced in the Ho-roots and Mo-roots. The expression of most genes encoding enzymes involved in glycolysis and the TCA cycle were suppressed in the Ho-roots, but enhanced in the Mo-roots. The suppressed glycolysis in Ho-roots would result in the accumulation of glucose and fructose which was not detected in the Mo-roots. A novel co-evolution pattern of fungi-host interaction is proposed which highlights the importance of plant host in the evolution of fungal symbioses.

  18. Molecular phylogeny, diversity and bioprospecting of endophytic fungi associated with wild ethnomedicinal North American plant Echinacea purpurea (Asteraceae)

    Science.gov (United States)

    The endophytic fungal community associated with the wild ethnomedicinal North American plant Echinacea purpurea was investigated as well as its potential for providing antifungal compounds against plant pathogenic fungi. A total of 233 endophytic fungal isolates were obtained and classified into 42 ...

  19. Antimycotic activities of selected plant flora, growing wild in Lebanon, against phytopathogenic fungi.

    Science.gov (United States)

    Abou-Jawdah, Yusuf; Sobh, Hana; Salameh, Abdu

    2002-05-22

    Petroleum ether (PE) and methanolic extracts of nine wild plant species were tested in vitro for their antimycotic activity against eight phytopathogenic fungi. The efficacy of PE extracts against all pathogens tested was higher than that of methanolic extracts. Wild marjoram (Origanum syriacum) PE extract showed the highest and widest range of activity. It resulted in complete inhibition of mycelial growth of six of eight fungi tested and also gave nearly complete inhibition of spore germination of the six fungi included in the assay, namely, Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, and Verticillium dahlia. The other plant extracts showed differential activities in the spore germination test, but none was highly active against mycelial growth. Inula viscosa and Mentha longifolia were highly effective (>88%) in spore germination tests against five of six fungi tested, whereas Centaurea pallescens, Cichorium intybus, Eryngium creticum, Salvia fruticosa, and Melia azedarach showed >95% inhibition of spore germination in at least two fungi. Foeniculum vulgare showed the least antimycotic activity. Fractionation followed by autobiography on TLC plates using Cladosporium sp. as a test organism showed that O. syriacum PE extracts contained three inhibition zones, and those of Inula viscosa and Cichorium intybus, two, whereas the PE extracts of the remaining plants showed each one inhibition zone. Some of the major compounds present in these inhibition zones were identified by GC-MS. The possibility for using these extracts, or their mixtures, to control plant diseases is discussed.

  20. Molecular battles between plant and pathogenic bacteria in the phyllosphere

    Directory of Open Access Journals (Sweden)

    C.M. Baker

    2010-08-01

    Full Text Available The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv tomato (Pst DC3000 use the virulence factor coronatine to suppress stomate-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases.

  1. Virulence-specific cell cycle and morphogenesis connections in pathogenic fungi.

    Science.gov (United States)

    Pérez-Martín, José; Bardetti, Paola; Castanheira, Sónia; de la Torre, Antonio; Tenorio-Gómez, María

    2016-09-01

    To initiate pathogenic development, pathogenic fungi respond to a set of inductive cues. Some of them are of an extracellular nature (environmental signals), while others are intracellular (developmental signals). These signals must be integrated into a single response whose major outcome is changes in the morphogenesis of the fungus. The regulation of the cell cycle is pivotal during these cellular differentiation steps; therefore, cell cycle regulation would likely provide control points for infectious development by fungal pathogens. Here, we provide clues to understanding how the control of the cell cycle is integrated with the morphogenesis program in pathogenic fungi, and we review current examples that support these connections.

  2. The cuticle and plant defense to pathogens

    Directory of Open Access Journals (Sweden)

    Jean-Pierre eMetraux

    2014-06-01

    Full Text Available The cuticle provides a physical barrier against water loss and protects against irradiation, xenobiotics and pathogens. Components of the cuticle are perceived by invading fungi and activate developmental processes during pathogenesis. In addition, cuticle alterations of various types induce a syndrome of reactions that often results in resistance to necrotrophs. This article reviews the current knowledge on the role of the cuticle in relation to the perception of pathogens and activation of defenses.

  3. Interactions between fungal plant pathogens on leaves. Especially simultaneous development of Rhynchosporium secalis and Drechslera teres on barley

    DEFF Research Database (Denmark)

    Vollmer, Jeanette Hyldal

    Plant diseases caused by fungi are major potential threats to yield in both organic and conventional cereal production, and generally several species of pathogenic fungi are found together on the same plants in the field. This PhD thesis concludes, thatinteraction between different foliar fungal ...

  4. Extended studies on the diversity of arthropod-pathogenic fungi in Austria and Poland

    Directory of Open Access Journals (Sweden)

    Cezary Tkaczyk

    2013-12-01

    Full Text Available Results of studies on diversity of arthropod-pathogenic fungi in selected habitats in Austria and Poland carried out in the years 2006-2007 and 2009-2010 are discussed. In total 47 species of entomopathogenic fungi were found as pathogens of different arthropods in Austria. Twenty six entomophthoralean species from different insects and one species from mites were identified and 16 of them are recorded as new to Austria. From among 21 species of anamorphic Hypocreales (Ascomycota affecting arthropods in Austria, 13 species so far have not been known from this country. In total 51 species of fungi affecting different arthropods in Poland were recorded, among them 28 species of Entomophthorales and 23 anamorphic Hypocreales (Ascomycota were separated. The most frequent species of the entomopathogenic fungi both in agricultural and afforested areas in Austria were the common and usually worldwide distributed cordycipitaceous anamorphs Beauveria bassiana, Isaria fumosorosea and in areas of this study less numerous I. farinosa. The most frequent pathogens occurring in mite communities on plants and in wood infested by insects were Hirsutella species. Several entomophthoralean species developed epizootics that caused high reduction in host populations of different arthropods in both countries. Especially interesting is the first record of mycoses (up to 60% mortality, caused by Zoophthora spp. on Phyllobius beetles in a mixed forest near Białowieża. During our joint research, we found the first time in Poland and Europe, the presence of the fungus Furia cf. shandongensis on earwigs and Hirsutella entomophila on Ips typographus adults in forest habitats. From the feeding sites of the latter bark beetle and other subcortical species in oak bark (mostly Dryocoetes villosus and D. alni in black alder over a dozen of various Lecanicillium strains - including few of the features not allowing to classify them to any of so far known species – were

  5. Plants versus pathogens: an evolutionary arms race.

    Science.gov (United States)

    Anderson, Jonathan P; Gleason, Cynthia A; Foley, Rhonda C; Thrall, Peter H; Burdon, Jeremy B; Singh, Karam B

    2010-05-20

    The analysis of plant-pathogen interactions is a rapidly moving research field and one that is very important for productive agricultural systems. The focus of this review is on the evolution of plant defence responses and the coevolution of their pathogens, primarily from a molecular-genetic perspective. It explores the evolution of the major types of plant defence responses including pathogen associated molecular patterns and effector triggered immunity as well as the forces driving pathogen evolution, such as the mechanisms by which pathogen lineages and species evolve. Advances in our understanding of plant defence signalling, stomatal regulation, R gene-effector interactions and host specific toxins are used to highlight recent insights into the coevolutionary arms race between pathogens and plants. Finally, the review considers the intriguing question of how plants have evolved the ability to distinguish friends such as rhizobia and mycorrhiza from their many foes.

  6. A domain-centric analysis of oomycete plant pathogen genomes reveals unique protein organization

    NARCIS (Netherlands)

    Seidl, M.F.; Ackerveken, van den G.; Govers, F.; Snel, B.

    2011-01-01

    Oomycetes comprise a diverse group of organisms that morphologically resemble fungi but belong to the stramenopile lineage within the supergroup of chromalveolates. Recent studies have shown that plant pathogenic oomycetes have expanded gene families that are possibly linked to their pathogenic life

  7. Plant and pathogen nutrient acquisition strategies

    OpenAIRE

    Fatima, Urooj; Senthil-Kumar, Muthappa

    2015-01-01

    Nutrients are indispensable elements required for the growth of all living organisms including plants and pathogens. Phyllosphere, rhizosphere, apoplast, phloem, xylem, and cell organelles are the nutrient niches in plants that are the target of bacterial pathogens. Depending upon nutrients availability, the pathogen adapts various acquisition strategies and inhabits the specific niche. In this review, we discuss the nutrient composition of different niches in plants, the mechanisms involved ...

  8. Endophytic fungi diversity of aquatic/riparian plants and their antifungal activity in vitro.

    Science.gov (United States)

    Li, Hai-Yan; Zhao, Chun-An; Liu, Chen-Jian; Xu, Xiao-Fei

    2010-02-01

    Two hundred and fourteen endophytic fungi were isolated from 500 segments of aquatic/riparian plants Ottelia acuminata, Myriophyllum verticillatum, Equisetum arvense, Cardamine multijuga, and Impatiens chinensis. They were identified to 31 taxa in which Cladosporium, Fusarium, and Geotrichum were the dominant genera. Among all isolates, 169 (79%) were anamorphic fungi, 1 (0.5%) was an teleomorphic ascomycete and 44 (21%) were sterile mycelia. There were significant differences in the colonization frequency of endophytes between the five plant species (X~2=51.128, P<0.001, Chi-square test). The riparian plants harboured more endophytes than the submerged plants. The antifungal activity of these isolates against Fusarium solani and Phytophthora nicotianae in vitro were tested and 28 (13.1%) isolates showed antifungal activities with more than 30% growth inhibition rate against the two pathogens.

  9. Development of modified medium for the enhancement in antifungal activity of P. steckii (MF1 mangrove fungi against verticillium wilt pathogenic fungi of rose

    Directory of Open Access Journals (Sweden)

    Jyotasanmayee Sabat

    2009-08-01

    Full Text Available The antifungal activity of Penicillium steckii (MF1 against pathogenic fungi of rose causing verticillium wilt was evaluated under differential nutrient condition. A suitable and modified medium was obtained in which test fungus exhibited enhanced antifungal activity and produced larger inhibition zone against the verticillium fungus. The study carried out to modify the medium components at level of nitrogen, carbon source and their concentration on agar plates. Addition of amino acids, metals and plant growth hormones did not show positive effect but glycerol enhanced the antifungal activity very much.

  10. Seasonality of pathogenic fungi in mites of rubber tree plantations adjacent to fragments of Cerrado

    Directory of Open Access Journals (Sweden)

    PR. Demite

    Full Text Available Fungi are the most frequently observed pathogens of mite populations, helping to control them on different crops. Twenty-five samples of leaves were collected from rubber tree plantations adjacent to two fragments of Cerrado vegetation. Each rubber tree plantation had 25 plants selected for sampling and seven leaves from around each tree top were collected up to seven to eight meters above ground. Approximately 250 individuals of Calacarus heveae Feres, Phyllocoptruta seringueirae Feres, and Tenuipalpus heveae Baker, collected randomly, were mounted from each plantation. Hirsutella thompsoni Fisher was observed on all three mites and T. heveae was the most infected species. The highest infestation levels occurred from November to February (rainy season. In the dry season, infestation levels were below 5%. Hirsutella thompsonii has potential to be used as mycoacaricide during the rainy season.

  11. Plant species distribution along environmental gradient: do belowground interactions with fungi matter?

    Directory of Open Access Journals (Sweden)

    Loïc ePellissier

    2013-12-01

    Full Text Available The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of abiotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models, we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients.

  12. Regulation of hypoxia adaptation: an overlooked virulence attribute of pathogenic fungi?

    Science.gov (United States)

    Grahl, Nora; Cramer, Robert A

    2010-02-01

    Over the past two decades, the incidence of fungal infections has dramatically increased. This is primarily due to increases in the population of immunocompromised individuals attributed to the HIV/AIDS pandemic and immunosuppression therapies associated with organ transplantation, cancer, and other diseases where new immunomodulatory therapies are utilized. Significant advances have been made in understanding how fungi cause disease, but clearly much remains to be learned about the pathophysiology of these often lethal infections. Fungal pathogens face numerous environmental challenges as they colonize and infect mammalian hosts. Regardless of a pathogen's complexity, its ability to adapt to environmental changes is critical for its survival and ability to cause disease. For example, at sites of fungal infections, the significant influx of immune effector cells and the necrosis of tissue by the invading pathogen generate hypoxic microenvironments to which both the pathogen and host cells must adapt in order to survive. However, our current knowledge of how pathogenic fungi adapt to and survive in hypoxic conditions during fungal pathogenesis is limited. Recent studies have begun to observe that the ability to adapt to various levels of hypoxia is an important component of the virulence arsenal of pathogenic fungi. In this review, we focus on known oxygen sensing mechanisms that non-pathogenic and pathogenic fungi utilize to adapt to hypoxic microenvironments and their possible relation to fungal virulence.

  13. Lipid transfer from plants to arbuscular mycorrhiza fungi

    Science.gov (United States)

    Keymer, Andreas; Pimprikar, Priya; Wewer, Vera; Huber, Claudia; Brands, Mathias; Bucerius, Simone L; Delaux, Pierre-Marc; Klingl, Verena; von Röpenack-Lahaye, Edda; Wang, Trevor L; Eisenreich, Wolfgang; Dörmann, Peter; Parniske, Martin; Gutjahr, Caroline

    2017-01-01

    Arbuscular mycorrhiza (AM) symbioses contribute to global carbon cycles as plant hosts divert up to 20% of photosynthate to the obligate biotrophic fungi. Previous studies suggested carbohydrates as the only form of carbon transferred to the fungi. However, de novo fatty acid (FA) synthesis has not been observed in AM fungi in absence of the plant. In a forward genetic approach, we identified two Lotus japonicus mutants defective in AM-specific paralogs of lipid biosynthesis genes (KASI and GPAT6). These mutants perturb fungal development and accumulation of emblematic fungal 16:1ω5 FAs. Using isotopolog profiling we demonstrate that 13C patterns of fungal FAs recapitulate those of wild-type hosts, indicating cross-kingdom lipid transfer from plants to fungi. This transfer of labelled FAs was not observed for the AM-specific lipid biosynthesis mutants. Thus, growth and development of beneficial AM fungi is not only fueled by sugars but depends on lipid transfer from plant hosts. DOI: http://dx.doi.org/10.7554/eLife.29107.001 PMID:28726631

  14. Strigolactones, signals for parasitic plants and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    García-Garrido, J M; Lendzemo, V; Castellanos-Morales, V; Steinkellner, S; Vierheilig, Horst

    2009-09-01

    Although strigolactones play a critical role as rhizospheric signaling molecules for the establishment of arbuscular mycorrhizal (AM) symbiosis and for seed germination of parasitic weeds, scarce data are available about interactions between AM fungi and strigolactones. In the present work, we present background data on strigolactones from studies on their seed germination activity on the parasitic weeds Orobanche and Striga, the importance of nitrogen and phosphorus for this seed germination activity, and what this could mean for AM fungi. We also present results on the susceptibility of plants to AM fungi and the possible involvement of strigolactones in this AM susceptibility and discuss the role of strigolactones for the formation and the regulation of the AM symbiosis as well as the possible implication of these compounds as plant signals in other soil-borne plant-microbe interactions.

  15. Epigenetic control of effectors in plant pathogens

    Directory of Open Access Journals (Sweden)

    Mark eGijzen

    2014-11-01

    Full Text Available Plant pathogens display impressive versatility in adapting to host immune systems. Pathogen effector proteins facilitate disease but can become avirulence (Avr factors when the host acquires discrete recognition capabilities that trigger immunity. The mechanisms that lead to changes to pathogen Avr factors that enable escape from host immunity are diverse, and include epigenetic switches that allow for reuse or recycling of effectors. This perspective outlines possibilities of how epigenetic control of Avr effector gene expression may have arisen and persisted in plant pathogens, and how it presents special problems for diagnosis and detection of specific pathogen strains or pathotypes.

  16. Arbuscular mycorrhizal fungi (Glomeromycota associated with roots of plants

    Directory of Open Access Journals (Sweden)

    Sławomir Kowalczyk

    2013-12-01

    Full Text Available The results of studies of the occurrence of arbuscular mycorrhizal fungi (AMF and arbuscular mycorrhizae of the phylum Glomeromycota associated with roots of 31 cultivated, uncultivated and protected plant species growing at 103 sites of the Lubuskie province NW Poland are presented and discussed. The AMF most frequently found were members of the genus Glomus. Other relatively frequently revealed fungi were Scutellospora spp. Spore populations of AMF generally were more abundant and diverse in cultivated soils. Most protected plant species harboured AMF.

  17. Fungal volatiles: an environmentally friendly tool to control pathogenic microorganisms in plants.

    Science.gov (United States)

    Schalchli, H; Tortella, G R; Rubilar, O; Parra, L; Hormazabal, E; Quiroz, A

    2016-01-01

    Fungi are an extraordinary and immensely diverse group of microorganisms that colonize many habitats even competing with other microorganisms. Fungi have received recognition for interesting metabolic activities that have an enormous variety of biotechnological applications. Previously, volatile organic compounds produced by fungi (FVOCs) have been demonstrated to have a great capacity for use as antagonist products against plant pathogens. However, in recent years, FVOCs have been received attention as potential alternatives to the use of traditional pesticides and, therefore, as important eco-friendly biotechnological tools to control plant pathogens. Therefore, highlighting the current state of knowledge of these fascinating FVOCs, the actual detection techniques and the bioactivity against plant pathogens is essential to the discovery of new products that can be used as biopesticides.

  18. Immune Interactions with Pathogenic and Commensal Fungi: A Two-Way Street.

    Science.gov (United States)

    Underhill, David M; Pearlman, Eric

    2015-11-17

    We are exposed to a wide spectrum of fungi including innocuous environmental organisms, opportunistic pathogens, commensal organisms, and fungi that can actively and explicitly cause disease. Much less is understood about effective host immunity to fungi than is generally known about immunity to bacterial and viral pathogens. Innate and adaptive arms of the immune system are required for effective host defense against Candida, Aspergillus, Cryptococcus, and others, with specific elements of the host response regulating specific types of fungal infections (e.g., mucocutaneous versus systemic). Here we will review themes and controversies that are currently shaping investigation of antifungal immunity (primarily to Candida and Aspergillus) and will also examine the emerging field of the role of fungi in the gut microbiome.

  19. Susceptibility of different parsley cultivars to infestation by pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Jacek Nawrocki

    2012-12-01

    Full Text Available The experiments were carried out in the years 2002 and 2003 on parsley seeds of 6 cultivars: Alba, Berlińska, Cukrowa, Kinga, Lenka, and Vistula. Mycological analysis of parsley seeds showed that the most common inhabitans were fungi from genus Alternaria (mainly A. alternata and A. radicina and Fusarium, especially F. avenaceum and F. oxysporum. During the glasshouse investigations fungi Alternaria radicina, A. alternata and Fusarium avenaceum were the main reason for parsley damping-off. The highest number of infected seedlings was observed for Berlińska and Kinga, because in both years of experiments these cultivars had the lowest number of healthy seedlings. The highest number of healthy seedlings had cultivars Alba and Lenka, especially in the second year of experiments. In the field experiments not only fungi from genus Alternaria and Fusarium were the most often isolated from diseased parsley seedlings. Fusarium oxysporum was more often isolated from diseased field seedlings than from glasshouse parsley seedlings. Other fungies isolated often from parsley seedlings cultivated in the field were: Pythium spp., Rhizoctonia solani, Cylindrocarpon destructans and Stemphylium botryosum.

  20. Friend or foe? Evolutionary history of glycoside hydrolase family 32 genes encoding for sucrolytic activity in fungi and its implications for plant-fungal symbioses

    Directory of Open Access Journals (Sweden)

    James Timothy Y

    2009-06-01

    Full Text Available Abstract Background Many fungi are obligate biotrophs of plants, growing in live plant tissues, gaining direct access to recently photosynthesized carbon. Photosynthate within plants is transported from source to sink tissues as sucrose, which is hydrolyzed by plant glycosyl hydrolase family 32 enzymes (GH32 into its constituent monosaccharides to meet plant cellular demands. A number of plant pathogenic fungi also use GH32 enzymes to access plant-derived sucrose, but less is known about the sucrose utilization ability of mutualistic and commensal plant biotrophic fungi, such as mycorrhizal and endophytic fungi. The aim of this study was to explore the distribution and abundance of GH32 genes in fungi to understand how sucrose utilization is structured within and among major ecological guilds and evolutionary lineages. Using bioinformatic and PCR-based analyses, we tested for GH32 gene presence in all available fungal genomes and an additional 149 species representing a broad phylogenetic and ecological range of biotrophic fungi. Results We detected 9 lineages of GH32 genes in fungi, 4 of which we describe for the first time. GH32 gene number in fungal genomes ranged from 0–12. Ancestral state reconstruction of GH32 gene abundance showed a strong correlation with nutritional mode, and gene family expansion was observed in several clades of pathogenic filamentous Ascomycota species. GH32 gene number was negatively correlated with animal pathogenicity and positively correlated with plant biotrophy, with the notable exception of mycorrhizal taxa. Few mycorrhizal species were found to have GH32 genes as compared to other guilds of plant-associated fungi, such as pathogens, endophytes and lichen-forming fungi. GH32 genes were also more prevalent in the Ascomycota than in the Basidiomycota. Conclusion We found a strong signature of both ecological strategy and phylogeny on GH32 gene number in fungi. These data suggest that plant biotrophic fungi

  1. Research on the Isolation Method of Single Spore of Most Plant Pathogenic Fungi%一种适用于多数植物病原真菌的单孢分离方法

    Institute of Scientific and Technical Information of China (English)

    邱小燕; 汤智鹏; 张敏; 荆海瑜

    2011-01-01

    [目的]研究一种可靠并广泛适用于各种病原真菌的单孢分离技术.[方法]以玉米小斑病菌的单孢分离为例,并综合改进其他单孢分离方法,通过组织分离、孢悬液涂布、挑针转移3个步骤,挑取分散在清水琼脂平板上已经萌发的孢子获得单孢.[结果]采用该法对多种病害标本进行单孢分离,成功率都在92%以上,部分达到100%,单个菌丝片段的分离成功率达到60%以上.[结论]多种真菌的分离表明,该法操作简便,材料设备简单,结果可靠,成功率高,适用性广.%[ Objective ] The isolation technique of single spore, which was suitable for various pathogenic fungi, was researched. [ Method ] The isolation technique of single spore of Bipolaria maydis was improved and the single spore, which had germinated and scattered in the water agar plate, was picked up after three steps: tissue isolation, coating spore suspension and removal of dissecting needle. [ Result] The single spore of most of samples was isolated with the technique, which successful rate was over 92% and partially 100%; the successful rate of the isolation of single hyphal fragment was over 60%. [ Conclusion] The experimental result showed that the method was easy to operation, the requirement to material and equipment was simple, the result was reliable, the successful rate was high and the approach of its applicability was wide.

  2. Solar photocatalytic disinfection of agricultural pathogenic fungi (Curvularia sp.) in real urban wastewater.

    Science.gov (United States)

    Aguas, Yelitza; Hincapie, Margarita; Fernández-Ibáñez, Pilar; Polo-López, María Inmaculada

    2017-12-31

    The interest in developing alternative water disinfection methods that increase the access to irrigation water free of pathogens for agricultural purposes is increasing in the last decades. Advanced Oxidation Processes (AOPs) have been demonstrated to be very efficient for the abatement of several kind of pathogens in contaminated water. The purpose of the current study was to evaluate and compare the capability of several solar AOPs for the inactivation of resistant spores of agricultural fungi. Solar photoassisted H2O2, solar photo-Fenton at acid and near-neutral pH, and solar heterogeneous photocatalysis using TiO2, with and without H2O2, have been studied for the inactivation of spores of Curvularia sp., a phytopathogenic fungi worldwide found in soils and crops. Different concentrations of reagents and catalysts were evaluated at bench scale (solar vessel reactors, 200mL) and at pilot plant scale (solar Compound Parabolic Collector-CPC reactor, 20L) under natural solar radiation using distilled water (DW) and real secondary effluents (SE) from a municipal wastewater treatment plant. Inactivation order of Curvularia sp. in distilled water was determined, i.e. TiO2/H2O2/sunlight (100/50mgL(-1))>H2O2/sunlight (40mgL(-1))>TiO2/sunlight (100mgL(-1))>photo-Fenton with 5/10mgL(-1) of Fe(2+)/H2O2 at pH3 and near-neutral pH. For the case of SE, at near neutral pH, the most efficient solar process was H2O2/Solar (60mgL(-1)); nevertheless, the best Curvularia sp. inactivation rate was obtained with photo-Fenton (10/20mgL(-1) of Fe(2+)/H2O2) requiring a previous water adicification to pH3, within 300 and 210min of solar treatment, respectively. These results show the efficiency of solar AOPs as a feasible option for the inactivation of resistant pathogens in water for crops irrigation, even in the presence of organic matter (average Dissolved Organic Carbon (DOC): 24mgL(-1)), and open a window for future wastewater reclamation and irrigation use. Copyright © 2017

  3. Progress on nitrogen regulation gene expression of plant pathogenic fungi under nitrogen starvation%氮源受限条件下植物病原真菌氮调控基因表达特性

    Institute of Scientific and Technical Information of China (English)

    周晓罡; 姚春馨; 丁玉梅; 陶南; 孙茂林; 张绍松

    2012-01-01

    研究证实植物病害的发生往往是由于植物病原真菌分泌的效应子诱导引起的,在此过程中,调控效应基因表达能够了解病原菌的侵染过程.细胞的营养状况据推测对于效应基因的表达起着重要的作用.已有研究表明在氮胁迫条件下相同效应基因的诱导作用在植株体内和体外是一致的,表明氮源缺乏的环境在植物体进化的早期就已经存在了.文章阐述了在氮受限条件下真菌致病系统中效应基因调控机制及其已经发现的氮调节基因特异性表达研究结果,通过对比几个病原菌中氮调控基因的功能,比较寄主植物体内和体外在氮限制条件下基因的诱导效应,从而揭示出氮的有效性在寄主植物病害发展过程中起到重要作用.%It has been confirmed that the occurrence of plant disease is caused by the effector molecules secreted by plant pathogens. The regulation effector gene expression is an important aspect in understanding of the infection process. The nutritional status of cells has been postulated to be a vital role for effector gene expression. Studies have indicated that the induction of the same effecter genes during growth in vitro as those during growth in planta under nitiogen-starved conditions. This showed that the nitrogen poor environment existed in the early time of plant evolution. This paper describes the system in the pathogenesis of several fungal pathogens and nitrogen in the process of gene expression effects from the results of several species by comparing and contrasting the function of nitrogen regulatory genes, as well as by studying plants in vivo and in vitro gene under nitrogen limitation inductive effect in order to reveal the effectiveness of nitrogen in the development process of host plant disease is an important factor.

  4. Detailed sterol compositions of two pathogenic rust fungi.

    Science.gov (United States)

    Giner, José-Luis; Zhao, Hui

    2004-08-01

    Teliospores of cedar-apple rust Gymnosporangium juniperi-virginianae were collected from the eastern red cedar Juniperus virginiana, and aeciospores of quince rust G. clavipes were collected from the fruit of English hawthorn Crataegus laevigata. The sterol fractions were separated by HPLC, and their identities were determined by 600 MHz 1H NMR. Twenty-six sterols were isolated from G. juniperi-virginianae and 18 sterols were isolated from G. clavipes. The principal sterol of both fungi was (Z)-stigmasta-7,24(28)-dien-3beta-ol. Other major sterols were (24S)-ergost-7-en-3beta-ol, (24S)-stigmast-7-en-3beta-ol, and (24S)-stigmasta-5,7-dien-3beta-ol. The sterols of the hosts were found to be very different from those of the fungi. The 24-alkyl sterols of the fungi had the 24alpha-configuration, whereas those of the hosts had the 24beta-configuration. Similarities to the sterol composition of the AIDS pneumonia fungus Pneumocystis carinii are discussed.

  5. Efficacy of plant extracts against stored-products fungi.

    Science.gov (United States)

    Magro, Ana; Carolino, Manuela; Bastos, Margarida; Mexia, António

    2006-09-01

    The fungistatic activity of six aqueous extracts of plants were tested against Aspergillus candidus, Aspergillus niger, Penicillium sp. and Fusarium culmorum. The plants were, chamomile (Anthemis nobilis L.), cinnamon (Cinnamomum verum J. Presl.), French lavender (Lavandula stoechas L.), garlic (Allium sativum L.), malva (Malva sylvestris L.) and peppermint (Mentha piperita L.). The more concentrated extracts of chamomile and malva inhibited totally the growth of the tested fungi with malva the most effective one.

  6. Contribution to the knowledge of pathogenic fungi of spiders in Argentina. Southernmost record in the world.

    Science.gov (United States)

    Manfrino, Romina G; González, Alda; Barneche, Jorge; Tornesello Galván, Julieta; Hywell-Jones, Nigel; López Lastra, Claudia C

    The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Endocytosis in the plant-pathogenic fungus Ustilago maydis.

    Science.gov (United States)

    Fuchs, U; Steinberg, G

    2005-10-01

    Filamentous fungi are an important group of tip-growing organisms, which include numerous plant pathogens such as Magnaporthe grisea and Ustilago maydis. Despite their ecological and economical relevance, we are just beginning to unravel the importance of endocytosis in filamentous fungi. Most evidence for endocytosis in filamentous fungi is based on the use of endocytic tracer dyes that are taken up into the cell and delivered to the vacuole. Moreover, genomewide screening for candidate genes in Neurospora crassa and U. maydis confirmed the presence of most components of the endocytic machinery, indicating that endocytosis participates in filamentous growth. Indeed, it was shown that in U. maydis early endosomes cluster at sites of growth, where they support morphogenesis and polar growth, most likely via endosome-based membrane recycling. In humans, such recycling processes to the plasma membrane involve small GTPases such as Rab4. A homologue of this protein is encoded in the genome of U. maydis but is absent from the yeast Saccharomyces cerevisiae, suggesting that Rab4-mediated recycling is important for filamentous growth. Furthermore, human Rab4 regulates traffic of early endosomes along microtubules, and a similar microtubule-based transport is described for U. maydis. These observations suggest that Rab4-like GTPases might regulate endosome- and microtubule-based recycling during tip growth of filamentous fungi.

  8. Seedborne Pathogenic Fungi in Common Bean (Phaseolus vulgaris cv. INTA Rojo) in Nicaragua.

    Science.gov (United States)

    Marcenaro, Delfia; Valkonen, Jari P T

    2016-01-01

    Common bean (Phaseolus vulgaris L.) is an important legume with high nutritional value. In Nicaragua, certified healthy seeds of local bean varieties are not available, and seedborne fungi have gained little attention. Here, were surveyed seedborne pathogenic fungi in an important local bean cultivar, 'INTA Rojo'. Beans grown in the four main production areas in Nicaragua (Boaco, Carazo, Estelí, Matagalpa) for future use as seed stock were sampled from four seed storehouses and six seed lots. A total of 133 fungal strains were isolated from surface-sterilized beans and inoculated to healthy lima beans (Phaseolus lunatus) under controlled conditions. Eighty-seven isolates caused symptoms of varying severity in the seedlings, including discoloration, necrotic lesions, cankers, rot, and lethal necrosis. Pathogenic isolates were divided into eight phenotypically distinguishable groups based on morphology and growth characteristics on artificial growth medium, and further identified by analysis of the internal transcribed spacer sequences (ITS1 and ITS2) of the ribosomal RNA genes. The pathogenic isolates belonged to eight genera. Fusarium spp. (F. chlamydosporum, F. equiseti, F. incarnatum), Lasiodiplodia theobromae, Macrophomina phaseolina, and Penicillium citrinum were the most damaging and common fungi found in the seed lots. Furthermore, Corynespora cassiicola, Colletotrichum capsisi, Colletotrichum gloeosporioides, Aspergillus flavus, and Diaporthe sp. (Phomopsis) were seedborne in cultivar 'INTA Rojo' and found to be pathogenic to bean seedlings. This study reveals, for the first time, many seedborne pathogenic fungi in beans in Nicaragua; furthermore, prior to this study, little information was available concerning F. equiseti, F. incarnatum, L. theobromae, C. cassiicola, and Diaporthe spp. as seedborne pathogens of common bean. Our results lay the basis for developing diagnostic tools for seed health inspection and for further study of the epidemiology

  9. Studies on parasitic fungi of plants occurring in the lake littoral of the Masurian Lakeland

    Directory of Open Access Journals (Sweden)

    Bożena Durska

    2014-11-01

    Full Text Available In the years 1969-1970 the parasitie mycoflora of plants occurring in the littoral of 51 lakes of the Olsztyn and Mrągowo lake distriets and inthe Land of Great Lakes was examined. 132 species of parasitic fungi on the 150 vascular plants species were found, 6 of them for the first time in Poland, and 9 on hosts hitherto not observed in Poland. The influence of ecological factors such as the zone of the littoral, the position and irradiation of the coast etc. on the occurrence of pathogens was noted. The effect of some pathogenes on the transpiration, level of nitrogen and phosphorus, calorific value and yield of host plants wasalso examined, maily for Phragmites communis Trin.

  10. Specific interactions between arbuscular mycorrhizal fungi and plant growth-promoting bacteria--as revealed by different combinations

    Energy Technology Data Exchange (ETDEWEB)

    Jaderlund, Lotta; Arthurson, Veronica; Granhall, Ulf; Jansson, Janet K.

    2008-05-15

    The interactions between two plant growth promoting rhizobacteria (PGPR), Pseudomonas fluorescens SBW25 and Paenibacillus brasilensis PB177, two arbuscular mycorrhizal (AM) fungi (Glomus mosseae and G. intraradices) and one pathogenic fungus (Microdochium nivale) were investigated on winter wheat (Triticum aestivum cultivar Tarso) in a greenhouse trial. PB177, but not SBW25, had strong inhibitory effects on M. nivale in dual culture plate assays. The results from the greenhouse experiment show very specific interactions; e.g. the two AM fungi react differently when interacting with the same bacteria on plants. G. intraradices (single inoculation or together with SBW25) increased plant dry weight on M. nivale infested plants, suggesting that the pathogenic fungus is counteracted by G. intraradices, but PB177 inhibited this positive effect. This is an example of two completely different reactions between the same AM fungus and two species of bacteria, previously known to enhance plant growth and inhibit pathogens. When searching for plant growth promoting microorganisms it is therefore important to test for the most suitable combination of plant, bacteria and fungi in order to get satisfactory plant growth benefits.

  11. Antibody-mediated resistance against plant pathogens.

    Science.gov (United States)

    Safarnejad, Mohammad Reza; Jouzani, Gholamreza Salehi; Tabatabaei, Meisam; Tabatabaie, Meisam; Twyman, Richard M; Schillberg, Stefan

    2011-01-01

    Plant diseases have a significant impact on the yield and quality of crops. Many strategies have been developed to combat plant diseases, including the transfer of resistance genes to crops by conventional breeding. However, resistance genes can only be introgressed from sexually-compatible species, so breeders need alternative measures to introduce resistance traits from more distant sources. In this context, genetic engineering provides an opportunity to exploit diverse and novel forms of resistance, e.g. the use of recombinant antibodies targeting plant pathogens. Native antibodies, as a part of the vertebrate adaptive immune system, can bind to foreign antigens and eliminate them from the body. The ectopic expression of antibodies in plants can also interfere with pathogen activity to confer disease resistance. With sufficient knowledge of the pathogen life cycle, it is possible to counter any disease by designing expression constructs so that pathogen-specific antibodies accumulate at high levels in appropriate sub-cellular compartments. Although first developed to tackle plant viruses and still used predominantly for this purpose, antibodies have been targeted against a diverse range of pathogens as well as proteins involved in plant-pathogen interactions. Here we comprehensively review the development and implementation of antibody-mediated disease resistance in plants.

  12. First survey on ecological host range of aphid pathogenic fungi (Phylum Entomophthoromycota) in Tunisia

    DEFF Research Database (Denmark)

    Ben Fekih, Ibtissem; Boukhris-Bouhachem, Sonia; Allagui, Mohamed Bechir;

    2015-01-01

    sites belonging to three different bioclimatic zones. Four pathogens from the phylum Entomophthoromycota were found to occur naturally in Tunisian ecosystems: Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae), Conidiobolus obscurus...... (Entomophthorales: Ancylistaceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). The occurrence of entomophthoralean fungi depended on the sampling area, the bioclimatic zone, and aphid species. P. neoaphidis and E. planchoniana were the predominant pathogens infecting a wide range of aphid species whereas...

  13. Pathogenic fungi and Bio-control agents: Competitive bio-assay research

    OpenAIRE

    2014-01-01

    Fungi of the genus Trichoderma have a track record of being antagonist to quite of a number of agricultural important pathogens. Trichoderma have some unique characteristics that make it scientifically proven and suitable bio-control agents against varieties of pathogenic organism infecting economic food crops. Trichoderma has the advantage of being environment friendly and not hazardous to the health of human beings, livestock, soil and environment. Competitive bio-assay experiment was carri...

  14. Isolation and screening of endophytic fungi from three plants used in traditional medicine in Nigeria for antimicrobial activity

    Directory of Open Access Journals (Sweden)

    R Abass Tolulope

    2015-01-01

    Full Text Available Background: Endophytes represent a promising source of biologically active metabolites for pharmaceutical and agricultural applications. Objective: This study was aimed to investigate the endophytic fungi diversity and the antimicrobial potential of three popular medicinal plants (Alstonia boonei-Ahun, Enantia chlorantha-Awopa and Kigelia africana-Pandoro that have ethnobotanical history in Nigeria. Materials and Methods: The stem barks were used for isolation of endophytic fungi and fermented, and the cell free fermentation broths were subjected to antimicrobial screening against six human pathogens; Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and Candida albicans by using standard agar well diffusion method. Results: A total of ten endophytic fungi were isolated from the stem bark of the plants. Seven of these fungi were identified, which include; Aspergillus niger, Macrophomina spp., Trichoderma spp. and four different Penicillium species, while three of the isolated endophytes remained unknown. Furthermore, nine of the isolated endophytes showed potential antimicrobial activity against at least one of the six tested pathogens. Conclusion: This study shows that endophytic fungi inhabiting the inner tissue of medicinal plants studied may be the source of the curative properties of the plants.

  15. Mitogen-Activated Protein Kinase Signaling in Plant-Interacting Fungi: Distinct Messages from Conserved Messengers[W

    Science.gov (United States)

    Hamel, Louis-Philippe; Nicole, Marie-Claude; Duplessis, Sébastien; Ellis, Brian E.

    2012-01-01

    Mitogen-activated protein kinases (MAPKs) are evolutionarily conserved proteins that function as key signal transduction components in fungi, plants, and mammals. During interaction between phytopathogenic fungi and plants, fungal MAPKs help to promote mechanical and/or enzymatic penetration of host tissues, while plant MAPKs are required for activation of plant immunity. However, new insights suggest that MAPK cascades in both organisms do not operate independently but that they mutually contribute to a highly interconnected molecular dialogue between the plant and the fungus. As a result, some pathogenesis-related processes controlled by fungal MAPKs lead to the activation of plant signaling, including the recruitment of plant MAPK cascades. Conversely, plant MAPKs promote defense mechanisms that threaten the survival of fungal cells, leading to a stress response mediated in part by fungal MAPK cascades. In this review, we make use of the genomic data available following completion of whole-genome sequencing projects to analyze the structure of MAPK protein families in 24 fungal taxa, including both plant pathogens and mycorrhizal symbionts. Based on conserved patterns of sequence diversification, we also propose the adoption of a unified fungal MAPK nomenclature derived from that established for the model species Saccharomyces cerevisiae. Finally, we summarize current knowledge of the functions of MAPK cascades in phytopathogenic fungi and highlight the central role played by MAPK signaling during the molecular dialogue between plants and invading fungal pathogens. PMID:22517321

  16. First records of fungi pathogenic on spiders for the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Savić, Dragiša

    2016-09-01

    Full Text Available During an investigation into parasitic fungi on arthropods in the mixed forests of Mt. Fruška Gora, Republic of Serbia, two pathogenic species were found: Cordyceps thaxteri Mains (anamorph: Cordyceps thaxteri Mains (Anamorph: Akanthomyces aranearum (Petch Mains and Torrubiella arachnophila (J.R. Johnst. Mains (Anamorph: Gibellula leiopus (Vuill. ex Maubl. Mains (Hypocreales, Cordycipitaceae. Both specimens were found in the anamorphic (asexual stage. Previously, there have been no investigations of this group of fungi in this region, thus these are the first records of pathogenic fungi for both Mt. Fruška Gora and the entire territory of the Republic of Serbia. Collected specimens are deposited in the Herbarium of the National Park Fruška Gora, Republic of Serbia.

  17. The two-speed genomes of filamentous pathogens: waltz with plants.

    Science.gov (United States)

    Dong, Suomeng; Raffaele, Sylvain; Kamoun, Sophien

    2015-12-01

    Fungi and oomycetes include deep and diverse lineages of eukaryotic plant pathogens. The last 10 years have seen the sequencing of the genomes of a multitude of species of these so-called filamentous plant pathogens. Already, fundamental concepts have emerged. Filamentous plant pathogen genomes tend to harbor large repertoires of genes encoding virulence effectors that modulate host plant processes. Effector genes are not randomly distributed across the genomes but tend to be associated with compartments enriched in repetitive sequences and transposable elements. These findings have led to the 'two-speed genome' model in which filamentous pathogen genomes have a bipartite architecture with gene sparse, repeat rich compartments serving as a cradle for adaptive evolution. Here, we review this concept and discuss how plant pathogens are great model systems to study evolutionary adaptations at multiple time scales. We will also introduce the next phase of research on this topic.

  18. The isolation and identification of pathogenic fungi from Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae

    Directory of Open Access Journals (Sweden)

    Xiang Meng

    2017-10-01

    Full Text Available Background Litchi stink-bug, Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae, is one of the most widespread and destructive pest species on Litchi chinensis Sonn and Dimocarpus longan Lour in Southern China. Inappropriate use of chemical pesticides has resulted in serious environmental problems and food pollution. Generating an improved Integrated Pest Management (IPM strategy for litchi stink-bug in orchard farming requires development of an effective biological control agent. Entomopathogenic fungi are regarded as a vital ecological factor in the suppression of pest populations under field conditions. With few effective fungi and pathogenic strains available to control litchi stink-bug, exploration of natural resources for promising entomopathogenic fungi is warranted. Methods & Results In this study, two pathogenic fungi were isolated from cadavers of adult T. papillosa. They were identified as Paecilomyces lilacinus and Beauveria bassiana by morphological identification and rDNA-ITS homogeneous analysis. Infection of T. papillosa with B. bassiana and P. lilacinus occurred initially from the antennae, metameres, and inter-segmental membranes. Biological tests showed that the two entomopathogenic fungi induced high mortality in 2nd and 5th instar nymphs of T. papillosa. B. bassiana was highly virulent on 2nd instar nymphs of T. papillosa, with values for cadaver rate, LC50 and LT50 of 88.89%, 1.92 × 107 conidia/mL and 4.34 days respectively. Discussion This study provides two valuable entomopathogenic fungi from T. papillosa. This finding suggests that the highly virulent P. lilacinus and B. bassiana play an important role in the biocontrol of T. papillosa in China. These pathogenic fungi had no pollution or residue risk, and could provide an alternative option for IPM of litchi stink-bug.

  19. Occurrence of invertebrate-pathogenic fungi in a Cerrado ecosystem in Central Brazil

    Science.gov (United States)

    Biological diversity of microorganisms in natural environments is threatened worldwide by human activities. In a protected area of Cerrado, Goiás State, Brazil, naturally occurring invertebrate-pathogenic fungi were isolated from soils, slurries and water samples collected during the dry season in 2...

  20. Snow in the city as a spore bank of potentially pathogenic fungi.

    Science.gov (United States)

    Ejdys, Elżbieta; Biedunkiewicz, Anna; Dynowska, Maria; Sucharzewska, Ewa

    2014-02-01

    This study evaluates the role of snow as a specific ecological niche and a vector in fungal spreading with particular emphasis on potential pathogens in seasonally and daily changing conditions. The experimental material was fungi isolated from the atmospheric air, snow cover, and fragments of ice and soil from underneath the snow cover. The total count of microfungi in the air before snowfall, i.e. in the autumn, reached 1756.1 CFU/m(3) on average. After the first snowfalls, it dropped to 85.2 CFU/m(3). The analyzed samples of snow cover contained from 101.6 to 8500.0 CFU/m(3) of fungi. Furthermore, 26 species of yeast and yeast-like fungi were isolated from the experimental material. Amongst the analyzed species, 13 were potential anthropopathogens. Though another three species were isolated from organ ontocenoses, i.e. Candida intermedia, Saccharomyces bayanus and Zygosaccharomyces rouxii, their pathogenic potential has not yet been explicitly confirmed. The results of the presented study may be applied in predicting concentrations of fungal spores responsible for mycoses. The first snowfalls significantly reduced the number of colony-forming units of fungi in the air. Under conditions of temperate climate, snow becomes a temporary bank of yeast-like fungi spores and while it melts cells of deposited microfungi migrate to the atmosphere. Hence, individuals with impaired immunity or in the course of immunosuppression or recovery should avoid long walks during periods of snow melting. The count of fungi in urban bioaerosol during the melt may be reduced through systematic removal of snow cover, which is a significant reservoir of potential pathogens. In addition, it should be noted that even a typical psychrophilic strain, capable of surviving at a temperature of 37°C, may bear a significant pathogenic potential.

  1. Advances on Plant Pathogenic Mycotoxin Binding Proteins

    Institute of Scientific and Technical Information of China (English)

    WANG Chao-hua; DONG Jin-gao

    2002-01-01

    Toxin-binding protein is one of the key subjects in plant pathogenic mycotoxin research. In this paper, new advances in toxin-binding proteins of 10 kinds of plant pathogenic mycotoxins belonging to Helminthosporium ,Alternaria ,Fusicoccum ,Verticillium were reviewed, especially the techniques and methods of toxin-binding proteins of HS-toxin, HV-toxin, HMT-toxin, HC-toxin. It was proposed that the isotope-labeling technique and immunological chemistry technique should be combined together in research of toxin-binding protein, which will be significant to study the molecular recognition mechanism between host and pathogenic fungus.

  2. Plant and pathogen nutrient acquisition strategies

    Directory of Open Access Journals (Sweden)

    Urooj eFatima

    2015-09-01

    Full Text Available Nutrients are indispensable elements required for the growth of all living organisms including plants and pathogens. Phyllosphere, rhizosphere, apoplast, phloem, xylem and cell organelles are the nutrient niches in plants that are the target of bacterial pathogens. Depending upon nutrients availability, the pathogen adapts various acquisition strategies and inhabits the specific niche. In this review, we discuss the nutrient composition of different niches in plants, the mechanisms involved in the recognition of nutrient niche and the sophisticated strategies used by the bacterial pathogens for acquiring nutrients. We provide insight into various nutrient acquisition strategies used by necrotrophic, biotrophic and hemi-biotrophic bacteria. Specifically we discuss both modulation of bacterial machinery and manipulation of host machinery. In addition, we highlight the current status of our understanding about the nutrient acquisition strategies used by bacterial pathogens, namely targeting the sugar transporters that are dedicated for the plant’s growth and development. Bacterial strategies for altering the plant cell membrane permeability to enhance the release of nutrients are also enumerated along with in-depth analysis of molecular mechanisms behind these strategies. The information presented in this review will be useful to understand the plant-pathogen interaction in nutrient perspective.

  3. Microbial Forensics and Plant Pathogens

    Science.gov (United States)

    New awareness of the vulnerability of a nation's agricultural infrastructure to the intentional introduction of pathogens or pests has led to the enhancement of programs for prevention and preparedness. A necessary component of a balanced bio-security plan is the capability to determine whether an ...

  4. Novel Micro-organisms controlling plant pathogens

    OpenAIRE

    Köhl, J

    2009-01-01

    The invention relates to control of pathogen caused diseases on leaves, fruits and ears in plants, such as apple scab (Venturia inaequalis by treatment of plant with an isolate of Cladosporium cladosporioides. The treatment is effective in both prevention and treatment of the fungal infection

  5. EPCOT, NASA and plant pathogens in space.

    Science.gov (United States)

    White, R

    1996-01-01

    Cooperative work between NASA and Walt Disney World's EPCOT Land Pavilion is described. Joint efforts include research about allelopathy in multi-species plant cropping in CELSS, LEDs as light sources in hydroponic systems, and the growth of plant pathogens in space.

  6. Independent expansion of zincin metalloproteinases in Onygenales fungi may be associated with their pathogenicity.

    Directory of Open Access Journals (Sweden)

    Juan Li

    Full Text Available To get a comprehensive view of fungal M35 family (deuterolysin and M36 family (fungalysin genes, we conducted genome-wide investigations and phylogenetic analyses of genes in these two families from 50 sequenced Ascomycota fungi with different life styles. Large variations in the number of M35 family and M36 family genes were found among different fungal genomes, indicating that these two gene families have been highly dynamic through fungal evolution. Moreover, we found obvious expansions of Meps in two families of Onygenales: Onygenaceae and Arthodermataceae, whereas species in family Ajellomycetace did not show expansion of these genes. The strikingly different gene duplication and loss patterns in Onygenales may be associated with the different pathogenicity of these species. Interestingly, likelihood ratio tests (LRT of both M35 family and M36 family genes suggested that several branches leading to the duplicated genes in dermatophytic and Coccidioides fungi had signatures of positive selection, indicating that the duplicated Mep genes have likely diverged functionally to play important roles during the evolution of pathogenicity of dermatophytic and Coccidioides fungi. The potentially positively selected residues discovered by our analysis may have contributed to the development of new physiological functions of the duplicated Mep genes in dermatophytic fungi and Coccidioides species. Our study adds to the current knowledge of the evolution of Meps in fungi and also establishes a theoretical foundation for future experimental investigations.

  7. Independent expansion of zincin metalloproteinases in Onygenales fungi may be associated with their pathogenicity.

    Science.gov (United States)

    Li, Juan; Zhang, Ke-Qin

    2014-01-01

    To get a comprehensive view of fungal M35 family (deuterolysin) and M36 family (fungalysin) genes, we conducted genome-wide investigations and phylogenetic analyses of genes in these two families from 50 sequenced Ascomycota fungi with different life styles. Large variations in the number of M35 family and M36 family genes were found among different fungal genomes, indicating that these two gene families have been highly dynamic through fungal evolution. Moreover, we found obvious expansions of Meps in two families of Onygenales: Onygenaceae and Arthodermataceae, whereas species in family Ajellomycetace did not show expansion of these genes. The strikingly different gene duplication and loss patterns in Onygenales may be associated with the different pathogenicity of these species. Interestingly, likelihood ratio tests (LRT) of both M35 family and M36 family genes suggested that several branches leading to the duplicated genes in dermatophytic and Coccidioides fungi had signatures of positive selection, indicating that the duplicated Mep genes have likely diverged functionally to play important roles during the evolution of pathogenicity of dermatophytic and Coccidioides fungi. The potentially positively selected residues discovered by our analysis may have contributed to the development of new physiological functions of the duplicated Mep genes in dermatophytic fungi and Coccidioides species. Our study adds to the current knowledge of the evolution of Meps in fungi and also establishes a theoretical foundation for future experimental investigations.

  8. Threats and opportunities of plant pathogenic bacteria.

    Science.gov (United States)

    Tarkowski, Petr; Vereecke, Danny

    2014-01-01

    Plant pathogenic bacteria can have devastating effects on plant productivity and yield. Nevertheless, because these often soil-dwelling bacteria have evolved to interact with eukaryotes, they generally exhibit a strong adaptivity, a versatile metabolism, and ingenious mechanisms tailored to modify the development of their hosts. Consequently, besides being a threat for agricultural practices, phytopathogens may also represent opportunities for plant production or be useful for specific biotechnological applications. Here, we illustrate this idea by reviewing the pathogenic strategies and the (potential) uses of five very different (hemi)biotrophic plant pathogenic bacteria: Agrobacterium tumefaciens, A. rhizogenes, Rhodococcus fascians, scab-inducing Streptomyces spp., and Pseudomonas syringae. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Swainsonine-containing plants and their relationship to endophytic fungi.

    Science.gov (United States)

    Cook, Daniel; Gardner, Dale R; Pfister, James A

    2014-07-30

    Swainsonine, an indolizidine alkaloid with significant physiological activity, is an α-mannosidase and mannosidase II inhibitor that alters glycoprotein processing and causes lysosomal storage disease. Swainsonine is present in a number of plant species worldwide and causes severe toxicosis in livestock grazing these plants. Consumption of these plants by grazing animals leads to a chronic wasting disease characterized by weight loss, depression, altered behavior, decreased libido, infertility, and death. This review focuses on the three plant families and the associated taxa that contain swainsonine; the fungi that produce swainsonine, specifically the fungal endophytes associated with swainsonine-containing taxa; studies investigating the plant, endophyte, and swainsonine relationship; the influence of environmental factors on swainsonine concentrations in planta; and areas of future research.

  10. Pathogenic Fungi Regulate Immunity by Inducing Neutrophilic Myeloid-Derived Suppressor Cells

    Science.gov (United States)

    Rieber, Nikolaus; Singh, Anurag; Öz, Hasan; Carevic, Melanie; Bouzani, Maria; Amich, Jorge; Ost, Michael; Ye, Zhiyong; Ballbach, Marlene; Schäfer, Iris; Mezger, Markus; Klimosch, Sascha N.; Weber, Alexander N.R.; Handgretinger, Rupert; Krappmann, Sven; Liese, Johannes; Engeholm, Maik; Schüle, Rebecca; Salih, Helmut Rainer; Marodi, Laszlo; Speckmann, Carsten; Grimbacher, Bodo; Ruland, Jürgen; Brown, Gordon D.; Beilhack, Andreas; Loeffler, Juergen; Hartl, Dominik

    2015-01-01

    Summary Despite continuous contact with fungi, immunocompetent individuals rarely develop pro-inflammatory antifungal immune responses. The underlying tolerogenic mechanisms are incompletely understood. Using both mouse models and human patients, we show that infection with the human pathogenic fungi Aspergillus fumigatus and Candida albicans induces a distinct subset of neutrophilic myeloid-derived suppressor cells (MDSCs), which functionally suppress T and NK cell responses. Mechanistically, pathogenic fungi induce neutrophilic MDSCs through the pattern recognition receptor Dectin-1 and its downstream adaptor protein CARD9. Fungal MDSC induction is further dependent on pathways downstream of Dectin-1 signaling, notably reactive oxygen species (ROS) generation as well as caspase-8 activity and interleukin-1 (IL-1) production. Additionally, exogenous IL-1β induces MDSCs to comparable levels observed during C. albicans infection. Adoptive transfer and survival experiments show that MDSCs are protective during invasive C. albicans infection, but not A. fumigatus infection. These studies define an innate immune mechanism by which pathogenic fungi regulate host defense. PMID:25771792

  11. Sobrevivência de fungos fitopatogênicos habitantes do solo, em microcosmo, simulando solarização com prévia incorporação de materiais orgânicos Survival of soilborne plant pathogenic fungi in soil solarization simulation (microcosm associated with the incorporation of organic materials

    Directory of Open Access Journals (Sweden)

    Márcia Michelle de Queiroz Ambrósio

    2009-02-01

    unfeasible vast agricultural areas. Organic materials associated race 2; Macrophomina phaseolina; Rhizoctonia solani AG-4 HGI with soil solarization helps the retention of volatile fungitoxic and Sclerotium rolfsii. A nylon bag containing structures of each compounds from the degradation of materials which are lethal to pathogen was placed in each one of the two glass cameras (microcosm several soil fungi. The objective of this experiment was to search for for each evaluated period. Structures of the fungi were also maintained new organic materials that produce volatile fungitoxic compounds in laboratory conditions as the check treatment. All materials when capable to control the resistance structures produced by the soilborne associated the simulation of the soil solarization gave the best control phytopathogenic fungi but in conditions of association with simulation of the structures of all the studied soilborne phytopathogenic fungi. of soil solarization (microcosm. The present work consisted of six However, variation was observed in the control of the fungi. The treatments (Solarization; Solarization+brocollis; Solarization + treatment which only simulated the solarization did not control any eucalyptus; Solarization+castor plants; Solarization + cassava and fungus.

  12. Effects of rainfall acidification on plant pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, D. S.; Cowling, E. B.

    1978-01-01

    Wind-blown rain, rain splash, and films of free moisture play important roles in the epidemiology of many plant diseases. The chemical nature of the aqueous microenvironment at the infection court is a potentially significant factor in the successful dissemination, establishment, and survival of plant pathogenic microorganisms. Acidic rainfall has a potential for influencing not only the pathogen, but also the host organism, and the host-pathogen complex. Although host-pathogen interactions add a degree of complexity to the study of abiotic environmental stress of plants, it is our hope, through the use of a combination of general concepts, theoretical postulations, and experimental data, to describe the potential role that rainfall acidity may play in the often subtle balance between populations of plants and populations of plant pathogens. The direct effects of acidic precipitation on vegetation are becoming increasingly better understood. The indirect consequences of both acute and chronic exposure of vegetation to acidic precipitation are very complex, however. Their effect is variable in time, and involves a variety of potential interactions which are only partially understood.

  13. Study of Pathogens of Fungal Keratitis and the Sensitivity of Pathogenic Fungi to Therapeutic Agents with the Disk Diffusion Method.

    Science.gov (United States)

    Wang, Lulu; Wang, Liya; Han, Lei; Yin, Weijing

    2015-01-01

    To identify the causative fungi of fungal keratitis, test their susceptibility to antifungal agents with the disk diffusion method and study the relationship between the organisms, the inhibition zones and the clinical outcomes. 535 patients with fungal keratitis in one eye were included in this study. Pathogenic fungi were isolated by corneal scraping, identified by fungal cultivation and subjected to drug sensitivity tests conducted with the disk diffusion method. The patients were treated initially with voriconazole, terbinafine and natamycin eye drops for one week. Further treatment continued using the most effective drug according to the drug sensitivity results. The patients were followed up every week until three months after cured. The inhibition zones of fungi cultured with voriconazole, terbinafine and natamycin were compared. The relationship between inhibition zones and organism, organism and treatment results measure, and each treatment results measure and inhibition zones were evaluated. Of 535 patients, 53.84%, 19.25% and 26.91% were infected with Aspergillus, Fusarium and other fungi, respectively. Keratitis patients infected with Aspergillus keratitis had the worst outcome. The size of the inhibition zones of Aspergillus spp., Fusarium spp. and other fungal genera differed significantly in response to voriconazole, terbinafine and natamycin. The inhibition zone associated with natamycin correlated significantly with the clinical outcome of fungal keratitis (OR = 0.925), but no other such correlations were found for the other drugs tested. Aspergillus and Fusarium were the predominant pathogenic genera causing fungal keratitis in our patients. Among the causative fungi, infections due to Aspergillus spp. were associated with the worst outcomes. The inhibition zones of fungal isolates in response to natamycin significantly correlated with the treatment outcomes of keratitis. Specifically, the smaller the natamycin inhibition zone, the lower the

  14. Poly(lactic- co-glycolic) acid nanoparticles uptake by Vitis vinifera and grapevine-pathogenic fungi

    Science.gov (United States)

    Valletta, Alessio; Chronopoulou, Laura; Palocci, Cleofe; Baldan, Barbara; Donati, Livia; Pasqua, Gabriella

    2014-12-01

    Poly(lactic- co-glycolic) acid (PLGA)-based NPs are currently considered among the most promising drug carriers, nevertheless their use in plants has never been investigated. In this work, for the first time, we demonstrated the ability of PLGA NPs to cross the plant cell wall and membrane of Vitis vinifera cell cultures and grapevine-pathogenic fungi. By means of fluorescence microscopy, we established that PLGA NPs can enter in grapevine leaf tissues through stomata openings and that they can be absorbed by the roots and transported to the shoot through vascular tissues. TEM analysis on cultured cells showed that NPs ≤ 50 nm could enter cells, while bigger ones remained attached to the cell wall. Viability tests demonstrated that PLGA NPs were not cytotoxic for V. vinifera-cultured cells. The cellular uptake of PLGA NPs by some important grapevine-pathogenic fungi has also been observed, thus suggesting that PLGA NPs could be used to deliver antifungal compounds within fungal cells. Overall the results reported suggest that such NPs may play a key role in future developments of agrobiotechnologies, as it is currently happening in biomedicine.

  15. Soil moisture and fungi affect seed survival in California grassland annual plants.

    Directory of Open Access Journals (Sweden)

    Erin A Mordecai

    Full Text Available Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season than in the summer (dry season, but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

  16. Soil moisture and fungi affect seed survival in California grassland annual plants.

    Science.gov (United States)

    Mordecai, Erin A

    2012-01-01

    Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season) than in the summer (dry season), but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

  17. Occurrence fungi causing black foot on young grapevines and nursery rootstock plants in Italy

    Directory of Open Access Journals (Sweden)

    Antonia CARLUCCI

    2017-05-01

    Full Text Available Summary. Young grapevine plants with decline and wood necrosis symptoms were collected from vineyards and nurseries in the Apulia and Molise regions, Italy, from 2013 to 2015. Isolations of fungi were prepared from 45 diseased grapevine plants, and the cultures were identified. Several species commonly associated with Petri disease, Botryosphaeria dieback, and black foot disease were isolated. A detailed study was carried out, and 182 isolates resembling Cylindrocarpon-like asexual forms were identified through morphological characterisation and DNA analysis of internal transcribed spacer regions 1 and 2 of the rRNA gene and the partial β-tubulin gene. Dactylonectria torrensensis and Ilyonectria liriodendri were identified based on morphological features and the partial histone 3 gene, so these fungi can be defined as the causal agents of black foot on grapevine for the first time in Italy. Thelonectria blackeriella is also described as a new species, through morphological characterisation and multigenic analysis using sequence data for five loci (large subunit RNA, internal transcribed spacers, β-tubulin, actin, RNA polymerase II subunit 1. This new species was associated with black foot symptoms according to preliminary pathogenicity tests, with representative isolates of each of the three species. Pathogenicity tests showed that these species can cause black streaking in the wood of 1-year-old grapevine rootstock shoots. The identification of D. torresensis, I. liriodendri and T. blackeriella from young grapevine plants and rooted rootstock highlights the importance of black foot disease in Italy, which has previously been overlooked.

  18. Betaine lipids and zwitterionic phospholipids in plants and fungi.

    Science.gov (United States)

    Künzler, K; Eichenberger, W

    1997-11-01

    Of spermatophytes, ferns, mosses, algae, lichens and fungi, 110 species not analysed so far were examined for diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), diaclyglycerylhydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by TLC by using Dragendorff's and molybdenum-blue reagents for detection. The limit of detection was 0.5 microgram per mg or 0.05 weight % of total lipid. The results reveal that betaine lipids are present exclusively in non-flowering plants, including lichens and fungi and, hence, are produced by autotrophic, as well as heterotrophic organisms. DGTS in small amounts is typical of some Rhodophytes, and in appreciable amounts, of vascular cryptogamic plants and some higher fungi. Estimation of the amounts of DGTS and PC in 29 different species reveal that the total amount of zwitterionic lipids varies considerably amongst organisms. No general correlation could be found for the amounts of DGTS and PC, although Rhodophytes contain traces of DGTS but high amounts of PC. On the basis of these results and the presently available data, the natural distribution of the betaine lipids DGTS, DGTA and diacylglycerylcarboxy-N-hydroxymethyl-choline (DGCC) is discussed. In terms of biochemical evolution, the capacity for the formation of DGTS might have been acquired first and, in organisms of the 'DGTS branch', kept until the present time. The formation of DGTA and DGCC might have evolved at a later stage of development in organisms of the 'DGTA-DGCC branch'.

  19. Damage response involves mechanisms conserved across plants, animals and fungi.

    Science.gov (United States)

    Hernández-Oñate, M A; Herrera-Estrella, A

    2015-08-01

    All organisms are constantly exposed to adverse environmental conditions including mechanical damage, which may alter various physiological aspects of growth, development and reproduction. In plant and animal systems, the damage response mechanism has been widely studied. Both systems posses a conserved and sophisticated mechanism that in general is aimed at repairing and preventing future damage, and causes dramatic changes in their transcriptomes, proteomes, and metabolomes. These damage-induced changes are mediated by elaborate signaling networks, which include receptors/sensors, calcium (Ca(2+)) influx, ATP release, kinase cascades, reactive oxygen species (ROS), and oxylipin signaling pathways. In contrast, our current knowledge of how fungi respond to injury is limited, even though various reports indicate that mechanical damage triggers reproductive processes. In fungi, the damage response mechanism has been studied more in depth in Trichoderma atroviride. Interestingly, these studies indicate that the mechanical damage response involves ROS, Ca(2+), kinase cascades, and lipid signaling pathways. Here we compare the response to mechanical damage in plants, animals and fungi and provide evidence that they appear to share signaling molecules and pathways, suggesting evolutionary conservation across the three kingdoms.

  20. Presence of arbuscular mycorrhizal fungi in South Florida native plants.

    Science.gov (United States)

    Fisher, Jack B; Jayachandran, K

    2005-11-01

    The roots of 27 species of South Florida plants in 15 families (including one cycad, six palms, one Smilax, and 19 dicotyledons) native to pine rockland and tropical hardwood hammock communities were examined for arbuscular mycorrhizal fungi (AMF). These plants grow in the biologically diverse but endangered Greater Everglades habitat. Roots from field-grown and potted plants were cleared and stained. All 27 species had AMF and include 14 species having an endangered or threatened status. The Paris-type colonization occurred in two species in the families Annonaceae and Smilacaceae. The Arum-type occurred in 22 species in the families Anacardiaceae, Arecaceae (Palmae), Boraginaceae, Cactaceae (questionable), Euphorbiaceae, Fabaceae, Lauraceae, Melastomataceae, Polygalaceae, Rubiaceae, Simaroubaceae, Ulmaceae, and Zamiaceae. Three species in the families Fabaceae, Lauraceae, and Simaroubaceae had a mix of Paris- and Arum-types. The results have implications for the restoration of these endangered plant communities in the Everglades.

  1. Plant Growth Promotion Activity of Keratinolytic Fungi Growing on a Recalcitrant Waste Known as “Hair Waste”

    Directory of Open Access Journals (Sweden)

    Ivana A. Cavello

    2015-01-01

    Full Text Available Purpureocillium lilacinum (Thom Samsom is one of the most studied fungi in the control of plant parasitic nematodes. However, there is not specific information on its ability to inhibit some pathogenic bacteria, fungi, or yeast. This work reports the production of several antifungal hydrolytic enzymes by a strain of P. lilacinum when it is grown in a medium containing hair waste. The growth of several plant-pathogenic fungi, Alternaria alternata, Aspergillus niger, and Fusarium culmorum, was considerably affected by the presence of P. lilacinum’s supernatant. Besides antifungal activity, P. lilacinum demonstrates the capability to produce indoleacetic acid and ammonia during time cultivation on hair waste medium. Plant growth-promoting activity by cell-free supernatant was evidenced through the increase of the percentage of tomato seed germination from 71 to 85% after 48 hours. A 21-day plant growth assay using tomato plants indicates that crude supernatant promotes the growth of the plants similar to a reference fertilizer (p>0.05. These results suggest that both strain and the supernatant may have potential to be considered as a potent biocontrol agent with multiple plant growth-promoting properties. To our knowledge, this is the first report on the antifungal, IAA production and tomato growth enhancing compounds produced by P. lilacinum LPSC #876.

  2. Plant Growth Promotion Activity of Keratinolytic Fungi Growing on a Recalcitrant Waste Known as “Hair Waste”

    Science.gov (United States)

    Cavello, Ivana A.; Crespo, Juan M.; García, Sabrina S.; Zapiola, José M.; Luna, María F.; Cavalitto, Sebastián F.

    2015-01-01

    Purpureocillium lilacinum (Thom) Samsom is one of the most studied fungi in the control of plant parasitic nematodes. However, there is not specific information on its ability to inhibit some pathogenic bacteria, fungi, or yeast. This work reports the production of several antifungal hydrolytic enzymes by a strain of P. lilacinum when it is grown in a medium containing hair waste. The growth of several plant-pathogenic fungi, Alternaria alternata, Aspergillus niger, and Fusarium culmorum, was considerably affected by the presence of P. lilacinum's supernatant. Besides antifungal activity, P. lilacinum demonstrates the capability to produce indoleacetic acid and ammonia during time cultivation on hair waste medium. Plant growth-promoting activity by cell-free supernatant was evidenced through the increase of the percentage of tomato seed germination from 71 to 85% after 48 hours. A 21-day plant growth assay using tomato plants indicates that crude supernatant promotes the growth of the plants similar to a reference fertilizer (p > 0.05). These results suggest that both strain and the supernatant may have potential to be considered as a potent biocontrol agent with multiple plant growth-promoting properties. To our knowledge, this is the first report on the antifungal, IAA production and tomato growth enhancing compounds produced by P. lilacinum LPSC #876. PMID:26697226

  3. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reducing...... Pythium root rot development. To test this hypothesis a fully factorial experiment was performed with AM fungi (Glomus intraradices, G. mosseae, G. claroideum or nonmycorrhizal), Pythium (± P. aphanidermatum) and harvest (7 and 14 days after pathogen inoculation (dapi)) as the main factors. Two weeks...... growth suppressions, but did not affect PR-1 gene expression or the phosphorous concentration in the host plant. Plants singly inoculated with P. aphanidermatum had an increased PR-1 expression and phosphorous concentration. Among the AM fungi included in the study only G. intraradices reduced...

  4. Diversity and biotransformative potential of endophytic fungi associated with the medicinal plant Kadsura angustifolia.

    Science.gov (United States)

    Huang, Qian; An, Hongmei; Song, Hongchuan; Mao, Hongqiang; Shen, Weiyun; Dong, Jinyan

    2015-01-01

    This study investigated the diversity and host component-transforming activity of endophytic fungi in medicinal plant Kadsura angustifolia. A total of 426 isolates obtained were grouped into 42 taxa belonging to Fungi Imperfecti (65.96%), Ascomycota (27.00%), Zygomycota (1.64%), Basidiomycota (0.47%) and Mycelia Sterilia (4.93%). The abundance, richness, and species composition of endophytic assemblages were significantly dependent on the tissue and the sampling site. Many phytopathogenic species associated with healthy K. angustifolia were found prevalent. Among them, Verticillium dahliae was dominant with 16.43% abundance. From 134 morphospecies selected, 39 showed remarkable biocatalytic activity and were further identified as species belonging to the genera Colletotrichum, Eupenicillium, Fusarium, Hypoxylon, Penicillium, Phomopsis, Trametes, Trichoderma, Umbelopsis, Verticillium and Xylaria on the basis of the sequence analysis of the internal transcribed spacer (ITS1-5.8S-ITS2). The results obtained in this work show that K. angustifolia is an interesting reservoir of pathogenic fungal species, and could be a community model for further ecological and evolutionary studies. Additionally, the converting potency screening of some endophytic fungi from this specific medicinal plant may provide an interesting niche on the search for novel biocatalysts. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Isolation and screening of endophytic fungi from Eritrean traditional medicinal plant Terminalia brownii leaves for antimicrobial activity

    Directory of Open Access Journals (Sweden)

    N Saleem Basha

    2012-01-01

    Full Text Available Plants formed the basis of sophisticated traditional medicine systems that have been in existence for thousands of years. But, the advent of drug resistance in human pathogenic bacteria and others has prompted a search for more and better antibiotics. This has led to the identification of a new promising source of antimicrobials known as endophytes. Hence, our study was aimed to investigate the ability of endophytic fungi isolated from T. brownii to produce secondary metabolites, which can act as antimicrobial agents. In this preliminary investigation, the leaves were used for isolation of endophytic fungi and fermented, and the cell free ferment broth was subjected to antimicrobial screening against six human pathogens; Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans by using standard protocol of agar well diffusion method. The results of the endophyte isolation gave three fungal isolates named TBF1, TBF2 and TBF3. According to morphological and microscopical characterizations, the isolates were found to be similar to Rhizophus oryzae (TBF1, Aspergillus niger (TBF2 and Aspergillus flavus (TBF3. Two of the three isolated endophytes i.e., TBF2 and TBF3 showed potential antimicrobial activity against S. aureus and no inhibition was found against other tested pathogens. The present study has proven that T. brownii may be a rich source of endophytic fungi with antimicrobial potential and our findings may form a basis for further studies on endophytic fungi from medicinal plants for antimicrobial activities.

  6. Aerosol dissemination veterinary pathogenic and human opportunistic thermophilic and thermotolerant fungi from thermal effluents of nuclear production reactors

    Energy Technology Data Exchange (ETDEWEB)

    Tansey, M.R.; Fliermans, C.B.; Kern, C.D.

    1979-01-01

    The extent to which veterinary pathogenic and human opportunistic species of thermophilic and thermotolerant fungi disseminate in aerosols from heated effluents of nuclear production reactors of the Savannah River Plant (SRP), South Carolina, has been measured. Aerosol samples were taken at 140 sites, from directly over thermal effluents to more than 100 kilometers from the SRP boundary. Sampling methods included settle plates, liquid impingement, filtration, and a particle sizing cascade impactor (Andersen Sampler). Soils, foams, and microbial mats from thermal effluents, and vegetation were sampled to study distribution of particular species. Sampling was done under a variety of conditions; hot weather and cold, wet and dry, day and night, windy and calm, reactor(s) operating and not, disturbed vegetation and undisturbed. At 102 of the aerosol sampling sites, sophisticated meterological analysis were used to allow sampling of air in the plume which originated from thermal effluents. Soil, foam, microbial mat, vegetation, and aerosol samples were quantitatively plated for detection of viable units; filters were halved and then both plated and observed microscopically. Significant dissemination of thermophilic and thermotolerant fungi from thermal effluents was not detected. Thermophilic and thermotolerant fungi were widely distributed in soil, air, and on vegetation. Dactylaria gallopava, the indicator species and dominant fungus in microbial mats lining SRP thermal effluents and the cause of epidemic fatal phaeohyphomycosis in flocks of turkeys and chickens in South Carolina, Georgia, and elsewhere, was isolated from air at a maximum of 50 meters from effluents.

  7. DNA topoisomerases from pathogenic fungi: targets for the discovery of antifungal drugs.

    OpenAIRE

    Shen, L L; Baranowski, J; Fostel, J.; Montgomery, D A; Lartey, P A

    1992-01-01

    DNA topoisomerases, a class of enzymes that change the topological structure of DNA, have been shown to be the target of many therapeutic agents, including antibacterial agents (quinolones) and anticancer agents. These drugs inhibit the enzyme in a unique way so that the enzyme is converted into a cellular poison. Candida albicans and Aspergillus niger are two major opportunistic fungal pathogens. Our results show that these fungi have high levels of both type I and type II topoisomerases (wi...

  8. Particle-size distributions and seasonal diversity of allergenic and pathogenic fungi in outdoor air

    OpenAIRE

    Yamamoto, Naomichi; BIBBY, KYLE; Qian, Jing; Hospodsky, Denina; Rismani-Yazdi, Hamid; Nazaroff, William W.; Peccia, Jordan

    2012-01-01

    Fungi are ubiquitous in outdoor air, and their concentration, aerodynamic diameters and taxonomic composition have potentially important implications for human health. Although exposure to fungal allergens is considered a strong risk factor for asthma prevalence and severity, limitations in tracking fungal diversity in air have thus far prevented a clear understanding of their human pathogenic properties. This study used a cascade impactor for sampling, and quantitative real-time PCR plus 454...

  9. The genomes of the fungal plant pathogens Cladosporium fulvum and Dothistroma septosporum reveal adaptation to different hosts and lifestyles but also signatures of common ancestry.

    NARCIS (Netherlands)

    de Wit, P.J.G.M.; van der Burgt, A.; Ökmen, B.; Stergiopoulos, I.; Abd-Elsalam, K.A.; Aerts, A.L.; Bahkali, A.H.; Beenen, H.G.; Chettri, P.; Cox, M.P.; Datema, E.; de Vries, R.P.; Dhillon, B.; Ganley, A.R.; Griffiths, S.A.; Guo, Y.; Hamelin, R.C.; Henrissat, B.; Kabir, M.S.; Jashni, M.K.; Kema, G.; Klaubauf, S.; Lapidus, A.; Levasseur, A.; Lindquist, E.; Mehrabi, R.; Ohm, R.A.; Owen, T.J.; Salamov, A.; Schwelm, A.; Schijlen, E.; Sun, H.; van den Burg, H.A.; van Ham, R.C.H.J.; Zhang, S.; Goodwin, S.B.; Grigoriev, I.V.; Collemare, J.; Bradshaw, R.E.

    2012-01-01

    We sequenced and compared the genomes of the Dothideomycete fungal plant pathogens Cladosporium fulvum (Cfu) (syn. Passalora fulva) and Dothistroma septosporum (Dse) that are closely related phylogenetically, but have different lifestyles and hosts. Although both fungi grow extracellularly in close

  10. Inteins in pathogenic fungi: a phylogenetic tool and perspectives for therapeutic applications

    Directory of Open Access Journals (Sweden)

    Raquel Cordeiro Theodoro

    2009-05-01

    Full Text Available Inteins or "internal proteins" are coding sequences that are transcribed and translated with flanking sequences (exteins. After translation, the inteins are excised by an autocatalytic process and the host protein assumes its normal conformation and develops its expected function. These parasitic genetic elements have been found in important, conserved proteins in all three domains of life. Most of the eukaryotic inteins are present in the fungi kingdom and the PRP8 intein is one of the most widespread inteins, occurring in important pathogens such as Cryptococcus neoformans (varieties grubii and neoformans, Cryptococcus gattii, Histoplasma capsulatum and Paracoccidioides brasiliensis. The knowledge of conserved and non-conserved domains in inteins have opened up new opportunities for the study of population variability in pathogenic fungi, including their phylogenetic relationships and recognition or diagnoses of species. Furthermore, inteins in pathogenic fungi should also be considered a promising therapeutic drug target, since once the autocatalytic splicing is inhibited, the host protein, which is typically vital, will not be able to perform its normal function and the fungal cell will not survive or reproduce.

  11. Pathogen and biological contamination management in plant tissue culture: phytopathogens, vitro pathogens, and vitro pests.

    Science.gov (United States)

    Cassells, Alan C

    2012-01-01

    The ability to establish and grow plant cell, organ, and tissue cultures has been widely exploited for basic and applied research, and for the commercial production of plants (micro-propagation). Regardless of whether the application is for research or commerce, it is essential that the cultures be established in vitro free of biological contamination and be maintained as aseptic cultures during manipulation, growth, and storage. The risks from microbial contamination are spurious experimental results due to the effects of latent contaminants or losses of valuable experimental or commercial cultures. Much of the emphasis in culture contamination management historically focussed on the elimination of phytopathogens and the maintenance of cultures free from laboratory contamination by environmental bacteria, fungi (collectively referred to as "vitro pathogens", i.e. pathogens or environmental micro-organisms which cause culture losses), and micro-arthropods ("vitro pests"). Microbial contamination of plant tissue cultures is due to the high nutrient availability in the almost universally used Murashige and Skoog (Physiol Plant 15:473-497, 1962) basal medium or variants of it. In recent years, it has been shown that many plants, especially perennials, are at least locally endophytically colonized intercellularly by bacteria. The latter, and intracellular pathogenic bacteria and viruses/viroids, may pass latently into culture and be spread horizontally and vertically in cultures. Growth of some potentially cultivable endophytes may be suppressed by the high salt and sugar content of the Murashige and Skoog basal medium and suboptimal temperatures for their growth in plant tissue growth rooms. The management of contamination in tissue culture involves three stages: disease screening (syn. disease indexing) of the stock plants with disease and endophyte elimination where detected; establishment and pathogen and contaminant screening of established initial cultures

  12. Suppression of soil-borne plant pathogens

    NARCIS (Netherlands)

    Agtmaal, van M.

    2015-01-01

    Soil borne plant pathogens considerably reduce crop yields worldwide and are difficult to control due to their ”masked” occurrence  in the heterogeneous soil environment. This hampers the efficacy of chemical - and microbiological control agents.   Outbreaks of crop diseas

  13. Speciation in fungal and oomycete plant pathogens.

    Science.gov (United States)

    Restrepo, Silvia; Tabima, Javier F; Mideros, Maria F; Grünwald, Niklaus J; Matute, Daniel R

    2014-01-01

    The process of speciation, by definition, involves evolution of one or more reproductive isolating mechanisms that split a single species into two that can no longer interbreed. Determination of which processes are responsible for speciation is important yet challenging. Several studies have proposed that speciation in pathogens is heavily influenced by host-pathogen dynamics and that traits that mediate such interactions (e.g., host mobility, reproductive mode of the pathogen, complexity of the life cycle, and host specificity) must lead to reproductive isolation and ultimately affect speciation rates. In this review, we summarize the main evolutionary processes that lead to speciation of fungal and oomycete plant pathogens and provide an outline of how speciation can be studied rigorously, including novel genetic/genomic developments.

  14. Rhizosphere communication of plants, parasitic plants and AM fungi

    NARCIS (Netherlands)

    Bouwmeester, H.J.; Roux, Chr.; Lopez Raez, J.A.; Bécard, G.

    2007-01-01

    Plants use an array of secondary metabolites to defend themselves against harmful organisms and to attract others that are beneficial. However, the attraction of beneficial organisms could also lead to abuse by malevolent organisms. An exciting example of such abuse is the relationship between plant

  15. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic and human pathogenic microorganisms

    NARCIS (Netherlands)

    Mendes, R.; Garbeva, P.; Raaijmakers, J.M.

    2013-01-01

    Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protect

  16. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic and human pathogenic microorganisms

    NARCIS (Netherlands)

    Mendes, R.; Garbeva, P.; Raaijmakers, J.M.

    2013-01-01

    Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protect

  17. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms

    NARCIS (Netherlands)

    Mendes, R.; Garbeva, P.V.; Raaijmakers, J.M.

    2013-01-01

    Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protect

  18. Pathogenicity, Ovicidal Action, and Median Lethal Concentrations (LC 50 ) of Entomopathogenic Fungi against Exotic Spiralling Whitefly, Aleurodicus dispersus Russell

    OpenAIRE

    Boopathi Thangavel; Karuppuchamy Palaniappan; Kalyanasundaram Manickavasagam Pillai; Mohankumar Subbarayalu; Ravi Madhaiyan

    2013-01-01

    Biological control using entomopathogenic fungi could be a promising alternative to chemical control. Entomopathogenic fungi, Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae (Metschnikoff) Sorokin, Lecanicillium lecanii (Zimmerm.) Zare and Gams, and Paecilomyces fumosoroseus (Wize) Brown and Smith, were tested for their pathogenicity, ovicidal effect, and median lethal concentrations (LC50) against exotic spiralling whitefly, Aleurodicus dispersus Russell. The applications were...

  19. Molecular Characterization and Analysis of Antimicrobial Activity of Endophytic Fungi From Medicinal Plants in Saudi Arabia

    OpenAIRE

    Gashgari, Rukaia; Gherbawy, Youssuf; Ameen, Fuad; Alsharari, Salam

    2016-01-01

    Background: Endophytic fungi, which have been reported in numerous plant species, are important components of the forest community and contribute significantly to the diversity of natural ecosystems. Objectives: The current study aimed to evaluate and characterize, at the molecular level, the diversity and antimicrobial activities of endophytic fungi from medicinal plants in Saudi Arabia. Materials and Methods: Fungi growing on plant segments were isolated and identified based on morphologica...

  20. New combinations of plant-associated fungi resulting from the change to one name for fungi.

    Science.gov (United States)

    Rossman, Amy Y; Allen, W Cavan; Castlebury, Lisa A

    2016-06-01

    In advancing to one scientific name for each fungus species, a number of name changes are required especially for plant-associated fungi. These include species names that are not in the correct genus. For example, the generic name Elsinoë is used for fungi causing scab diseases but a number of these species were described in the asexually typified genus Sphaceloma and must be placed in Elsinoë. In other cases species names were determined to be unrelated to the type species of the genus in which they are currently placed and are placed in a more appropriate genus. For each new name the history, rationale and importance of the name is discussed. The following new combinations are made: Acanthohelicospora aurea, A. scopula, Bifusella ahmadii, Botryobasidium capitatum, B. rubiginosum, Colletotrichum magnum, Crandallia acuminata, C. antarctica, Elsinoë arachadis, E. freyliniae, E. necator, E. perseae, E. poinsettiae, E. punicae, Entyloma gibbum, Harknessia farinosa, Passalora alocasiae, Protoventuria veronicae, Pseudocercosporella ranunculi, Psiloglonium stygium, Ramularia pseudomaculiformis, Seimatosporium tostum, Thielaviopsis radicicola combs. nov., and Venturia effusa.

  1. Fungicide resistance assays for fungal plant pathogens.

    Science.gov (United States)

    Secor, Gary A; Rivera, Viviana V

    2012-01-01

    Fungicide resistance assays are useful to determine if a fungal pathogen has developed resistance to a fungicide used to manage the disease it causes. Laboratory assays are used to determine loss of sensitivity, or resistance, to a fungicide and can explain fungicide failures and for developing successful fungicide recommendations in the field. Laboratory assays for fungicide resistance are conducted by measuring reductions in growth or spore germination of fungi in the presence of fungicide, or by molecular procedures. This chapter describes two techniques for measuring fungicide resistance, using the sugarbeet leaf spot fungus Cercospora beticola as a model for the protocol. Two procedures are described for fungicides from two different classes; growth reduction for triazole (sterol demethylation inhibitor; DMI) fungicides, and inhibition of spore germination for quinone outside inhibitor (QoI) fungicides.

  2. Particle-size distributions and seasonal diversity of allergenic and pathogenic fungi in outdoor air.

    Science.gov (United States)

    Yamamoto, Naomichi; Bibby, Kyle; Qian, Jing; Hospodsky, Denina; Rismani-Yazdi, Hamid; Nazaroff, William W; Peccia, Jordan

    2012-10-01

    Fungi are ubiquitous in outdoor air, and their concentration, aerodynamic diameters and taxonomic composition have potentially important implications for human health. Although exposure to fungal allergens is considered a strong risk factor for asthma prevalence and severity, limitations in tracking fungal diversity in air have thus far prevented a clear understanding of their human pathogenic properties. This study used a cascade impactor for sampling, and quantitative real-time PCR plus 454 pyrosequencing for analysis to investigate seasonal, size-resolved fungal communities in outdoor air in an urban setting in the northeastern United States. From the 20 libraries produced with an average of ∼800 internal transcribed spacer (ITS) sequences (total 15 326 reads), 12 864 and 11 280 sequences were determined to the genus and species levels, respectively, and 558 different genera and 1172 different species were identified, including allergens and infectious pathogens. These analyses revealed strong relationships between fungal aerodynamic diameters and features of taxonomic compositions. The relative abundance of airborne allergenic fungi ranged from 2.8% to 10.7% of total airborne fungal taxa, peaked in the fall, and increased with increasing aerodynamic diameter. Fungi that can cause invasive fungal infections peaked in the spring, comprised 0.1-1.6% of fungal taxa and typically increased in relative abundance with decreasing aerodynamic diameter. Atmospheric fungal ecology is a strong function of aerodynamic diameter, whereby through physical processes, the size influences the diversity of airborne fungi that deposit in human airways and the efficiencies with which specific groups of fungi partition from outdoor air to indoor environments.

  3. Importance of seed-borne fungi of sorghum and pearl millet in Burkina Faso and their control using plant extracts.

    Science.gov (United States)

    Zida, Pawindé Elisabeth; Sérémé, Paco; Leth, Vibeke; Sankara, Philippe; Somda, Irénée; Néya, Adama

    2008-02-01

    Seed-borne fungi of sorghum and pearl millet in Burkina Faso were surveyed. A total of 188 seed samples from various locations, collected in 1989 (42) and 2002 (146), were tested, using the blotter, dry inspection and washing methods. Infection experiments were carried out with the major fungi recorded on each crop by the blotter test. Six essential oils of plants were investigated for their inhibitory activity against eight pathogenic fungi. Thirty four and 27 fungal species were found in seed samples of sorghum and pearl millet, respectively. Phoma sp. and Fusarium moniliforme infected 95 to 100% of the seed samples of both sorghum and pearl millet. Sphacelotheca sorghi and Tolyposporium ehrenbergii were encountered in respectively, 75 and 33% of seed samples of sorghum. T. penicillariae, Sclerospora graminicola and Claviceps fusiformis were present in 88, 41 and 32% of seed samples of pearl millet, respectively. Seeds inoculated with Acremonium strictum, Curvularia oryzae, F. equiseti, F. moniliforme and F. subglutinans and sown in sterilized soil, showed considerable mortality of the seedlings. Three essential oils inhibited in vitro the mycelial growth of all the fungi used by 85 to 100% and reduced significantly sorghum and pearl millet seed infection rates of Phoma sp., Fusarium sp., Curvularia sp., Colletotrichum graminicola and Exserohilum sp. Presence of many pathogenic fungi in considerable number of seed samples indicates the need of field surveys for these and other pathogens. Development of plant extracts for the control of seed-borne pathogens and public awareness on seed-borne diseases management measures for maintaining quality seed should be increased.

  4. solation and Identification of Fungi from Spices and Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Farid M. Toma

    2013-03-01

    Full Text Available This investigation was designed to throw light on the microbial status of some crude herbal materials. A total of 16 samples, representing different types of spices and medicinal plants were collected from common market in the Erbil city. Ten different fungal genera and 16 species were isolated and identified as Alternaria alternata, Aspergillus spp., Gliocladium sp., Hyalodendron diddeus, Memmoniella sp., Penicillium spp., Rhizopus spp., Syncephalastrum sp., Cladosporium lignicolum and Ulocladium botrytis. The total number of isolated fungi from the all sixteen selected samples was serially diluted and plated on Potato Dextrose Agar (PDA medium was (203×103 cfu/g. samples. Aspergillus spp. and Penicillium spp. were more frequently detected, while Stachybotrys sp., Syncephalastrum racemocum, Uocladium botrytis, Alternaria alternata, Cladosporium lignicolum and Gliocladium catenulatum ere less frequently detected. Detection of mycotoxin on Dichloran Rose Bengal Chloramphincol agar (DRBC for fungi isolated from spices and medicinal plant samples, A. flavus, A. Niger and A. ochraceous show positive results on the culture for mycotoxin production. Estimation of natural occurrence of Aflatoxin (AT and Ochratoxin (OT in some selected dried samples by using ELISA method, the high result of aflatoxin and ochratoxin show in Red tea (150.5, 387.3 ppb while the low result of aflatoxin and ochratoxin show in Garlic (1.4, 0 ppb respectively.

  5. [Air pollution biomonitoring with plants and fungi: concepts and uses].

    Science.gov (United States)

    Cuny, D

    2012-07-01

    Air pollution remains a major environmental concern of the French. Since about 30 years, due to evolution and diversification of sources, pollution became more and more complex, constituting a true "cocktail". Today, it is very important to know environmental and health effects of this cocktail. In this context air biomonitoring using plants and fungi can bring a lot of information. Biomonitoring includes four concepts: the use of biomarkers, bioindication biointegration and bioaccumulation. These four concepts are articulated according to the levels of biological organization, what links up biosurveillance on fundamental plan with ecotoxicology. It is a complementary approach of the physicochemical techniques of air pollution measurements. The main objectives of biomonitoring studies are the monitoring of the space and temporal distribution of pollutants effect; the monitoring of local sources; participation in the health risks assessment; the information of people and the help to decision in public policies. Biomonitoring of air quality is a method, which made its proof in numerous domains of application and brings fundamental information on the impacts of the quality of air. Recent evolution of low concerning biggest industries allows us to envisage the increase of air quality biomonitoring with plants and fungi applications in the field of the valuation of environmental and health risks. The recent normalization (French and European) of different methods will also allow the development of uses.

  6. Uniform categorization of biocommunication in bacteria, fungi and plants

    Science.gov (United States)

    Witzany, Günther

    2010-01-01

    This article describes a coherent biocommunication categorization for the kingdoms of bacteria, fungi and plants. The investigation further shows that, besides biotic sign use in trans-, inter- and intraorganismic communication processes, a common trait is interpretation of abiotic influences as indicators to generate an appropriate adaptive behaviour. Far from being mechanistic interactions, communication processes within organisms and between organisms are sign-mediated interactions. Sign-mediated interactions are the precondition for every cooperation and coordination between at least two biological agents such as cells, tissues, organs and organisms. Signs of biocommunicative processes are chemical molecules in most cases. The signs that are used in a great variety of signaling processes follow syntactic (combinatorial), pragmatic (context-dependent) and semantic (content-specific) rules. These three levels of semiotic rules are helpful tools to investigate communication processes throughout all organismic kingdoms. It is not the aim to present the latest empirical data concerning communication in these three kingdoms but to present a unifying perspective that is able to interconnect transdisciplinary research on bacteria, fungi and plants. PMID:21541001

  7. Uniform categorization of biocommunication in bacteria,fungi and plants

    Institute of Scientific and Technical Information of China (English)

    Günther; Witzany

    2010-01-01

    This article describes a coherent biocommunication categorization for the kingdoms of bacteria,fungi and plants. The investigation further shows that,besides biotic sign use in trans-,inter-and intraorganismic communication processes,a common trait is interpretation of abiotic influences as indicators to generate an appropriate adaptive behaviour.Far from being mechanistic interactions,communication processes within organisms and between organisms are sign-mediated interactions.Sign-mediated interactions are the precondition for every cooperation and coordination between at least two biological agents such as cells,tissues,organs and organisms.Signs of biocommunicative processes are chemical molecules in most cases.The signs that are used in a great variety of signaling processes follow syntactic(combinatorial) ,pragmatic(context-dependent) and semantic(contentspecific) rules.These three levels of semiotic rules are helpful tools to investigate communication processes throughout all organismic kingdoms.It is not the aim to present the latest empirical data concerning communication in these three kingdoms but to present a unifying perspective that is able to interconnect transdisciplinary research on bacteria,fungi and plants.

  8. The xylem as battleground for plant hosts and vascular wilt pathogens

    Directory of Open Access Journals (Sweden)

    Koste eYadeta

    2013-04-01

    Full Text Available Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate and obstruct the transportation of water and minerals. As a consequence, leaves wilt and die, which may lead to impairment of the whole plant and eventually to death of the plant. Cultural, chemical and biological measures to control this group of plant pathogens are generally ineffective, and the most effective control strategy is the use of genetic resistance. Owing to the fact that vascular wilt pathogens live deep in the interior of their host plants, studies into the biology of vascular pathogens are complicated. However, to design novel strategies to combat vascular wilt diseases, understanding the (molecular biology of vascular pathogens and the molecular mechanisms underlying plant defense against these pathogens is crucial. In this review we discuss the current knowledge on interactions of vascular wilt pathogens with their host plants, with emphasis on host defense responses against this group of pathogens.

  9. Endophytic fungi associated with Monarda citriodora, an aromatic and medicinal plant and their biocontrol potential.

    Science.gov (United States)

    Katoch, Meenu; Pull, Shipra

    2017-12-01

    The Food and Agriculture Organization has estimated that every year considerable losses of the food crops occur due to plant diseases. Although fungicides are extensively used for management of plant diseases, they are expensive and hazardous to the environment and human health. Alternatively, biological control is the safe way to overcome the effects of plant diseases and to sustain agriculture. Since Monarda citriodora Cerv. ex Lag. (Lamiaceae/Labiatae) is known for its antifungal properties, it was chosen for the study. The isolation of endophytic fungi from M. citriodora and assessing their biocontrol potential. The isolated endophytes were characterized using ITS-5.8 S rDNA sequencing. Their biocontrol potential was assessed using different antagonistic assays against major plant pathogens. Twenty-eight endophytes representing 11 genera were isolated, of which, around 82% endophytes showed biocontrol potential against plant pathogens. MC-2 L (Fusarium oxysporum), MC-14 F (F. oxysporum), MC-22 F (F. oxysporum) and MC-25 F (F. redolens) displayed significant antagonistic activity against all the tested pathogens. Interestingly, MC-10 L (Muscodor yucatanensis) completely inhibited the growth of Sclerotinia sp., Colletotrichum capsici, Aspergillus flavus and A. fumigatus in dual culture assay, whereas MC-8 L (A. oryzae) and MC-9 L (Penicillium commune) completely inhibited the growth of the Sclerotinia sp. in fumigation assay. Endophytes MC-2 L, MC-14 F, MC-22 F and MC-25 F could effectively be used to control broad range of phytopathogens, while MC-10 L, MC-8 L and MC-9 L could be used to control specific pathogens. Secondly, endophytes showing varying degrees of antagonism in different assays represented the chemo-diversity not only as promising biocontrol agents but also as a resource of defensive and bioactive metabolites.

  10. The ascomycete Verticillium longisporum is a hybrid and a plant pathogen with an expanded host range.

    Directory of Open Access Journals (Sweden)

    Patrik Inderbitzin

    Full Text Available Hybridization plays a central role in plant evolution, but its overall importance in fungi is unknown. New plant pathogens are thought to arise by hybridization between formerly separated fungal species. Evolution of hybrid plant pathogens from non-pathogenic ancestors in the fungal-like protist Phytophthora has been demonstrated, but in fungi, the most important group of plant pathogens, there are few well-characterized examples of hybrids. We focused our attention on the hybrid and plant pathogen Verticillium longisporum, the causal agent of the Verticillium wilt disease in crucifer crops. In order to address questions related to the evolutionary origin of V. longisporum, we used phylogenetic analyses of seven nuclear loci and a dataset of 203 isolates of V. longisporum, V. dahliae and related species. We confirmed that V. longisporum was diploid, and originated three different times, involving four different lineages and three different parental species. All hybrids shared a common parent, species A1, that hybridized respectively with species D1, V. dahliae lineage D2 and V. dahliae lineage D3, to give rise to three different lineages of V. longisporum. Species A1 and species D1 constituted as yet unknown taxa. Verticillium longisporum likely originated recently, as each V. longisporum lineage was genetically homogenous, and comprised species A1 alleles that were identical across lineages.

  11. Membrane microdomains, rafts, and detergent-resistant membranes in plants and fungi.

    Science.gov (United States)

    Malinsky, Jan; Opekarová, Miroslava; Grossmann, Guido; Tanner, Widmar

    2013-01-01

    The existence of specialized microdomains in plasma membranes, postulated for almost 25 years, has been popularized by the concept of lipid or membrane rafts. The idea that detergent-resistant membranes are equivalent to lipid rafts, which was generally abandoned after a decade of vigorous data accumulation, contributed to intense discussions about the validity of the raft concept. The existence of membrane microdomains, meanwhile, has been verified by unequivocal independent evidence. This review summarizes the current state of research in plants and fungi with respect to common aspects of both kingdoms. In these organisms, principally immobile microdomains large enough for microscopic detection have been visualized. These microdomains are found in the context of cell-cell interactions (plant symbionts and pathogens), membrane transport, stress, and polarized growth, and the data corroborate at least three mechanisms of formation. As documented in this review, modern methods of visualization of lateral membrane compartments are also able to uncover the functional relevance of membrane microdomains.

  12. Occurrence of entomopathogenic fungi in tejocote (Crataegus mexicana) orchard soils and their pathogenicity against Rhagoletis pomonella.

    Science.gov (United States)

    Muñiz-Reyes, E; Guzmán-Franco, A W; Sánchez-Escudero, J; Nieto-Angel, R

    2014-11-01

    To determine the abundance and diversity of entomopathogenic fungi in tejocote orchard soils and evaluate their ability to infect Rhagoletis pomonella Walsh., the main pest of tejocote. Surveys were made in two locations in Mexico state and two in Puebla state. Soil from selected locations was baited for entomopathogenic fungi with Galleria mellonella (L.). All isolates were identified morphologically to genus level and to species level using Bloc and elongation factor 1-α gene sequence information, respectively; Beauveria bassiana ((Bals.-Criv.) Vuill.), B. pseudobassiana (S.A. Rehner & Humber) and Metarhizium robertsii (J.F. Bisch., Rehner & Humber) were found, with B. bassiana being the most abundant and widely distributed. Pathogenicity of five selected B. bassiana isolates and three M. robertsii isolates was evaluated against larvae and pupae of R. pomonella. All isolates infected larvae resulting in an average mortality of 35%. Pupae were not susceptible; however, adults emerging from inoculated pupae did die due to infection. At least three species of entomopathogenic fungi are present in the soil from tejocote orchards, with B. bassiana being the most abundant and widely distributed. Rhagoletis pomonella larvae were more susceptible to infection than pupae. Our study has produced new information about the distribution of entomopathogenic fungi in cultivated soils from this region of North America, contributing to a better understanding of their natural occurrence and underpinning the development of biological control approaches. © 2014 The Society for Applied Microbiology.

  13. Pathogenic Fungi Transmitted Through Cucumber Seeds and Safely Elimination by Application of Peppermint Extract and Oil

    Directory of Open Access Journals (Sweden)

    Eman S.H. FARRAG

    2012-08-01

    Full Text Available Diseases induced by Fusarium, like damping-off and wilt on cucumber, are serious problems around the world. Samples of cucumber seeds were collected from commercial markets in Egypt and tested for seed-borne fungi. In order to detect the maximum number of internal and external seed-borne fungi, agar plate examination of disinfected and non-disinfected seeds were used. Two species of Fusarium were the most frequent and predominant fungi. Facultative parasites of the genera Alternaria, Rhizoctonia, Helminthosporium and Penicillium were also found. A total 33 isolates of Fusarium spp. were obtained using Komadas selective medium. Fusarium oxysporum and F. solani were highly frequent. Pathogenicity test indicated that, F. oxysporum isolate (Fem8 was the main causal organism of pre- and post-emergence damping off. Furthermore, it occurred in all seed parts tested. Some infected seeds germinate, but they were either rapidly overgrown by F. oxysporum or they developed into a diseased seedling. The water extract of garlic, peppermint and rheum completely inhibited the conidiospore germination and mycelial growth of F. oxysporum at tested conc. 3, 2 and 3%, respectively. Soaked seeds in 2% peppermint extract and evaporated seeds by vapor of peppermint oil caused a highly reduction in the infection and reduced transmission of the referred fungi from seeds to the growing seedlings. The vigor of cucumber seedlings raised from the treated seeds was better than that developed from untreated ones.

  14. Pathogenic Fungi Transmitted Through Cucumber Seeds and Safely Elimination by Application of Peppermint Extract and Oil

    Directory of Open Access Journals (Sweden)

    Eman S.H. FARRAG

    2012-08-01

    Full Text Available Diseases induced by Fusarium, like damping-off and wilt on cucumber, are serious problems around the world. Samples of cucumber seeds were collected from commercial markets in Egypt and tested for seed-borne fungi. In order to detect the maximum number of internal and external seed-borne fungi, agar plate examination of disinfected and non-disinfected seeds were used. Two species of Fusarium were the most frequent and predominant fungi. Facultative parasites of the genera Alternaria, Rhizoctonia, Helminthosporium and Penicillium were also found. A total 33 isolates of Fusarium spp. were obtained using Komada�s selective medium. Fusarium oxysporum and F. solani were highly frequent. Pathogenicity test indicated that, F. oxysporum isolate (Fem8 was the main causal organism of pre- and post-emergence damping off. Furthermore, it occurred in all seed parts tested. Some infected seeds germinate, but they were either rapidly overgrown by F. oxysporum or they developed into a diseased seedling. The water extract of garlic, peppermint and rheum completely inhibited the conidiospore germination and mycelial growth of F. oxysporum at tested conc. 3, 2 and 3%, respectively. Soaked seeds in 2% peppermint extract and evaporated seeds by vapor of peppermint oil caused a highly reduction in the infection and reduced transmission of the referred fungi from seeds to the growing seedlings. The vigor of cucumber seedlings raised from the treated seeds was better than that developed from untreated ones.

  15. Rhizosphere communication of plants, parasitic plants and AM fungi

    NARCIS (Netherlands)

    Bouwmeester, H.J.; Roux, Chr.; Lopez Raez, J.A.; Bécard, G.

    2007-01-01

    Plants use an array of secondary metabolites to defend themselves against harmful organisms and to attract others that are beneficial. However, the attraction of beneficial organisms could also lead to abuse by malevolent organisms. An exciting example of such abuse is the relationship between

  16. The modular nature of dendritic cell responses to commensal and pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    Lisa Rizzetto

    Full Text Available The type of adaptive immune response following host-fungi interaction is largely determined at the level of the antigen-presenting cells, and in particular by dendritic cells (DCs. The extent to which transcriptional regulatory events determine the decision making process in DCs is still an open question. By applying the highly structured DC-ATLAS pathways to analyze DC responses, we classified the various stimuli by revealing the modular nature of the different transcriptional programs governing the recognition of either pathogenic or commensal fungi. Through comparison of the network parts affected by DC stimulation with fungal cells and purified single agonists, we could determine the contribution of each receptor during the recognition process. We observed that initial recognition of a fungus creates a temporal window during which the simultaneous recruitment of cell surface receptors can intensify, complement and sustain the DC activation process. The breakdown of the response to whole live cells, through the purified components, showed how the response to invading fungi uses a set of specific modules. We find that at the start of fungal recognition, DCs rapidly initiate the activation process. Ligand recognition is further enhanced by over-expression of the receptor genes, with a significant correspondence between gene expression and protein levels and function. Then a marked decrease in the receptor levels follows, suggesting that at this moment the DC commits to a specific fate. Overall our pathway based studies show that the temporal window of the fungal recognition process depends on the availability of ligands and is different for pathogens and commensals. Modular analysis of receptor and signalling-adaptor expression changes, in the early phase of pathogen recognition, is a valuable tool for rapid and efficient dissection of the pathogen derived components that determine the phenotype of the DC and thereby the type of immune response

  17. Understanding the plant-pathogen interactions in the context of proteomics-generated apoplastic proteins inventory.

    Science.gov (United States)

    Gupta, Ravi; Lee, So Eui; Agrawal, Ganesh K; Rakwal, Randeep; Park, Sangryeol; Wang, Yiming; Kim, Sun T

    2015-01-01

    The extracellular space between cell wall and plasma membrane acts as the first battle field between plants and pathogens. Bacteria, fungi, and oomycetes that colonize the living plant tissues are encased in this narrow region in the initial step of infection. Therefore, the apoplastic region is believed to be an interface which mediates the first crosstalk between host and pathogen. The secreted proteins and other metabolites, derived from both host and pathogen, interact in this apoplastic region and govern the final relationship between them. Hence, investigation of protein secretion and apoplastic interaction could provide a better understanding of plant-microbe interaction. Here, we are briefly discussing the methods available for the isolation and normalization of the apoplastic proteins, as well as the current state of secretome studies focused on the in-planta interaction between the host and the pathogen.

  18. Viruses of the plant pathogenic fungus Sclerotinia sclerotiorum.

    Science.gov (United States)

    Jiang, Daohong; Fu, Yanping; Guoqing, Li; Ghabrial, Said A

    2013-01-01

    Sclerotinia sclerotiorum is a notorious plant fungal pathogen with a broad host range including many important crops, such as oilseed rape, soybean, and numerous vegetable crops. Hypovirulence-associated mycoviruses have attracted much attention because of their potential as biological control agents for combating plant fungal diseases and for use in fundamental studies on fungal pathogenicity and other properties. This chapter describes several mycoviruses that were isolated from hypovirulent strains except for strain Sunf-M, which has a normal phenotype. These viruses include the geminivirus-like mycovirus Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1), Sclerotinia debilitation-associated RNA virus (SsDRV), Sclerotinia sclerotiorum RNA virus L (SsRV-L), Sclerotinia sclerotiorum hypovirus 1 (SsHV-1), Sclerotinia sclerotiorum mitoviruses 1 and 2 (SsMV-1, SsMV-2), and Sclerotinia sclerotiorum partitivirus S (SsPV-S). Unlike many other fungi, incidences of mixed infections with two or more mycoviruses in S. sclerotiorum are particularly high and very common. The interaction between SsDRV and S. sclerotiorum is likely to be unique. The significance of these mycoviruses to fungal ecology and viral evolution and the potential for biological control of Sclerotinia diseases using mycoviruses are discussed.

  19. [Potentially pathogenic fungi in the waters of the Charzykowskie Lake in Zaborski Landscape Park].

    Science.gov (United States)

    Kurnatowski, Piotr; Rózga, Anna; Rózga, Błazei; Babski, Piotr; Wójcik, Anna

    2007-01-01

    The occurrence of potentially pathogenic fungal strains in the Charzykowskie Lake and runnels flowing into and out of it was investigated. The study material was obtained in 2005 and in 2006, in the periods of spring intermix and summer stagnation, and in 2005 in the period of autumn intermix. The fungi found in the Charzykowski Lake belonged to 5 genera: Rhodotorula (R. minuta, R. rubra and R. glutinis), Cryptoccocus (C. neoformans, C. laurentii, C. terreus and C. laurentii), Candida (C. inconspicua, C. lusitaniae, C. tropicalis, C. pelliculosa, C. kefir, C. glabrata, C. inconspicua, C. parapsilosis, C. ciferrii and C. colliculosa), Trichosporon (T. cutaneum) and Klockera (K. apiculata). The fungi found in runnels flowing into and out of the Charzykowskie Lake belonged to 4 genera: Rhodotorula (R. rubra and R. glutinis), Cryptoccocus (C. laurentii, C. neoformans, C. albidus and C. terreus), Candida (C. colliculosa, C. lusitaniae, C. tropicalis, C. pelliculosa, C. cifferii, C. glabrata) and Trichosporon (T. cutaneum).

  20. Emerging trends in molecular interactions between plants and the broad host range fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    Malick eMbengue

    2016-03-01

    Full Text Available Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum , the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi.

  1. Phytotoxic terpenes produced by phytopathogenic fungi and allelopathic plants.

    Science.gov (United States)

    Cimmino, Alessio; Andolfi, Anna; Evidente, Antonio

    2014-03-01

    This review is about the isolation as well as chemical and biological characterization of simple and complex mono-, sesqui-, di-, sester- and tri-terpenes produced by fungal pathogens of agrarian and forest plants and by some allelopathic plants. In several cases, the structure activity relationships are also discussed, as well as their potential application in agriculture as natural safe herbicides, fungicides and bactericides. Furthermore, the potential application of some fungal terpenes as anticancer compounds with a new mode of action is also discussed.

  2. Isolation and Identification of Pathogenic Fungi from Thorns and Thistles in Isfahan and Adjacent Cities

    Directory of Open Access Journals (Sweden)

    M Emami

    2007-12-01

    Full Text Available Introduction: The most important subcutaneous fungal infections in man are caused by injury due to contaminated thistles and thorns. From an epidemiological point of view , it is important to recognize the fungi as well as their frequency of them in various thistles and thorns Methods: The present research has been conducted on thorns and thistles of 16 regions including cities and villages of Isfahan province. 800 samples have been collected. Specimens were inoculated and incubated at 25◦C in S & SCC medium. In order to isolate and identify the fungi, cultures in specific media, intraperitoneal injections of mice and disc diffusion test have been applied. Results: Over one year of study, 1676 colonies of actinomycetes and fungi were recognized. The most common fungi were as follows: Alternaria (22/4%,Aspergillus(11/8% , Cladosporium (10/8%,Esteril mycellium(10/6% and Penicillium (9/7%. The prevalence was most in Shahreza city(10/2% , while the least was in Ardestan(3%. The most prevalent yeasts were Candida tropicalis (50% , Rodotrula rubra (12/5% , Candida kerusei(11/4%,Trichosporon candida (7/9% , Unknown yeasts (6/8%, Candida gillermondi (5/7%, Saccharomyces cervisia (3/4%, Geotricum candidum and Trichosporon glabrata (Candida glabrata each one (1/1%. The prevalence was most in Khansar city(19/2%. In this study, 4 species similar to Coccidioides immitis, Phialophora verrucosa (4 species and Exophiala jeanselmei (3 species were identified. Conclusion: In this study done for the first time in this area, pathogenic and opportunistic fungi were isolated. Furthermore, Exophiala jeanselmei and Nocardiopsis dassonvillei were isolated for the first time from thorns in the country.

  3. Isolation of Endophytic Fungi from Scutellaria baicalensis Growing in Shangluo Region and Screening of Their Inhibitory Activities to Plant Pathogens%商洛黄芩内生真菌分离鉴定及抗植物病原菌活性筛选

    Institute of Scientific and Technical Information of China (English)

    冀玉良; 李丹青; 李堆淑; 朱广启; 高宝云; 杨亚莉

    2011-01-01

    采用组织分离法从健康黄芩(Scutellaria baicalensis Georgi)植株的根、茎、叶中分离获得36株内生真菌,经鉴定隶属于12属,链格霉属为优势属.对峙试验结果显示,分离获得的内生菌中有31株对一种或多种植物病原菌有不同程度的抑制作用,占分离菌的86%;有6株菌对一种或多种病原菌的抑菌率在75%以上,占分离菌的17%.对这6株菌培养滤液的抑菌活性也进行了测定,结果表明对峙试验中产生抑菌带的菌株其培养滤液抑菌活性也高.在6株筛选到的活性菌株中,SBF02和SBF06对棉立枯病菌抑制效果较好;SBF08和SBF27对苹果干腐病菌抑制效果较好;SBF11和SBF27对茄腐皮病镰孢霉抑制效果较好;SBF08和SBF32分别对烟草赤星病菌和草燕麦镰孢霉抑制效果较好.%Thirty-six strains of endophytic fungi were isolated from the roots,stems and leaves of healthy Scutellaria baicalen-sis Georgi with tissue method. They were identified as twelve fungal genera among which Alternaria was the dominant genus. The results of antagonistic cultivation indicated that thirty-one strains of endophytic fungi, accounting for 86% of all the isolates, could inhibit one plant pathogens or more to some extent; and the inhibitory activity of six strains, seventeen percent of total isolates; was significant at least to one plant pathogens, with the anti-bacterial ratio higher than 75%. Antimicrobial activity of six strains's culture filtrates were also detected and presented that the strains producing inhibition band in antagonistic cultivation also showed remarkable inhibitory activity to indicative pathogens in the test of culture filtrates. Among six screened strains, SBF02 and SBF06 showed remarkable inhibitory activity to Rhizoctonia solani Kiihn, SBF08 and SBF27 showed remarkable inhibitory activities to Botryosphae riadothidea, SBF11 and SBF27 showed remarkable inhibitory activities to Fusarium solani(Mart.), and SBF08 and SBF32

  4. Soil eukaryotic microorganism succession as affected by continuous cropping of peanut--pathogenic and beneficial fungi were selected.

    Directory of Open Access Journals (Sweden)

    Mingna Chen

    Full Text Available Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping.

  5. Soil eukaryotic microorganism succession as affected by continuous cropping of peanut--pathogenic and beneficial fungi were selected.

    Science.gov (United States)

    Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

    2012-01-01

    Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping.

  6. Phylogenomic Analyses Indicate that Early Fungi Evolved Digesting Cell Walls of Algal Ancestors of Land Plants

    NARCIS (Netherlands)

    Chang, Ying; Wang, Sishuo; Sekimoto, Satoshi; Aerts, Andrea L; Choi, Cindy; Clum, Alicia; LaButti, Kurt M; Lindquist, Erika A; Yee Ngan, Chew; Ohm, Robin A|info:eu-repo/dai/nl/304837628; Salamov, Asaf A; Grigoriev, Igor V; Spatafora, Joseph W; Berbee, Mary L

    2015-01-01

    As decomposers, fungi are key players in recycling plant material in global carbon cycles. We hypothesized that genomes of early diverging fungi may have inherited pectinases from an ancestral species that had been able to extract nutrients from pectin-containing land plants and their algal allies (

  7. Seed and Root Endophytic Fungi in a Range Expanding and a Related Plant Species

    Directory of Open Access Journals (Sweden)

    Stefan Geisen

    2017-08-01

    Full Text Available Climate change is accelerating the spread of plants and their associated species to new ranges. The differences in range shift capacity of the various types of species may disrupt long-term co-evolved relationships especially those belowground, however, this may be less so for seed-borne endophytic microbes. We collected seeds and soil of the range-expanding Centaurea stoebe and the congeneric Centaurea jacea from three populations growing in Slovenia (native range of both Centaurea species and the Netherlands (expanded range of C. stoebe, native range of C. jacea. We isolated and identified endophytic fungi directly from seeds, as well as from roots of the plants grown in Slovenian, Dutch or sterilized soil to compare fungal endophyte composition. Furthermore, we investigated whether C. stoebe hosts a reduced community composition of endophytes in the expanded range due to release from plant-species specific fungi while endophyte communities in C. jacea in both ranges are similar. We cultivated 46 unique and phylogenetically diverse endophytes. A majority of the seed endophytes resembled potential pathogens, while most root endophytes were not likely to be pathogenic. Only one endophyte was found in both roots and seeds, but was isolated from different plant species. Unexpectedly, seed endophyte diversity of southern C. stoebe populations was lower than of populations from the north, while the seed endophyte community composition of northern C. stoebe populations was significantly different southern C. stoebe as well as northern and southern C. jacea populations. Root endophyte diversity was considerably lower in C. stoebe than in C. jacea independent of plant and soil origin, but this difference disappeared when plants were grown in sterile soils. We conclude that the community composition of fungal endophytes not only differs between related plant species but also between populations of plants that expand their range compared to their native

  8. The Genetic and Molecular Basis of Plant Resistance to Pathogens

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Thomas Lubberstedt; Mingliang Xu

    2013-01-01

    Plant pathogens have evolved numerous strategies to obtain nutritive materials from their host,and plants in turn have evolved the preformed physical and chemical barriers as well as sophisticated two-tiered immune system to combat pathogen attacks.Genetically,plant resistance to pathogens can be divided into qualitative and quantitative disease resistance,conditioned by major gene(s) and multiple genes with minor effects,respectively.Qualitative disease resistance has been mostly detected in plant defense against biotrophic pathogens,whereas quantitative disease resistance is involved in defense response to all plant pathogens,from biotrophs,hemibiotrophs to necrotrophs.Plant resistance is achieved through interception of pathogen-derived effectors and elicitation of defense response.In recent years,great progress has been made related to the molecular basis underlying host-pathogen interactions.In this review,we would like to provide an update on genetic and molecular aspects of plant resistance to pathogens.

  9. Mycorrhizal fungi of Vanilla: diversity, specificity and effects on seed germination and plant growth.

    Science.gov (United States)

    Porras-Alfaro, Andrea; Bayman, Paul

    2007-01-01

    Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some temperate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function of mycorrhizal fungi in Vanilla, a pantropical genus that is both terrestrial and epiphytic. Mycorrhizal roots were collected from four Vanilla species in Puerto Rico, Costa Rica and Cuba. Cultured and uncultured mycorrhizal fungi were identified by sequencing the internal transcribed spacer region of nuclear rDNA (nrITS) and part of the mitochondrial ribosomal large subunit (mtLSU), and by counting number of nuclei in hyphae. Vanilla spp. were associated with a wide range of mycorrhizal fungi: Ceratobasidium, Thanatephorus and Tulasnella. Related fungi were found in different species of Vanilla, although at different relative frequencies. Ceratobasidium was more common in roots in soil and Tulasnella was more common in roots on tree bark, but several clades of fungi included strains from both substrates. Relative frequencies of genera of mycorrhizal fungi differed significantly between cultured fungi and those detected by direct amplification. Ceratobasidium and Tulasnella were tested for effects on seed germination of Vanilla and effects on growth of Vanilla and Dendrobium plants. We found significant differences among fungi in effects on seed germination and plant growth. Effects of mycorrhizal fungi on Vanilla and Dendrobium were similar: a clade of Ceratobasidium had a consistently positive effect on plant growth and seed germination. This clade has potential use in germination and propagation of orchids. Results confirmed that a single orchid species can be associated with several mycorrhizal fungi with different functional consequences for the plant.

  10. The pathogenic fungi in mushroom cultivation of Agaricus bisporus (Lange. Imbach.

    Directory of Open Access Journals (Sweden)

    Agata Tekiela

    2012-12-01

    Full Text Available The research was conducted in a mushroom growing facility located near Rzeszów, consisting of three production cycles. The number and composition of microorganisms which accompany the mushroom cultivation depended on the healthiness of: the compost, casing and spawn of Agaricus bisporus. The presence of pathogenic fungi in the cultivation halls at the beginning of the production cycle is a serious threat to the cultivation of common mushroom because their rapid development shortens the span of fruiting body harvests.

  11. Visual Comparative Omics of Fungi for Plant Biomass Deconstruction

    Science.gov (United States)

    Miyauchi, Shingo; Navarro, David; Grigoriev, Igor V.; Lipzen, Anna; Riley, Robert; Chevret, Didier; Grisel, Sacha; Berrin, Jean-Guy; Henrissat, Bernard; Rosso, Marie-Noëlle

    2016-01-01

    Wood-decay fungi contain the cellular mechanisms to decompose such plant cell wall components as cellulose, hemicellulose, and lignin. A multi-omics approach to the comparative analysis of wood-decay fungi gives not only new insights into their strategies for decomposing recalcitrant plant biomass, but also an understanding of how to exploit these mechanisms for biotechnological applications. We have developed an analytical workflow, Applied Biomass Conversion Design for Efficient Fungal Green Technology (ABCDEFGT), to simplify the analysis and interpretation of transcriptomic and secretomic data. ABCDEFGT utilizes self-organizing maps for grouping genes with similar transcription patterns, and an overlay with secreted proteins. The key feature of ABCDEFGT is simple graphic outputs of genome-wide transcriptomic and secretomic topographies, which enables visual inspection without a priori of the omics data and facilitates discoveries of co-regulated genes and proteins. Genome-wide omics landscapes were built with the newly sequenced fungal species Pycnoporus coccineus, Pycnoporus sanguineus, and Pycnoporus cinnabarinus grown on various carbon sources. Integration of the post-genomic data revealed a global overlap, confirming the pertinence of the genome-wide approach. ABCDEFGT was evaluated by comparison with the latest clustering method for ease of output interpretation, and ABCDEFGT gave a better biological representation of fungal behaviors. The genome-wide multi-omics strategy allowed us to determine the potential synergy of particular enzymes decomposing cellulose, hemicellulose, and lignin such as Lytic Polysaccharide Monooxygenases, modular enzymes associated with a cellulose binding module1, and Class II Peroxidase isoforms co-regulated with oxido-reductases. Overall, ABCDEFGT was capable of visualizing genome-wide transcriptional and secretomic profiles for intuitive interpretations and is suitable for exploration of newly-sequenced organisms. PMID:27605927

  12. Phylogenomic analysis demonstrates a pattern of rare and ancient horizontal gene transfer between plants and fungi.

    Science.gov (United States)

    Richards, Thomas A; Soanes, Darren M; Foster, Peter G; Leonard, Guy; Thornton, Christopher R; Talbot, Nicholas J

    2009-07-01

    Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries and is an important evolutionary phenomenon in the ancestry of many microbes. The role of HGT in plant evolutionary history is, however, largely unexplored. Here, we compare the genomes of six plant species with those of 159 prokaryotic and eukaryotic species and identify 1689 genes that show the highest similarity to corresponding genes from fungi. We constructed a phylogeny for all 1689 genes identified and all homolog groups available from the rice (Oryza sativa) genome (3177 gene families) and used these to define 14 candidate plant-fungi HGT events. Comprehensive phylogenetic analyses of these 14 data sets, using methods that account for site rate heterogeneity, demonstrated support for nine HGT events, demonstrating an infrequent pattern of HGT between plants and fungi. Five HGTs were fungi-to-plant transfers and four were plant-to-fungi HGTs. None of the fungal-to-plant HGTs involved angiosperm recipients. These results alter the current view of organismal barriers to HGT, suggesting that phagotrophy, the consumption of a whole cell by another, is not necessarily a prerequisite for HGT between eukaryotes. Putative functional annotation of the HGT candidate genes suggests that two fungi-to-plant transfers have added phenotypes important for life in a soil environment. Our study suggests that genetic exchange between plants and fungi is exceedingly rare, particularly among the angiosperms, but has occurred during their evolutionary history and added important metabolic traits to plant lineages.

  13. Ecotoxicological effects of carbon nanomaterials on algae, fungi and plants.

    Science.gov (United States)

    Basiuk, Elena V; Ochoa-Olmos, Omar E; De la Mora-Estrada, León F

    2011-04-01

    The ecotoxicological effects of carbon nanomateriales (CNMs), namely fullerenes and carbon nanotubes, on algae, fungi and plants are analyzed. In different toxicity tests, both direct and indirect effects were found. The direct effects are determined by nanomaterial chemical composition and surface reactivity, which might catalyze redox reactions in contact with organic molecules and affect respiratory processes. Some indirect effects of carbon nanoparticles (CNPs) are physical restraints or release of toxic ions. Accumulation of CNPs in photosynthetic organs provokes obstruction in stomata, foliar heating and alteration in physiological processes. The phytotoxicity studies of CNMs should be focused on determining phytotoxicity mechanisms, size distribution of CNPs in solution, uptake and translocation of nanoparticles by plants, on characterization of their physical and chemical properties in rhizosphere and on root surfaces. More studies on plants and algae, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. Correct and detailed physical and chemical characterization of CNMs is very important to establish the exposure conditions matching the realistic ones. Ecotoxicity experiments should include examinations of both short and long-term effects. One must take into account that real carbon nanomaterials are complex mixtures of carbon forms and metal residues of variable chemistry and particle size, and the toxicity reported may reflect these byproducts/residues/impurities rather than the primary material structure. One more recommendation is not only to focus on the inherent toxicity of nanoparticles, but also consider their possible interactions with existing environmental contaminants.

  14. Emission of bacteria and fungi in the air from wastewater treatment plants - a review.

    Science.gov (United States)

    Korzeniewska, Ewa

    2011-01-01

    An increase in global population, coupled with intensive development of industry and agriculture, has resulted in the generation and accumulation of large amounts of waste around the world. The spread of pathogenic microorganisms, endotoxins, odours and dust particles in the air is an inevitable consequence of waste production and waste management. Thus, the risk of infections associated with wastewater treatment plants (WWTPs) has become of a particular importance in recent decades. Sewage and unstable sludge contain various pathogens such as viruses, bacteria, and human and animal parasites. These microorganisms can be transmitted to the ambient air in wastewater droplets, which are generated during aeration or mechanical moving of the sewage. Bioaerosols generated during wastewater treatment may therefore pose a potential health hazard to workers of these plants or to habitants of their surroundings. The degree of human exposure to airborne bacteria, fungi, endotoxin and other allergens may vary significantly depending upon the type and the capacity of a plant, kind of the facilities, performed activities and meteorological conditions.

  15. Fungos endofíticos associados a plantas medicinais Endophytic fungi associated with medicinal plants

    Directory of Open Access Journals (Sweden)

    V Mussi-Dias

    2012-01-01

    properties, as well as the quality of the stored and commercialized product. Therefore, the aim of this study was to isolate and identify the endophytic flora from eleven randomly chosen medicinal species. Pure cultures were obtained from the fungi Phomopsis, Colletotrichum, Pestalotia, Trichoderma, Fusarium, Nigrospora and Glomerella endophytically occurring in Plectranthus barbatus, Vernonia condensata, Pfaffia paniculata, Foeniculum vulgare, Cymbopogon citratus, Cymbopogon nardus, Cordia curassavica, Maytenus ilicifolia, Punica granatum, Morus nigra and Bauhinia forficata. The plant species that presented the highest number of endophytic fungi were Vernonia condensata, Punica granatum and Morus nigra. All fungi recovered in this study showed strictly endophytic features, not manifesting pathogenicity in their host species. Among the detected fungi, special attention must be given to the genus Fusarium, since a wide range of species of this genus are known to produce mycotoxins and constitute important post-harvest pathogens.

  16. Visual comparative omics of fungi for plant biomass deconstruction

    Directory of Open Access Journals (Sweden)

    Shingo Miyauchi

    2016-08-01

    Full Text Available Wood-decay fungi are able to decompose plant cell wall components such as cellulose, hemicelluloses and lignin. Such fungal capabilities may be exploited for the enhancement of directed enzymatic degradation of recalcitrant plant biomass. The comparative analysis of wood-decay fungi using a multi-omics approach gives not only new insights into the strategies for decomposing complex plant materials but also basic knowledge for the design of combinations of enzymes for biotechnological applications. We have developed an analytical workflow, Applied Biomass Conversion Design for Efficient Fungal Green Technology (ABCDEFGT, to simplify the analysis and interpretation of transcriptomic and secretomic data. The ABCDEFGT workflow is primarily constructed of self-organizing maps for grouping genes with similar transcription patterns and an overlay with secreted proteins. The ABCDEFGT workflow produces simple graphic outputs of genome-wide transcriptomes and secretomes. It enables visual inspection without a priori of the omics data, facilitating discoveries of co-regulated genes and proteins. Genome-wide omics landscapes were built with the newly sequenced fungal species Pycnoporus coccineus, Pycnoporus sanguineus, and Pycnoporus cinnabarinus grown on various carbon sources. Integration of the post-genomic data showed a global overlap, confirming the pertinence of the genome-wide approach to study the fungal biological responses to the carbon sources. Our method was compared to a recently-developed clustering method in order to assess the biological relevance of the method and ease of interpretation. Our approach provided a better biological representation of fungal behaviors. The genome-wide multi-omics strategy allowed us to determine the potential synergy of enzymes participating in the decomposition of cellulose, hemicellulose and lignin such as Lytic Polysaccharide Monooxygenases (LPMO, modular enzymes associated with a cellulose binding module

  17. In vitro antifungal activity of silver nanoparticles against ocular pathogenic filamentous fungi.

    Science.gov (United States)

    Xu, Yan; Gao, Chuanwen; Li, Xiaohua; He, Yi; Zhou, Lutan; Pang, Guangren; Sun, Shengtao

    2013-03-01

    Fungal keratitis is emerging as a major cause of vision loss in a developing country such as China because of higher incidence and the unavailability of effective antifungals. It is urgent to explore broad-spectrum antifungals to effectively suppress ocular fungal pathogens, and to develop new antifungal eye drops to combat this vision-threatening infection. The aim of this study is to investigate the antifungal activity of silver nanoparticles (nano-Ag) in comparison with that of natamycin against ocular pathogenic filamentous fungi in vitro. Susceptibility tests were performed against 216 strains of fungi isolated from patients with fungal keratitis from the Henan Eye Institute in China by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute M38-A document. The isolates included 112 Fusarium isolates (82 Fusarium solani species complex, 20 Fusarium verticillioides species complex, and 10 Fusarium oxysporum species complex), 94 Aspergillus isolates (61 Aspergillus flavus species complex, 11 Aspergillus fumigatus species complex, 12 Aspergillus versicolor species complex, and 10 Aspergillus niger species complex), and 10 Alternaria alternata isolates. The minimum inhibitory concentration (MIC) range and mode, the MIC for 50% of the strains tested (MIC50 value), and the MIC90 value were provided for the isolates with the SPSS statistical package. MIC50 value of nano-Ag were 1, 0.5, and 0.5 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC90 values of nano-Ag were 1, 1, and 1 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC50 values of natamycin were 4, 32, and 4 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC90 values of natamycin were 8, 32, and 4 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. Nano-Ag, relative to natamycin, exhibits potent in vitro activity against

  18. Evidence for transmission of aphid-pathogenic fungi by migratory flight of Myzus persicae alates

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The alates of the green peach aphid, Myzus persicae, were daily trapped from the air from late October through early January and carried to laboratory for determination of fungal infection by individually rearing them for 7 d on detached cabbage leaves in Petri dishes. Among 760 alates trapped, 266 (35%) were found carrying various fungal pathogens, 87.3% of them died due to mycosis during the first 3-day period of rearing and the rest died in the following two days. Most of the deaths of the alates were attributed to entomophthoralean fungi, taking 94.4%, and the rest were the hyphomycetous fungus Beauveria bassiana. Among the Entomophthorales-killed alates, P. neoaphidis took a proportion of 66.1%, Z. anhuiensis 22.6%, E. planchoniana 9.7%, and N. fresenii 1.6%, respectively. Two alates were found suffering from cross infection of two fungal species, i.e. P. neoaphidis with Z. anhuiensis and N. fresenii, respectively. The results represent the first report on transmission of aphid-pathogenic fungi by M. persicae alates through migratory flight.

  19. Histone deacetylases: revealing the molecular base of dimorphism in pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2015-11-01

    Full Text Available Fungi, as every living organism, interact with the external world and have to adapt to its fluctuations. For pathogenic fungi, such interaction involves adapting to the hostile environment of their host. Survival depends on the capacity of fungi to detect and respond to external stimuli, which is achieved through a tight and efficient genetic control. Chromatin modifications represent a well-known layer of regulation that controls gene expression in response to environmental signals. However, less is known about the chromatin modifications that are involved in fungal virulence and the specific cues and signalling pathways that target chromatin modifications to specific genes. In a recently published study, our research group identified one such regulatory pathway. We demonstrated that the histone deacetylase (HDAC Hos2 is involved in yeast-to-hyphal transition (dimorphism and it is associated with the virulence of the maize pathogen Ustilago maydis, the causative agent of smut disease in corn. Hos2 activates mating-type genes by directly binding to their gene bodies. Furthermore, Hos2 acts downstream of the nutrient-sensing cyclic AMP-Protein Kinase A pathway. We also found that another HDAC, Clr3, contributes to this regulation, possibly in cooperation with Hos2. As a whole, our data suggest that there is a direct link between changes in the environment and acetylation of nucleosomes within certain genes. We propose that histone acetylation is critical to the proper timing and induction of transcription of the genes encoding factors that coordinate changes in morphology with pathogenesis.

  20. A systems biology perspective on plant-microbe interactions: biochemical and structural targets of pathogen effectors.

    Science.gov (United States)

    Pritchard, Leighton; Birch, Paul

    2011-04-01

    Plants have biochemical defences against stresses from predators, parasites and pathogens. In this review we discuss the interaction of plant defences with microbial pathogens such as bacteria, fungi and oomycetes, and viruses. We examine principles of complex dynamic networks that allow identification of network components that are differentially and predictably sensitive to perturbation, thus making them likely effector targets. We relate these principles to recent developments in our understanding of known effector targets in plant-pathogen systems, and propose a systems-level framework for the interpretation and modelling of host-microbe interactions mediated by effectors. We describe this framework briefly, and conclude by discussing useful experimental approaches for populating this framework.

  1. The role of strigolactones during plant interactions with the pathogenic fungus Fusarium oxysporum.

    Science.gov (United States)

    Foo, Eloise; Blake, Sara N; Fisher, Brendan J; Smith, Jason A; Reid, James B

    2016-06-01

    Strigolactones (SLs) do not influence spore germination or hyphal growth of Fusarium oxysporum. Mutant studies revealed no role for SLs but a role for ethylene signalling in defence against this pathogen in pea. Strigolactones (SLs) play important roles both inside the plant as a hormone and outside the plant as a rhizosphere signal in interactions with mycorrhizal fungi and parasitic weeds. What is less well understood is any potential role SLs may play in interactions with disease causing microbes such as pathogenic fungi. In this paper we investigate the influence of SLs on the hemibiotrophic pathogen Fusarium oxysporum f.sp. pisi both directly via their effects on fungal growth and inside the plant through the use of a mutant deficient in SL. Given that various stereoisomers of synthetic and naturally occuring SLs can display different biological activities, we used (+)-GR24, (-)-GR24 and the naturally occurring SL, (+)-strigol, as well as a racemic mixture of 5-deoxystrigol. As a positive control, we examined the influence of a plant mutant with altered ethylene signalling, ein2, on disease development. We found no evidence that SLs influence spore germination or hyphal growth of Fusarium oxysporum and that, while ethylene signalling influences pea susceptibility to this pathogen, SLs do not.

  2. Horizontal transfer of a subtilisin gene from plants into an ancestor of the plant pathogenic fungal genus Colletotrichum.

    Directory of Open Access Journals (Sweden)

    Vinicio Danilo Armijos Jaramillo

    Full Text Available The genus Colletotrichum contains a large number of phytopathogenic fungi that produce enormous economic losses around the world. The effect of horizontal gene transfer (HGT has not been studied yet in these organisms. Inter-Kingdom HGT into fungal genomes has been reported in the past but knowledge about the HGT between plants and fungi is particularly limited. We describe a gene in the genome of several species of the genus Colletotrichum with a strong resemblance to subtilisins typically found in plant genomes. Subtilisins are an important group of serine proteases, widely distributed in all of the kingdoms of life. Our hypothesis is that the gene was acquired by Colletotrichum spp. through (HGT from plants to a Colletotrichum ancestor. We provide evidence to support this hypothesis in the form of phylogenetic analyses as well as a characterization of the similarity of the subtilisin at the primary, secondary and tertiary structural levels. The remarkable level of structural conservation of Colletotrichum plant-like subtilisin (CPLS with plant subtilisins and the differences with the rest of Colletotrichum subtilisins suggests the possibility of molecular mimicry. Our phylogenetic analysis indicates that the HGT event would have occurred approximately 150-155 million years ago, after the divergence of the Colletotrichum lineage from other fungi. Gene expression analysis shows that the gene is modulated during the infection of maize by C. graminicola suggesting that it has a role in plant disease. Furthermore, the upregulation of the CPLS coincides with the downregulation of several plant genes encoding subtilisins. Based on the known roles of subtilisins in plant pathogenic fungi and the gene expression pattern that we observed, we postulate that the CPLSs have an important role in plant infection.

  3. Horizontal transfer of a subtilisin gene from plants into an ancestor of the plant pathogenic fungal genus Colletotrichum.

    Science.gov (United States)

    Armijos Jaramillo, Vinicio Danilo; Vargas, Walter Alberto; Sukno, Serenella Ana; Thon, Michael R

    2013-01-01

    The genus Colletotrichum contains a large number of phytopathogenic fungi that produce enormous economic losses around the world. The effect of horizontal gene transfer (HGT) has not been studied yet in these organisms. Inter-Kingdom HGT into fungal genomes has been reported in the past but knowledge about the HGT between plants and fungi is particularly limited. We describe a gene in the genome of several species of the genus Colletotrichum with a strong resemblance to subtilisins typically found in plant genomes. Subtilisins are an important group of serine proteases, widely distributed in all of the kingdoms of life. Our hypothesis is that the gene was acquired by Colletotrichum spp. through (HGT) from plants to a Colletotrichum ancestor. We provide evidence to support this hypothesis in the form of phylogenetic analyses as well as a characterization of the similarity of the subtilisin at the primary, secondary and tertiary structural levels. The remarkable level of structural conservation of Colletotrichum plant-like subtilisin (CPLS) with plant subtilisins and the differences with the rest of Colletotrichum subtilisins suggests the possibility of molecular mimicry. Our phylogenetic analysis indicates that the HGT event would have occurred approximately 150-155 million years ago, after the divergence of the Colletotrichum lineage from other fungi. Gene expression analysis shows that the gene is modulated during the infection of maize by C. graminicola suggesting that it has a role in plant disease. Furthermore, the upregulation of the CPLS coincides with the downregulation of several plant genes encoding subtilisins. Based on the known roles of subtilisins in plant pathogenic fungi and the gene expression pattern that we observed, we postulate that the CPLSs have an important role in plant infection.

  4. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabian; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; Wit, Pierre J. G. M. de; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-02-29

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core) genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE)-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP) mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress.

  5. Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi.

    Directory of Open Access Journals (Sweden)

    Robin A Ohm

    Full Text Available The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemibiotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress.

  6. Taxonomic similarity, more than contact opportunity, explains novel plant-pathogen associations between native and alien taxa.

    Science.gov (United States)

    Bufford, Jennifer L; Hulme, Philip E; Sikes, Benjamin A; Cooper, Jerry A; Johnston, Peter R; Duncan, Richard P

    2016-11-01

    Novel associations between plants and pathogens can have serious impacts on managed and natural ecosystems world-wide. The introduction of alien plants increases the potential for biogeographically novel plant-pathogen associations to arise when pathogens are transmitted from native to alien plant species and vice versa. We quantified biogeographically novel associations recorded in New Zealand over the last 150 yr between plant pathogens (fungi, oomycetes and plasmodiophorids) and vascular plants. We examined the extent to which taxonomic similarity, pathogen traits, contact opportunity and sampling effort could explain the number of novel associates for host and pathogen species. Novel associations were common; approximately one-third of surveyed plants and pathogens were recorded with at least one biogeographically novel associate. Native plants had more alien pathogens than vice versa. Taxonomic similarity between the native and alien flora and the total number of recorded associations (a measure of sampling effort) best explained the number of novel associates among species. The frequency of novel associations and the importance of sampling effort as an explanatory variable emphasize the need for effective monitoring and risk assessment tools to mitigate the potential environmental and economic impact of novel pathogen associations.

  7. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms.

    Science.gov (United States)

    Mendes, Rodrigo; Garbeva, Paolina; Raaijmakers, Jos M

    2013-09-01

    Microbial communities play a pivotal role in the functioning of plants by influencing their physiology and development. While many members of the rhizosphere microbiome are beneficial to plant growth, also plant pathogenic microorganisms colonize the rhizosphere striving to break through the protective microbial shield and to overcome the innate plant defense mechanisms in order to cause disease. A third group of microorganisms that can be found in the rhizosphere are the true and opportunistic human pathogenic bacteria, which can be carried on or in plant tissue and may cause disease when introduced into debilitated humans. Although the importance of the rhizosphere microbiome for plant growth has been widely recognized, for the vast majority of rhizosphere microorganisms no knowledge exists. To enhance plant growth and health, it is essential to know which microorganism is present in the rhizosphere microbiome and what they are doing. Here, we review the main functions of rhizosphere microorganisms and how they impact on health and disease. We discuss the mechanisms involved in the multitrophic interactions and chemical dialogues that occur in the rhizosphere. Finally, we highlight several strategies to redirect or reshape the rhizosphere microbiome in favor of microorganisms that are beneficial to plant growth and health. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  8. Effect of arbuscular mycorrhizal (AM) fungi on 137Cs uptake by plants grown on different soils.

    Science.gov (United States)

    Vinichuk, M; Mårtensson, A; Ericsson, T; Rosén, K

    2013-01-01

    The potential use of mycorrhiza as a bioremediation agent for soils contaminated by radiocesium was evaluated in a greenhouse experiment. The uptake of (137)Cs by cucumber, perennial ryegrass, and sunflower after inoculation with a commercial arbuscular mycorrhizal (AM) product in soils contaminated with (137)Cs was investigated, with non-mycorrhizal quinoa included as a "reference" plant. The effect of cucumber and ryegrass inoculation with AM fungi on (137)Cs uptake was inconsistent. The effect of AM fungi was most pronounced in sunflower: both plant biomass and (137)Cs uptake increased on loamy sand and loamy soils. The total (137)Cs activity accumulated within AM host sunflower on loamy sand and loamy soils was 2.4 and 3.2-fold higher than in non-inoculated plants. Although the enhanced uptake of (137)Cs by quinoa plants on loamy soil inoculated by the AM fungi was observed, the infection of the fungi to the plants was not confirmed.

  9. Take advantage of mycorrhizal fungi for improved soil fertility and plant health

    Science.gov (United States)

    Arbuscular mycorrhizal [AM] fungi are naturally-occurring soil fungi that form a beneficial symbiosis with the roots of most crops. The plants benefit because the symbiosis increases mineral nutrient uptake, drought resistance, and disease resistance. These characteristics make utilization of AM f...

  10. Interactive effects of root endophytes and arbuscular mycorrhizal fungi on an experimental plant community.

    Science.gov (United States)

    Rillig, Matthias C; Wendt, Stefanie; Antonovics, Janis; Hempel, Stefan; Kohler, Josef; Wehner, Jeannine; Caruso, Tancredi

    2014-01-01

    Plant-soil microbial interactions have moved into focus as an important mechanism for understanding plant coexistence and composition of communities. Both arbuscular mycorrhizal (AM) as well as other root endophytic fungi co-occur in plant roots, and therefore have the potential to influence relative abundances of plant species in local assemblages. However, no study has experimentally examined how these key root endosymbiont groups might interact and affect plant community composition. Here, using an assemblage of five plant species in mesocosms in a fully factorial experiment, we added an assemblage of AM fungi and/or a mixture of root endophytic fungal isolates, all obtained from the same grassland field site. The results demonstrate that the AM fungi and root endophytes interact to affect plant community composition by changing relative species abundance, and consequently aboveground productivity. Our study highlights the need to explicitly consider interactions of root-inhabiting fungal groups in studies of plant assemblages.

  11. Biological Control of Aquatic Plants with Pathogenic Fungi

    Science.gov (United States)

    1981-01-01

    been found thus far in nature or under arti- ficial treatments of uredia- bearing leaves of waterhyacinth in labora- tory. In the absence of knowledge...of these bacteria on healthy hydrilla. D5 Table DI Description of Seven Isolated Bacteria Grown on NA Plates Isolate 1 White, gummy , some slime...6 White, very slow growth, myceloid 7 Pink, some slime, gummy , slow growth, myceloid Table D2 Visual Comparison of Hydrilla Sprigs Three Weeks After

  12. LIFEGUARD proteins support plant colonization by biotrophic powdery mildew fungi.

    Science.gov (United States)

    Weis, Corina; Hückelhoven, Ralph; Eichmann, Ruth

    2013-09-01

    Pathogenic microbes manipulate eukaryotic cells during invasion and target plant proteins to achieve host susceptibility. BAX INHIBITOR-1 (BI-1) is an endoplasmic reticulum-resident cell death suppressor in plants and animals and is required for full susceptibility of barley to the barley powdery mildew fungus Blumeria graminis f.sp. hordei. LIFEGUARD (LFG) proteins resemble BI-1 proteins in terms of predicted membrane topology and cell-death-inhibiting function in metazoans, but display clear sequence-specific distinctions. This work shows that barley (Hordeum vulgare L.) and Arabidopsis thaliana genomes harbour five LFG genes, HvLFGa-HvLFGe and AtLFG1-AtLFG5, whose functions are largely uncharacterized. As observed for HvBI-1, single-cell overexpression of HvLFGa supports penetration success of B. graminis f.sp. hordei into barley epidermal cells, while transient-induced gene silencing restricts it. In penetrated barley epidermal cells, a green fluorescent protein-tagged HvLFGa protein accumulates at the site of fungal entry, around fungal haustoria and in endosomal or vacuolar membranes. The data further suggest a role of LFG proteins in plant-powdery mildew interactions in both monocot and dicot plants, because stable overexpression or knockdown of AtLFG1 or AtLFG2 also support or delay development of the powdery mildew fungus Erysiphe cruciferarum on the respective Arabidopsis mutants. Together, this work has identified new modulators of plant-powdery mildew interactions, and the data further support functional similarities between BI-1 and LFG proteins beyond cell death regulation.

  13. Uncovering plant-pathogen crosstalk through apoplastic proteomic studies

    Directory of Open Access Journals (Sweden)

    Bertrand eDelaunois

    2014-06-01

    Full Text Available Plant pathogens have evolved by developing different strategies to infect their host, which in turn have elaborated immune responses to counter the pathogen invasion. The apoplast, including the cell wall and extracellular space outside the plasma membrane, is one of the first compartments where pathogen-host interaction occurs. The plant cell wall is composed of a complex network of polysaccharides polymers and glycoproteins and serves as a natural physical barrier against pathogen invasion. The apoplastic fluid, circulating through the cell wall and intercellular spaces, provides a means for delivering molecules and facilitating intercellular communications. Some plant-pathogen interactions lead to plant cell wall degradation allowing pathogens to penetrate into the cells. In turn, the plant immune system recognizes microbial- or damage-associated molecular patterns (MAMPs or DAMPs and initiates a set of basal immune responses, including the strengthening of the plant cell wall. The establishment of defense requires the regulation of a wide variety of proteins that are involved at different levels, from receptor perception of the pathogen via signaling mechanisms to the strengthening of the cell wall or degradation of the pathogen itself. A fine regulation of apoplastic proteins is therefore essential for rapid and effective pathogen perception and for maintaining cell wall integrity. This review aims to provide insight into analyses using proteomic approaches of the apoplast to highlight the modulation of the apoplastic protein patterns during pathogen infection and to unravel the key players involved in plant-pathogen interaction.

  14. Entomopathogenic fungi as biological controllers: New insights into their virulence and pathogenicity

    Directory of Open Access Journals (Sweden)

    Shahid Ali Ahmad

    2012-01-01

    Full Text Available Entomopathogenic fungi vary considerably in their mode of action and virulence. Successful infection depends primarily on the adherence and penetration ability of a fungus to the host integuments. A variety of extracellular enzymes is produced during the degradation of insect integument. The attempts to control insects have changed over time from chemicals to natural control methods. This is why the development of natural methods of insect control or biopesticides, is preferred. By the use of fungal entomopathogens, insect pests can be controlled. There is no doubt that insects have been used for many years, but their effective use in the field remains elusive. However, their additional role in nature has also been discovered. Comparison of entomopathogens with conventional chemical pesticides depends on their efficiency and cost. In addition to efficiency, there are advantages in using microbial control agents, such as human safety and other non-target organisms; pesticide residues are minimized in food and biodiversity increased in managed ecosystems. In the present review the pathogenicity and virulence of entomopathogenic fungi and their role as biological control agents using biotechnology will be discussed.

  15. Pathogenicity of endophytic entomopathogenic fungi to Ornithodoros erraticus and Ornithodoros moubata (Acari: Argasidae).

    Science.gov (United States)

    Zabalgogeazcoa, Iñigo; Oleaga, Ana; Pérez-Sánchez, Ricardo

    2008-12-20

    The argasid ticks O. erraticus and O. moubata are of great medical and veterinary importance because they are vectors of the African swine fever virus and several species of human relapsing fever borreliae. Biocontrol of these ticks using entomopathogenic fungi has not been previously reported. We examined the pathogenicity to different developmental stages of these two argasids of six strains of the fungal species Beauveria bassiana (strains Bb1764 and Bb2157), Lecanicillium lecanii (strains Ll586, Ll618 and Ll3047) and Tolypocladium cylindrosporum (strain Tc3398). Three strains, Bb1764, Bb2157, and Tc3398, caused in Spanish O. erraticus mean mortality rates between 34.4% and 62% in 14-28 days post-inoculation. Additionally, Bb2157 also induced in African O. moubata mean mortality rates of 31.9%. The remaining strains caused lower mortality rates and were not considered effective. This is the first study in which some strains of entomopathogenic fungi are found to be effective against argasid ticks of the genus Ornithodoros, and its results might justify further efforts towards the application of entomopathogenic fungal strains as anti-argasid biocontrol agents.

  16. Asymmetric total synthesis of 6-Tuliposide B and its biological activities against tulip pathogenic fungi.

    Science.gov (United States)

    Shigetomi, Kengo; Omoto, Shoko; Kato, Yasuo; Ubukata, Makoto

    2011-01-01

    The structure-activity relationship was investigated to evaluate the antifungal activities of tuliposides and tulipalins against tulip pathogenic fungi. 6-Tuliposide B was effectively synthesized via the asymmetric Baylis-Hillman reaction. Tuliposides and tulipalins showed antifungal activities against most of the strains tested at high concentrations (2.5 mM), while Botrytis tulipae was resistant to tuliposides. Tulipalin formation was involved in the antifungal activity, tulipalin A showed higher inhibitory activity than 6-tuliposide B and tulipalin B. Both the tuliposides and tulipalins showed pigment-inducing activity against Gibberella zeae and inhibitory activity against Fusarium oxysporum f. sp tulipae. These activities were induced at a much lower concentration (0.05 mM) than the antifungal MIC values.

  17. Biosynthesis of silver nanoparticles by the endophytic fungus Epicoccum nigrum and their activity against pathogenic fungi.

    Science.gov (United States)

    Qian, Yongqing; Yu, Huimei; He, Dan; Yang, Hui; Wang, Wanting; Wan, Xue; Wang, Li

    2013-11-01

    There is an enormous interest in developing safe, cost-effective and environmentally friendly technologies for nano-materials synthesis. In the present study, extracellular biosynthesis of silver nanoparticles was achieved by Epicoccum nigrum, an endophytic fungus isolated from the cambium of Phellodendron amurense. The reduction of the silver ions was monitored by UV-visible spectrophotometry, and the characterization of the Ag NPs was carried out by X-ray diffraction and transmission electron microscopy. The synthesized Ag NPs were exceptionally stable. It was found that an alkaline pH favored the formation of Ag NPs and elevated temperature accelerated the reduction process. Furthermore, the antifungal activity of the Ag NPs was assessed using a microdilution method. The biosynthesized Ag NPs showed considerable activity against the pathogenic fungi. The current research opens a new path for the green synthesis of Ag NPs and the process is easy to scale up for biomedical applications.

  18. Molecular and phenotypic characterization of anamorphic fungi

    OpenAIRE

    Madrid Lorca, Hugo

    2011-01-01

    Anamorphic fungi (those reproducing asexually) are a big part of kingdom Fungi. Most of them occur as saprobes in nature, but numerous species are pathogenic to plants and animals including man. With the aim of contributing to the knowledge of the diversity and distribution of anamorphic fungi, we performed a phenotypic and molecular characterization of environmental and clinical isolates of these fungi. Based on a polyphasic taxonomy approach which included morphology, physiology and DNA seq...

  19. Isolation and characterization of soil Streptomyces species as potential biological control agents against fungal plant pathogens.

    Science.gov (United States)

    Evangelista-Martínez, Zahaed

    2014-05-01

    The use of antagonist microorganisms against fungal plant pathogens is an attractive and ecologically alternative to the use of chemical pesticides. Streptomyces are beneficial soil bacteria and potential candidates for biocontrol agents. This study reports the isolation, characterization and antagonist activity of soil streptomycetes from the Los Petenes Biosphere Reserve, a Natural protected area in Campeche, Mexico. The results showed morphological, physiological and biochemical characterization of six actinomycetes and their inhibitory activity against Curvularia sp., Aspergillus niger, Helminthosporium sp. and Fusarium sp. One isolate, identified as Streptomyces sp. CACIS-1.16CA showed the potential to inhibit additional pathogens as Alternaria sp., Phytophthora capsici, Colletotrichum sp. and Rhizoctonia sp. with percentages ranging from 47 to 90 %. This study identified a streptomycete strain with a broad antagonist activity that could be used for biocontrol of plant pathogenic fungi.

  20. Plant Identity Exerts Stronger Effect than Fertilization on Soil Arbuscular Mycorrhizal Fungi in a Sown Pasture.

    Science.gov (United States)

    Zheng, Yong; Chen, Liang; Luo, Cai-Yun; Zhang, Zhen-Hua; Wang, Shi-Ping; Guo, Liang-Dong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

  1. Aromatic metabolism of filamentous fungi in relation to the presence of aromatic compounds in plant biomass.

    Science.gov (United States)

    Mäkelä, Miia R; Marinović, Mila; Nousiainen, Paula; Liwanag, April J M; Benoit, Isabelle; Sipilä, Jussi; Hatakka, Annele; de Vries, Ronald P; Hildén, Kristiina S

    2015-01-01

    The biological conversion of plant lignocellulose plays an essential role not only in carbon cycling in terrestrial ecosystems but also is an important part of the production of second generation biofuels and biochemicals. The presence of the recalcitrant aromatic polymer lignin is one of the major obstacles in the biofuel/biochemical production process and therefore microbial degradation of lignin is receiving a great deal of attention. Fungi are the main degraders of plant biomass, and in particular the basidiomycete white rot fungi are of major importance in converting plant aromatics due to their ability to degrade lignin. However, the aromatic monomers that are released from lignin and other aromatic compounds of plant biomass are toxic for most fungi already at low levels, and therefore conversion of these compounds to less toxic metabolites is essential for fungi. Although the release of aromatic compounds from plant biomass by fungi has been studied extensively, relatively little attention has been given to the metabolic pathways that convert the resulting aromatic monomers. In this review we provide an overview of the aromatic components of plant biomass, and their release and conversion by fungi. Finally, we will summarize the applications of fungal systems related to plant aromatics. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Early planting and hand sorting effectively controls seed-borne fungi in farm-retained bean seed

    Directory of Open Access Journals (Sweden)

    Ernest Dube

    2014-11-01

    Full Text Available Home-saved bean (Phaseolus vulgaris L. seed can be hand-sorted to remove discoloured seed, thereby reducing the level of contamination by certain seed-borne fungi and improving seed germination. In this study, the effect of planting date on the infection and discolouration of bean seed by seed-borne fungi was investigated in order to improve the quality of hand-sorted, farm-retained bean seeds used by resource poor smallholder farmers. The germination quality and level of seed-borne fungi in hand-sorted first-generation bean seed harvested from an early-, mid- and late-summer season planted crop was therefore assessed. The highest percentage of discoloured seed (68% was obtained from the mid-summer season planting. Non-discoloured seed from early- and late-season plantings had significantly (p"less than"0.001 higher normal germination (82% and 77%, respectively than that from the mid-season planting date (58%. Irrespective of planting date, unsorted seed and discoloured seed had higher levels of infection by Fusarium spp. and Phaeoisariopsis spp. than the non-discoloured seed. Removal of discoloured seed by hand sorting eliminated Rhizoctonia spp. from all seed lots. Farmers can eliminate this pathogen by simply removing discoloured seed. Non-discoloured seed from the early-planted crop had the lowest level of infection by Fusarium spp. and Phaeoisariopsis spp. The results indicate that planting date is an important consideration in improving the quality of hand-sorted farm-retained bean seed.

  3. Diversity of leaf endophytic fungi in mangrove plants of Northeast Brazil

    National Research Council Canada - National Science Library

    Costa, Isabella P. M. Wanderley; Maia, Leonor Costa; Cavalcanti, Maria Auxiliadora

    2012-01-01

    With the aim of increasing the knowledge about endophytic fungi, a group of microorganisms with high biotechnological potential and a valuable source of useful metabolites, a survey in leaves of mangrove plants...

  4. Insights from the genome of the biotrophic fungal plant pathogen Ustilago maydis.

    Science.gov (United States)

    Kämper, Jörg; Kahmann, Regine; Bölker, Michael; Ma, Li-Jun; Brefort, Thomas; Saville, Barry J; Banuett, Flora; Kronstad, James W; Gold, Scott E; Müller, Olaf; Perlin, Michael H; Wösten, Han A B; de Vries, Ronald; Ruiz-Herrera, José; Reynaga-Peña, Cristina G; Snetselaar, Karen; McCann, Michael; Pérez-Martín, José; Feldbrügge, Michael; Basse, Christoph W; Steinberg, Gero; Ibeas, Jose I; Holloman, William; Guzman, Plinio; Farman, Mark; Stajich, Jason E; Sentandreu, Rafael; González-Prieto, Juan M; Kennell, John C; Molina, Lazaro; Schirawski, Jan; Mendoza-Mendoza, Artemio; Greilinger, Doris; Münch, Karin; Rössel, Nicole; Scherer, Mario; Vranes, Miroslav; Ladendorf, Oliver; Vincon, Volker; Fuchs, Uta; Sandrock, Björn; Meng, Shaowu; Ho, Eric C H; Cahill, Matt J; Boyce, Kylie J; Klose, Jana; Klosterman, Steven J; Deelstra, Heine J; Ortiz-Castellanos, Lucila; Li, Weixi; Sanchez-Alonso, Patricia; Schreier, Peter H; Häuser-Hahn, Isolde; Vaupel, Martin; Koopmann, Edda; Friedrich, Gabi; Voss, Hartmut; Schlüter, Thomas; Margolis, Jonathan; Platt, Darren; Swimmer, Candace; Gnirke, Andreas; Chen, Feng; Vysotskaia, Valentina; Mannhaupt, Gertrud; Güldener, Ulrich; Münsterkötter, Martin; Haase, Dirk; Oesterheld, Matthias; Mewes, Hans-Werner; Mauceli, Evan W; DeCaprio, David; Wade, Claire M; Butler, Jonathan; Young, Sarah; Jaffe, David B; Calvo, Sarah; Nusbaum, Chad; Galagan, James; Birren, Bruce W

    2006-11-02

    Ustilago maydis is a ubiquitous pathogen of maize and a well-established model organism for the study of plant-microbe interactions. This basidiomycete fungus does not use aggressive virulence strategies to kill its host. U. maydis belongs to the group of biotrophic parasites (the smuts) that depend on living tissue for proliferation and development. Here we report the genome sequence for a member of this economically important group of biotrophic fungi. The 20.5-million-base U. maydis genome assembly contains 6,902 predicted protein-encoding genes and lacks pathogenicity signatures found in the genomes of aggressive pathogenic fungi, for example a battery of cell-wall-degrading enzymes. However, we detected unexpected genomic features responsible for the pathogenicity of this organism. Specifically, we found 12 clusters of genes encoding small secreted proteins with unknown function. A significant fraction of these genes exists in small gene families. Expression analysis showed that most of the genes contained in these clusters are regulated together and induced in infected tissue. Deletion of individual clusters altered the virulence of U. maydis in five cases, ranging from a complete lack of symptoms to hypervirulence. Despite years of research into the mechanism of pathogenicity in U. maydis, no 'true' virulence factors had been previously identified. Thus, the discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi. Genomic analysis is, similarly, likely to open up new avenues for the discovery of virulence determinants in other pathogens.

  5. Horizontal acquisition of toxic alkaloid synthesis in a clade of plant associated fungi.

    Science.gov (United States)

    Marcet-Houben, Marina; Gabaldón, Toni

    2016-01-01

    Clavicipitaceae is a fungal group that comprises species that closely interact with plants as pathogens, parasites or symbionts. A key factor in these interactions is the ability of these fungi to synthesize toxic alkaloid compounds that contribute to the protection of the plant host against herbivores. Some of these compounds such as ergot alkaloids are toxic to humans and have caused important epidemics throughout history. The gene clusters encoding the proteins responsible for the synthesis of ergot alkaloids and lolines in Clavicipitaceae have been elucidated. Notably, homologs to these gene clusters can be found in distantly related species such as Aspergillus fumigatus and Penicillium expansum, which diverged from Clavicipitaceae more than 400 million years ago. We here use a phylogenetic approach to analyze the evolution of these gene clusters. We found that the gene clusters conferring the ability to synthesize ergot alkaloids and loline emerged first in Eurotiomycetes and were then likely transferred horizontally to Clavicipitaceae. Horizontal gene transfer is known to play a role in shaping the distribution of secondary metabolism clusters across distantly related fungal species. We propose that HGT events have played an important role in the capability of Clavicipitaceae to produce two key secondary metabolites that have enhanced the ability of these species to protect their plant hosts, therefore favoring their interactions.

  6. Microscopic fungi on Nymphaeaceae plants of the Lake Płociczno in Drawa National Park (NW Poland

    Directory of Open Access Journals (Sweden)

    Kinga Mazurkiewicz-Zapałowicz

    2016-07-01

    Full Text Available The aim of this study was to determine the occurrence of micromycetes associated with disease symptoms on the leaves and flowers of three plant species, Nymphaea alba (NA, Nymphaea candida (NC, and Nuphar lutea (NL, forming nympheid phytocoenoses on Lake Płociczno in Drawa National Park during the years 2009 to 2012. From all collected plant specimens, an overall number of 38 distinct taxa of fungi and chromistan fungal analogues was isolated. The largest diversity of taxa was found on NL (37 taxa, the lowest was on NC (4 taxa, and NA contained 12 taxa. Each year, anamorphic forms of Ascomycota were dominant in the taxonomic structure. For the first time in Poland, Septoria nupharis (NA, NL, NC and Colletotrichum nymphaeae (NL, NC were found on their spotted leaves. For both of the mentioned pathogens, Nymphaea candida is a new host plant in Poland. Botrytis cinerea, Elongisporangium undulatum (= Pythium undulatum, Epicoccum nigrum, Fusarium incarnatum (= F. semitectum, and Gibberella avenacea (= Fusarium avenaceum were found each year in the studied phytocoenoses. The confirmation of NA and NL flower infections by Botrytis cinerea, which leads to gangrene, is an important aspect of the gray mold epidemiology. Until now, the occurrence of smut fungi on nympheids in Drawa National Park was not observed. The taxonomic structure and the predomination of asexual stages of fungi, as well as the similarity coefficients, suggest that the seasonal decomposition of nympheids run naturally and contribute to maintaining the stability of the lake ecosystem.

  7. Biosynthesis of UDP-4-keto-6-deoxyglucose and UDP-rhamnose in pathogenic fungi Magnaporthe grisea and Botryotinia fuckeliana

    National Research Council Canada - National Science Library

    Martinez, Viviana; Ingwers, Miles; Smith, James; Glushka, John; Yang, Ting; Bar-Peled, Maor

    2012-01-01

    .... Nevertheless, little is known about the pathways for the synthesis of these glycans. We show that rhamnose is present in glycans isolated from the rice pathogen Magnaporthe grisea and from the plant pathogen Botryotinia fuckeliana...

  8. Impact of selected antagonistic fungi on Fusarium species – toxigenic cereal pathogens

    Directory of Open Access Journals (Sweden)

    Delfina Popiel

    2013-12-01

    Full Text Available Fusarium-ear blight is a destructive disease in various cereal-growing regions and leads to significant yield and quality losses for farmers and to contamination of cereal grains with mycotoxins, mainly deoxynivalenol and derivatives, zearalenone and moniliformin. Fusarium pathogens grow well and produce significant inoculum on crop resiudues. Reduction of mycotoxins production and pathogen sporulation may be influenced by saprophytic fungi, exhibiting antagonistic effect. Dual culture bioassays were used to examine the impact of 92 isolates (belonging to 29 fungal species against three toxigenic species, i.e. Fusarium avenaceum (Corda Saccardo, F. culmorum (W.G.Smith Saccardo and F. graminearum Schwabe. Both F.culmorum and F. graminearum isolates produce trichothecene mycotoxins and mycohormone zearalenone and are considered to be the most important cereal pathogens worldwide. Infection with those pathogens leads to accumulation of mycotoxins: deoxynivalenol (DON and zearalenone (ZEA in grains. Fusarium avenaceum isolates are producers of moniliformin (MON and enniatins. Isolates of Trichoderma sp. were found to be the most effective ones to control the growth of examined Fusarium species. The response of Fusarium isolates to antagonistic activity of Trichoderma isolates varied and also the isolates of Trichoderma differed in their antagonistic activity against Fusarium isolates. The production of MON by two isolates of F. avenaceum in dual culture on rice was reduced by 95% to 100% by T. atroviride isolate AN 35. The same antagonist reduced the amount of moniliformin from 100 μg/g to 6.5 μg/g when inoculated to rice culture contaminated with MON, which suggests the possible decomposition of this mycotoxin.

  9. About the species composition of microscopic fungi in soils and woody plant roots in urban environment

    Directory of Open Access Journals (Sweden)

    Bukharina Irina,

    2016-11-01

    Full Text Available The living state and the presence of mycorrhizal fungi in the roots of woody plants in relation to the level of soil pollution in the urban environment have been studied. The DNA analysis of the roots and soil revealed that in a more severe pollution in the roots of woody plants in a good living state the DNA of end trophic mycorrhizal fungi was detected.

  10. Pathogenicity, Ovicidal Action, and Median Lethal Concentrations (LC50 of Entomopathogenic Fungi against Exotic Spiralling Whitefly, Aleurodicus dispersus Russell

    Directory of Open Access Journals (Sweden)

    Boopathi Thangavel

    2013-01-01

    Full Text Available Biological control using entomopathogenic fungi could be a promising alternative to chemical control. Entomopathogenic fungi, Beauveria bassiana (Balsamo Vuillemin, Metarhizium anisopliae (Metschnikoff Sorokin, Lecanicillium lecanii (Zimmerm. Zare and Gams, and Paecilomyces fumosoroseus (Wize Brown and Smith, were tested for their pathogenicity, ovicidal effect, and median lethal concentrations (LC50 against exotic spiralling whitefly, Aleurodicus dispersus Russell. The applications were made at the rate of 2 × 109 conidia mL−1 for evaluating the pathogenicity and ovicidal effect of entomopathogenic fungi against A. dispersus. The results of pathogenicity test showed that P. fumosoroseus (P1 strain was highly pathogenic to A. dispersus recording 100% mortality at 15 days after treatment (DAT. M. anisopliae (M2 strain had more ovicidal effect causing 37.3% egg mortality at 8 DAT. However, L. lecanii (L1 strain caused minimum egg hatchability (23.2% at 10 DAT as compared to control (92.6%. The lowest LC50 produced by P. fumosoroseus (P1 strain as 8.189 × 107 conidia mL−1 indicated higher virulence against A. dispersus. Hence, there is potential for use of entomopathogenic fungi in the field conditions as an alternate control method in combating the insect pests and other arthropod pests since they are considered natural mortality agents and are environmentally safe.

  11. Pathogenicity, Ovicidal Action, and Median Lethal Concentrations (LC 50 ) of Entomopathogenic Fungi against Exotic Spiralling Whitefly, Aleurodicus dispersus Russell.

    Science.gov (United States)

    Thangavel, Boopathi; Palaniappan, Karuppuchamy; Manickavasagam Pillai, Kalyanasundaram; Subbarayalu, Mohankumar; Madhaiyan, Ravi

    2013-01-01

    Biological control using entomopathogenic fungi could be a promising alternative to chemical control. Entomopathogenic fungi, Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae (Metschnikoff) Sorokin, Lecanicillium lecanii (Zimmerm.) Zare and Gams, and Paecilomyces fumosoroseus (Wize) Brown and Smith, were tested for their pathogenicity, ovicidal effect, and median lethal concentrations (LC50) against exotic spiralling whitefly, Aleurodicus dispersus Russell. The applications were made at the rate of 2 × 10(9) conidia mL(-1) for evaluating the pathogenicity and ovicidal effect of entomopathogenic fungi against A. dispersus. The results of pathogenicity test showed that P. fumosoroseus (P1 strain) was highly pathogenic to A. dispersus recording 100% mortality at 15 days after treatment (DAT). M. anisopliae (M2 strain) had more ovicidal effect causing 37.3% egg mortality at 8 DAT. However, L. lecanii (L1 strain) caused minimum egg hatchability (23.2%) at 10 DAT as compared to control (92.6%). The lowest LC50 produced by P. fumosoroseus (P1 strain) as 8.189 × 10(7) conidia mL(-1) indicated higher virulence against A. dispersus. Hence, there is potential for use of entomopathogenic fungi in the field conditions as an alternate control method in combating the insect pests and other arthropod pests since they are considered natural mortality agents and are environmentally safe.

  12. RIPEN FRUITS OF INDIAN GINSENG: PHYTO-CHEMICAL AND PHARMACOLOGICAL EXAMINATION AGAINST HUMAN AND PLANT PATHOGENS

    Directory of Open Access Journals (Sweden)

    Premlata Singariya

    2012-05-01

    Full Text Available The ripen fruit extracts of Withania somniferawere evaluated against medically importantbacteria viz.Proteusmerabilis, Klebsiella pnemoniae, Agerobacterium tumefaciens(plant pathogenandone fungi Aspergillus niger.The dried and powdered ripen fruits were successively extracted with a seriesof non polar to polar solvents using soxhlet assembly. The antimicrobial assay was done by both discdiffusion and broth dilution methods. Glacial acetic acid extract of W. somniferashow highest activityagainst A. tumefaciens(plant pathogen and water extract againstK. pnemoniaeto varying degrees in theterms of high inhibition zone and activity index. A. tumefacienswas the most susceptible organism incompare to the other organism. Gentamycin and Ketoconazole, the standard antibacterial and antifungalused was effective against the bacteria and fungi. The extract of W. somniferaalso significantly (P>0.005inhibited the bacterial and fungal growth. The inhibitory effect is very identical in magnitude andcomparable with that of standard antibiotics used.

  13. Global patterns of plant root colonization intensity by mycorrhizal fungi explained by climate and soil chemistry

    NARCIS (Netherlands)

    Soudzilovskaia, N.A.; Douma, J.C.; Akhmetzhanova, A.A.; Bodegom, van P.M.; Cornwell, W.K.; Moens, E.J.; Treseder, K.K.; Tibbett, M.; Wang, Y.P.; Cornelissen, J.H.C.

    2015-01-01

    Aim Most vascular plants on Earth form mycorrhizae, a symbiotic relationship between plants and fungi. Despite the broad recognition of the importance of mycorrhizae for global carbon and nutrient cycling, we do not know how soil and climate variables relate to the intensity of colonization of plant

  14. [Effect of flooding time length on mycorrhizal colonization of three AM fungi in two wetland plants].

    Science.gov (United States)

    Ma, Lei-Meng; Wang, Peng-Teng; Wang, Shu-Guang

    2014-01-01

    In order to provide information for elucidating effect of flooding on the formation and function of AM in wetland plants, three AM fungi (Glomus intraradices, Glomus versiforme, Glomus etunicatum) were used to investigate the effects of flooding time length on their colonization in cattail (Typha orientalis) and rice (Oryza sativa L. ). The results showed that the mycorrhizal colonization rate (MCR) presented downtrend with increasing flooding time length. In cattail, MCR of the fungus F3 was higher than those of fungi F1 and F2, but no significant difference in MCR was found between fungi F1 and F2. In rice, the MCRs of fungi F2 and F3 were higher than that of E1. In both plants, the proportional frequency of hyphae was the highest while the proportional frequency of arbuscules and vesicles was very low in all treatments, indicating that hyphal colonization was the main route for AM formation. The proportional frequency of hyphae in cattail increased with the flooding time length, but no significant trend was observed in rice plant. The proportional frequency of arhuscules decreased with the increase of flooding time, and was the highest in the treatment without flooding (treatment IV). The number of spores produced by AM fungi increased with increasing flooding time, and reached the highest in the treatment of long time flooding (treatment I). In the same treatment, the fungus F3 produced more spores than fungi F1 and F2. Changes in wet weight of the two plants showed that AM could increase cattail growth under flooding, hut little effect on rice growth was found. It is concluded that flooding time length significantly affected the mycorrhizal colonization rate and the proportional frequency of colonization. AM could enhance the growth of wetland plant, but this depends on the mycorrhizal dependence of host plant on AM fungi. Therefore, flooding time length should be considered in the inoculation of wetland plants with AM fungi.

  15. Sentinel trees as a tool to forecast invasions of alien plant pathogens.

    Directory of Open Access Journals (Sweden)

    AnnaMaria Vettraino

    Full Text Available Recent disease outbreaks caused by alien invasive pathogens into European forests posed a serious threat to forest sustainability with relevant environmental and economic effects. Many of the alien tree pathogens recently introduced into Europe were not previously included on any quarantine lists, thus they were not subject to phytosanitary inspections. The identification and description of alien fungi potentially pathogenic to native European flora before their introduction in Europe, is a paramount need in order to limit the risk of invasion and the impact to forest ecosystems. To determine the potential invasive fungi, a sentinel trees plot was established in Fuyang, China, using healthy seedlings of European tree species including Quercus petreae, Q. suber, and Q. ilex. The fungal assemblage associated with symptomatic specimens was studied using the tag-encoded 454 pyrosequencing of the nuclear ribosomal internal transcribed spacer-1 (ITS 1. Taxa with probable Asiatic origin were identified and included plant pathogenic genera. These results indicate that sentinel plants may be a strategic tool to improve the prevention of bioinvasions.

  16. Azole drugs are imported by facilitated diffusion in Candida albicans and other pathogenic fungi.

    Directory of Open Access Journals (Sweden)

    Bryce E Mansfield

    Full Text Available Despite the wealth of knowledge regarding the mechanisms of action and the mechanisms of resistance to azole antifungals, very little is known about how the azoles are imported into pathogenic fungal cells. Here the in-vitro accumulation and import of Fluconazole (FLC was examined in the pathogenic fungus, Candida albicans. In energized cells, FLC accumulation correlates inversely with expression of ATP-dependent efflux pumps. In de-energized cells, all strains accumulate FLC, suggesting that FLC import is not ATP-dependent. The kinetics of import in de-energized cells displays saturation kinetics with a K(m of 0.64 μM and V(max of 0.0056 pmol/min/10⁸ cells, demonstrating that FLC import proceeds via facilitated diffusion through a transporter rather than passive diffusion. Other azoles inhibit FLC import on a mole/mole basis, suggesting that all azoles utilize the same facilitated diffusion mechanism. An analysis of related compounds indicates that competition for azole import depends on an aromatic ring and an imidazole or triazole ring together in one molecule. Import of FLC by facilitated diffusion is observed in other fungi, including Cryptococcus neoformans, Saccharomyces cerevisiae, and Candida krusei, indicating that the mechanism of transport is conserved among fungal species. FLC import was shown to vary among Candida albicans resistant clinical isolates, suggesting that altered facilitated diffusion may be a previously uncharacterized mechanism of resistance to azole drugs.

  17. Azole drugs are imported by facilitated diffusion in Candida albicans and other pathogenic fungi.

    Science.gov (United States)

    Mansfield, Bryce E; Oltean, Hanna N; Oliver, Brian G; Hoot, Samantha J; Leyde, Sarah E; Hedstrom, Lizbeth; White, Theodore C

    2010-09-30

    Despite the wealth of knowledge regarding the mechanisms of action and the mechanisms of resistance to azole antifungals, very little is known about how the azoles are imported into pathogenic fungal cells. Here the in-vitro accumulation and import of Fluconazole (FLC) was examined in the pathogenic fungus, Candida albicans. In energized cells, FLC accumulation correlates inversely with expression of ATP-dependent efflux pumps. In de-energized cells, all strains accumulate FLC, suggesting that FLC import is not ATP-dependent. The kinetics of import in de-energized cells displays saturation kinetics with a K(m) of 0.64 μM and V(max) of 0.0056 pmol/min/10⁸ cells, demonstrating that FLC import proceeds via facilitated diffusion through a transporter rather than passive diffusion. Other azoles inhibit FLC import on a mole/mole basis, suggesting that all azoles utilize the same facilitated diffusion mechanism. An analysis of related compounds indicates that competition for azole import depends on an aromatic ring and an imidazole or triazole ring together in one molecule. Import of FLC by facilitated diffusion is observed in other fungi, including Cryptococcus neoformans, Saccharomyces cerevisiae, and Candida krusei, indicating that the mechanism of transport is conserved among fungal species. FLC import was shown to vary among Candida albicans resistant clinical isolates, suggesting that altered facilitated diffusion may be a previously uncharacterized mechanism of resistance to azole drugs.

  18. Phytotoxicity of pathogenic fungi and their mycotoxins to cereal seedling viability.

    Science.gov (United States)

    Hasan, H A

    2001-01-01

    Aspergillus flavus, Alternaria alternata and Fusarium oxysporum were found to be the pathogenic fungi mostly reducing cereal (barley, sorghum and wheat) seedlings. The pathogens have the ability to produce aflatoxin B1 and G1, diacetoxyscirpenol, kojic acid and tenuazonic acid that reduced seedling viability. The inhibition dose for 50% reduction (LD50) was recorded by aflatoxins at 0.83 mg L-1 for barley, 1.74 mg L-1 for wheat and 2.75 mg L-1 for sorghum. Diacetoxyscirpenol produced its inhibition at 1.26 mg L-1 for barley, 3.98 mg L-1 for wheat and 10 mg L-1 for sorghum. Kojic acid induced 50% inhibition at 63 mg L-1 for barley, 105 mg L-1 for wheat and 251 mg L-1 for sorghum. However, tenuazonic acid was less toxic where, the toxicity was ranged between 79-550 mg L-1. The inhibition in germination was more pronounced in barley followed by wheat and negligible in sorghum to all tested mycotoxins. This inhibition attributed to the reduction in seedling amylase activity. Amylase was also reduced in the same trend: barley > wheat > sorghum. Grain treatment with carboxin-captan and thiophanatemethyl-thiram at 1 g kg-1 grain increased seedlings vigour of wheat in sterilized soil by 45 and 22%, barley by 24 and 33% and sorghum by 15 and 30%, respectively. These fungicides have also a positive effect on cereal when soil was inoculated with A. flavus, A. alternata and F. oxysporum.

  19. Molecular Phylogeny, Diversity, and Bioprospecting of Endophytic Fungi Associated with wild Ethnomedicinal North American Plant Echinacea purpurea (Asteraceae).

    Science.gov (United States)

    Carvalho, Camila R; Wedge, David E; Cantrell, Charles L; Silva-Hughes, Alice F; Pan, Zhiqiang; Moraes, Rita M; Madoxx, Victor L; Rosa, Luiz H

    2016-07-01

    The endophytic fungal community associated with the ethnomedicinal plant Echinacea purpurea was investigated as well as its potential for providing antifungal compounds against plant pathogenic fungi. A total of 233 endophytic fungal isolates were obtained and classified into 42 different taxa of 16 genera, of which Alternaria alternata, Colletotrichum dematium, and Stagonosporopsis sp. 2 are the most frequent colonizers. The extracts of 29 endophytic fungi displayed activities against important phytopathogenic fungi. Eight antifungal extracts were selected for chemical analysis. Forty fatty acids were identified by gas chromatography-flame-ionization detection (GC-FID) analysis. The compounds (-)-5-methylmellein and (-)-(3R)-8-hydroxy-6-methoxy-3,5-dimethyl-3,4-dihydroisocoumarin were isolated from Biscogniauxia mediterraneaEPU38CA crude extract. (-)-5-Methylmellein showed weak activity against Phomopsis obscurans, P. viticola, and Fusarium oxysporum, and caused growth stimulation of C. fragariae, C. acutatum, C. gloeosporioides, and Botrytis cinerea. (-)-(3R)-8-Hydroxy-6-methoxy-3,5-dimethyl-3,4-dihydroisocoumarin appeared slightly more active in the microtiter environment than 5-methylmellein. Our results indicate that E. purpurea lives symbiotically with different endophytic fungi, which are able to produce bioactive fatty acids and aromatic compounds active against important phytopathogenic fungi. The detection of the different fatty acids and aromatic compounds produced by the endophytic community associated with wild E. purpurea suggests that it may have intrinsic mutualistic resistance against phytopathogen attacks in its natural environment.

  20. Potential for Combined Biocontrol Activity against Fungal Fish and Plant Pathogens by Bacterial Isolates from a Model Aquaponic System

    Directory of Open Access Journals (Sweden)

    Ivaylo Sirakov

    2016-11-01

    Full Text Available One of the main challenges in aquaponics is disease control. One possible solution for this is biological control with organisms exerting inhibitory effects on fish and plant pathogens. The aim of this study was to examine the potential of isolating microorganisms that exert an inhibitory effect on both plant and fish pathogens from an established aquaponic system. We obtained 924 isolates on selective King’s B agar and 101 isolates on MRS agar from different compartments of a model aquaponic system and tested them for antagonism against the plant pathogen Pythium ultimum and fish pathogen Saprolegnia parasitica. Overall, 42 isolates were able to inhibit both fungi. Although not yet tested in vivo, these findings open new options for the implementation of biological control of diseases in aquaponics, where plants and fish are cultivated in the same water recirculating system.

  1. Fungicidal activity of L-696, 474 and cytochalasin D from the ascomycete Daldinia concentrica against plant pathogenic fungi%从子囊菌炭球菌中分离的活性成分L-696,474和cytochalasin D对植物病原真菌的活性

    Institute of Scientific and Technical Information of China (English)

    罗都强; 唐宏亮; 杨小龙; 王飞; 刘吉开

    2007-01-01

    In the course of screening for novel naturally occurring fungicides from mushrooms in Yunnan Province, China, the ethanol extract of the fruiting bodies of Daldinia concentria was found to show antifungal activity against plant pathogenic fungi. The active compounds were isolated from the fruiting bodies of D. concentria by bioassay-guided of the fractionation of the extract and identified as L-696,474 and cytochalasin D by IR, 1H and 13C NMR and mass spectral analysis. Their antifungal activities were evaluated in vitro against 10 plant pathogenic fungi and in vivo against the plant disease of Erysiphe graminis. In vitro, R. solani and Sclerotinina sclerotiorum were the most sensitive to L-696, 474, and their mycelial growth inhibitions were 83.5% and 82.9% at 10 μg/mL, respectively. Rhizoctonia solani, Gaeumannomyces graminis, S. sclerotiorum, Fusicladium pyrnum, Gloeosporium fructigenum were the most sensitive to cytochalasin D, and their mycelial growth inhibitions were 83.6%, 82.4%, 81.9%, 80.5% and 79.7% at 10 μg/mL, respectively. Spore germination of G. fructigenum was almost completely inhibited by 200 μg/mL for L-696, 474 and cytochalasin D. In vivo, the curative effects of L-696,474 and cytochalasin D on E. graminis were 74.3% and 85.7% at 500 μg/mL, respectively, after 10 days. The preventive effects of L-696, 474 and cytochalasin D on E. graminis were 67.1% and 79.5 % at 500 μg/mL, respectively,after 10 days.%在我国云南省高等真菌中寻找新的天然农用抗真菌活性物质时,发现炭球菌子实体甲醇提取物具有较强的离体抗真菌活性.采用生物活性追踪和化学分离相结合的方法,从中分离得到2个具有较强农用抗真菌活性化合物,经红外、质谱、氢谱和碳谱确定其为L-696,474和cytochalasinD.在离体和活体条件下分别测定了L-696,474和cytochalasin D对10种植物病原菌的菌丝抑制率和2种植物病原菌的孢子萌发率,并评价了其对小麦白粉病的治疗

  2. Sugar catabolism in Aspergillus and other fungi related to the utilization of plant biomass.

    Science.gov (United States)

    Khosravi, Claire; Benocci, Tiziano; Battaglia, Evy; Benoit, Isabelle; de Vries, Ronald P

    2015-01-01

    Fungi are found in all natural and artificial biotopes and can use highly diverse carbon sources. They play a major role in the global carbon cycle by decomposing plant biomass and this biomass is the main carbon source for many fungi. Plant biomass is composed of cell wall polysaccharides (cellulose, hemicellulose, pectin) and lignin. To degrade cell wall polysaccharides to different monosaccharides, fungi produce a broad range of enzymes with a large variety in activities. Through a series of enzymatic reactions, sugar-specific and central metabolic pathways convert these monosaccharides into energy or metabolic precursors needed for the biosynthesis of biomolecules. This chapter describes the carbon catabolic pathways that are required to efficiently use plant biomass as a carbon source. It will give an overview of the known metabolic pathways in fungi, their interconnections, and the differences between fungal species.

  3. Molecular detection of plant pathogenic bacteria using polymerase chain reaction single-strand conformation polymorphism.

    Science.gov (United States)

    Srinivasa, Chandrashekar; Sharanaiah, Umesha; Shivamallu, Chandan

    2012-03-01

    The application of polymerase chain reaction (PCR) technology to molecular diagnostics holds great promise for the early identification of agriculturally important plant pathogens. Ralstonia solanacearum, Xanthomoans axonopodis pv. vesicatoria, and Xanthomonas oryzae pv. oryzae are phytopathogenic bacteria, which can infect vegetables, cause severe yield loss. PCR-single-strand conformation polymorphism (PCR-SSCP) is a simple and powerful technique for identifying sequence changes in amplified DNA. The technique of PCR-SSCP is being exploited so far, only to detect and diagnose human bacterial pathogens in addition to plant pathogenic fungi. Selective media and serology are the commonly used methods for the detection of plant pathogens in infected plant materials. In this study, we developed PCR-SSCP technique to identify phytopathogenic bacteria. The PCR product was denatured and separated on a non-denaturing polyacrylamide gel. SSCP banding patterns were detected by silver staining of nucleic acids. We tested over 56 isolates of R. solanacearum, 44 isolates of X. axonopodis pv. vesicatoria, and 20 isolates of X. oryzae pv. oryzae. With the use of universal primer 16S rRNA, we could discriminate such species at the genus and species levels. Species-specific patterns were obtained for bacteria R. solanacearum, X. axonopodis pv. vesicatoria, and X. oryzae pv. oryzae. The potential use of PCR-SSCP technique for the detection and diagnosis of phytobacterial pathogens is discussed in the present paper.

  4. Molecular detection of plant pathogenic bacteria using polymerase chain reaction single-strand conformation polymorphism

    Institute of Scientific and Technical Information of China (English)

    Chandrashekar Srinivasa; Umesha Sharanaiah; Chandan Shivamallu

    2012-01-01

    The application of polymerase chain reaction (PCR) technology to molecular diagnostics holds great promise for the early identification of agriculturally important plant pathogens.Ralstonia solanacearum,Xanthomoans axonopodis pv.vesicatoria,and Xanthomonas oryzae pv.oryzae are phytopathogenic bacteria,which can infect vegetables,cause severe yield loss.PCR-single-strand conformation polymorphism (PCR-SSCP) is a simple and powerful technique for identifying sequence changes in amplified DNA.The technique of PCR-SSCP is being exploited so far,only to detect and diagnose human bacterial pathogens in addition to plant pathogenic fungi.Selective media and serology are the commonly used methods for the detection of plant pathogens in infected plant materials.In this study,we developed PCR-SSCP technique to identify phytopathogenic bacteria.The PCR product was denatured and separated on a non-denaturing polyacrylamide gel.SSCP banding patterns were detected by silver staining of nucleic acids.We tested over 56 isolates of R. solanacearum,44 isolates of X. axonopodis pv.vesicatoria,and 20 isolates of X.oryzae pv.oryzae.With the use of universal primer 16S rRNA,we could discriminate such species at the genus and species levels.Speciesspecific patterns were obtained for bacteria R.solanacearum,X.axonopodis pv.vesicatoria,and X.oryzae pv.oryzae.The potential use of PCR-SSCP technique for the detection and diagnosis of phytobacterial pathogens is discussed in the present paper.

  5. Antifungal activity of plant extracts with potential to control plant pathogens in pineapple

    Institute of Scientific and Technical Information of China (English)

    Maria Diana Cerqueira Sales; Helber Barcellos Costa; Jose Aires Ventura; Debora Dummer Meira

    2016-01-01

    Objective: To evaluate the in vitro antifungal activity of extracts, resins, oils and mother tinctures from plants against the filamentous fungi Fusarium guttiforme (F. guttiforme) and Chalara paradoxa, and to evaluate the control of the pineapple fusariosis in situ using mother tinctures. Methods: The screening of the antifungal potential of 131 extract forms from 63 plant species was performed in vitro by using plate-hole method. To control pineapple fusar-iosis in situ, preventive and post-infection treatments were performed on detached pineapple leaves of cv. P´erola (susceptible). Results: The quantitative study indicated that among the 49 mother tincture samples analyzed, 46% were effective against F. guttiforme and 29% for the Chalara paradoxa. The natural plant extracts, mother tincture of Glycyrrhiza glabra (MTGG1), mother tincture of Myroxylon balsamum (MTBT2), mother tincture of Aloe vera (MTAV3), mother tincture of Allium sativum (MTAS4), resin of Protium heptaphyllum (RESAM5) and crude extracts of Rhizophora mangle (CEMV6), exhibited an antifungal activity against F. guttiforme. In the preventive treatment against pineapple fusariosis, MTAV3, MTAS4 and MTGG1 were statistically similar to the treatment with tebuconazol fungicide. The curative treatments with MTAV3, MTAS4, MTGG1 and MTBT2 presented similar activity to fungicide (P Conclusions: The findings of the present study concluded that mother tinctures can effectively control phytopathogens. The mother tincture extract of Myroxylon balsamum showed antifungal activity and was used here for the first time for inhibition of phyto-pathogenic fungi. This study paves the way for the development of bioactive natural products with phytosanitary applications, with the added benefits of an environmentally safe and economically viable product.

  6. Fresh perspectives on the roles of arbuscular mycorrhizal fungi in plant nutrition and growth.

    Science.gov (United States)

    Smith, Sally E; Smith, F Andrew

    2012-01-01

    Recent research on arbuscular mycorrhizas has demonstrated that AM fungi play a significant role in plant phosphorus (P) uptake, regardless of whether the plant responds positively to colonization in terms of growth or P content. Here we focus particularly on implications of this finding for consideration of the balance between organic carbon (C) use by the fungi and P delivery (i.e. the C-P trade between the symbionts). Positive growth responses to arbuscular mycorrhizal (AM) colonization are attributed frequently to increased P uptake via the fungus, which results in relief of P deficiency and increased growth. Zero AM responses, compared with non-mycorrhizal (NM) plants, have conventionally been attributed to failure of the fungi to deliver P to the plants. Negative responses, combined with excessive C use, have been attributed to this failure. The fungi were viewed as parasites. Demonstration that the AM pathway of P uptake operates in such plants indicates that direct P uptake by the roots is reduced and that the fungi are not parasites but mutualists because they deliver P as well as using C. We suggest that poor plant growth is the result of P deficiency because AM fungi lower the amount of P taken up directly by roots but the AM uptake of P does compensate for the reduction. The implications of interplay between direct root uptake and AM fungal uptake of P also include increased tolerance of AM plants to toxins such as arsenate and increased success when competing with NM plants. Finally we discuss the new information on C-P trade in the context of control of the symbiosis by the fungus or the plant, including new information (from NM plants) on sugar transport and on the role of sucrose in the signaling network involved in responses of plants to P deprivation.

  7. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the extracell

  8. Insights into Cross-Kingdom Plant Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Morgan W.B. Kirzinger

    2011-11-01

    Full Text Available Plant and human pathogens have evolved disease factors to successfully exploit their respective hosts. Phytopathogens utilize specific determinants that help to breach reinforced cell walls and manipulate plant physiology to facilitate the disease process, while human pathogens use determinants for exploiting mammalian physiology and overcoming highly developed adaptive immune responses. Emerging research, however, has highlighted the ability of seemingly dedicated human pathogens to cause plant disease, and specialized plant pathogens to cause human disease. Such microbes represent interesting systems for studying the evolution of cross-kingdom pathogenicity, and the benefits and tradeoffs of exploiting multiple hosts with drastically different morphologies and physiologies. This review will explore cross-kingdom pathogenicity, where plants and humans are common hosts. We illustrate that while cross-kingdom pathogenicity appears to be maintained, the directionality of host association (plant to human, or human to plant is difficult to determine. Cross-kingdom human pathogens, and their potential plant reservoirs, have important implications for the emergence of infectious diseases.

  9. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the

  10. The top 10 oomycete pathogens in molecular plant pathology

    Science.gov (United States)

    Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens that threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant pathogenic oomycete taxa based on scientific and economic importance. In total, ...

  11. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the extracell

  12. The Top 10 oomycete pathogens in molecular plant pathology

    NARCIS (Netherlands)

    Kamoun, Sophien; Furzer, Oliver; Jones, Jonathan D G; Judelson, Howard S; Ali, Gul Shad; Dalio, Ronaldo J D; Roy, Sanjoy Guha; Schena, Leonardo; Zambounis, Antonios; Panabières, Franck; Cahill, David; Ruocco, Michelina; Figueiredo, Andreia; Chen, Xiao-Ren; Hulvey, Jon; Stam, Remco; Lamour, Kurt; Gijzen, Mark; Tyler, Brett M; Grünwald, Niklaus J; Mukhtar, M Shahid; Tomé, Daniel F A; Tör, Mahmut; Van Den Ackerveken, Guido; McDowell, John; Daayf, Fouad; Fry, William E; Lindqvist-Kreuze, Hannele; Meijer, Harold J G; Petre, Benjamin; Ristaino, Jean; Yoshida, Kentaro; Birch, Paul R J; Govers, Francine

    2015-01-01

    Oomycetes form a deep lineage of eukaryotic organisms that includes a large number of plant pathogens which threaten natural and managed ecosystems. We undertook a survey to query the community for their ranking of plant-pathogenic oomycete species based on scientific and economic importance. In tot

  13. Plant-microbe interactions: Plant hormone production by phylloplane fungi. Research report

    Energy Technology Data Exchange (ETDEWEB)

    Tuomi, T.; Ilvesoksa, J.; Rosenqvist, H.

    1993-06-23

    The molds Botrytis cinerea, Cladosporium cladosporioides and the yeast Aureobasidium pullulans, isolated from the leaves of three short-rotation Salix clones, were found to produce indole-3-acetic acid (a growth promoter of plants). Abscisic acid (a growth inhibitor of plants) production was detected in B. cinerea. The contents of indole-3-acetic acid and abscisic acid in the leaves of the Salix clones and the amounts of fungal propagules in these leaves were also measured, in order to evaluate whether the amounts of plant growth regulators produced by the fungi would make a significant contribution to the hormonal quantities of the leaves. The content of abscisic acid, and to a lesser degree that of indole-3-acetic acid, showed a positive correlation with the frequency of infection by the hormone producing organisms. The amounts of hormone producing fungi on leaves that bore visible colonies were, however, not sufficiently high to support the argument that neither the fungal production of abscisic nor indole-3-acetic acid would to a significant degree contribute to the hormonal contents of the leaves of the Salix clones.

  14. The Venturia Apple Pathosystem: Pathogenicity Mechanisms and Plant Defense Responses

    Directory of Open Access Journals (Sweden)

    Gopaljee Jha

    2009-01-01

    Full Text Available Venturia inaequalis is the causal agent of apple scab, a devastating disease of apple. We outline several unique features of this pathogen which are useful for molecular genetics studies intended to understand plant-pathogen interactions. The pathogenicity mechanisms of the pathogen and overview of apple defense responses, monogenic and polygenic resistance, and their utilization in scab resistance breeding programs are also reviewed.

  15. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants.

    Science.gov (United States)

    Barak, Jeri D; Schroeder, Brenda K

    2012-01-01

    Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.

  16. Lutein, a Natural Carotenoid, Induces α-1,3-Glucan Accumulation on the Cell Wall Surface of Fungal Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Junnosuke Otaka

    2016-07-01

    Full Text Available α-1,3-Glucan, a component of the fungal cell wall, is a refractory polysaccharide for most plants. Previously, we showed that various fungal plant pathogens masked their cell wall surfaces with α-1,3-glucan to evade plant immunity. This surface accumulation of α-1,3-glucan was infection specific, suggesting that plant factors might induce its production in fungi. Through immunofluorescence observations of fungal cell walls, we found that carrot (Daucus carota extract induced the accumulation of α-1,3-glucan on germlings in Colletotrichum fioriniae, a polyphagous fungal pathogen that causes anthracnose disease in various dicot plants. Bioassay-guided fractionation of carrot leaf extract successfully identified two active substances that caused α-1,3-glucan accumulation in this fungus: lutein, a carotenoid widely distributed in plants, and stigmasterol, a plant-specific membrane component. Lutein, which had a greater effect on C. fioriniae, also induced α-1,3-glucan accumulation in other Colletotrichum species and in the phylogenetically distant rice pathogen Cochliobolus miyabeanus, but not in the rice pathogen Magnaporthe oryzae belonging to the same phylogenetic subclass as Colletotrichum. Our results suggested that fungal plant pathogens reorganize their cell wall components in response to specific plant-derived compounds, which these pathogens may encounter during infection.

  17. External lipid PI3P mediates entry of eukaryotic pathogen effectors into plant and animal host cells.

    Science.gov (United States)

    Kale, Shiv D; Gu, Biao; Capelluto, Daniel G S; Dou, Daolong; Feldman, Emily; Rumore, Amanda; Arredondo, Felipe D; Hanlon, Regina; Fudal, Isabelle; Rouxel, Thierry; Lawrence, Christopher B; Shan, Weixing; Tyler, Brett M

    2010-07-23

    Pathogens of plants and animals produce effector proteins that are transferred into the cytoplasm of host cells to suppress host defenses. One type of plant pathogens, oomycetes, produces effector proteins with N-terminal RXLR and dEER motifs that enable entry into host cells. We show here that effectors of another pathogen type, fungi, contain functional variants of the RXLR motif, and that the oomycete and fungal RXLR motifs enable binding to the phospholipid, phosphatidylinositol-3-phosphate (PI3P). We find that PI3P is abundant on the outer surface of plant cell plasma membranes and, furthermore, on some animal cells. All effectors could also enter human cells, suggesting that PI3P-mediated effector entry may be very widespread in plant, animal and human pathogenesis. Entry into both plant and animal cells involves lipid raft-mediated endocytosis. Blocking PI3P binding inhibited effector entry, suggesting new therapeutic avenues.

  18. Phylogenomic Analyses Indicate that Early Fungi Evolved Digesting Cell Walls of Algal Ancestors of Land Plants.

    Science.gov (United States)

    Chang, Ying; Wang, Sishuo; Sekimoto, Satoshi; Aerts, Andrea L; Choi, Cindy; Clum, Alicia; LaButti, Kurt M; Lindquist, Erika A; Yee Ngan, Chew; Ohm, Robin A; Salamov, Asaf A; Grigoriev, Igor V; Spatafora, Joseph W; Berbee, Mary L

    2015-05-14

    As decomposers, fungi are key players in recycling plant material in global carbon cycles. We hypothesized that genomes of early diverging fungi may have inherited pectinases from an ancestral species that had been able to extract nutrients from pectin-containing land plants and their algal allies (Streptophytes). We aimed to infer, based on pectinase gene expansions and on the organismal phylogeny, the geological timing of the plant-fungus association. We analyzed 40 fungal genomes, three of which, including Gonapodya prolifera, were sequenced for this study. In the organismal phylogeny from 136 housekeeping loci, Rozella diverged first from all other fungi. Gonapodya prolifera was included among the flagellated, predominantly aquatic fungal species in Chytridiomycota. Sister to Chytridiomycota were the predominantly terrestrial fungi including zygomycota I and zygomycota II, along with the ascomycetes and basidiomycetes that comprise Dikarya. The Gonapodya genome has 27 genes representing five of the seven classes of pectin-specific enzymes known from fungi. Most of these share a common ancestry with pectinases from Dikarya. Indicating functional and sequence similarity, Gonapodya, like many Dikarya, can use pectin as a carbon source for growth in pure culture. Shared pectinases of Dikarya and Gonapodya provide evidence that even ancient aquatic fungi had adapted to extract nutrients from the plants in the green lineage. This implies that 750 million years, the estimated maximum age of origin of the pectin-containing streptophytes represents a maximum age for the divergence of Chytridiomycota from the lineage including Dikarya.

  19. Bacterial pathogen phytosensing in transgenic tobacco and Arabidopsis plants.

    Science.gov (United States)

    Liu, Wusheng; Mazarei, Mitra; Rudis, Mary R; Fethe, Michael H; Peng, Yanhui; Millwood, Reginald J; Schoene, Gisele; Burris, Jason N; Stewart, C Neal

    2013-01-01

    Plants are subject to attack by a wide range of phytopathogens. Current pathogen detection methods and technologies are largely constrained to those occurring post-symptomatically. Recent efforts were made to generate plant sentinels (phytosensors) that can be used for sensing and reporting pathogen contamination in crops. Engineered phytosensors indicating the presence of plant pathogens as early-warning sentinels potentially have tremendous utility as wide-area detectors. We previously showed that synthetic promoters containing pathogen and/or defence signalling inducible cis-acting regulatory elements (RE) fused to a fluorescent protein (FP) reporter could detect phytopathogenic bacteria in a transient phytosensing system. Here, we further advanced this phytosensing system by developing stable transgenic tobacco and Arabidopsis plants containing candidate constructs. The inducibility of each synthetic promoter was examined in response to biotic (bacterial pathogens) or chemical (plant signal molecules salicylic acid, ethylene and methyl jasmonate) treatments using stably transgenic plants. The treated plants were visualized using epifluorescence microscopy and quantified using spectrofluorometry for FP synthesis upon induction. Time-course analyses of FP synthesis showed that both transgenic tobacco and Arabidopsis plants were capable to respond in predictable ways to pathogen and chemical treatments. These results provide insights into the potential applications of transgenic plants as phytosensors and the implementation of emerging technologies for monitoring plant disease outbreaks in agricultural fields.

  20. Polyglycine hydrolases secreted by Pleosporineae fungi that target the linker region of plant class IV chitinases.

    Science.gov (United States)

    Naumann, Todd A; Wicklow, Donald T; Price, Neil P J

    2014-06-01

    Cmps (chitinase-modifying proteins) are fungal proteases that truncate plant class IV chitinases by cleaving near their N-termini. We previously described Fv-cmp, a fungalysin protease that cleaves a conserved glycine-cysteine bond within the hevein domain. In the present paper we describe a new type of cmp, polyglycine hydrolases, as proteases that selectively cleave glycine-glycine peptide bonds within the polyglycine linker of plant class IV chitinases. Polyglycine hydrolases were purified from Cochliobolus carbonum (syn. Bipolaris zeicola; Bz-cmp) and Epicoccum sorghi (syn. Phoma sorghina; Es-cmp) and were shown to cleave three different maize class IV chitinase substrates. The proteolytic cleavage sites were assessed by SDS/PAGE and MALDI-TOF-MS and indicated the cleavage of multiple peptide bonds within the polyglycine linker regions. Site-directed mutagenesis was used to produce mutants of maize ChitB chitinase in which two serine residues in its linker were systematically modified to glycine. Serine to glycine changes in the ChitB linker resulted in higher susceptibility to truncation by Bz-cmp and altered substrate specificity for Bz-cmp and Es-cmp, such that different glycine-glycine peptide bonds were cleaved. Removal of the hevein domain led to loss of Es-cmp activity, indicating that interactions outside of the active site are important for recognition. Our findings demonstrate that plant class IV chitinases with polyglycine linkers are targeted for truncation by selective polyglycine hydrolases that are secreted by plant pathogenic fungi. This novel proteolysis of polyglycine motifs is previously unreported, but the specificity is similar to that of bacterial lysostaphin proteases, which cleave pentaglycine cross-links from peptidoglycan.

  1. Diverse Plant-Associated Pleosporalean Fungi from Saline Areas: Ecological Tolerance and Nitrogen-Status Dependent Effects on Plant Growth.

    Science.gov (United States)

    Qin, Yuan; Pan, Xueyu; Kubicek, Christian; Druzhinina, Irina; Chenthamara, Komal; Labbé, Jessy; Yuan, Zhilin

    2017-01-01

    Similar to mycorrhizal mutualists, the rhizospheric and endophytic fungi are also considered to act as active regulators of host fitness (e.g., nutrition and stress tolerance). Despite considerable work in selected model systems, it is generally poorly understood how plant-associated fungi are structured in habitats with extreme conditions and to what extent they contribute to improved plant performance. Here, we investigate the community composition of root and seed-associated fungi from six halophytes growing in saline areas of China, and found that the pleosporalean taxa (Ascomycota) were most frequently isolated across samples. A total of twenty-seven representative isolates were selected for construction of the phylogeny based on the multi-locus data (partial 18S rDNA, 28S rDNA, and transcription elongation factor 1-α), which classified them into seven families, one clade potentially representing a novel lineage. Fungal isolates were subjected to growth response assays by imposing temperature, pH, ionic and osmotic conditions. The fungi had a wide pH tolerance, while most isolates showed a variable degree of sensitivity to increasing concentration of either salt or sorbitol. Subsequent plant-fungal co-culture assays indicated that most isolates had only neutral or even adverse effects on plant growth in the presence of inorganic nitrogen. Interestingly, when provided with organic nitrogen sources the majority of the isolates enhanced plant growth especially aboveground biomass. Most of the fungi preferred organic nitrogen over its inorganic counterpart, suggesting that these fungi can readily mineralize organic nitrogen into inorganic nitrogen. Microscopy revealed that several isolates can successfully colonize roots and form melanized hyphae and/or microsclerotia-like structures within cortical cells suggesting a phylogenetic assignment as dark septate endophytes. This work provides a better understanding of the symbiotic relationship between plants and

  2. Induced mutation and somatic recombination as tools for genetic analysis and breeding of imperfect fungi.

    NARCIS (Netherlands)

    Bos, C.J.

    1986-01-01

    Many fungi which are important in Agriculture as plant pathogens or in Biotechnology as producers of organic acids, antibiotics or enzymes, are imperfect fungi. These fungi do not have a sexual stage, which implies that they lack a meiotic recombination mechanism.However, many imperfect fungi have e

  3. Isolation of endophytic fungi from Coscinium fenestratum- a red listed endangered medicinal plant

    Directory of Open Access Journals (Sweden)

    Santhosh Wilson Goveas

    2011-08-01

    Full Text Available Enumeration of the endophytic fungi from the red listed, critically endangered medicinal plant, Coscinium fenestratum was investigated for the first time. The ubiquitous presence of 41 endophytic fungi belonging to sixteen different taxa was identified from 195 samples of healthy leaves and stem using traditional morphological methods. The overall colonization rate of endophytes in both the leaf and the stem was found to be 21.02%.The stem showed low percentage frequency of colonization of the endophytic fungi when compared to leaf segments. Among the endophytic flora, Phomopsis jacquiniana was found to be the core-group fungus with a colonization frequency of 4.6%.

  4. Epigenetic regulation of development and pathogenesis in fungal plant pathogens.

    Science.gov (United States)

    Dubey, Akanksha; Jeon, Junhyun

    2017-08-01

    Evidently, epigenetics is at forefront in explaining the mechanisms underlying the success of human pathogens and in the identification of pathogen-induced modifications within host plants. However, there is a lack of studies highlighting the role of epigenetics in the modulation of the growth and pathogenicity of fungal plant pathogens. In this review, we attempt to highlight and discuss the role of epigenetics in the regulation of the growth and pathogenicity of fungal phytopathogens using Magnaporthe oryzae, a devastating fungal plant pathogen, as a model system. With the perspective of wide application in the understanding of the development, pathogenesis and control of other fungal pathogens, we attempt to provide a synthesized view of the epigenetic studies conducted on M. oryzae to date. First, we discuss the mechanisms of epigenetic modifications in M. oryzae and their impact on fungal development and pathogenicity. Second, we highlight the unexplored epigenetic mechanisms and areas of research that should be considered in the near future to construct a holistic view of epigenetic functioning in M. oryzae and other fungal plant pathogens. Importantly, the development of a complete understanding of the modulation of epigenetic regulation in fungal pathogens can help in the identification of target points to combat fungal pathogenesis. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  5. Monotropa uniflora plants of eastern Massachusetts form mycorrhizae with a diversity of russulacean fungi.

    Science.gov (United States)

    Yang, S; Pfister, D H

    2006-01-01

    Plant species in the subfamily Monotropoideae are mycoheterotrophs; they obtain fixed carbon from photosynthetic plants via a shared mycorrhizal network. Previous findings show mycoheterotrophic plants exhibit a high level of specificity to their mycorrhizal fungi. In this study we explore the association of mycorrhizal fungi and Monotropa uniflora (Monotropoideae: Ericaceae) in eastern North America. We collected M. uniflora roots and nearby basidiomycete sporocarps from four sites within a 100 km2 area in eastern Massachusetts. We analyzed DNA sequences of the internal transcribed spacer region (ITS) from the fungal nuclear ribosomal gene to assess the genetic diversity of fungi associating with M. uniflora roots. In this analysis we included 20 ITS sequences from Russula sporocarps collected nearby, 44 sequences of Russula or Lactarius species from GenBank and 12 GenBank sequences of fungi isolated from M. uniflora roots in previous studies. We found that all 56 sampled M. uniflora mycorrhizal fungi were members of the Russulaceae, confirming previous research. The analysis showed that most of the diversity of mycorrhizal fungi spreads across the genus Russula. ITS sequences of the mycorrhizal fungi consisted of 20 different phylotypes: 18 of the genus Russula and two of Lactarius, based on GenBank searches. Of the sampled plants, 57% associated with only three of the 20 mycorrhizal fungi detected in roots, and of the 25 sporocarp phylotypes collected three, were associated with M. uniflora. Furthermore the results indicate that the number of different fungal phylotypes associating with M. uniflora of eastern North America is higher than that of western North America but patterns of fungal species abundance might be similar between mycorrhizae from the two locations.

  6. Saprobe fungi decreased the sensitivity to the toxic effect of dry olive mill residue on arbuscular mycorrhizal plants.

    Science.gov (United States)

    Sampedro, I; Aranda, E; Díaz, R; García-Sanchez, M; Ocampo, J A; García-Romera, I

    2008-02-01

    We studied the influence of olive mill dry residue (DOR) treated with saprobe fungi on growth of tomato and alfalfa colonized by Glomus deserticola. The application of 25g kg(-1) of dry DOR to soil decreased the shoot and root dry weight of tomato and alfalfa. Plants were more sensitive to the toxicity of DOR when colonized with the arbuscular mycorrhizal (AM) fungi. The sensitivity of both plants to the toxicity of DOR differed according to whether they were colonized by G. deserticola or by indigenous AM fungi. The phytotoxicity of DOR towards tomato and alfalfa was decreased by incubation the residue before planting with saprobe fungi for 20wk. The beneficial effects of AM fungi on plant growth added with DOR incubated with saprobe fungi depend of the type of the plant and AM fungi. The contribution of AM fungi to the beneficial effect of DOR incubated with saprobe fungi varied according to the type of the plant and AM fungi. G. deserticola increased the shoot and root dry weight of plants when they were grown in the presence of DOR incubated with saprobe fungi for 20wk. The beneficial effect of saprobe fungi on the dry weight and the level of AM mycorrhization of plants seem to be related to the decrease caused by these fungi in the phenol concentration in DOR. However, the toxicity of DOR due to substances other than phenols can not be ignored. The use of certain saprobe and AM fungi allows the possibility of using DOR as an organic fertilizer.

  7. Effects of Mycorrhizal Fungi on Rooting of Stem Cuttings and In Vitro Shoots of Woody Plants

    Science.gov (United States)

    Plants with roots colonized by mycorrhizal fungi are potentially more effective at nutrient and water acquisition, less susceptible to disease, and can be more productive under certain stressful environmental growing conditions than plants without mycorrhizae. Although a great deal of research has b...

  8. Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups...

  9. Evaluation of fungicides enestroburin and SYP1620 on their inhibitory activities to fungi and oomycetes and systemic translocation in plants.

    Science.gov (United States)

    Liu, Pengfei; Wang, Haiqiang; Zhou, Yuxin; Meng, Qingxiao; Si, Naiguo; Hao, Jianjun J; Liu, Xili

    2014-06-01

    Enestroburin and SYP1620 are newly developed strobilurin chemicals carrying fungicidal activity and need to be fully characterized in activities of anti-oomycete or anti-fungi, disease prevention and systemic translocation in planta. Their inhibitory activities were examined by amending the chemical in agar media, on which selected plant pathogens were grown and mycelial growth were measured. Effective concentrations for 50% inhibition (EC50) of mycelial growth were calculated to determine the level of fungicide sensitivity of the pathogen. Azoxystrobin was used as control. To examine the prevention and systemic translocation in plants, the fungicides were either sprayed on wheat leaves or dipped on wheat roots, which then were detected using high performance liquid chromatography. All the three fungicides inhibited mycelial growth of Sphacelotheca reiliana, Phytophthora infestans, Peronophythora litchi, and Magnaporthe oryzae, with EC50 values ranging from 0.02 to 2.84μg/ml; EC50 of SYP1620 was significantly lower than that of azoxystrobin and enestroburin on Valsa mali, Gaeumannomyces graminis, Alternaria solani, and Colletotrichun orbiculare. The three QoI fungicides showed strong inhibitory activities on spore germination against the 13 pathogens tested and were highly effective on biotrophic pathogens tested. Enestroburin and SYP1620 penetrated and spread in wheat leaves, but the penetration and translocation levels were lower compared to azoxystrobin. The three fungicides were all rapidly taken up by wheat roots and transported upwards, with greater fungicide concentrations in roots than in stems and leaves. The results indicate that enestroburin and SYP1620 are systemic fungicides that inhibit a broad spectrum of fungi and oomycetes.

  10. Phylogenomic Analyses Indicate that Early Fungi Evolved Digesting Cell Walls of Algal Ancestors of Land Plants

    Science.gov (United States)

    Chang, Ying; Wang, Sishuo; Sekimoto, Satoshi; Aerts, Andrea L.; Choi, Cindy; Clum, Alicia; LaButti, Kurt M.; Lindquist, Erika A.; Yee Ngan, Chew; Ohm, Robin A.; Salamov, Asaf A.; Grigoriev, Igor V.; Spatafora, Joseph W.; Berbee, Mary L.

    2015-01-01

    As decomposers, fungi are key players in recycling plant material in global carbon cycles. We hypothesized that genomes of early diverging fungi may have inherited pectinases from an ancestral species that had been able to extract nutrients from pectin-containing land plants and their algal allies (Streptophytes). We aimed to infer, based on pectinase gene expansions and on the organismal phylogeny, the geological timing of the plant–fungus association. We analyzed 40 fungal genomes, three of which, including Gonapodya prolifera, were sequenced for this study. In the organismal phylogeny from 136 housekeeping loci, Rozella diverged first from all other fungi. Gonapodya prolifera was included among the flagellated, predominantly aquatic fungal species in Chytridiomycota. Sister to Chytridiomycota were the predominantly terrestrial fungi including zygomycota I and zygomycota II, along with the ascomycetes and basidiomycetes that comprise Dikarya. The Gonapodya genome has 27 genes representing five of the seven classes of pectin-specific enzymes known from fungi. Most of these share a common ancestry with pectinases from Dikarya. Indicating functional and sequence similarity, Gonapodya, like many Dikarya, can use pectin as a carbon source for growth in pure culture. Shared pectinases of Dikarya and Gonapodya provide evidence that even ancient aquatic fungi had adapted to extract nutrients from the plants in the green lineage. This implies that 750 million years, the estimated maximum age of origin of the pectin-containing streptophytes represents a maximum age for the divergence of Chytridiomycota from the lineage including Dikarya. PMID:25977457

  11. Relationship between plant hormone level excreted by ectomycorrhizal fungi and growth of poplar NL-895

    Institute of Scientific and Technical Information of China (English)

    Lei MA; Xiaoqin WU; Ling ZHENG

    2009-01-01

    To explore the effects of plant hormones levels excreted by ectomycorrhizal (ECM) fungi on the growth of poplars, Populus x euramericana cv. NL-895 seedlings were inoculated with nine species of ECM fungi. We investigated the status of ectomycorrhizal formation and the effects of these fungi on poplar growth, and using the HPLC method, we measured the contents of four kinds of plant hormones, indole acetic acid (IAA), zeatin (Z), gibberellin (GA) and abscisic acid (ABA) in both the culture filtrate and the mycelium of these fungi. The results showed that the effects of nine ECM fungi on the growth of poplar NL-895 varied. The inoculated seedlings, whether or not obvious mycorrhizas were developed, grew better than those non-inoculated ones. All nine ectomycorrhizal fungi excreted the four plant hormones, but at different levels. The hormone contents in culture filtrate were higher than that in mycelium, which showed a definite relationship with poplar growth. Significantly, correlation analysis suggested the height and stem diameter of the poplar were positively correlated with zeatin contents in the mycelium, and were negatively correlated with the levels of ABA or IAA in the mycelium.

  12. Agent-based modeling approach of immune defense against spores of opportunistic human pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Christian eTokarski

    2012-04-01

    Full Text Available Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a majorthreat to immunocompromised patients. An impaired immune system renders the body vulnerable to inva-sive mycoses that often lead to the death of the patient. While the number of immunocompromised patientsis rising with medical progress, the process and dynamics of defence against invaded and ready to germinatefungal conidia are still insufficiently understood.Besides macrophages, neutrophil granulocytes form an important line of defence in that they clear conidia.Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, drag-ging and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modelingapproach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regard-ing their clearing efficiency: random walk, short term persistence in their recent direction, chemotaxis ofchemokines excreted by conidia and communication between phagocytes.

  13. An efficient method for DNA extraction from Cladosporioid fungi

    NARCIS (Netherlands)

    Moslem, M.A.; Bahkali, A.H.; Abd-Elsalam, K.A.; Wit, de P.J.G.M.

    2010-01-01

    We developed an efficient method for DNA extraction from Cladosporioid fungi, which are important fungal plant pathogens. The cell wall of Cladosporioid fungi is often melanized, which makes it difficult to extract DNA from their cells. In order to overcome this we grew these fungi for three days on

  14. An efficient method for DNA extraction from Cladosporioid fungi

    NARCIS (Netherlands)

    Moslem, M.A.; Bahkali, A.H.; Abd-Elsalam, K.A.; Wit, de P.J.G.M.

    2010-01-01

    We developed an efficient method for DNA extraction from Cladosporioid fungi, which are important fungal plant pathogens. The cell wall of Cladosporioid fungi is often melanized, which makes it difficult to extract DNA from their cells. In order to overcome this we grew these fungi for three days on

  15. Silencing and Innate Immunity in Plant Defense Against Viral and Non-Viral Pathogens

    Directory of Open Access Journals (Sweden)

    Anna S. Zvereva

    2012-10-01

    Full Text Available The frontline of plant defense against non-viral pathogens such as bacteria, fungi and oomycetes is provided by transmembrane pattern recognition receptors that detect conserved pathogen-associated molecular patterns (PAMPs, leading to pattern-triggered immunity (PTI. To counteract this innate defense, pathogens deploy effector proteins with a primary function to suppress PTI. In specific cases, plants have evolved intracellular resistance (R proteins detecting isolate-specific pathogen effectors, leading to effector-triggered immunity (ETI, an amplified version of PTI, often associated with hypersensitive response (HR and programmed cell death (PCD. In the case of plant viruses, no conserved PAMP was identified so far and the primary plant defense is thought to be based mainly on RNA silencing, an evolutionary conserved, sequence-specific mechanism that regulates gene expression and chromatin states and represses invasive nucleic acids such as transposons. Endogenous silencing pathways generate 21-24 nt small (sRNAs, miRNAs and short interfering (siRNAs, that repress genes post-transcriptionally and/or transcriptionally. Four distinct Dicer-like (DCL proteins, which normally produce endogenous miRNAs and siRNAs, all contribute to the biogenesis of viral siRNAs in infected plants. Growing evidence indicates that RNA silencing also contributes to plant defense against non-viral pathogens. Conversely, PTI-based innate responses may contribute to antiviral defense. Intracellular R proteins of the same NB-LRR family are able to recognize both non-viral effectors and avirulence (Avr proteins of RNA viruses, and, as a result, trigger HR and PCD in virus-resistant hosts. In some cases, viral Avr proteins also function as silencing suppressors. We hypothesize that RNA silencing and innate immunity (PTI and ETI function in concert to fight plant viruses. Viruses counteract this dual defense by effectors that suppress both PTI-/ETI-based innate responses

  16. Microorganism and filamentous fungi drive evolution of plant synapses.

    Science.gov (United States)

    Baluška, František; Mancuso, Stefano

    2013-01-01

    In the course of plant evolution, there is an obvious trend toward an increased complexity of plant bodies, as well as an increased sophistication of plant behavior and communication. Phenotypic plasticity of plants is based on the polar auxin transport machinery that is directly linked with plant sensory systems impinging on plant behavior and adaptive responses. Similar to the emergence and evolution of eukaryotic cells, evolution of land plants was also shaped and driven by infective and symbiotic microorganisms. These microorganisms are the driving force behind the evolution of plant synapses and other neuronal aspects of higher plants; this is especially pronounced in the root apices. Plant synapses allow synaptic cell-cell communication and coordination in plants, as well as sensory-motor integration in root apices searching for water and mineral nutrition. These neuronal aspects of higher plants are closely linked with their unique ability to adapt to environmental changes.

  17. Effect of biosolids-derived triclosan and triclocarban on the colonization of plant roots by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Prosser, R S; Lissemore, L; Shahmohamadloo, R S; Sibley, P K

    2015-03-01

    Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with the majority of crop plants. AMF provide plants with nutrients (e.g., P), modulate the effect of metal and pathogen exposure, and increase tolerance to moisture stress. The benefits of AMF to plant growth make them important to the development of sustainable agriculture. The land application of biosolids is becoming an increasingly common practice in sustainable agriculture, as a source of nutrients. However, biosolids have been found to contain numerous pharmaceutical and personal care products including antimicrobial chemicals such as triclosan and triclocarban. The potential risks that these two compounds may pose to plant-AMF interactions are poorly understood. The current study investigated whether biosolids-derived triclosan and triclocarban affect the colonization of the roots of lettuce and corn plants by AMF. Plants were grown in soil amended with biosolids that contained increasing concentrations of triclosan (0 to 307 μg/g dw) or triclocarban (0 to 304 μg/g dw). A relationship between the concentration of triclosan or triclocarban and colonization of plants roots by AMF was not observed. The presence of biosolids did not have a significant (p>0.05) effect on percent colonization of corn roots but had a significant, positive effect (ptriclosan and triclocarban did not inhibit the colonization of crop plant roots by AMF.

  18. Chromatin versus pathogens: the function of epigenetics in plant immunity

    Directory of Open Access Journals (Sweden)

    Bo eDing

    2015-09-01

    Full Text Available To defend against pathogens, plants have developed a sophisticated innate immunity that includes effector recognition, signal transduction, and rapid defense responses. Recent evidence has demonstrated that plants utilize the epigenetic control of gene expression to fine-tune their defense when challenged by pathogens. In this review, we highlight the current understanding of the molecular mechanisms of histone modifications (i.e., methylation, acetylation, and ubiquitination and chromatin remodeling that contribute to plant immunity against pathogens. Functions of key histone-modifying and chromatin remodeling enzymes are discussed.

  19. In Vitro Morphogenesis of Arabidopsis to Search for Novel Endophytic Fungi Modulating Plant Growth.

    Science.gov (United States)

    Dovana, Francesco; Mucciarelli, Marco; Mascarello, Maurizio; Fusconi, Anna

    2015-01-01

    Fungal endophytes have shown to affect plant growth and to confer stress tolerance to the host; however, effects of endophytes isolated from water plants have been poorly investigated. In this study, fungi isolated from stems (stem-E) and roots (root-E) of Mentha aquatica L. (water mint) were identified, and their morphogenetic properties analysed on in vitro cultured Arabidopsis (L.) Heynh., 14 and 21 days after inoculation (DAI). Nineteen fungi were analysed and, based on ITS analysis, 17 isolates showed to be genetically distinct. The overall effect of water mint endophytes on Arabidopsis fresh (FW) and dry weight (DW) was neutral and positive, respectively, and the increased DW, mainly occurring 14 DAI, was possibly related to plant defence mechanism. Only three fungi increased both FW and DW of Arabidopsis at 14 and 21 DAI, thus behaving as plant growth promoting (PGP) fungi. E-treatment caused a reduction of root depth and primary root length in most cases and inhibition-to-promotion of root area and lateral root length, from 14 DAI. Only Phoma macrostoma, among the water mint PGP fungi, increased both root area and depth, 21 DAI. Root depth and area 14 DAI were shown to influence DWs, indicating that the extension of the root system, and thus nutrient uptake, was an important determinant of plant dry biomass. Reduction of Arabidopsis root depth occurred to a great extent when plants where treated with stem-E while root area decreased or increased under the effects of stem-E and root-E, respectively, pointing to an influence of the endophyte origin on root extension. M. aquatica and many other perennial hydrophytes have growing worldwide application in water pollution remediation. The present study provided a model for directed screening of endophytes able to modulate plant growth in the perspective of future field applications of these fungi.

  20. In Vitro Morphogenesis of Arabidopsis to Search for Novel Endophytic Fungi Modulating Plant Growth.

    Directory of Open Access Journals (Sweden)

    Francesco Dovana

    Full Text Available Fungal endophytes have shown to affect plant growth and to confer stress tolerance to the host; however, effects of endophytes isolated from water plants have been poorly investigated. In this study, fungi isolated from stems (stem-E and roots (root-E of Mentha aquatica L. (water mint were identified, and their morphogenetic properties analysed on in vitro cultured Arabidopsis (L. Heynh., 14 and 21 days after inoculation (DAI. Nineteen fungi were analysed and, based on ITS analysis, 17 isolates showed to be genetically distinct. The overall effect of water mint endophytes on Arabidopsis fresh (FW and dry weight (DW was neutral and positive, respectively, and the increased DW, mainly occurring 14 DAI, was possibly related to plant defence mechanism. Only three fungi increased both FW and DW of Arabidopsis at 14 and 21 DAI, thus behaving as plant growth promoting (PGP fungi. E-treatment caused a reduction of root depth and primary root length in most cases and inhibition-to-promotion of root area and lateral root length, from 14 DAI. Only Phoma macrostoma, among the water mint PGP fungi, increased both root area and depth, 21 DAI. Root depth and area 14 DAI were shown to influence DWs, indicating that the extension of the root system, and thus nutrient uptake, was an important determinant of plant dry biomass. Reduction of Arabidopsis root depth occurred to a great extent when plants where treated with stem-E while root area decreased or increased under the effects of stem-E and root-E, respectively, pointing to an influence of the endophyte origin on root extension. M. aquatica and many other perennial hydrophytes have growing worldwide application in water pollution remediation. The present study provided a model for directed screening of endophytes able to modulate plant growth in the perspective of future field applications of these fungi.

  1. Mycorrhizal and Dark-Septate Fungi in Plant Roots above 4270 Meters Elevation in the Andes and Rocky Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Steven K. [University of Colorado; Sobieniak-Wiseman, L. Cheyanne [University of Colorado; Kageyama, Stacy A. [Oregon State University; Halloy, Stephen [Instituto de Ecologia, Universidad Mayor de San Andres, La Paz, Bolivia; Schadt, Christopher Warren [ORNL

    2008-01-01

    Arbuscular mycorrhizal (AM) and dark-septate endophytic (DSE) fungi were quantified in plant roots from high-elevation sites in the Cordillera Vilcanota of the Andes (Per ) and the Front Range of the Colorado Rocky Mountains (U.S.A.). At the highest sites in the Andes (5391 m) AM fungi were absent in the two species of plants sampled (both Compositae) but roots of both were heavily colonized by DSE fungi. At slightly lower elevations (5240 5250 m) AM fungi were present in roots while DSE fungi were rare in plants outside of the composite family. At the highest sites sampled in Colorado (4300 m) AM fungi were present, but at very low levels and all plants sampled contained DSE fungi. Hyphae of coarse AM fungi decreased significantly in plant roots at higher altitude in Colorado, but no other structures showed significant decreases with altitude. These new findings indicate that the altitudinal distribution of mycorrhizal fungi observed for European mountains do not necessarily apply to higher and drier mountains that cover much of the Earth (e.g. the Himalaya, Hindu Kush, Andes, and Rockies) where plant growth is more limited by nutrients and water than in European mountains. This paper describes the highest altitudinal records for both AM and DSE fungi, surpassing previous reported altitudinal maxima by about 1500 meters.

  2. IN VITRO ANTAGONISM AND EVALUATION OF CHITINASE ACTIVITY OF BACTERIAâBACILLUS CIRCULANS AGAINST PATHOGENIC FUNGI IN VIGNA UNGUICULATA

    OpenAIRE

    Florentyna Rodrigues; Priadharsini.K; S. Suja; P. Palani

    2014-01-01

    Scientists of agriculture and plant pathology are on the lookout for potential biological control agents to control the plant pathogenic organisms in order to avoid soil contamination. Rhizospheric bacteria are excellent agents to control soil-borne plant pathogens. In this study an attempt has been made to evaluate the antagonistic activity of a bacterial strain Bacillus circulans against Curvularia lunata, Alternaria alternata and Cladosporium sp., which are important seed and soil borne pa...

  3. Diversity and ecological distribution of endophytic fungi associated with medicinal plants

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A total of 973 isolates of endophytic fungi were recovered from 1144 tissue fragments of the six me-dicinal plant species belonging to 4 families collected in the Beijing Botanical Garden. Of these isolates 778 sporulated and were identified into 21 taxa by morphological characteristics. Among the taxa 11 belonged to Coelomycetes, 6 to Ascomycetes, and 4 to Hyphomycetes. Various numbers of endophytic fungi (5―8 taxa) were obtained from each plant. Alternaria alternata was the dominant species in the 6 plants, and Microsphaeropsis conielloides was also dominant in Eucommia ulmoides. There were high colonization rates (47.9%―63.1%) and isolation rates (0.7―0.93) of endophytic fungi, and they were conspicuously higher in twigs than those in leaves in the 6 plants examined. The colonization and isolation rates of endophytic fungi increased with the twig age. The results based on the analyses of cluster and Sorenson’s similarity coefficients indicated that some endophytic fungi showed a certain degree of host and tissue preference.

  4. Diversity and ecological distribution of endophytic fungi associated with medicinal plants.

    Science.gov (United States)

    Sun, Jianqiu; Guo, Liangdong; Zang, Wei; Ping, Wenxiang; Chi, Defu

    2008-08-01

    A total of 973 isolates of endophytic fungi were recovered from 1,144 tissue fragments of the six medicinal plant species belonging to 4 families collected in the Beijing Botanical Garden. Of these isolates 778 sporulated and were identified into 21 taxa by morphological characteristics. Among the taxa 11 belonged to Coelomycetes, 6 to Ascomycetes, and 4 to Hyphomycetes. Various numbers of endophytic fungi (5-8 taxa) were obtained from each plant. Alternaria alternata was the dominant species in the 6 plants, and Microsphaeropsis conielloides was also dominant in Eucommia ulmoides. There were high colonization rates (47.9%-63.1%) and isolation rates (0.7-0.93) of endophytic fungi, and they were conspicuously higher in twigs than those in leaves in the 6 plants examined. The colonization and isolation rates of endophytic fungi increased with the twig age. The results based on the analyses of cluster and Sorenson's similarity coefficients indicated that some endophytic fungi showed a certain degree of host and tissue preference.

  5. Diversity and ecological distribution of endophytic fungi associated with medicinal plants

    Institute of Scientific and Technical Information of China (English)

    SUN JianQiu; GUO LiangDong; ZANG Wei; PING WenXiang; CHI DeFu

    2008-01-01

    A total of 973 isolates of endophytic fungi were recovered from 1144 tissue fragments of the six me-dicinal plant species belonging to 4 families collected in the Beijing Botanical Garden. Of these isolates 778 sporulated and were identified into 21 taxa by morphological characteristics. Among the taxa 11 belonged to Coelomycetes, 6 to Ascomycetes, and 4 to Hyphomycetes. Various numbers of endophytic fungi (5-8 taxa) were obtained from each plant. Alternaria alternata was the dominant species in the 6 plants, and Microsphaeropsis conielloides was also dominant in Eucommia ulmoides. There were high colonization rates (47.9%-63.1%) and isolation rates (0.7-0.93) of endophytic fungi, and they were conspicuously higher in twigs than those in leaves in the 6 plants examined. The colonization and isolation rates of endophytic fungi increased with the twig age. The results based on the analyses of cluster and Sorenson's similarity coefficients indicated that some endophytic fungi showed a certain degree of host and tissue preference.

  6. Environmental behaviour and ecotoxicity of engineered nanoparticles to algae, plants and fungi

    DEFF Research Database (Denmark)

    Navarro, E.; Baun, Anders; Behra, R.

    2008-01-01

    for their aggregation behavior, and thus for their mobility in aquatic and terrestrial systems and for their interactions with algae, plants and, fungi. Interactions of ENPs with natural organic matter have to be considered as well, as those will alter the ENPs aggregation behavior in surface waters or in soils. Cells...... of plants, algae, and fungi possess cell walls that constitute a primary site for interaction and a barrier for the entrance of ENPs. Mechanisms allowing ENPs to pass through cell walls and membranes are as yet poorly understood. Inside cells, ENPs might directly provoke alterations of membranes and other...... the bioavailability of ENPs, their uptake by algae, plants, and fungi and the toxicity mechanisms remain to be elucidated...

  7. Regulation of primary plant metabolism during plant-pathogen interactions and its contribution to plant defense

    Directory of Open Access Journals (Sweden)

    Clemencia M Rojas

    2014-02-01

    Full Text Available Plants are constantly exposed to microorganisms in the environment and, as a result, have evolved intricate mechanisms to recognize and defend themselves against potential pathogens. One of these responses is the downregulation of photosynthesis and other processes associated with primary metabolism that are essential for plant growth. It has been suggested that the energy saved by downregulation of primary metabolism is diverted and used for defense responses. However, several studies have shown that upregulation of primary metabolism also occurs during plant-pathogen interactions. We propose that upregulation of primary metabolism modulates signal transduction cascades that lead to plant defense responses. In support of this thought, we here compile evidence from the literature to show that upon exposure to pathogens or elicitors, plants induce several genes associated with primary metabolic pathways, such as those involved in the synthesis or degradation of carbohydrates, amino acids and lipids. In addition, genetic studies have confirmed the involvement of these metabolic pathways in plant defense responses. This review provides a new perspective highlighting the relevance of primary metabolism in regulating plant defense against pathogens with the hope to stimulate further research in this area.

  8. Oligo-DNA custom macroarray for monitoring major pathogenic and non-pathogenic fungi and bacteria in the phyllosphere of apple trees.

    Directory of Open Access Journals (Sweden)

    Ying-Hong He

    Full Text Available BACKGROUND: To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. METHODS AND FINDINGS: First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 10(3 CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. CONCLUSIONS: The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in

  9. Diversity and taxonomy of endophytic xylariaceous fungi from medicinal plants of Dendrobium (Orchidaceae.

    Directory of Open Access Journals (Sweden)

    Juan Chen

    Full Text Available Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS, large subunit of ribosomal DNA (LSU, and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs. The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery.

  10. Diversity and taxonomy of endophytic xylariaceous fungi from medicinal plants of Dendrobium (Orchidaceae).

    Science.gov (United States)

    Chen, Juan; Zhang, Li-Chun; Xing, Yong-Mei; Wang, Yun-Qiang; Xing, Xiao-Ke; Zhang, Da-Wei; Liang, Han-Qiao; Guo, Shun-Xing

    2013-01-01

    Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids) have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae) were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa) were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS), large subunit of ribosomal DNA (LSU), and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs). The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery.

  11. Stimulatory effects of arsenic-tolerant soil fungi on plant growth promotion and soil properties.

    Science.gov (United States)

    Srivastava, Pankaj Kumar; Shenoy, Belle Damodara; Gupta, Manjul; Vaish, Aradhana; Mannan, Shivee; Singh, Nandita; Tewari, Shri Krishna; Tripathi, Rudra Deo

    2012-01-01

    Fifteen fungi were obtained from arsenic-contaminated agricultural fields in West Bengal, India and examined for their arsenic tolerance and removal ability in our previous study. Of these, the four best arsenic-remediating isolates were tested for plant growth promotion effects on rice and pea in the present study. A greenhouse-based pot experiment was conducted using soil inocula of individual fungi. The results indicated a significant (Psoil properties in inoculated soils compared to the control. A significant increase in plant growth was recorded in treated soils and varied from 16-293%. Soil chemical and enzymatic properties varied from 20-222% and 34-760%, respectively, in inoculated soil. Plants inoculated with inocula of Westerdykella and Trichoderma showed better stimulatory effects on plant growth and soil nutrient availability than Rhizopus and Lasiodiplodia. These fungi improved soil nutrient content and enhanced plant growth. These fungi may be used as bioinoculants for plant growth promotion and improved soil properties in arsenic-contaminated agricultural soils.

  12. Negative feedback loops leading to nitrate homeostasis and oscillatory nitrate assimilation in plants and fungi.

    OpenAIRE

    Huang, Yongshun

    2011-01-01

    Nitrate is an important nutrient for plants and fungi. For plants it has been shown that cytosolic nitrate levels are under homeostatic control. Here we describe two networks that can obtain robust, i.e. perturbation independent, homeostatic behavior in cytosolic nitrate concentration. One of the networks, a member in the family of outflow controllers, is based on a negative feedback loop containing a nitrate-induced activation of a controller molecule which removes nitrate. In plants this co...

  13. [Effects of soil factors on arbuscular mycorrhizae (AM) fungi around roots of wild plants].

    Science.gov (United States)

    Gai, Jingping; Liu, Runjin

    2003-03-01

    150 rhizospheric soil samples were collected from 45 wild plants distributed in Shandong Province during 1995-1997. More than forty species of AM fungi were isolated, and the effects of some soil factors on AM fungi were also investigated. It was proved that soil conditions were important factors to the colonization, growth, and distribution of AM fungi. Spore numbers were highest in brown earth, and lowest in alkali-saline soil. Glomus occurred in all types of soil. The occurrence frequency of Gigaspora and Scutellospora was much higher in brown earth. The distribution of AM fungi was also affected by soil pH. Glomus occurred in soil with a wide pH range. The greater of soil alkalinity, the more Glomus were found, while the greater of soil acidity, the more Acaulospora were isolated. Scutellospora occurred mostly in soil with pH of 6.0-7.0, and Gigaspora distributed mainly in acid soil.

  14. Recent developments in pathogen detection arrays: implications for fungal plant pathogens and use in practica

    NARCIS (Netherlands)

    Lievens, B.; Thomma, B.P.H.J.

    2005-01-01

    The failure to adequately identify plant pathogens from culture-based morphological techniques has led to the development of culture-independent molecular approaches. Increasingly, diagnostic laboratories are pursuing fast routine methods that provide reliable identification, sensitive detection, an

  15. Carbohydrate-related enzymes of important Phytophthora plant pathogens

    NARCIS (Netherlands)

    Brouwer, Henk; Coutinho, Pedro M; Henrissat, Bernard; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    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 CAZy

  16. Polyacetylenes from terrestrial plants and fungi: Recent phytochemical and biological advances.

    Science.gov (United States)

    Negri, Roberto

    2015-10-01

    Polyacetylenes are a class of polyketides related to fatty acids that occur in plants, fungi, marine organisms and animals. These compounds show a pleiotropic profile of bioactivity, that includes antitumor, antibacterial, antimicrobial or antifungal properties. Because of this, the literature on these compounds has grown exponentially, and this review aims at summarizing the inventory of polyacetylenes occurring in terrestrial eukaryotic organisms (plants and fungi) during the last 15 years, and at discussing progress in their bioactivities and in the identification of their biological targets.

  17. Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion.

    Science.gov (United States)

    Zhang, Qian; Yang, Ruyi; Tang, Jianjun; Yang, Haishui; Hu, Shuijin; Chen, Xin

    2010-08-24

    Negative or positive feedback between arbuscular mycorrhizal fungi (AMF) and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb.) Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum) while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum) that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant.

  18. Plant defenses against parasitic plants show similarities to those induced by herbivores and pathogens

    Science.gov (United States)

    Justin B. Runyon; Mark C. Mescher; Consuelo M. De Moraes

    2010-01-01

    Herbivores and pathogens come quickly to mind when one thinks of the biotic challenges faced by plants. Important but less appreciated enemies are parasitic plants, which can have important consequences for the fitness and survival of their hosts. Our knowledge of plant perception, signaling and response to herbivores and pathogens has expanded rapidly in recent years...

  19. Chromatin versus pathogens: the function of epigenetics in plant immunity

    OpenAIRE

    Ding, Bo; Wang, Guo-Liang

    2015-01-01

    To defend against pathogens, plants have developed a sophisticated innate immunity that includes effector recognition, signal transduction, and rapid defense responses. Recent evidence has demonstrated that plants utilize the epigenetic control of gene expression to fine-tune their defense when challenged by pathogens. In this review, we highlight the current understanding of the molecular mechanisms of histone modifications (i.e., methylation, acetylation, and ubiquitination) and chromatin r...

  20. Engineered resistance against fungal plant pathogens

    NARCIS (Netherlands)

    Honée, G.

    1999-01-01

    Development of genetic engineering technology and molecular characterization of plant defense responses have provided strategies for controlling plant diseases additional to those based on chemical control or classical breeding programs. Most of these alternative strategies are based on the overprod

  1. Detection and Diagnostics of Plant Pathogens

    NARCIS (Netherlands)

    Gullino, M.L.; Bonants, P.J.M.

    2014-01-01

    This book is part of the Plant Pathology in the 21st Century Series, started in the occasion of the IX International Congress of Plant Pathology, Torino, 2008. In conjunction with the Xth International Congress of Plant Pathology, held in Beijing in August 2013. Although deriving from a Congress, th

  2. Interactions between Fusarium verticillioides, Ustilago maydis, and Zea mays: an endophyte, a pathogen, and their shared plant host.

    Science.gov (United States)

    Rodriguez Estrada, Alma E; Jonkers, Wilfried; Kistler, H Corby; May, Georgiana

    2012-07-01

    Highly diverse communities of microbial symbionts occupy eukaryotic organisms, including plants. While many well-studied symbionts may be characterized as either parasites or as mutualists, the prevalent but cryptic endophytic fungi are less easily qualified because they do not cause observable symptoms of their presence within their host. Here, we investigate the interactions of an endophytic fungus, Fusarium verticillioides with a pathogen, Ustilago maydis, as they occur within maize (Zea mays). We used experimental inoculations to evaluate metabolic mechanisms by which these three organisms might interact. We assessed the impacts of fungal-fungal interactions on endophyte and pathogen growth within the plant, and on plant growth. We find that F. verticillioides modulates the growth of U. maydis and thus decreases the pathogen's aggressiveness toward the plant. With co-inoculation of the endophyte with the pathogen, plant growth is similar to that which would be gained without the pathogen present. However, the endophyte may also break down plant compounds that limit U. maydis growth, and obtains a growth benefit from the presence of the pathogen. Thus, an endophyte such as F. verticillioides may function as both a defensive mutualist and a parasite, and express nutritional modes that depend on ecological context. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Antimicrobial activities of chicken β -defensin (4 and 10 peptides against pathogenic bacteria and fungi

    Directory of Open Access Journals (Sweden)

    Haitham Ahmed Yacoub

    2015-04-01

    Full Text Available Host Defense Peptides (HDPs are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4 and 10 (sAvBD-4 derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of P. aeruginosa and Str. bovis strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.

  4. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi.

    Science.gov (United States)

    Yacoub, Haitham A; Elazzazy, Ahmed M; Abuzinadah, Osama A H; Al-Hejin, Ahmed M; Mahmoud, Maged M; Harakeh, Steve M

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.

  5. Forgotten natural enemies: interactions between Coccinellids and insect-pathogenic fungi

    Science.gov (United States)

    The research literature on insect pest species and entomopathogenic fungi is abundant. In stark contrast, little research has been done on the interactions of natural populations of Coccinellidae with entomopathogenic fungi. Most research on entomopathogens and Coccinellidae focuses on the non-tar...

  6. Extracellular enzymatic profiles and taxonomic identification of endophytic fungi isolated from four plant species.

    Science.gov (United States)

    Alberto, R N; Costa, A T; Polonio, J C; Santos, M S; Rhoden, S A; Azevedo, J L; Pamphile, J A

    2016-11-03

    Plants of medicinal and economic importance have been studied to investigate the presence of enzyme-producing endophytic fungi. The characterization of isolates with distinct enzyme production potential may identify suitable alternatives for specialized industry. At Universidade Estadual de Maringá Laboratory of Microbial Biotechnology, approximately 500 isolates of endophytic fungi have been studied over the last decade from various host plants, including medicinally and economically important species, such as Luehea divaricata (Martius et Zuccarini), Trichilia elegans A. Juss, Sapindus saponaria L., Piper hispidum Swartz, and Saccharum spp. However, only a fraction of these endophytes have been identified and evaluated for their biotechnological application, having been initially grouped by morphological characteristics, with at least one representative of each morphogroup tested. In the current study, several fungal strains from four plants (L. divaricata, T. elegans, S. saponaria, and Saccharum spp) were identified by ribosomal DNA typing and evaluated semi-quantitatively for their enzymatic properties, including amylase, cellulase, pectinase, and protease activity. Phylogenetic analysis revealed the presence of four genera of endophytic fungi (Diaporthe, Saccharicola, Bipolaris, and Phoma) in the plants examined. According to enzymatic tests, 62% of the isolates exhibited amylase, approximately 93% cellulase, 50% pectinase, and 64% protease activity. Our results verified that the composition and abundance of endophytic fungi differed between the plants tested, and that these endophytes are a potential enzyme production resource of commercial and biotechnological value.

  7. Endogone, one of the oldest plant-associated fungi, host unique Mollicutes-related endobacteria.

    Science.gov (United States)

    Desirò, Alessandro; Faccio, Antonella; Kaech, Andres; Bidartondo, Martin I; Bonfante, Paola

    2015-03-01

    Glomeromycota have been considered the most ancient group of fungi capable of positively interacting with plants for many years. Recently, other basal fungi, the Endogone Mucoromycotina fungi, have been identified as novel plant symbionts, challenging the paradigm of Glomeromycota as the unique ancestral symbionts of land plants. Glomeromycota are known to host endobacteria and recent evidences show that also some Mucoromycotina contain endobacteria. In order to examine similarities between basal groups of plant-associated fungi, we tested whether Endogone contained endobacteria. Twenty-nine Endogone were investigated in order to identify Mollicutes-related endobacteria (Mre). Fruiting bodies were processed for transmission electron microscopy and molecularly investigated using fungal and Mre-specific primers. We demonstrate that Mre are present inside 13 out of 29 Endogone: endobacteria are directly embedded in the fungal cytoplasm and their 16S rDNA sequences cluster together with the ones retrieved from Glomeromycota, forming, however, a separate new clade. Our findings provide new insights on the evolutionary relations between Glomeromycota, Mucoromycotina and endobacteria, raising new questions on the role of these still enigmatic microbes in the ecology, evolution and diversification of their fungal hosts during the history of plant-fungal symbiosis.

  8. Recognition of bacterial plant pathogens: local, systemic and transgenerational immunity.

    Science.gov (United States)

    Henry, Elizabeth; Yadeta, Koste A; Coaker, Gitta

    2013-09-01

    Bacterial pathogens can cause multiple plant diseases and plants rely on their innate immune system to recognize and actively respond to these microbes. The plant innate immune system comprises extracellular pattern recognition receptors that recognize conserved microbial patterns and intracellular nucleotide binding leucine-rich repeat (NLR) proteins that recognize specific bacterial effectors delivered into host cells. Plants lack the adaptive immune branch present in animals, but still afford flexibility to pathogen attack through systemic and transgenerational resistance. Here, we focus on current research in plant immune responses against bacterial pathogens. Recent studies shed light onto the activation and inactivation of pattern recognition receptors and systemic acquired resistance. New research has also uncovered additional layers of complexity surrounding NLR immune receptor activation, cooperation and sub-cellular localizations. Taken together, these recent advances bring us closer to understanding the web of molecular interactions responsible for coordinating defense responses and ultimately resistance.

  9. Biotransformations of terpenes by fungi from Amazonian citrus plants.

    Science.gov (United States)

    Moreno Rueda, Maria Gabriela; Guerrini, Alessandra; Giovannini, Pier Paolo; Medici, Alessandro; Grandini, Alessandro; Sacchetti, Gianni; Pedrini, Paola

    2013-10-01

    The biotransformations of (RS)-linalool (1), (S)-citronellal (2), and sabinene (3) with fungi isolated from the epicarp of fruits of Citrus genus of the Amazonian forest (i.e., C. limon, C. aurantifolia, C. aurantium, and C. paradisiaca) are reported. The more active strains have been characterized, and they belong to the genus Penicillium and Fusarium. Different biotransformation products have been obtained depending on fungi and substrates. (RS)-Linalool (1) afforded the (E)- and (Z)-furanlinalool oxides (7 and 8, resp.; 39 and 37% yield, resp.) with Fusarium sp. (1D2), 6-methylhept-5-en-2-one (4; 49%) with F. fujikuroi, and 1-methyl-1-(4-methypentyl)oxiranemethanol (6; 42%) with F. concentricum. (S)-Citronellal (2) gave (S)-citronellol (12; 36-76%) and (S)-citronellic acid (11; 5-43%) with Fusarium species, while diastereoisomeric p-menthane-3,8-diols 13 and 14 (20 and 50% yield, resp.) were obtained as main products with Penicillium paxilli. Finally, both Fusarium species and P. paxilli biotransformed sabinene (3) to give mainly 4-terpineol (19; 23-56%), and (Z)- and (E)-sabinene hydrates (17 (3-21%) and 18 (11-17%), resp.).

  10. Impact of Moringa aqueous extract on pathogenic bacteria and fungi in vitro

    Directory of Open Access Journals (Sweden)

    Latifa A. Al_husnan

    2016-12-01

    Full Text Available Moringa peregrine have many benefits. In this study aqueous extract of Moringa plant inhibited the activity of these bacteria which include Bacillus cereus; Staphylococcus aureus; Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli; Enterococcus cloacae; Salmonella typhi and; Proteus vulgaris. Moringa extracts has shown an impact on the growth of bacteria on the Blood with inhibition zone variable (23.5 ± 0.45 to 12.5 ± 0.50 mm according to the type of bacteria. The mean growth inhibition percentages were 85.9 ± 0.42 to 65.3 ± 0.34 nm against all tested bacteria. As regards to fungi, high potency extract displayed zones of inhibition of ⩾10 mm, moderate potent extracts gave zones of inhibition between <10 and 9 mm. The results indicated that, Moringa aqueous extract played variable antifungal activity ranged from high (18 ± 0.54 mm, moderate (13.2 ± 0.58 mm and low (6.6 ± 0.47 mm. The inhibition zones diameter in millimeters against A. niger, A. flavus, P. italicum, F. oxysporum, R. stolonifer, Alternaria sp., C. albicans, C. parapsilosis were 15.2 ± 0.52, 12.4 ± 0.55, 10.5 ± 0.26, 9.4 ± 0.71, 13.2 ± 0.58, 6.6 ± 0.47, 12 ± 0.44 and 18 ± 0.54, respectively. On the other hand, the mean inhibition of growth (as percentages were 75.2 ± 0.55, 59.4 ± 0.75, 58.2 ± 0.63, 46.5 ± 0.63, 62.5 ± 0.77, 24.5 ± 0.65, 20.3 ± 0.75 and 80.00 ± 0.70% respectively. Thus, the aqueous extract of Moringa leaves showed antimicrobial activity against tested bacteria, fungi and yeasts at different concentrations.

  11. Heterokaryon incompatibility is suppressed following conidial anastomosis tube fusion in a fungal plant pathogen.

    Science.gov (United States)

    Ishikawa, Francine H; Souza, Elaine A; Shoji, Jun-Ya; Connolly, Lanelle; Freitag, Michael; Read, Nick D; Roca, M Gabriela

    2012-01-01

    It has been hypothesized that horizontal gene/chromosome transfer and parasexual recombination following hyphal fusion between different strains may contribute to the emergence of wide genetic variability in plant pathogenic and other fungi. However, the significance of vegetative (heterokaryon) incompatibility responses, which commonly result in cell death, in preventing these processes is not known. In this study, we have assessed this issue following different types of hyphal fusion during colony initiation and in the mature colony. We used vegetatively compatible and incompatible strains of the common bean pathogen Colletotrichum lindemuthianum in which nuclei were labelled with either a green or red fluorescent protein in order to microscopically monitor the fates of nuclei and heterokaryotic cells following hyphal fusion. As opposed to fusion of hyphae in mature colonies that resulted in cell death within 3 h, fusions by conidial anastomosis tubes (CAT) between two incompatible strains during colony initiation did not induce the vegetative incompatibility response. Instead, fused conidia and germlings survived and formed heterokaryotic colonies that in turn produced uninucleate conidia that germinated to form colonies with phenotypic features different to those of either parental strain. Our results demonstrate that the vegetative incompatibility response is suppressed during colony initiation in C. lindemuthianum. Thus, CAT fusion may allow asexual fungi to increase their genetic diversity, and to acquire new pathogenic traits.

  12. Heterokaryon incompatibility is suppressed following conidial anastomosis tube fusion in a fungal plant pathogen.

    Directory of Open Access Journals (Sweden)

    Francine H Ishikawa

    Full Text Available It has been hypothesized that horizontal gene/chromosome transfer and parasexual recombination following hyphal fusion between different strains may contribute to the emergence of wide genetic variability in plant pathogenic and other fungi. However, the significance of vegetative (heterokaryon incompatibility responses, which commonly result in cell death, in preventing these processes is not known. In this study, we have assessed this issue following different types of hyphal fusion during colony initiation and in the mature colony. We used vegetatively compatible and incompatible strains of the common bean pathogen Colletotrichum lindemuthianum in which nuclei were labelled with either a green or red fluorescent protein in order to microscopically monitor the fates of nuclei and heterokaryotic cells following hyphal fusion. As opposed to fusion of hyphae in mature colonies that resulted in cell death within 3 h, fusions by conidial anastomosis tubes (CAT between two incompatible strains during colony initiation did not induce the vegetative incompatibility response. Instead, fused conidia and germlings survived and formed heterokaryotic colonies that in turn produced uninucleate conidia that germinated to form colonies with phenotypic features different to those of either parental strain. Our results demonstrate that the vegetative incompatibility response is suppressed during colony initiation in C. lindemuthianum. Thus, CAT fusion may allow asexual fungi to increase their genetic diversity, and to acquire new pathogenic traits.

  13. Beneficial role of plant growth promoting bacteria and arbuscular mycorrhizal fungi on plant responses to heavy metal stress.

    Science.gov (United States)

    Gamalero, Elisa; Lingua, Guido; Berta, Graziella; Glick, Bernard R

    2009-05-01

    Heavy metal pollution is a major worldwide environmental concern that has recently motivated researchers to develop a variety of novel approaches towards its cleanup. As an alternative to traditional physical and chemical methods of environmental cleanup, scientists have developed phytoremediation approaches that include the use of plants to remove or render harmless a range of compounds. Both plant growth promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) can be used to facilitate the process of phytoremediation and the growth of plants in metal-contaminated soils. This review focuses on the recent literature dealing with the effects of plant growth-promoting bacteria and AM fungi on the response of plants to heavy metal stress and points the way to strategies that may facilitate the practical realization of this technology.

  14. 14-3-3 proteins in plant-pathogen interactions.

    Science.gov (United States)

    Lozano-Durán, Rosa; Robatzek, Silke

    2015-05-01

    14-3-3 proteins define a eukaryotic-specific protein family with a general role in signal transduction. Primarily, 14-3-3 proteins act as phosphosensors, binding phosphorylated client proteins and modulating their functions. Since phosphorylation regulates a plethora of different physiological responses in plants, 14-3-3 proteins play roles in multiple signaling pathways, including those controlling metabolism, hormone signaling, cell division, and responses to abiotic and biotic stimuli. Increasing evidence supports a prominent role of 14-3-3 proteins in regulating plant immunity against pathogens at various levels. In this review, potential links between 14-3-3 function and the regulation of plant-pathogen interactions are discussed, with a special focus on the regulation of 14-3-3 proteins in response to pathogen perception, interactions between 14-3-3 proteins and defense-related proteins, and 14-3-3 proteins as targets of pathogen effectors.

  15. The potential role of arbuscular mycorrhizal fungi in protecting endangered plants and habitats.

    Science.gov (United States)

    Bothe, Hermann; Turnau, Katarzyna; Regvar, Marjana

    2010-10-01

    Ecosystems worldwide are threatened with the extinction of plants and, at the same time, invasion by new species. Plant invasiveness and loss of species can be caused by similar but opposing pressures on the community structures. Arbuscular mycorrhizal fungi (AMF) can have multiple positive effects on plant growth, productivity, health, and stress relief. Many endangered species live in symbiosis with AMF. However, the list of the International Union for Conservation of Nature and Natural Resources (IUCN Red List of Threatened Species) indicates that the mycorrhizal status of most of the threatened species has not been assessed. Rare plants often occur in specialized and also endangered habitats and might utilize specialized or unique AMF. The specificity of any endangered plant to its AMF population has not been investigated. Because most of the current AMF isolates that are available colonize a broad range of plant species, selected inocula could be used to promote growth of endangered plants before the proper and more effective indigenous AMF are characterized. Application of AMF in field sites to protect endangered plants is hardly feasible due to the complexity of plant community structures and the large amount of fungal inocula needed. Endangered plants could, however, be grown as greenhouse cultures together with appropriate fungi, and, at the relevant developmental stage, they could be re-planted into native sites to prevent extinction and to preserve plant community ecology.

  16. Mycorrhization level in truffle plants and presence of concurrent fungi

    Directory of Open Access Journals (Sweden)

    Leonardo B. Falini

    2013-12-01

    Full Text Available In Italy, to improve good practices for truffle cultivation, some regional governments require specific certification of mycorrhization level and plant quality for marketing, out-planting and establishment of truffle orchards. The Department of Applied Biology at the University of Perugia has dealt with certification of truffle plants since the 1980’s. Here we show the mycorrhization analysis of different host species previously inoculated with truffle spores by an Italian commercial nursery.

  17. Characterization of glycosyl inositol phosphoryl ceramides from plants and fungi by mass spectrometry.

    Science.gov (United States)

    Buré, Corinne; Cacas, Jean-Luc; Mongrand, Sébastien; Schmitter, Jean-Marie

    2014-02-01

    Although glycosyl inositol phosphoryl ceramides (GIPCs) represent the most abundant class of sphingolipids in plants, they still remain poorly characterized in terms of structure and biodiversity. More than 50 years after their discovery, little is known about their subcellular distribution and their exact roles in membrane structure and biological functions. This review is focused on extraction and characterization methods of GIPCs occurring in plants and fungi. Global methods for characterizing ceramide moieties of GIPCs revealed the structures of long-chain bases (LCBs) and fatty acids (FAs): LCBs are dominated by tri-hydroxylated molecules such as monounsaturated and saturated phytosphingosine (t18:1 and t18:0, respectively) in plants and mainly phytosphingosine (t18:0 and t20:0) in fungi; FA are generally 14-26 carbon atoms long in plants and 16-26 carbon atoms long in fungi, these chains being often hydroxylated in position 2. Mass spectrometry plays a pivotal role in the assessment of GIPC diversity and the characterization of their structures. Indeed, it allowed to determine that the core structure of GIPC polar heads in plants is Hex(R1)-HexA-IPC, with R1 being a hydroxyl, an amine, or a N-acetylamine group, whereas the core structure in fungi is Man-IPC. Notably, information gained from tandem mass spectrometry spectra was most useful to describe the huge variety of structures encountered in plants and fungi and reveal GIPCs with yet uncharacterized polar head structures, such as hexose-inositol phosphoceramide in Chondracanthus acicularis and (hexuronic acid)4-inositol phosphoceramide and hexose-(hexuronic acid)3-inositol phosphoceramide in Ulva lactuca.

  18. Migrate or evolve: options for plant pathogens under climate change.

    Science.gov (United States)

    Chakraborty, Sukumar

    2013-07-01

    Findings on climate change influence on plant pathogens are often inconsistent and context dependent. Knowledge of pathogens affecting agricultural crops and natural plant communities remains fragmented along disciplinary lines. By broadening the perspective beyond agriculture, this review integrates cross-disciplinary knowledge to show that at scales relevant to climate change, accelerated evolution and changing geographic distribution will be the main implications for pathogens. New races may evolve rapidly under elevated temperature and CO2 , as evolutionary forces act on massive pathogen populations boosted by a combination of increased fecundity and infection cycles under favourable microclimate within enlarged canopy. Changing geographic distribution will bring together diverse lineages/genotypes that do not share common ecological niche, potentially increasing pathogen diversity. However, the uncertainty of model predictions and a lack of synthesis of fragmented knowledge remain as major deficiencies in knowledge. The review contends that the failure to consider scale and human intervention through new technology are major sources of uncertainty. Recognizing that improved biophysical models alone will not reduce uncertainty, it proposes a generic framework to increase focus and outlines ways to integrate biophysical elements and technology change with human intervention scenarios to minimize uncertainty. To synthesize knowledge of pathogen biology and life history, the review borrows the concept of 'fitness' from population biology as a comprehensive measure of pathogen strengths and vulnerabilities, and explores the implications of pathogen mode of nutrition to fitness and its interactions with plants suffering chronic abiotic stress under climate change. Current and future disease management options can then be judged for their ability to impair pathogenic and saprophytic fitness. The review pinpoints improving confidence in model prediction by minimizing

  19. Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant Echinacea purpurea (L.) Moench

    Science.gov (United States)

    2012-08-01

    indicus have been described as a human pathogen causing subcutaneous phaeohyphomycosis [25]. The sequence of UM24 M. indicus was phylogenetically...metabolites including fusaric acid, moniliformin, fumonisins, zearalenon, enniatins and trichothecenes [33]. The phylotyes F. oxysporum UM16 and...Chen and K. D. Hyde, “In Vitro Studies of Endophytic Fungi from Tripterygium wilfordii with Anti-Proliferative Activity on Human Peripheral Blood

  20. Endophytic fungi produce gibberellins and indoleacetic acid and promotes host-plant growth during stress.

    Science.gov (United States)

    Waqas, Muhammad; Khan, Abdul Latif; Kamran, Muhammad; Hamayun, Muhammad; Kang, Sang-Mo; Kim, Yoon-Ha; Lee, In-Jung

    2012-09-07

    We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.

  1. Endophytic Fungi Produce Gibberellins and Indoleacetic Acid and Promotes Host-Plant Growth during Stress

    Directory of Open Access Journals (Sweden)

    In-Jung Lee

    2012-09-01

    Full Text Available We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs and indoleacetic acid (IAA and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7 in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.

  2. Symbiotic interactions between arbuscular mycorrhizal (AM) fungi and male papaya plants: its status, role and implications.

    Science.gov (United States)

    Khade, Sharda W; Rodrigues, Bernard F; Sharma, Prabhat K

    2010-01-01

    Experiments were conducted to study the arbuscular mycorrhizal (AM) status and its role in P-uptake through assay of root phosphatases activities in four varieties of male Carica papaya L. viz. CO-1, CO-2, Honey Dew and Washington during flowering stages. In the present study, mean total root colonization of AM fungi recorded peak increase in flowering stage-II while mean root phosphatase (acid and alkaline) activities recorded peak increase in flowering stage-I. Unlike root colonization and root phosphatase activities, spore density did not exhibit any definite patterns and recorded a narrow range of fluctuation during different flowering stages of male C. papaya. The study brought out the fact that root colonization and spore density of AM fungi along with root phosphatase activities varied significantly within the four varieties of male C. papaya plants during each flowering stage. The study also recorded consistently higher acid root phosphatase activity than alkaline root phosphatase activity under P-deficient, acidic soil conditions during all flowering stages of male C. papaya plants. Studies revealed that the root colonization of AM fungi influenced root phosphatase activities (acid and alkaline) positively and significantly during all flowering stages of male C. papaya plants. A total of twelve species of AM fungi belonging to five genera viz. Acaulospora, Dentiscutata, Gigaspora, Glomus, and Racocetra were recovered from the rhizosphere of male C. papaya plants.

  3. The importance of individuals: intraspecific diversity of mycorrhizal plants and fungi in ecosystems.

    Science.gov (United States)

    Johnson, David; Martin, Francis; Cairney, John W G; Anderson, Ian C

    2012-05-01

    A key component of biodiversity is the number and abundance of individuals (i.e. genotypes), and yet such intraspecific diversity is rarely considered when investigating the effects of biodiversity of mycorrhizal plants and fungi on ecosystem processes. Within a species, individuals vary considerably in important reproductive and functional attributes, including carbon fixation, mycelial growth and nutrient utilization, but this is driven by both genetic and environmental (including climatic) factors. The interactions between individual plants and mycorrhizal fungi can have important consequences for the maintenance of biodiversity and regulation of resource transfers in ecosystems. There is also emerging evidence that assemblages of genotypes may affect ecosystem processes to a similar extent as assemblages of species. The application of whole-genome sequencing and population genomics to mycorrhizal plants and fungi will be crucial to determine the extent to which individual variation in key functional attributes is genetically based. We argue the need to unravel the importance of the diversity (especially assemblages of different evenness and richness) of individuals of both mycorrhizal plants and fungi, and the need to take a 'community genetics' approach to better understand the functional significance of the biodiversity of mycorrhizal symbioses. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  4. Plant systems for recognition of pathogen-associated molecular patterns.

    Science.gov (United States)

    Postel, Sandra; Kemmerling, Birgit

    2009-12-01

    Research of the last decade has revealed that plant immunity consists of different layers of defense that have evolved by the co-evolutional battle of plants with its pathogens. Particular light has been shed on PAMP- (pathogen-associated molecular pattern) triggered immunity (PTI) mediated by pattern recognition receptors. Striking similarities exist between the plant and animal innate immune system that point for a common optimized mechanism that has evolved independently in both kingdoms. Pattern recognition receptors (PRRs) from both kingdoms consist of leucine-rich repeat receptor complexes that allow recognition of invading pathogens at the cell surface. In plants, PRRs like FLS2 and EFR are controlled by a co-receptor SERK3/BAK1, also a leucine-rich repeat receptor that dimerizes with the PRRs to support their function. Pathogens can inject effector proteins into the plant cells to suppress the immune responses initiated after perception of PAMPs by PRRs via inhibition or degradation of the receptors. Plants have acquired the ability to recognize the presence of some of these effector proteins which leads to a quick and hypersensitive response to arrest and terminate pathogen growth.

  5. Microbial pathogens in source and treated waters from drinking water treatment plants in the United States and implications for human health

    Science.gov (United States)

    An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Aspe...

  6. How do filamentous pathogens deliver effector proteins into plant cells?

    Directory of Open Access Journals (Sweden)

    Benjamin Petre

    2014-02-01

    Full Text Available Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens.

  7. How Do Filamentous Pathogens Deliver Effector Proteins into Plant Cells?

    Science.gov (United States)

    Petre, Benjamin; Kamoun, Sophien

    2014-01-01

    Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens. PMID:24586116

  8. The use of plants to protect plants and food against fungal pathogens

    African Journals Online (AJOL)

    The use of plants to protect plants and food against fungal pathogens: a review. ... associated with these chemicals have motivated researchers and cultivators to ... may be lower if the different compounds affect a different metabolic process.

  9. Heterologous expression of the glucose oxidase gene in Trichoderma atroviride leads enhanced ability to attack phytopathogenic fungi and induction of plant systemic disease resistance

    Institute of Scientific and Technical Information of China (English)

    Robert L Mach; Brunner Kurt; Matteo Lorito; Susanne Zeilinger; Rosalia Ciliento; Sheridan Woo

    2004-01-01

    @@ A transgenic strain of Trichoderma atroviride that expresses the Aspergillus niger glucose oxidase gene goxA under a homologous pathogen-inducible promoter (nag1) has been constructed, with the aim of increasing the ability of this biocontrol agent (BCA) to attack phytopathogenic fungi and enhance plant systemic disease resistance. The sporulation and growth rate of the transgenic progenies were similar to the wild-type strain Pl. goxA expression occurred immediately after contact with the plant pathogen,and the glucose oxidase formed was secreted extracellularly. The transformed strain SJ3 4, containing 12-14 copies of the transgene, produced significantly less N-acetyl-glucosaminidase and endochitinase then wild type. However, the ability of its culture filtrate to inhibit the germination of Botrytis cinerea spores was increased by about 3-fold. In comparison to P1, the transgenic strain more quickly overgrew and lysed in vitro the pathogens Rhizoctonia solani and Pythium ultimum.

  10. Modulation of Plant RAB GTPase-Mediated Membrane Trafficking Pathway at the Interface Between Plants and Obligate Biotrophic Pathogens.

    Science.gov (United States)

    Inada, Noriko; Betsuyaku, Shigeyuki; Shimada, Takashi L; Ebine, Kazuo; Ito, Emi; Kutsuna, Natsumaro; Hasezawa, Seiichiro; Takano, Yoshitaka; Fukuda, Hiroo; Nakano, Akihiko; Ueda, Takashi

    2016-09-01

    RAB5 is a small GTPase that acts in endosomal trafficking. In addition to canonical RAB5 members that are homologous to animal RAB5, land plants harbor a plant-specific RAB5, the ARA6 group, which regulates trafficking events distinct from canonical RAB5 GTPases. Here, we report that plant RAB5, both canonical and plant-specific members, accumulate at the interface between host plants and biotrophic fungal and oomycete pathogens. Biotrophic fungi and oomycetes colonize living plant tissues by establishing specialized infection hyphae, the haustorium, within host plant cells. We found that Arabidopsis thaliana ARA6/RABF1, a plant-specific RAB5, is localized to the specialized membrane that surrounds the haustorium, the extrahaustorial membrane (EHM), formed by the A. thaliana-adapted powdery mildew fungus Golovinomyces orontii Whereas the conventional RAB5 ARA7/RABF2b was also localized to the EHM, endosomal SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) and RAB5-activating proteins were not, which suggests that the EHM has modified endosomal characteristic. The recruitment of host RAB5 to the EHM was a property shared by the barley-adapted powdery mildew fungus Blumeria graminis f.sp. hordei and the oomycete Hyaloperonospora arabidopsidis, but the extrahyphal membrane surrounding the hypha of the hemibiotrophic fungus Colletotrichum higginsianum at the biotrophic stage was devoid of RAB5. The localization of RAB5 to the EHM appears to correlate with the functionality of the haustorium. Our discovery sheds light on a novel relationship between plant RAB5 and obligate biotrophic pathogens.

  11. Interactions between co-habitating fungi elicit synthesis of Taxol from an endophytic fungus in host Taxus plants

    Directory of Open Access Journals (Sweden)

    Sameh S.M. Soliman

    2013-01-01

    Full Text Available Within a plant, there can exist an ecosystem of pathogens and endophytes, the latter described as bacteria and fungal inhabitants that thrive without causing disease to the host. Interactions between microbial inhabitants represent a novel area of study for natural products research. Here we analyzed the interactions between the fungal endophytes of Taxus (yew trees. Fungal endophytes of Taxus have been proposed to produce the terpenoid secondary metabolite, Taxol, an anti-cancer drug. It is widely reported that plant extracts stimulate endophytic fungal Taxol production, but the underlying mechanism is not understood. Here, Taxus bark extracts stimulated fungal Taxol production 30-fold compared to a 10-fold induction with wood extracts. However, candidate plant-derived defence compounds (i.e. salicylic acid, benzoic acid were found to act only as modest elicitors of fungal Taxol production from the endophytic fungus Paraconiothyrium SSM001, consistent with previous studies. We hypothesized the Taxus plant extracts may contain elicitors derived from other microbes inhabiting these tissues. We investigated the effects of co-culturing SSM001 with other fungi observed to inhabit Taxus bark, but not wood. Surprisingly, co-culture of SSM001 with a bark fungus (Alternaria caused a ~3-fold increase in Taxol production. When SSM001 was pyramided with both the Alternaria endophyte along with another fungus (Phomopsis observed to inhabit Taxus, there was an ~eight-fold increase in fungal Taxol production from SSM001. These results suggest that resident fungi within a host plant interact with one another to stimulate Taxol biosynthesis, either directly or through their metabolites. More generally, our results suggest that endophyte secondary metabolism should be studied in the context of its native ecosystem.

  12. Interactions between Co-Habitating fungi Elicit Synthesis of Taxol from an Endophytic Fungus in Host Taxus Plants.

    Science.gov (United States)

    Soliman, Sameh S M; Raizada, Manish N

    2013-01-01

    Within a plant, there can exist an ecosystem of pathogens and endophytes, the latter described as bacterial and fungal inhabitants that thrive without causing disease to the host. Interactions between microbial inhabitants represent a novel area of study for natural products research. Here we analyzed the interactions between the fungal endophytes of Taxus (yew) trees. Fungal endophytes of Taxus have been proposed to produce the terpenoid secondary metabolite, Taxol, an anti-cancer drug. It is widely reported that plant extracts stimulate endophytic fungal Taxol production, but the underlying mechanism is not understood. Here, Taxus bark extracts stimulated fungal Taxol production 30-fold compared to a 10-fold induction with wood extracts. However, candidate plant-derived defense compounds (i.e., salicylic acid, benzoic acid) were found to act only as modest elicitors of fungal Taxol production from the endophytic fungus Paraconiothyrium SSM001, consistent with previous studies. We hypothesized the Taxus plant extracts may contain elicitors derived from other microbes inhabiting these tissues. We investigated the effects of co-culturing SSM001 with other fungi observed to inhabit Taxus bark, but not wood. Surprisingly, co-culture of SSM001 with a bark fungus (Alternaria) caused a ∼threefold increase in Taxol production. When SSM001 was pyramided with both the Alternaria endophyte along with another fungus (Phomopsis) observed to inhabit Taxus, there was an ∼eightfold increase in fungal Taxol production from SSM001. These results suggest that resident fungi within a host plant interact with one another to stimulate Taxol biosynthesis, either directly or through their metabolites. More generally, our results suggest that endophyte secondary metabolism should be studied in the context of its native ecosystem.

  13. Characterization of community structure of culturable endophytic fungi in sweet cherry composite trees and their growth-retarding effect against pathogens.

    Science.gov (United States)

    Haddadderafshi, Neda; Pósa, Tímea Borbála; Péter, Gábor; Gáspár, László; Ladányi, Márta; Hrotkó, Károly; Lukács, Noémi; Halász, Krisztián

    2016-09-01

    Endophytic fungi have the potential to protect their host plants in stress situations. Characterizing the ecology and complex interaction between these endophytes and their host plants is therefore of great practical importance, particularly in horticultural plants. Among horticultural plants, fruit trees form a special category because of their longevity and because they are composites of rootstock and scion, which often belong to different plant species. Here we present the first characterization of culturable endophytic fungal community of sweet cherry. Samples from the Hungarian cultivar 'Petrus' grafted on 11 different rootstocks were collected in autumn and in spring in a bearing orchard and the dependence of colonization rate and endophyte diversity on rootstock, organ and season was analysed. On the basis of their ITS sequences 26 fungal operational taxonomic units were identified at least down to the genus level. The dominant genus, comprising more than 50% of all isolates, was Alternaria, followed by different Fusarium and Epicoccum species. We observed some organ-specificity amongst endophytes, and organs showed more sizeable differences in colonization rates and endophyte diversity than rootstocks. Most dynamic endophyte populations, strongly influenced by environmental conditions and crop management, were observed in leaves. The potential of selected endophytes to confer protection against Monilinia laxa was also analysed and 7 isolates were found to inhibit the growth of this pathogen in vitro.

  14. 53 review article a review of the virulence factors of pathogenic fungi

    African Journals Online (AJOL)

    boaz

    various virulence factors which help with fungal survival and persistence in the host resulting in tissue damage and disease. This review ... Mannitol which protect against reactive oxygen species (ROS). Some fungi ..... Sun SH, and Hearn VM.

  15. Online Databases for Taxonomy and Identification of Pathogenic Fungi and Proposal for a Cloud-Based Dynamic Data Network Platform.

    Science.gov (United States)

    Prakash, Peralam Yegneswaran; Irinyi, Laszlo; Halliday, Catriona; Chen, Sharon; Robert, Vincent; Meyer, Wieland

    2017-04-01

    The increase in public online databases dedicated to fungal identification is noteworthy. This can be attributed to improved access to molecular approaches to characterize fungi, as well as to delineate species within specific fungal groups in the last 2 decades, leading to an ever-increasing complexity of taxonomic assortments and nomenclatural reassignments. Thus, well-curated fungal databases with substantial accurate sequence data play a pivotal role for further research and diagnostics in the field of mycology. This minireview aims to provide an overview of currently available online databases for the taxonomy and identification of human and animal-pathogenic fungi and calls for the establishment of a cloud-based dynamic data network platform. Copyright © 2017 American Society for Microbiology.

  16. Changing fitness of a necrotrophic plant pathogen under increasing temperature.

    Science.gov (United States)

    Sabburg, Rosalie; Obanor, Friday; Aitken, Elizabeth; Chakraborty, Sukumar

    2015-08-01

    Warmer temperatures associated with climate change are expected to have a direct impact on plant pathogens, challenging crops and altering plant disease profiles in the future. In this study, we have investigated the effect of increasing temperature on the pathogenic fitness of Fusarium pseudograminearum, an important necrotrophic plant pathogen associated with crown rot disease of wheat in Australia. Eleven wheat lines with different levels of crown rot resistance were artificially inoculated with F. pseudograminearum and maintained at four diurnal temperatures 15/15°C, 20/15°C, 25/15°C and 28/15°C in a controlled glasshouse. To quantify the success of F. pseudograminearum three fitness measures, these being disease severity, pathogen biomass in stem base and flag leaf node, and deoxynivalenol (DON) in stem base and flag leaf node of mature plants were used. F. pseudograminearum showed superior overall fitness at 15/15°C, and this was reduced with increasing temperature. Pathogen fitness was significantly influenced by the level of crown rot resistance of wheat lines, but the influence of line declined with increasing temperature. Lines that exhibited superior crown rot resistance in the field were generally associated with reduced overall pathogen fitness. However, the relative performance of the wheat lines was dependent on the measure of pathogen fitness, and lines that were associated with one reduced measure of pathogen fitness did not always reduce another. There was a strong correlation between DON in stem base tissue and disease severity, but length of browning was not a good predictor of Fusarium biomass in the stem base. We report that a combination of host resistance and rising temperature will reduce pathogen fitness under increasing temperature, but further studies combining the effect of rising CO2 are essential for more realistic assessments. © 2015 John Wiley & Sons Ltd.

  17. Genomic Encyclopedia of Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-08-10

    Genomes of fungi relevant to energy and environment are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 150 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such parts suggested by comparative genomics and functional analysis in these areas are presented here.

  18. Antifungal membranolytic activity of the tyrocidines against filamentous plant fungi.

    Science.gov (United States)

    Rautenbach, Marina; Troskie, Anscha M; Vosloo, Johan A; Dathe, Margitta E

    2016-11-01

    The tyrocidines and analogues are cyclic decapeptides produced by Brevibacillus parabrevis with a conserved sequence of cyclo(D-Phe(1)-Pro(2)-X(3)-x(4)-Asn(5)-Gln(6)-X(7)-Val(8)-X(9)-Leu(10)) with Trp(3,4)/Phe(3,4) in the aromatic dipeptide unit, Lys(9)/Orn(9) as their cationic residue and Tyr (tyrocidines), Trp (tryptocidines) or Phe (phenicidines) in position 7. Previous studies indicated they have a broad antifungal spectrum with the peptides containing a Tyr residue in position 7 being more active than those with a Phe or Trp residue in this position. Detailed analysis of antifungal inhibition parameters revealed that Phe(3)-D-Phe(4) in the aromatic dipeptide unit lead to more consistent activity against the three filamentous fungi in this study. These peptides exhibited high membrane activity and fast leakage kinetics against model membranes emulating fungal membranes, with selectivity towards ergosterol containing membranes. More fluid membranes and doping of liposomes with the sphingolipid, glucosylceramide, led to a decreased permeabilising activity. Peptide-induced uptake of membrane impermeable dyes was observed in hyphae of both Fusarium solani and Botrytis cinerea, with uptake more pronounced at the hyphal growth tips that are known to contain ergosterol-sphigolipid rich lipid rafts. Tyrocidine interaction with these rafts may lead to the previously observed fungal hyperbranching. However, the leakage of model membranes and Bot. cinerea did not correlate directly with the antifungal inhibition parameters, indicating another target or mode of action. Proteinase K treatment of target fungi had a minimal influence or even improved the tyrocidine activity, ruling out a mannoprotein target in the fungal cell wall. β-glucanase treatment of Bot. cinerea did not significantly affect the tyrocidine activity, but there was a significant loss in activity towards the β-glucanase treated F. solani. This study showed the tyrocidine antifungal membrane activity is

  19. Banana Musa tissue culture plants enhanced by endophytic fungi

    African Journals Online (AJOL)

    Mo

    In vivo screenhouse experiments using tissue culture plants revealed that the endophytic strain ... some of these strains against both C. sordidus eggs and vermiform R. similis stages ... A 5 µl drop of spore suspension or sterile PDB was added.

  20. The relationship between swainsonine containing plants and endophytic fungi

    Science.gov (United States)

    Swainsonine, an indolizidine alkaloid with significant physiological activity, is an a-mannosidase and mannosidase II inhibitor that alters glycoprotein processing and causes lysosomal storage disease. Swainsonine is present in a number of plant families worldwide including the Convolvulaceae, Faba...

  1. Naturally occurring bioactive Cyclobutane-containing (CBC) alkaloids in fungi, fungal endophytes, and plants.

    Science.gov (United States)

    Dembitsky, Valery M

    2014-10-15

    This article focuses on the occurrence and biological activities of cyclobutane-containing (CBC) alkaloids obtained from fungi, fungal endophytes, and plants. Naturally occurring CBC alkaloids are of particular interest because many of these compounds display important biological activities and possess antitumour, antibacterial, antimicrobial, antifungal, and immunosuppressive properties. Therefore, these compounds are of great interest in the fields of medicine, pharmacology, medicinal chemistry, and the pharmaceutical industry. Fermentation and production of CBC alkaloids by fungi and/or fungal endophytes is also discussed. This review presents the structures and describes the activities of 98 CBC alkaloids.

  2. Host-Pathogen Interactions: VII. Plant Pathogens Secrete Proteins which Inhibit Enzymes of the Host Capable of Attacking the Pathogen.

    Science.gov (United States)

    Albersheim, P; Valent, B S

    1974-05-01

    The results presented demonstrate that microbial pathogens of plants have the ability to secrete proteins which effectively inhibit an enzyme synthesized by the host; an enzyme whose substrate is a constituent of the cell wall of the pathogen. The system in which this was discovered is the anthracnose-causing fungal pathogen (Colletotrichum lindemuthianum) and its host, the French bean (Phaseolus vulgaris). An endo-beta-1, 3-glucanase present in the bean leaves is specifically inhibited by a protein secreted by C. lindemuthianum. The cell walls of C. lindemuthianum are shown to be composed largely of a 1, 3-glucan.

  3. Antifungal activity of extracts from endophytic fungi associated with Smallanthus maintained in vitro as autotrophic cultures and as pot plants in the greenhouse.

    Science.gov (United States)

    Rosa, Luiz H; Tabanca, Nurhayat; Techen, Natascha; Pan, Zhiqiang; Wedge, David E; Moraes, Rita M

    2012-10-01

    The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely related to species of the genera Bionectria , Cladosporium , Colletotrichum , Fusarium , Gibberella , Hypocrea , Lecythophora , Nigrospora , Plectosphaerella , and Trichoderma . The endophytic assemblages of S. sonchifolius presented a greater diversity than the group isolated from S. uvedalius and demonstrated the presence of dominant generalist fungi. Extracts of all fungi were screened against the fungal plant pathogens. Ten extracts (41.6%) displayed antifungal activities; some of them had a broad antifungal activity. The phylotypes Lecythophora sp. 1, Lecythophora sp. 2, and Fusarium oxysporum were isolated from in vitro autotrophic cultures and displayed antifungal activity. The presence of bioactive endophytic fungi within S. sonchifolius and S. uvedalius suggests an ecological advantage against pathogenic attacks. This study revealed reduced numbers of endophytes in association with both Smallanthus species in controlled cultivation conditions compared with the endophytic communities of hosts collected in the wild environments. Even as reduced endophytic communities, these fungi continue to provide chemical protection for the host.

  4. Mycorrhizal and dark septate endophytic fungi under the canopies of desert plants in Mu Us Sandy Land of China

    Institute of Scientific and Technical Information of China (English)

    Yanqing WU; Tiantian LIU; Xueli HE

    2009-01-01

    Biodiversity of arbuscular mycorrhizal colonization and spore density was investigated in 20 desert plants (dominant or common species) collected from different locations of Mu Us Sandy Land of China. We observed three mycorrhizal types including Arum-type, Paris-type, and an intermediate type among the plants. Another type of potentially beneficial fungi associated with roots of all species was also observed, namely, dark septate endophytic fungi (DSEF). Of the 20 sample plants examined, all species were coinfected by the two target fungi (Arbuscular mycorrhizal fungi (AMF) colonization of Salixpsammophila and DSEF colonization of Periploca septum were as low as 4%). Based on this investigation, we speculated that the DSEF are ubiquitous in desert ecosystems and can co-occur with AMF in desert plants, functioning much like mycorrhizal fungi. Further studies will be required to elucidate interactional mechanisms with AMF and the mechanisms operating in desert ecosystem.

  5. Endophytic fungi from medicinal plant Bauhinia forficata : Diversity and biotechnological potential

    Science.gov (United States)

    Bezerra, Jadson D.P.; Nascimento, Carlos C.F.; Barbosa, Renan do N.; da Silva, Dianny C.V.; Svedese, Virgínia M.; Silva-Nogueira, Eliane B.; Gomes, Bruno S.; Paiva, Laura M.; Souza-Motta, Cristina M.

    2015-01-01

    Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential. PMID:26221088

  6. Endophytic fungi from medicinal plant Bauhinia forficata: Diversity and biotechnological potential.

    Science.gov (United States)

    Bezerra, Jadson D P; Nascimento, Carlos C F; Barbosa, Renan do N; da Silva, Dianny C V; Svedese, Virgínia M; Silva-Nogueira, Eliane B; Gomes, Bruno S; Paiva, Laura M; Souza-Motta, Cristina M

    2015-03-01

    Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen's index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.

  7. Endophytic fungi from medicinal plant Bauhinia forficata: Diversity and biotechnological potential

    Directory of Open Access Journals (Sweden)

    Jadson D.P. Bezerra

    2015-03-01

    Full Text Available Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds, comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%, Aspergillus ochraceus (7.37%, Gibberella fujikuroi (10.53%, Myrothecium verrucaria (10.53% and Trichoderma piluliferum(7.37%. Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus, Gibberella baccata, Penicillium commune, and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes. Thirteen species showed proteolytic activity, particularly Phoma putaminum. Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri. All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum. It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.

  8. Computational analysis of the fructosyltransferase enzymes in plants, fungi and bacteria.

    Science.gov (United States)

    Alméciga-Díaz, Carlos J; Gutierrez, Angela M; Bahamon, Isabella; Rodríguez, Alexander; Rodríguez, Mauro A; Sánchez, Oscar F

    2011-09-15

    Fructosyltransferases (FTases) are enzymes produced by plants, fungi, and bacteria, which are responsible for the synthesis of fructooligosaccharides. In this study, we conducted a computational analysis of reported sequences for FTase from a diverse source of organisms, such as plants, fungi, and bacteria. Ninety-one proteins sequences were obtained; all belonging to the glycoside hydrolase 32 (GH32) and 68 (GH68) families. The sequences were grouped in seven clades, five for plants, one for fungi, and one for bacteria. Our findings suggest that FTases from fungi and bacteria likely evolved from dicotyledonous FTases. The analysis of catalytic domains A, D and E, which contain the amino acids involved in the catalytic binding site, allowed the identification of clade-specific conserved characteristics. The analysis of sequence motifs involved in donor/acceptor molecule affinity showed that additional sequences could be responsible for donor/acceptor molecule affinity. The correlation of this large set of FTases allowed to identify additional features that might be used for the identification and classification of new FTases, and to improve the understanding of these valuable enzymes.

  9. Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the clavicipitaceae reveals dynamics of alkaloid loci.

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    Christopher L Schardl

    Full Text Available The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species, which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne, and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species, a morning-glory symbiont (Periglandula ipomoeae, and a bamboo pathogen (Aciculosporium take, and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories

  10. Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the clavicipitaceae reveals dynamics of alkaloid loci.

    Science.gov (United States)

    Schardl, Christopher L; Young, Carolyn A; Hesse, Uljana; Amyotte, Stefan G; Andreeva, Kalina; Calie, Patrick J; Fleetwood, Damien J; Haws, David C; Moore, Neil; Oeser, Birgitt; Panaccione, Daniel G; Schweri, Kathryn K; Voisey, Christine R; Farman, Mark L; Jaromczyk, Jerzy W; Roe, Bruce A; O'Sullivan, Donal M; Scott, Barry; Tudzynski, Paul; An, Zhiqiang; Arnaoudova, Elissaveta G; Bullock, Charles T; Charlton, Nikki D; Chen, Li; Cox, Murray; Dinkins, Randy D; Florea, Simona; Glenn, Anthony E; Gordon, Anna; Güldener, Ulrich; Harris, Daniel R; Hollin, Walter; Jaromczyk, Jolanta; Johnson, Richard D; Khan, Anar K; Leistner, Eckhard; Leuchtmann, Adrian; Li, Chunjie; Liu, JinGe; Liu, Jinze; Liu, Miao; Mace, Wade; Machado, Caroline; Nagabhyru, Padmaja; Pan, Juan; Schmid, Jan; Sugawara, Koya; Steiner, Ulrike; Takach, Johanna E; Tanaka, Eiji; Webb, Jennifer S; Wilson, Ella V; Wiseman, Jennifer L; Yoshida, Ruriko; Zeng, Zheng

    2013-01-01

    The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the

  11. Hexose transporters of a hemibiotrophic plant pathogen: functional variations and regulatory differences at different stages of infection.

    Science.gov (United States)

    Lingner, Ulrike; Münch, Steffen; Deising, Holger B; Sauer, Norbert

    2011-06-10

    Plant pathogenic fungi use a wide range of different strategies to gain access to the carbon sources of their host plants. The hemibiotrophic maize pathogen Colletotrichum graminicola (teleomorph Glomerella graminicola) colonizes its host plants, and, after a short biotrophic phase, switches to destructive, necrotrophic development. Here we present the identification of five hexose transporter genes from C. graminicola, CgHXT1 to CgHXT5, the functional characterization of the encoded proteins, and detailed expression studies for these genes during vegetative and pathogenic development. Whereas CgHXT4 is expressed under all conditions analyzed, transcript abundances of CgHXT1 and CgHXT3 are transiently up-regulated during the biotrophic phase, and CgHXT2 and CgHXT5 are expressed exclusively during necrotrophic development. Analyses of the encoded proteins characterized CgHXT5 as a low-affinity/high-capacity hexose transporter with a narrow substrate specificity for glucose and mannose. In contrast, CgHXT1 to CgHXT3 are high affinity/low capacity transporters that also accept other substrates, including fructose, galactose, or xylose. CgHXT4, the largest of the identified proteins, has only little transport activity and may function as a sugar sensor. Phylogenetic studies revealed hexose transporters closely related to the five CgHXT proteins also in other pathogenic fungi suggesting conserved functions of these proteins during fungal pathogenesis.

  12. Babaco (Vasconcellea heilbornii var. pentagona Badillo. Major plant pathogens and control strategies

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    Angel Rolando Robles-Carrión

    2016-04-01

    Full Text Available This work was carried out with the aim of documenting the importance of Babaco for the Andean region, its main plant pathogens, and possible control strategies and integrated management, emphasizing the MVB. Was performed a systematic review of scientific papers published in prestigious journals and thesis diplomas, masters and doctorates from various universities. As a criterion for inclusion-exclusion studies were taken into account in the genus Vasconcellea. Ecuador has 15 of the 21 described species, of which more than half are located in the province of Loja. Vascular Wilt Babaco (MVB is caused by a complex of Fusarium fungi that interact with the plant. There are no integrated management strategies for Vascular Wilt Babaco scientifically proven.

  13. Efficacy of Origanum essential oils for inhibition of potentially pathogenic fungi

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    Nadábia Almeida B Souza

    2010-09-01

    Full Text Available This study aimed to assess the efficacy of O. vulgare L. and O. majorana L. essential oil in inhibiting the growth and survival of potentially pathogenic fungal strains and also sought to evaluate the possible mechanisms involved in the establishment of the antifungal property of the tested essential oils through assays of osmotic stability and morphogenesis. Test strains included in this study were Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 and Cladosporium herbarium ATCC 26362. O. vulgare essential oil presented a MIC value of 80 µL/mL, while for O. majorana this was 160 µL/mL. C. krusei LM-09 was the only strain resistant to all assayed concentrations of both essential oils. O. vulgare and O. majorana essential oil at their MIC values provided a cidal effect against C. albicans ATCC 7645 after 4 h of exposure. O. vulgare essential oil at 80 µL/mL exhibited 100 % inhibition of the radial mycelia growth of T. rubrum ATCC 28184 and M. canis LM-36 for 14 days. Assayed fungus strain protected by sorbitol (osmo-protectant agent grew in media containing higher concentrations of O. vulgare and O. majorana essential oil in comparison to media without sorbitol, suggesting some specificity of these essential oils for targeting cell wall in the fungi cell. Main morphological changes observed under light microscopy provided by the essential oil of O. vulgare in A. flavus LM-02 were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. These results suggest that essential oils from Origanum could be regarded as a potential antifungal compound for controlling the growth of pathogen fungi and the occurrence of mycoses.O objetivo deste estudo foi observar a eficácia do óleo essencial de O

  14. Molecular diversity at the plant-pathogen interface.

    Science.gov (United States)

    McDowell, John M; Simon, Stacey A

    2008-01-01

    Plants have evolved a robust innate immune system that exhibits striking similarities as well as significant differences with various metazoan innate immune systems. For example, plants are capable of perceiving pathogen-associated molecular patterns through pattern recognition receptors that bear structural similarities to animal Toll-like receptors. In addition, plants have evolved a second surveillance system based on cytoplasmic "NB-LRR" proteins (nucleotide-binding, leucine-rich repeat) that are structurally similar to animal nucleotide-binding and oligomerization domain (NOD)-like receptors. Plant NB-LRR proteins do not detect PAMPs; rather, they perceive effector proteins that pathogens secrete into plant cells to promote virulence. This review summarizes the current state of knowledge about the molecular functionality and evolution of these immune surveillance genes.

  15. Plant Extract Control of the Fungi Associated with Different Egyptian Wheat Cultivars Grains

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    Mohamed Baka Zakaria Awad

    2014-07-01

    Full Text Available Grain samples of 14 Egyptian wheat cultivars were tested for seed-borne fungi. The deep freezing method was used. Five seed-borne fungi viz., Aspergillus flavus, A. niger, Curvularia lunata, Fusarium moniliforme and Penicillium chrysogenum were isolated from the wheat cultivars viz., Bani Suef 4, Bani Suef 5, Gemmiza 7, Gemmiza 9, Gemmiza 10, Giza 168, Misr 1, Misr 2, Sakha 93, Sakha 94, Shandaweel 1, Sids 1, Sids 2 and Sids 3. A. flavus, A. niger and F. moniliforme were the most prevalent fungal species. Their incidence ranged from 21.0-53.5%, 16.0-37.5%, and 12.0-31.0%, respectively. The antifungal potential of water extracts from aerial parts of five wild medicinal plants (Asclepias sinaica, Farsetia aegyptia, Hypericum sinaicum, Phagnalon sinaicum, and Salvia aegyptiaca were collected from the Sinai Peninsula, Egypt. The antifungal potential of water extracts from the aerial parts of these five plants were tested in the laboratory against the dominant fungi isolated from the wheat cultivars. All the aqueous plant extracts significantly (p ≤ 0.05 reduced the incidence of the tested seed-borne fungi. But the extract of Asclepias sinaica exhibited the most antifungal activity on tested fungi at all concentrations used when compared with other plant extracts. Maximum infested grain germination was observed in Giza 168 and minimum in Bani Suef 5. Treating grains with plant extract of A. sinaica (10% enhanced the percentage of grain germination of all cultivars in both laboratory and pot experiments. Maximum root and shoot length of seedlings was recorded in Bani Suef 4 during fungal infestation or treatment by plant extract. For one hour before sowing or storage, the aqueous extract of A. sinaica can be used to treat wheat grains, to reduce the fungal incidence. Aqueous extracts of the aerial parts of selected medicinal plants, particularly A. sinaica, are promising for protecting Egyptian wheat grain cultivars against major seed-borne fungi

  16. Arbuscular mycorrhizal fungi alter the competitive hierarchy among old-field plant species.

    Science.gov (United States)

    Stanescu, Sabina; Maherali, Hafiz

    2017-02-01

    Inoculation with arbuscular mycorrhizal (AM) fungi is known to increase the species diversity of plant communities. One mechanism that can increase the likelihood of species co-existence, and thus species diversity, is a trade-off between competitive ability and the magnitude of plant growth response to AM fungal inoculation. By suppressing the growth of strong competitors while simultaneously enhancing the growth of weak competitors, this trade-off would cause the competitive hierarchy to be less pronounced in soil inoculated with AM fungi relative to non-inoculated conditions. To test whether such a trade-off exists, we quantified competitive abilities and mycorrhizal growth response (MGR) among 21 species that co-occur in old fields in southern Ontario. Competitive ability was determined by calculating competitive effect (CE), or the degree to which each species suppressed the biomass of a common phytometer species, Plantago lanceolata. Higher CE values represent stronger competitive ability. Old-field species varied in their ability to suppress the biomass of the phytometer and MGR was generally positive. There was a statistically significant negative correlation between CE in non-inoculated soil and MGR (r = -0.49, P = 0.02). In addition, variance in CE was 73% lower in soil inoculated with AM fungi compared to non-inoculated soil (P = 0.0023). These findings support the hypothesis that AM fungi weaken strong competitors while enhancing the performance of weak competitors. Because this trade-off compressed the competitive hierarchy among old-field species in soil inoculated with AM fungi, it may be a mechanism by which mycorrhizal fungi enhance species evenness and diversity.

  17. Archaea and bacteria mediate the effects of native species root loss on fungi during plant invasion.

    Science.gov (United States)

    Mamet, Steven D; Lamb, Eric G; Piper, Candace L; Winsley, Tristrom; Siciliano, Steven D

    2017-05-01

    Although invasive plants can drive ecosystem change, little is known about the directional nature of belowground interactions between invasive plants, native roots, bacteria, archaea and fungi. We used detailed bioinformatics and a recently developed root assay on soils collected in fescue grassland along a gradient of smooth brome (Bromus inermis Leyss) invasion to examine the links between smooth brome shoot litter and root, archaea, bacteria and fungal communities. We examined (1) aboveground versus belowground influences of smooth brome on soil microbial communities, (2) the importance of direct versus microbe-mediated impacts of plants on soil fungal communities, and (3) the web of roots, shoots, archaea, bacteria and fungi interactions across the A and B soil horizons in invaded and non-invaded sites. Archaea and bacteria influenced fungal composition, but not vice versa, as indicated by redundancy analyses. Co-inertia analyses suggested that bacterial-fungal variance was driven primarily by 12 bacterial operational taxonomic units (OTUs). Brome increased bacterial diversity via smooth brome litter in the A horizon and roots in the B horizon, which then reduced fungal diversity. Archaea increased abundance of several bacterial OTUs, and the key bacterial OTUs mediated changes in the fungi's response to invasion. Overall, native root diversity loss and bacterial mediation were more important drivers of fungal composition than were the direct effects of increases in smooth brome. Critically, native plant species displacement and root loss appeared to be the most important driver of fungal composition during invasion. This causal web likely gives rise to the plant-fungi feedbacks, which are an essential factor determining plant diversity in invaded grassland ecosystems.

  18. CHARACTERIZATION OF SOIL TRICHODERMA ISOLATES FOR POTENTIAL BIOCONTROL OF PLANT PATHOGENS

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    S. Matei

    2011-12-01

    Full Text Available Various fungal strains belonging to genus Trichoderma act as biological control agents for soil born plant pathogens. Two new strains of Trichoderma harzianum (T.h. and Trichoderma viride (T.v. were isolated from forest soils in Ilfov county and their morphological aspects, enzymatic and antagonistic activity were examined. Current chemical fungicides had constantly, in time, less influence on pathogens due to their diversity, adaptability and increasing resistance.The paper present the morphological characterization of two strains of Trichoderma isolated from forest soils. Growth rate was higher in strain T.v.SP456 (0,675mm/h than in strain T.h.P8 (0,505mm/h when fungi were grown on Czapek culture medium.Morphological description is completed with photographs of colonies in Petri plates and microscopical aspects of fungal structures belonging to Trichoderma strains SP456 and P8.Comparative aspects concerning the level of main enzymes released by T.h. isolate P8 and T.v.SP456 in liquid culture media showed differences as a function of genetic structure of each fungal isolate. The optimum culture media for inducing peroxidase, polyphenol-oxidase, β-1,3-glucanase activity in T.v.SP456 isolate was Czapek and PDA for phenil-alanin-ammonium-oxidase and chitinase. T.v.SP456 was more efficient than T.h.P8 concerning enzymes activity.The interaction between Trichoderma fungal strains SP456 and P8 and strawberry plant pathogen strains, three belonging to Botrytis cinerea (S1, P1, P2 and one to Phytophtora spp. were examined, also. Both Trichoderma strains act as mycoparasites for plant pathogens. The inhibition percent of radial growth was higher for T.v.SP456 when compared with T.h.P8 for almost all pathogenic isolates.

  19. Spread of plant pathogens and insect vectors at the northern range margin of cypress in Italy

    Science.gov (United States)

    Zocca, Alessia; Zanini, Corrado; Aimi, Andrea; Frigimelica, Gabriella; La Porta, Nicola; Battisti, Andrea

    2008-05-01

    The Mediterranean cypress ( Cupressus sempervirens) is a multi-purpose tree widely used in the Mediterranean region. An anthropogenic range expansion of cypress has taken place at the northern margin of the range in Italy in recent decades, driven by ornamental planting in spite of climatic constraints imposed by low winter temperature. The expansion has created new habitats for pathogens and pests, which strongly limit tree survival in the historical (core) part of the range. Based on the enemy release hypothesis, we predicted that damage should be lower in the expansion area. By comparing tree and seed cone damage by pathogens and pests in core and expansion areas of Trentino, a district in the southern Alps, we showed that tree damage was significantly higher in the core area. Seed cones of C. sempervirens are intensively colonized by an aggressive and specific pathogen (the canker fungus Seiridium cardinale, Coelomycetes), associated with seed insect vectors Megastigmus wachtli (Hymenoptera Torymidae) and Orsillus maculatus (Heteroptera Lygaeidae). In contrast, we observed lower tree damage in the expansion area, where a non-aggressive fungus ( Pestalotiopsis funerea, Coelomycetes) was more frequently associated with the same insect vectors. Our results indicate that both insect species have a great potential to reach the range margin, representing a continuous threat of the arrival of fungal pathogens to trees planted at extreme sites. Global warming may accelerate this process since both insects and fungi profit from increased temperature. In the future, cypress planted at the range margin may then face similar pest and pathogen threats as in the historical range.

  20. In Vitro Studies of Chromone-Tetrazoles against Pathogenic Protozoa, Bacteria, and Fungi

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    Pedro A. Cano

    2015-07-01

    Full Text Available In vitro studies to fourteen previously synthesized chromone-tetrazoles and four novel fluorine-containing analogs were conducted against pathogenic protozoan (Entamoeba histolytica, pathogenic bacteria (Pseudomonas aeruginosa, and Staphylococcus aureus, and human fungal pathogens (Sporothrix schenckii, Candida albicans, and Candida tropicalis, which have become in a serious health problem, mainly in tropical countries.

  1. In Vitro Studies of Chromone-Tetrazoles against Pathogenic Protozoa, Bacteria, and Fungi.

    Science.gov (United States)

    Cano, Pedro A; Islas-Jácome, Alejandro; Rangel-Serrano, Ángeles; Anaya-Velázquez, Fernando; Padilla-Vaca, Felipe; Trujillo-Esquivel, Elías; Ponce-Noyola, Patricia; Martínez-Richa, Antonio; Gámez-Montaño, Rocío

    2015-07-08

    In vitro studies to fourteen previously synthesized chromone-tetrazoles and four novel fluorine-containing analogs were conducted against pathogenic protozoan (Entamoeba histolytica), pathogenic bacteria (Pseudomonas aeruginosa, and Staphylococcus aureus), and human fungal pathogens (Sporothrix schenckii, Candida albicans, and Candida tropicalis), which have become in a serious health problem, mainly in tropical countries.

  2. An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen.

    Science.gov (United States)

    Tollot, Marie; Wong Sak Hoi, Joanne; van Tuinen, Diederik; Arnould, Christine; Chatagnier, Odile; Dumas, Bernard; Gianinazzi-Pearson, Vivienne; Seddas, Pascale M A

    2009-01-01

    Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. Using degenerated primers and rapid amplification of cDNA ends, we isolated the full-length cDNA of an STE12-like gene, GintSTE, from Glomus intraradices and profiled GintSTE expression by real-time and in situ RT-PCR. GintSTE activity and function were investigated by heterologous complementation of a yeast ste12Delta mutant and a Colletotrichum lindemuthianum clste12Delta mutant. * Sequence data indicate that GintSTE is similar to STE12 from hemibiotrophic plant pathogens, especially Colletotrichum spp. Introduction of GintSTE into a noninvasive mutant of C. lindemuthianum restored fungal infectivity of plant tissues. GintSTE expression was specifically localized in extraradicular fungal structures and was up-regulated when G. intraradices penetrated roots of wild-type Medicago truncatula as compared with an incompatible mutant. Results suggest a possible role for GintSTE in early steps of root penetration by AM fungi, and that pathogenic and symbiotic fungi may share common regulatory mechanisms for invasion of plant tissues.

  3. Photodynamic treatment with phenothiazinium photosensitizers kills both ungerminated and germinated microconidia of the pathogenic fungi Fusarium oxysporum, Fusarium moniliforme and Fusarium solani.

    Science.gov (United States)

    de Menezes, Henrique Dantas; Tonani, Ludmilla; Bachmann, Luciano; Wainwright, Mark; Braga, Gilberto Úbida Leite; von Zeska Kress, Marcia Regina

    2016-11-01

    The search for alternatives to control microorganisms is necessary both in clinical and agricultural areas. Antimicrobial photodynamic treatment (APDT) is a promising light-based approach that can be used to control both human and plant pathogenic fungi. In the present study, we evaluated the effects of photodynamic treatment with red light and four phenothiazinium photosensitizers (PS): methylene blue (MB), toluidine blue O (TBO), new methylene blue N (NMBN) and the phenothiazinium derivative S137 on ungerminated and germinated microconidia of Fusarium oxysporum, F. moniliforme, and F. solani. APDT with each PS killed efficiently both the quiescent ungerminated microconidia and metabolically active germinated microconidia of the three Fusarium species. Washing away the unbound PS from the microconidia (both ungerminated and germinated) before red light exposure reduced but did not prevent the effect of APDT. Subcelullar localization of PS in ungerminated and germinated microconidia and the effects of photodynamic treatment on cell membranes were also evaluated in the three Fusarium species. APDT with MB, TBO, NMBN or S137 increased the membrane permeability in microconidia and APDT with NMBN or S137 increased the lipids peroxidation in microconidia of the three Fusarium species. These findings expand the understanding of photodynamic inactivation of filamentous fungi with phenothiazinium PS. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Land-use intensity and host plant identity interactively shape communities of arbuscular mycorrhizal fungi in roots of grassland plants.

    Science.gov (United States)

    Vályi, Kriszta; Rillig, Matthias C; Hempel, Stefan

    2015-03-01

    We studied the effect of host plant identity and land-use intensity (LUI) on arbuscular mycorrhizal fungi (AMF, Glomeromycota) communities in roots of grassland plants. These are relevant factors for intraradical AMF communities in temperate grasslands, which are habitats where AMF are present in high abundance and diversity. In order to focus on fungi that directly interact with the plant at the time, we investigated root-colonizing communities. Our study sites represent an LUI gradient with different combinations of grazing, mowing, and fertilization. We used massively parallel multitag pyrosequencing to investigate AMF communities in a large number of root samples, while being able to track the identity of the host. We showed that host plants significantly differed in AMF community composition, while land use modified this effect in a plant species-specific manner. Communities in medium and low land-use sites were subsets of high land-use communities, suggesting a differential effect of land use on the dispersal of AMF species with different abundances and competitive abilities. We demonstrate that in these grasslands, there is a small group of highly abundant, generalist fungi which represent the dominating species in the AMF community.

  5. Bacteriocins active against plant pathogenic bacteria.

    Science.gov (United States)

    Grinter, Rhys; Milner, Joel; Walker, Daniel

    2012-12-01

    Gram-negative phytopathogens cause significant losses in a diverse range of economically important crop plants. The effectiveness of traditional countermeasures, such as the breeding and introduction of resistant cultivars, is often limited by the dearth of available sources of genetic resistance. An alternative strategy to reduce loss to specific bacterial phytopathogens is to use narrow-spectrum protein antibiotics such as colicin-like bacteriocins as biocontrol agents. A number of colicin-like bacteriocins active against phytopathogenic bacteria have been described previously as have strategies for their application to biocontrol. In the present paper, we discuss these strategies and our own recent work on the identification and characterization of candidate bacteriocins and how these potent and selective antimicrobial agents can be effectively applied to the control of economically important plant disease.

  6. Phosphate Solubilization Potential of Rhizosphere Fungi Isolated from Plants in Jimma Zone, Southwest Ethiopia

    Science.gov (United States)

    Elias, Firew

    2016-01-01

    Phosphorus (P) is one of the major bioelements limiting agricultural production. Phosphate solubilizing fungi play a noteworthy role in increasing the bioavailability of soil phosphates for plants. The present study was aimed at isolating and characterizing phosphate solubilizing fungi from different rhizospheres using both solid and liquid Pikovskaya (PVK) medium. A total of 359 fungal isolates were obtained from 150 rhizosphere soil samples of haricot bean, faba bean, cabbage, tomato, and sugarcane. Among the isolates, 167 (46.52%) solubilized inorganic phosphate. The isolated phosphate solubilizing fungi belonged to genera of Aspergillus (55.69%), Penicillium spp. (23.35%), and Fusarium (9.58%). Solubilization index (SI) ranged from 1.10 to 3.05. Isolates designated as JUHbF95 (Aspergillus sp.) and JUFbF59 (Penicillium sp.) solubilized maximum amount of P 728.77 μg·mL−1 and 514.44 μg mL−1, respectively, from TCP (tricalcium phosphate) after 15 days of incubation. The highest (363 μg mL−1) soluble-P was released from RP with the inoculation of JUHbF95 in the PVK broth after 10 days of incubation. The present study indicated the presence of diverse plant associated P-solubilizing fungi that may serve as potential biofertilizers. PMID:27688771

  7. Pathogenic amoebae in power-plant cooling lakes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tyndall, R.L.; Willaert, E.; Stevens, A.R.

    1981-06-01

    Cooling waters and associated algae and sediments from four northern and four southern/western electric power plants were tested for the presence of pathogenic amoebae. Unheated control waters and algae/sediments from four northern and five southern/western sites were also tested. When comparing results from the test versus control sites, a significantly higher proportion (P less than or equal to 0.05) of the samples from the test sites were positive for thermophilic amoeba, thermophilic Naegleria and pathogenic Naegleria. The difference in number of samples positive for thermophilic Naegleria between heated and unheated waters, however, was attributable predominantly to the northern waters and algae/sediments. While two of four northern test sites yielded pathogenic Naegleria, seven of the eight isolates were obtained from one site. Seasonality effects relative to the isolation of the pathogen were also noted at this site. One pathogen was isolated from a southwestern test site. Pathogens were not isolated from any control sites. Some of the pathogenic isolates were analyzed serologically and classified as pathogenic Naegleria fowleri. Salinity, pH, conductivity, and bacteriological profiles did not obviously correlate with the presence or absence of pathogenic Naegleria. While thermal addition was significantly associated with the presence of thermophilic Naegleria (P less than or equal to 0.05), the data implicate other as yet undefined parameters associated with the presence of the pathogenic thermophile. Until further delineation of these parameters is effected, generalizations cannot be made concerning the effect of thermal impact on the growth of pathogenic amoeba in a particular cooling system.

  8. Levels of rhizome endophytic fungi fluctuate in Paris polyphylla var. yunnanensis as plants age

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-02-01

    Full Text Available Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and -independent (metagenomics approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes (four, six, and eight years old. In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments (90 per age class. Based on morphological and genetic characteristics, Fusarium oxysporum (46.55% frequency of occurrence was the predominant endophyte, followed by Leptodontidium sp. (8.66% and Trichoderma viride (6.81%. Colonization of endophytic fungi was maximized in the eight-year-old rhizomes (33.33% when compared with four-year-old (21.21% and six-year-old (15.15% rhizomes. Certain fungal species were present only at particular ages. For example, Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of (metagenomics community DNA extracted from different-aged samples revealed that, at the class level, the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.

  9. Sex-specific interaction between arbuscular mycorrhizal and dark septate fungi in the dioecious plant Antennaria dioica (Asteraceae).

    Science.gov (United States)

    Vega-Frutis, R; Varga, S; Kytöviita, M-M

    2013-05-01

    Male and female plants of dioecious species often differ in their resource demands and this has been linked to secondary sexual dimorphism, including sex-specific interactions with other organisms such as herbivores and pollinators. However, little is known about the interaction between dioecious plants and fungal root endophytes. Plants may be simultaneously colonised by arbuscular mycorrhizal (AM) and dark septate (DS) fungi. While it is well established that AM mutualism involves reciprocal transfer of photosynthates and mineral nutrients between roots of host plants and these fungi, the role of DS fungi remains controversial. Here, we report the temporal and spatial variation in AM and DS fungi in female, male and non-reproductive Antennaria dioica plants in three natural populations in Finland during flowering and after seed production. Females had higher colonisation by AM fungi, but lower colonisation by DS fungi than male and non-reproductive plants. The higher AM colonisation was observed during flowering, and this difference varied among populations. Our results suggest that females and males of A. dioica interact with AM and DS fungi differently and that this relationship is dependent on soil fertility.

  10. Arbuscular mycorrhizal fungi alter phosphorus relations of broomsedge (Andropogon virginicus L.) plants

    Energy Technology Data Exchange (ETDEWEB)

    Ning, J.C.; Cumming, J.R.

    2001-07-01

    Broomsedge (Andropogon virginicus L.) is a dominant grass revegetating many abandoned coal-mined lands in West Virginia, USA. Residual soils on such sites are often characterized by low pH, low nutrients, and high aluminium. Experiments were conducted to assess the resistance of broomsedge to limited phosphorus (Pi) availability and to investigate the role that arbuscular mycorrhizal (AM) fungi play in aiding plant growth under low Pi conditions. Pregerminated mycorrhizal and non-mycorrhizal seedlings were grown in a sand-culture system with nutrient solutions containing Pi concentrations ranging from 10 to 100 {mu}M for 8 weeks. Non-mycorrhizal plants exhibited severe inhibition of growth under Pi limitation ({lt}60 {mu}M). Colonization by AM fungi greatly enhanced host plant growth at low Pi concentrations, but did not benefit growth when Pi was readily available (100 {mu}M). In comparison to non-mycorrhizal plants, mycorrhizal plants had higher phosphorus use efficiency at low Pi concentrations and maintained nearly constant tissue nutrient concentrations across the gradient of Pi concentrations investigated. Manganese (Mn) and sodium (Na) accumulated in shoots of nonmycorrhizal plants under Pi limitation. Mycorrhizal plants exhibited lower instantaneous Pi uptake rates and significantly lower C-min values compared to non-mycorrhizal plants. These patterns suggest that the symbiotic association between broomsedge roots and AM fungi effectively maintains nutrient homeostasis through changes in physiological properties, including nutrient uptake, allocation and use. The mycorrhizal association is thus a major adaptation that allows broomsedge to become established on infertile mined lands.

  11. Allelopathic effects of essential oil from Eucalyptus grandis × E.urophylla on pathogenic fungi and pest insects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This study on the allelopathic effects and chemical components of the essential oil from Eucalyptus grandis × E.urophylla shows that the leaf oil emulsion of E.grandis × E.urophylla can inhibit the proliferation of pathogenic fungi Fusarium oxysporum,Pyriculerie grisea,Glorosprium musa rum and Phytophthora capsici.Pupation and feeding of the pest insects Spodopteralitura Fabricius and Helicoverpa armigera Hubner are shown to be affected with restraining effects which increase with the increasing levels of oil concentration.A GC/MS analysis of the leaf oil indicated that the main components,with a relative content of≥3%,were alloocimene (43.22%),α-pinene (13.63%),γ-terpinene (5.49%),(E)-3,7-dimethyl-2,6-octadien-1-ol (3.58%),β-fenchyl alcohol (4.58%),and 2-amino-3,5-dicyano-6-(4-methoxyphenoxy)-pyridine (3.67%).Terpenes played an important role in the inhibitory effects of E.grandis × E.urophylla essential oil on pathogenic fungi and pest insects.Poor biodiversity of eucalyptus plantations is a function of allelopathy.

  12. Plant integrity: an important factor in plant-pathogen interactions

    DEFF Research Database (Denmark)

    Orlowska, Elzbieta Zofia; Llorente, Briardo; Cvitanich, Cristina

    2013-01-01

    the hemibiotrophic oomycete pathogen Phytophthora infestans. Furthermore, in the Sarpo Mira–P. infestans interactions, the plant’s meristems, the stalks or both, seem to be associated with the development of the hypersensitive response and both the plant’s roots and shoots contain antimicrobial compounds when...

  13. Recently fixed carbon allocation in strawberry plants and concurrent inorganic nitrogen uptake through arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Tomè, Elisabetta; Tagliavini, Massimo; Scandellari, Francesca

    2015-05-01

    Most crop species form a symbiotic association with arbuscular mycorrhizal (AM) fungi, receiving plant photosynthate and exchanging nutrients from the soil. The plant carbon (C) allocation to AM fungi and the nitrogen feedback are rarely studied together. In this study, a dual (13)CO2 and (15)NH4(15)NO3 pulse labeling experiment was carried out to determine the allocation of recent photosynthates to mycorrhizal hyphae and the translocation of N absorbed by hyphae to strawberry plants. Plants were grown in pots in which a 50 μm mesh net allowed the physical separation of the mycorrhizal hyphae from the roots in one portion of the pot. An inorganic source of (15)N was added to the hyphal compartment at the same time of the (13)CO2 pulse labeling. One and seven days after pulse labeling, the plants were destructively harvested and the amount of the recently fixed carbon (C) and of the absorbed N was determined. (13)C allocated to belowground organs such as roots and mycorrhizal hyphae accounted for an average of 10%, with 4.3% allocated to mycorrhizal hyphae within the first 24h after the pulse labeling. Mycorrhizae absorbed labeled inorganic nitrogen, of which almost 23% was retained in the fungal mycelium. The N uptake was linearly correlated with the (13)C fixed by the plants suggesting a positive correlation between a plant photosynthetic rate and the hyphal absorption capacity.

  14. Air-conditioning vs. presence of pathogenic fungi in hospital operating theatre environment.

    Science.gov (United States)

    Gniadek, Agnieszka; Macura, Anna B

    2011-01-01

    Infections related to modern surgical procedures present a difficult problem for contemporary medicine. Infections acquired during surgery represent a risk factor related to therapeutical interventions. Eradication of microorganisms from hospital operating theatre environment may contribute to reduction of infections as the laminar flow air-conditioning considerably reduces the number of microorganisms in the hospital environment. The objective of the study was to evaluate the occurrence of fungi in air-conditioned operating theatre rooms. The study was carried out in one of the hospitals in Krak6w during December 2009. Indoor air samples and imprints from the walls were collected from five operating theatre rooms. A total of fifty indoor air samples were collected with a MAS-100 device, and twenty five imprints from the walls were collected using a Count Tact method. Fungal growth was observed in 48 air samples; the average numbers of fungi were within the range of 5-100 c.f.u. in one cubic metre of the air. Fungi were detected only in four samples of the wall imprints; the number of fungi was 0.01 c.f.u. per one square centimetre of the surface. The mould genus Aspergillus was most frequently isolated, and the species A. fumigatus and A. versicolor were the dominating ones. To ensure microbiological cleanness of hospital operating theatre, the air-conditioning system should be properly maintained. Domination of the Aspergillus fungi in indoor air as well as increase in the number of moulds in the samples taken in evenings (p < 0.05) may suggest that the room decontamination procedures were neglected.

  15. Advances in Genomics of Entomopathogenic Fungi.

    Science.gov (United States)

    Wang, J B; St Leger, R J; Wang, C

    2016-01-01

    Fungi are the commonest pathogens of insects and crucial regulators of insect populations. The rapid advance of genome technologies has revolutionized our understanding of entomopathogenic fungi with multiple Metarhizium spp. sequenced, as well as Beauveria bassiana, Cordyceps militaris, and Ophiocordyceps sinensis among others. Phylogenomic analysis suggests that the ancestors of many of these fungi were plant endophytes or pathogens, with entomopathogenicity being an acquired characteristic. These fungi now occupy a wide range of habitats and hosts, and their genomes have provided a wealth of information on the evolution of virulence-related characteristics, as well as the protein families and genomic structure associated with ecological and econutritional heterogeneity, genome evolution, and host range diversification. In particular, their evolutionary transition from plant pathogens or endophytes to insect pathogens provides a novel perspective on how new functional mechanisms important for host switching and virulence are acquired. Importantly, genomic resources have helped make entomopathogenic fungi ideal model systems for answering basic questions in parasitology, entomology, and speciation. At the same time, identifying the selective forces that act upon entomopathogen fitness traits could underpin both the development of new mycoinsecticides and further our understanding of the natural roles of these fungi in nature. These roles frequently include mutualistic relationships with plants. Genomics has also facilitated the rapid identification of genes encoding biologically useful molecules, with implications for the development of pharmaceuticals and the use of these fungi as bioreactors. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Cell-to-cell communication in plants, animals, and fungi: a comparative review

    Science.gov (United States)

    Bloemendal, Sandra; Kück, Ulrich

    2013-01-01

    Cell-to-cell communication is a prerequisite for differentiation and development in multicellular organisms. This communication has to be tightly regulated to ensure that cellular components such as organelles, macromolecules, hormones, or viruses leave the cell in a precisely organized way. During evolution, plants, animals, and fungi have developed similar ways of responding to this biological challenge. For example, in higher plants, plasmodesmata connect adjacent cells and allow communication to regulate differentiation and development. In animals, two main general structures that enable short- and long-range intercellular communication are known, namely gap junctions and tunneling nanotubes, respectively. Finally, filamentous fungi have also developed specialized structures called septal pores that allow intercellular communication via cytoplasmic flow. This review summarizes the underlying mechanisms for intercellular communication in these three eukaryotic groups and discusses its consequences for the regulation of differentiation and developmental processes.

  17. Cell-to-cell communication in plants, animals, and fungi: a comparative review.

    Science.gov (United States)

    Bloemendal, Sandra; Kück, Ulrich

    2013-01-01

    Cell-to-cell communication is a prerequisite for differentiation and development in multicellular organisms. This communication has to be tightly regulated to ensure that cellular components such as organelles, macromolecules, hormones, or viruses leave the cell in a precisely organized way. During evolution, plants, animals, and fungi have developed similar ways of responding to this biological challenge. For example, in higher plants, plasmodesmata connect adjacent cells and allow communication to regulate differentiation and development. In animals, two main general structures that enable short- and long-range intercellular communication are known, namely gap junctions and tunneling nanotubes, respectively. Finally, filamentous fungi have also developed specialized structures called septal pores that allow intercellular communication via cytoplasmic flow. This review summarizes the underlying mechanisms for intercellular communication in these three eukaryotic groups and discusses its consequences for the regulation of differentiation and developmental processes.

  18. COMBINED EFFECTS OF PLANT GROWTH PROMOTING RHIZOBACTERIA AND FUNGI ON MUNG BEAN (VIGNA RADIATA L.

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Gangwar, Gaurav Bhushan Jaspal Singh *, Sudhir K. Upadhyay and A.P. Singh

    2013-11-01

    Full Text Available In the present study, screened PGPR and Fungi were influence the growth of Mung bean (Vigna radiata plant in the pot. Two rhizobacteria viz. Rhizobium sp., Pseudomonas putida and three fungi Aspergillus niger, Rhizopus sp. and Trichoderma viride were isolated and purified. The effect of inoculation of different strains of bacteria and fungus on growth responses of Vigna radiata under pot condition was enumerated. The result revealed that the single and dual inoculation of these microbial strains enhances the plant growth in terms of root and shoot length and dry-biomass. The maximum increase in root length (up to 86.57%, shoot length (up to 56.91%, root dry weight (up to 94.42%, and shoot dry weight (up to 56.09% was observed in response to dual inoculation of Pseudomonas putida with Trichoderma viride compared to uninoculated control.

  19. Unraveling Plant Responses to Bacterial Pathogens through Proteomics

    Directory of Open Access Journals (Sweden)

    Tamara Zimaro

    2011-01-01

    Full Text Available Plant pathogenic bacteria cause diseases in important crops and seriously and negatively impact agricultural production. Therefore, an understanding of the mechanisms by which plants resist bacterial infection at the stage of the basal immune response or mount a successful specific R-dependent defense response is crucial since a better understanding of the biochemical and cellular mechanisms underlying these interactions will enable molecular and transgenic approaches to crops with increased biotic resistance. In recent years, proteomics has been used to gain in-depth understanding of many aspects of the host defense against pathogens and has allowed monitoring differences in abundance of proteins as well as posttranscriptional and posttranslational processes, protein activation/inactivation, and turnover. Proteomics also offers a window to study protein trafficking and routes of communication between organelles. Here, we summarize and discuss current progress in proteomics of the basal and specific host defense responses elicited by bacterial pathogens.

  20. Unraveling plant responses to bacterial pathogens through proteomics

    KAUST Repository

    Zimaro, Tamara

    2011-11-03

    Plant pathogenic bacteria cause diseases in important crops and seriously and negatively impact agricultural production. Therefore, an understanding of the mechanisms by which plants resist bacterial infection at the stage of the basal immune response or mount a successful specific R-dependent defense response is crucial since a better understanding of the biochemical and cellular mechanisms underlying these interactions will enable molecular and transgenic approaches to crops with increased biotic resistance. In recent years, proteomics has been used to gain in-depth understanding of many aspects of the host defense against pathogens and has allowed monitoring differences in abundance of proteins as well as posttranscriptional and posttranslational processes, protein activation/inactivation, and turnover. Proteomics also offers a window to study protein trafficking and routes of communication between organelles. Here, we summarize and discuss current progress in proteomics of the basal and specific host defense responses elicited by bacterial pathogens. Copyright 2011 Tamara Zimaro et al.

  1. Avirulence proteins of plant pathogens: determinants of victory and defeat

    NARCIS (Netherlands)

    Luderer, R.; Joosten, M.H.A.J.

    2001-01-01

    The simplest way to explain the biochemical basis of the gene-for-gene concept is by direct interaction between a pathogen-derived avirulence (Avr) gene product and a receptor protein, which is encoded by the matching resistance (R) gene of the host plant. The number