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Sample records for alternaria alternata pathogenic

  1. Molecular genetic characterisation of the Asc locus of tomato conferring resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici

    NARCIS (Netherlands)

    Biezen, E.A. van der; Overduin, B.; Kneppers, T.J.A.; Mesbah, L.A.; Nijkamp, H.J.J.; Hille, J.

    1994-01-01

    The Alternaria stem canker disease of tomato is caused by the fungal pathogen Alternaria alternata f. sp. lycopersici and its host-selective AAL-toxins. Resistance to the pathogen and insensitivity to the toxins are conferred by the Asc locus on chromosome 3L. Sensitivity to AAL-toxins is a relative

  2. Most AAL toxin-sensitive Nicotiana species are resistant to the tomato fungal pathogen Alternaria alternata f. sp lycopersici

    NARCIS (Netherlands)

    Brandwagt, Bas F.; Kneppers, Tarcies J.A.; Weerden, Gerard M. van der; Nijkamp, H. John J.; Hille, Jacques

    2001-01-01

    The phytopathogenic fungus Alternaria alternata f. sp, lycopersici produces AAL toxins required to colonize susceptible tomato (Lycopersicon esculentum) plants, AAL toxins and fumonisins of the unrelated fungus Fusarium moniliforme are sphinganine-analog mycotoxins (SAMs), which are toxic for some p

  3. PATHOGENIC BEHAVIOUR OF ALTERNARIA ALTERNATA AND PHYTOTOXICITY OF ITS CULTURE FILTRATES ON LEPIDIUM SATIVUM: A MEDICINAL HERB OF IMMENSE PHARMACOLOGICAL POTENTIAL

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    U. K. KHARE

    2013-01-01

    Full Text Available Alternaria alternata causing leaf spot in Lepidium sativum was isolated and purified from diseased leaf tissuescollected from collected from the Medicinal and Aromatic plant garden, Department of Crop and HerbalPhysiology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (M.P.; isolated and purified on Potato DextroseAgar media. Microscopic examination of a seven days old culture revealed hyaline, septate and branched mycelia,conidiophores with 30.0-80.2 µ length and 3-6 µ width and obclavate to obpyriform conidia (23-30 x 9.2-12.7µ with short conical beak arranged in acropetal fashion. The isolated culture and its culture filtrates wereinoculated to germinated seedlings of chandrasur and also incubated with healthy leaves in a growth chamber.Typical symptoms of Alternaria leaf spot was observed both in in vivo and in vitro inoculated plantlets anddetached leaves respectively. Chlorosis on the hypocotyls and leaves were observed. A. alternata was consistentlyreisolated from symptomatic leaf tissues on PDA. Thus, an efficient and reliable screening method wherein theeffect of the selection agent (pathogen culture, culture filtrate/phytotoxin was demonstrated providing soundpharmacological rational in terms of micro propagation and development of Alternaria resistant L. sativum, animportant medicinal herb.

  4. Alternaria alternata infection associated osteomyelitis of maxilla: A rare disease entity

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    Vidhi Chhabra

    2013-01-01

    Full Text Available Alternaria alternata is one of the rarest fungi associated with paranasal sinusitis. Alternaria species are pigmented (also known as dematiaceous or phaeoid filamentous fungi, which are well-known soil saprophytes and plant pathogens that infrequently cause infection in humans mainly, cutaneous lesions. We present a case of osteomyelitis of maxilla caused by a rare fungus- A. alternata in a diabetic patient with poor glycemic control who was successfully treated with antifungal and surgical debridement over the period of 6 months.

  5. Requisitos nutricionais para o fungo Alternaria alternata Nutritional requirements for the fungus Alternaria alternata

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    Celia Maria Maganhotto de S. Silva

    1999-03-01

    Full Text Available Uma linhagem de Alternaria alternata (ALT A foi cultivada em meio sintético com diferentes fontes de C, N e vitaminas. O crescimento micelial foi avaliado durante sete dias após a semeadura e a esporulação no décimo dia de incubação. O meio sintético básico suplementado com biotina, NH4Cl e os carboidratos maltose e glicose suportaram um bom crescimento micelial (em média 0,75 cm/dia. Galactose e arabinose induziram significativamente a produção de esporos (mL-1, da ordem de 5,0 x10³ e 4,1 x 10³, respectivamente. Nas diferentes fontes de vitamina e N não houve diferenças significativas quanto ao crescimento micelial e à esporulação.A strain of Alternaria alternata (ALT A was tested using different sources of C, N and vitamins in order to find a medium for its growth and sporulation. The mycelial growth was evaluated for seven days after sowing and the sporulation on the tenth day of incubation. Among various C, N and vitamins compounds tested, highest mycelial growth was achieved with maltose and glucose (C, NH4Cl (N and biotin, with an average ratio of 0.75 cm/day. Sporulation reached highest values with galactose and arabinose (5.0 x 10³ and 4.1 x 10³ conidia mL-1, respectively. Others vitamins and N compounds did not influence the growth and sporulation.

  6. Proteomic analysis of Alternaria alternata (Fr.) Keissler responds to COS fumigation.

    Science.gov (United States)

    Liu, Tao; Li, Li; Qu, Haixia; Zhan, Guoping; Liu, Bo; Wang, Yuejin

    2010-01-01

    Carbonyl sulfide (COS) is a new fumigant which has been a potential alternative to methyl bromide and phosphine in many applications. In this study, we investigated the fungitoxicity of COS towards the pathogen of pear black spot disease Alternaria alternata (Fr.) Keissler (A. alternata). Moreover, proteomic analysis and RT-PCR was performed and our results showed that during the fumigation, the regulation of 21 proteins in protein expression and mRNA accumulation levels is involved, which respond to growth inhibition caused by COS. These results provide new clues for the mechanism of the fungitoxicity of COS.

  7. Leaf proteome profiling of transgenic mint infected with Alternaria alternata.

    Science.gov (United States)

    Sinha, Ragini; Bhattacharyya, Dipto; Majumdar, Aparupa Bose; Datta, Riddhi; Hazra, Saptarshi; Chattopadhyay, Sharmila

    2013-11-20

    The genus Mentha has been widely used in food, flavor, culinary, cosmetic and pharmaceutical industries. Substantial damage to this crop happened regularly due to environmental stresses like metal toxicity and pathogen attack. Here, an approach has been taken to raise transgenic mint over-expressing γ-glutamyl-cysteine synthetase (γ-ECS), the rate-limiting enzyme of GSH biosynthesis, resulted enhanced GSH content and its in planta expression confers significant tolerance towards abiotic/biotic stresses viz. metal toxicity - Cd, Zn as well as against infection of Alternaria alternata and Rhizoctonia solani. A differential proteomic analysis through 2-DE and MALDI TOF-TOF MSMS was performed to focus on the altered abundance of functionally important protein species in control and infected transgenic mint. Results showed a significant variation in the protein profile of the infected transgenic plant as compared to the wild/control transgenic counterpart. In addition to protein species related to stress and defense, redox regulation, transcription factors and energy & metabolism, protein species related to signaling and gene regulation as well as cell division also showed differential accumulation in infected transgenic. Hence, proteomics can be used as a tool to decipher the mechanism of action of GSH in providing tolerance against a necrotrophic fungus, A. alternata in transgenic mint. The reported work describes a comparative proteomics of non-model unsequenced plants like Mentha. There is a comparative protein profile between transgenic and its wild counterparts under control and infected condition. The work has an impact in crop proteomics and also tries to explain the application of proteomic approach to decipher the mechanism by which a foreign metabolite mediates stress tolerance in plant under control and infected condition. This article is part of a Special Issue entitled: Translational Plant Proteomics. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Trichoderma harzianum as a biocontrol agent against Alternaria alternata on tobacco

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    Jugoslav Ziberoski

    2012-06-01

    Full Text Available Trichoderma fungi are the most popular agents used in a biological control. Therefore, our aim was to determine an impact of Trichoderma harzianum on the fungus Alternaria alternata - a causing agent of the brown spot disease on tobacco. In vitro analyses were made in several variants of double culture, in order to study the effect of difusible and volatile metabolites. There was strong reducing effect on the development of A.alternata with various mechanisms of antagonistic influence. The volatile metabolites have also shown reducing effect. Some abnormalities were observed in the pathogen's morphology both in difusible and volatile metabolites. The strong reducing effect of T.harzianum towards A. alternata can be applied in biological control of this pathogen.

  9. A Major Facilitator Superfamily Transporter-Mediated Resistance to Oxidative Stress and Fungicides Requires Yap1, Skn7, and MAP Kinases in the Citrus Fungal Pathogen Alternaria alternata

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    Chen, Li-Hung; Tsai, Hsieh-Chin; Yu, Pei-Ling

    2017-01-01

    Major Facilitator Superfamily (MFS) transporters play an important role in multidrug resistance in fungi. We report an AaMFS19 gene encoding a MFS transporter required for cellular resistance to oxidative stress and fungicides in the phytopathogenic fungus Alternaria alternata. AaMFS19, containing 12 transmembrane domains, displays activity toward a broad range of substrates. Fungal mutants lacking AaMFS19 display profound hypersensitivities to cumyl hydroperoxide, potassium superoxide, many singlet oxygen-generating compounds (eosin Y, rose Bengal, hematoporphyrin, methylene blue, and cercosporin), and the cell wall biosynthesis inhibitor, Congo red. AaMFS19 mutants also increase sensitivity to copper ions, clotrimazole, fludioxonil, and kocide fungicides, 2-chloro-5-hydroxypyridine (CHP), and 2,3,5-triiodobenzoic acid (TIBA). AaMFS19 mutants induce smaller necrotic lesions on leaves of a susceptible citrus cultivar. All observed phenotypes in the mutant are restored by introducing and expressing a wild-type copy of AaMFS19. The wild-type strain of A. alternata treated with either CHP or TIBA reduces radial growth and formation and germination of conidia, increases hyphal branching, and results in decreased expression of the AaMFS19 gene. The expression of AaMFS19 is regulated by the Yap1 transcription activator, the Hog1 and Fus3 mitogen-activated protein (MAP) kinases, the ‘two component’ histidine kinase, and the Skn7 response regulator. Our results demonstrate that A. alternata confers resistance to different chemicals via a membrane-bound MFS transporter. PMID:28060864

  10. [Cellulase and xylanase activity of phytopathogenic and endophytic fungal strains of Alternaria alternata (Fr.) Keissler].

    Science.gov (United States)

    Kurchenko, I M; Sokolova, O V; Zhdanova, N M; Iarynchyn, A M; Iovenko, O M

    2008-01-01

    A comparative analysis of cellulase and xylanase activity of 25 fungal strains of phytopathogenic and endophytic Alternaria alternata had been realized for the first time using the qualitative reactions. The rate of their linear growth on the media with carboxymethylcellulose or xylane had been studied. The cellulase and xylanase activities clearly depended on the distinct strain. The absence of distinct dependence of cellulase and xylanase activities on the species and organs of host plants was demonstrated. The majority of investigated strains of A. alternata did not possess a cellulase activity or the latter was low, but as a whole the phytopathogenic strains were more active than endophytic ones. Xylanase activity was considerable for the fungal strains of all trophyc groups. It was shown that the level of xylanase activity cannot become a biochemical marker of the A. alternata isolate pathogenicity.

  11. Morphogenetic Alterations of Alternaria alternata Exposed to Dicarboximide Fungicide, Iprodione

    Science.gov (United States)

    Kim, Eunji; Lee, Hye Min; Kim, Young Ho

    2017-01-01

    Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4–5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G. PMID:28167893

  12. Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata.

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    Peever, T L; Carpenter-Boggs, L; Timmer, L W; Carris, L M; Bhatia, A

    2005-05-01

    ABSTRACT Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata.

  13. Genomic and transcriptomic analyses of the tangerine pathotype of Alternaria alternata in response to oxidative stress

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    Wang, Mingshuang; Sun, Xuepeng; Yu, Dongliang; Xu, Jianping; Chung, Kuangren; Li, Hongye

    2016-01-01

    The tangerine pathotype of Alternaria alternata produces the A. citri toxin (ACT) and is the causal agent of citrus brown spot that results in significant yield losses worldwide. Both the production of ACT and the ability to detoxify reactive oxygen species (ROS) are required for A. alternata pathogenicity in citrus. In this study, we report the 34.41 Mb genome sequence of strain Z7 of the tangerine pathotype of A. alternata. The host selective ACT gene cluster in strain Z7 was identified, which included 25 genes with 19 of them not reported previously. Of these, 10 genes were present only in the tangerine pathotype, representing the most likely candidate genes for this pathotype specialization. A transcriptome analysis of the global effects of H2O2 on gene expression revealed 1108 up-regulated and 498 down-regulated genes. Expressions of those genes encoding catalase, peroxiredoxin, thioredoxin and glutathione were highly induced. Genes encoding several protein families including kinases, transcription factors, transporters, cytochrome P450, ubiquitin and heat shock proteins were found associated with adaptation to oxidative stress. Our data not only revealed the molecular basis of ACT biosynthesis but also provided new insights into the potential pathways that the phytopathogen A. alternata copes with oxidative stress. PMID:27582273

  14. Alternaria alternata invasive fungal infection in a patient with Fanconi's anemia after an unrelated bone marrow transplant.

    Science.gov (United States)

    Ferreira, Isabelina de Sousa; Teixeira, Gilda; Abecasis, Manuel

    2013-02-01

    Alternaria spp. have emerged as opportunistic pathogens particularly in immunosuppressed patients, such as bone marrow transplant recipients. The authors present a case of Alternaria alternata in a patient with Fanconi's anemia, who received antifungal prophylaxis with posaconazole after an unrelated bone marrow transplantation, followed by empirical antifungal treatment with caspofungin when persistent fever emerged until cutaneous lesions eventually appeared. At that time there were clinical reasons to assume that the patient had an infection with an emerging fungus. This consideration triggered a change of the antifungal therapy from caspofungin to liposomal amphotericin B. After collecting sufficient evidence for the presence of an invasive fungal infection by A. alternata and given the severity of neutropenia and other immunosuppression, oral posaconazole was added to liposomal amphotericin B. The course of disease in this case suggests a possibly synergistic interaction between liposomal amphotericin B and posaconazole when administered simultaneously to treat an invasive systemic infection by Alternaria spp. in immunocompromised patients.

  15. Sesquiterpene emissions from Alternaria alternata and Fusarium oxysporum: Effects of age, nutrient availability, and co-cultivation.

    Science.gov (United States)

    Weikl, Fabian; Ghirardo, Andrea; Schnitzler, Jörg-Peter; Pritsch, Karin

    2016-02-26

    Alternaria alternata is one of the most studied fungi to date because of its impact on human life - from plant pathogenicity to allergenicity. However, its sesquiterpene emissions have not been systematically explored. Alternaria regularly co-occurs with Fusarium fungi, which are common plant pathogens, on withering plants. We analyzed the diversity and determined the absolute quantities of volatile organic compounds (VOCs) in the headspace above mycelial cultures of A. alternata and Fusarium oxysporum under different conditions (nutrient rich and poor, single cultures and co-cultivation) and at different mycelial ages. Using stir bar sorptive extraction and gas chromatography-mass spectrometry, we observed A. alternata to strongly emit sesquiterpenes, particularly during the early growth stages, while emissions from F. oxysporum consistently remained comparatively low. The emission profile characterizing A. alternata comprised over 20 sesquiterpenes with few effects from nutrient quality and age on the overall emission profile. Co-cultivation with F. oxysporum resulted in reduced amounts of VOCs emitted from A. alternata although its profile remained similar. Both fungi showed distinct emission profiles, rendering them suitable biomarkers for growth-detection of their phylotype in ambient air. The study highlights the importance of thorough and quantitative evaluations of fungal emissions of volatile infochemicals such as sesquiterpenes.

  16. Efficacy of a pyrimidine derivative to control spot disease on Solanum melongena caused by Alternaria alternata

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    Nemat M. Hassan

    2013-07-01

    Full Text Available The pyrimidine derivative (4,6-dimethyl-N-phenyldiethyl pyrimidine, DPDP was tested as a foliar spray fungicide at 50 mg l−1 for protection of eggplant (Solanum melongena from spot disease caused by Alternaria alternata. Varied concentrations of DPDP (10–50 mg l−1 differentially inhibited mycelial growth, conidial count and conidial germination of A. alternata growth in vitro; the magnitude of inhibition increased with increasing concentration. In vivo, an experiment was conducted in pots using a complete block randomized design and repeated twice with three replications and four treatments (control, A. alternata alone, DPDP alone and combination of DPDP and A. alternata for 5 weeks (1 plant in pot × 3 pots per set (3 replications per treatment × 4 sets (4 treatments × 5 weeks × 2 experimental repetitions = 120 pots. In this experiment, 10-day-old eggplant seedlings were transplanted in pots and then inoculated with A. alternata, DPDP or their combination 1 week later. Leaves of the A. alternata-infected eggplant suffered from chlorosis, necrosis and brown spots during the subsequent 5 weeks. Disease intensity was obvious in infected leaves but withdrawn by DPDP. There were relationships between incidence and severity, greater in plant leaves infected A. alternata alone and diminished with the presence of DPDP. Moreover, the infection resulted in reductions in growth, decreases in contents of anthocyanins, chlorophylls, carotenoids and thiols as well as inhibitions in activities of superoxide dismutase (SOD, glutathione peroxidase (GPX and glutathione-S-transferase (GST. Nonetheless, the application of DPDP at 50 mg led to a recovery of the infected eggplant; the infection-induced deleterious effects were mostly reversed by DPDP. However, treatment with DPDP alone seemed with no significant impacts. Due to its safe use to host and the inhibition for the pathogen, DPDP could be suggested as an efficient fungicide for

  17. Proteome Analysis for Defense Response of Apple Leaves Induced by Alternaria Blotch ,Alternaria alternata Apple Pathotype

    Institute of Scientific and Technical Information of China (English)

    Caixia Zhang; Zhuang Li; Liyi Zhang; Yi Tian; Guodong Kang; Ying Chen; Peihua Cong

    2012-01-01

    Apple (Ma/us domestica) is considered a model fruit plant owing to its world-wide economic importance,and a large number of cultivars dominate world fruit production.To date,the cultivation of apple has been limited by many kinds of fungal diseases,and among the many fungal diseases affecting apple trees,Alternaria blotch,the disease caused by Alternaria alternata apple pathotype,is spreading worldwide and results in severe negative effect on apple production.Currently,management of a fungal disease such as Alternaria blotch mainly through traditional chemical control agents instead of using resistant cultivars.As in apple,the molecular mechanism of disease resistance against A.altemata apple pathotype has not been illustrated clearly,although most of the genes have been identified in apple,little is known about the biological roles for each protein in that plant.Considering that apple Altemaria blotch is the usual diseases influencing apple production,further studies about the interaction mechanism between the pathogen and its host,particularly some host self-defense response mechanisms which closely related to the anti-disease properties of apple should be performed.In this work we aimed to generate fundamental insights into the plant' s defense responses to infection with Altemaria blotch using a proteomics approach,to aid in the development and breeding of high-quality disease-resistant apple varieties.One seedlings which derived from the cross of ‘Huacui’ and ‘Golden Delicious’,with highly resistant,were chosen to be hosts for this study.The sample leaves were inoculated with spore suspension of A.altemata apple pathotype,and the control samples were treated with water instead of inoculums.Following inoculation,the samples were harvested 48 h after inoculation.The whole experiment was repeated three times in order to get a reliable result.The total soluble protein extracts prepared using modified phenol-precipitation procedures.Total protein extracts

  18. Scopoletin is a phytoalexin against Alternaria alternata in wild tobacco dependent on jasmonate signalling

    OpenAIRE

    Sun, Huanhuan; WANG, Lei; ZHANG, BAOQIN; Ma, Junhong; Hettenhausen, Christian; Cao, Guoyan; Sun, Guiling; Wu, Jianqiang; Wu, Jinsong

    2014-01-01

    Alternaria alternata (tobacco pathotype) is a necrotrophic fungus causing severe losses in Nicotiana species by infection of mature leaves. Similar to what has been observed in cultivated tobacco, N. tabacum, young leaves of wild tobacco, N. attenuata, were more resistant to A. alternata than mature leaves, and this was correlated with stronger blue fluorescence induced after infection. However, the nature of the fluorescence-emitting compound, its role in defence, and its regulation were not...

  19. Localization of melanin in conidia of Alternaria alternata using phage display antibodies.

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    Carzaniga, Raffaella; Fiocco, Daniela; Bowyer, Paul; O'Connell, Richard J

    2002-03-01

    Melanins derived from 1,8-dihydroxynaphthalene (DHN) are important for the pathogenicity and survival of fungi causing disease in both plants and animals. However, precise information on their location within fungal cell walls is lacking. To obtain antibodies for the immunocytochemical localization of melanin, 83 phage antibodies binding to 1,8-DHN were selected from a naive semisynthetic single-chain Fv (scFv) phage display library. Sequence analysis of the heavy chain binding domains of 17 antibodies showed a high frequency of positively charged amino acids. One antibody, designated M1, was characterized in detail. M1 bound specifically to 1,8-DHN in competitive inhibition enzyme-linked immunosorbent assays, showing no cross-reaction with nine structurally related phenolic compounds. Epitope recognition required two hydroxyl groups in a 1,8 configuration. M1 also bound to naturally occurring melanin isolated from mycelia of Alternaria alternata, suggesting that epitopes remain accessible in polymerized melanin. Transmission electron microscopy-immunogold labeling, using M1 in the form of soluble scFv fragments, showed that melanin was located in the septa and outer (primary) walls of wild-type A. alternata conidia, but not those of an albino mutant, AKT88-1. The M1 antibody provides a new tool for detecting melanized pathogens in plant and animal tissues and for precisely mapping the distribution of the polymer within spores, appressoria, and hyphae.

  20. Alternaria alternata allergens: Markers of exposure, phylogeny and risk of fungi-induced respiratory allergy.

    Science.gov (United States)

    Gabriel, Marta F; Postigo, Idoia; Tomaz, Cândida T; Martínez, Jorge

    2016-01-01

    Alternaria alternata spores are considered a well-known biological contaminant and a very common potent aeroallergen source that is found in environmental samples. The most intense exposure to A. alternata allergens is likely to occur outdoors; however, Alternaria and other allergenic fungi can colonize in indoor environments and thereby increase the fungal aeroallergen exposure levels. A consequence of human exposure to fungal aeroallergens, sensitization to A. alternata, has been unequivocally associated with increased asthma severity. Among allergenic proteins described in this fungal specie, the major allergen, Alt a 1, has been reported as the main elicitor of airborne allergies in patients affected by a mold allergy and considered a marker of primary sensitization to A. alternata. Moreover, A. alternata sensitization seems to be a triggering factor in the development of poly-sensitization, most likely because of the capability of A. alternata to produce, in addition to Alt a 1, a broad and complex array of cross-reactive allergens that present homologs in several other allergenic sources. The study and understanding of A. alternata allergen information may be the key to explaining why sensitization to A. alternata is a risk factor for asthma and also why the severity of asthma is associated to this mold. Compared to other common environmental allergenic sources, such as pollens and dust mites, fungi are reported to be neglected and underestimated. The rise of the A. alternata allergy has enabled more research into the role of this fungal specie and its allergenic components in the induction of IgE-mediated respiratory diseases. Indeed, recent research on the identification and characterization of A. alternata allergens has allowed for the consideration of new perspectives in the categorization of allergenic molds, assessment of exposure and diagnosis of fungi-induced allergies.

  1. A rare case of allergic bronchopulmonary mycosis caused by Alternaria alternata.

    NARCIS (Netherlands)

    Chowdhary, A.; Agarwal, K.; Randhawa, H.S.; Kathuria, S.; Gaur, S.N.; Najafzadeh, M.J.; Roy, P.; Arora, N.; Khanna, G.; Meis, J.F.G.M.

    2012-01-01

    A rare case of allergic bronchopulmonary mycosis (ABPM), caused by Alternaria alternata, is reported in an immunocompetent resident of Delhi. Her complaints included a generalized, urticarial skin rash and occasional pain in the right lower chest. Her differential count showed eosinophils, 22%; abso

  2. Determination of Alternaria Brown Spot (Alternaria alternata f.sp. citri) Disease on Minneola Tangelo in Çukurova Region

    OpenAIRE

    ERKILIÇ, Ali; CANIHOŞ, Yeter; BİÇİCİ, Mehmet

    1998-01-01

    In this study, the incidence and severity of Alternaria brown spot disease (Alternaria alternata f.sp. citri) in the Çukurova region were determined. Thirty-five Minneola tangelo orchards, with a total area of 2497 da, in 24 different locations were surveyed for this purpose. Leaf infections in all orchards were observed in the spring flushing period. Disease severity was found to be 0-10 % in 10 orchards, 11-20 % in 10 orchards, 21-30 % in 7 orchards, 31-40 % in 5 orchards, 42.5 % in 1 orch...

  3. Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina.

    Science.gov (United States)

    Broggi, Leticia Elvira; González, Héctor Horacio Lucas; Resnik, Silvia Liliana; Pacin, Ana

    2007-03-01

    A mycological survey was carried out at Entre Ríos province, Argentina, on sorghum grain, maize, rice, soybean seeds and on freshly harvested and stored wheat. The isolation frequencies and relative densities of species belonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and other fungi were calculated. Alternaria alternata was the major fungal species isolated from sorghum, rice, soybean seeds and on freshly harvested wheat, and a low incidence of Fusarium species was observed on the same substrates. In maize the major fungal species isolated was Fusarium verticillioides. The high incidence levels of A. alternata observed,suggest that it may be necessary to determine, among other mycotoxins, if Alternaria toxins occur in these commodities.

  4. Systemic jasmonic acid modulation in mycorrhizal tomato plants and its role in induced resistance against Alternaria alternata.

    Science.gov (United States)

    Nair, A; Kolet, S P; Thulasiram, H V; Bhargava, S

    2015-05-01

    Tomato plants colonised with the arbuscular mycorrhizal (AM) fungus Glomus fasciculatum show systemic induced resistance to the foliar pathogen Alternaria alternata, as observed in interactions of other AM-colonised plants with a range of pathogens. The role of jasmonic (JA) and salicylic (SA) acid in expression of this mycorrhiza-induced resistance (MIR) against A. alternata was studied by measuring: (i) activity of enzymes reported to be involved in their biosynthesis, namely lipoxygenase (LOX) and phenylammonia lyase (PAL); and (ii) levels of methyl jasmonate (MeJA) and SA. Transcript abundance of some defence genes associated with JA and SA response pathways were also studied. Both LOX and PAL activity increased twofold in response to pathogen application to control plants. AM-colonised plants had three-fold higher LOX activity compared to control plants, but unlike controls, this did not increase further in response to pathogen application. Higher LOX activity in AM-colonised plants correlated with four-fold higher MeJA in leaves of AM-colonised plants compared to controls. Treatment of plants with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM) led to 50% lower MeJA in both control and AM-colonised plants and correlated with increased susceptibility to A. alternata, suggesting a causal role for JA in expression of MIR against the pathogen. Genes involved in JA biosynthesis (OPR3) and response (COI1) showed six- and 42-fold higher expression, respectively, in leaves of AM-colonised plants compared to controls. AM-colonised plants also showed increased expression of the SA response gene PR1 and that of the wound-inducible polypeptide prosystemin. Our results suggest that the systemic increase in JA in response to AM colonisation plays a key role in expression of MIR against A. alternata.

  5. 枣缩果病初侵染链格孢菌的抗硫酸铜标记及稳定性%Resistance-Labeling and Stability of Jujube Shrunken-Fruit Disease Pathogen Alternaria alternata to Copper Sulfate

    Institute of Scientific and Technical Information of China (English)

    赵乐; 邢艺林; 李正楠; 郭金堂; 冉隆贤

    2016-01-01

    Objective]In order to determine the suitable agent and method for labeling Alternaria alternata,the pathogen of jujube shrunken-fruit disease,and to explore its primary infection period,the labeling system with copper sulfate in A. alternata was established,which will facilitate the study of infection mechanisms and pathogenicity of the pathogen,and effective management of the disease in the field. [Method]Copper sulfate was selected for the reagent of resistance-labeling in A. alternata wild type strain CN193 from the four fungicidal chemicals,i. e. copper sulfate,cobalt chloride,silver nitrate and cycloheximide by using inhibition zone method on PDA plate. With the inhibition method of spore germination,the mixture of conidial spore suspension with either 1. 0 mg·mL -1 ,1. 5 mg·mL -1 or 2. 0 mg·mL -1 concentration of the copper sulfate in a ratio of 1∶1 was dropped into concave slides. The germinated spores were scored after a 12 h incubation,and the initial concentration of copper sulfate was determined. A copper sulfate-resistant mutant strain CN193Cur was obtained by culturing the fungus on PDA medium containing copper sulfate from 1. 5 mg·mL -1 up to 4. 5 mg·mL -1 . The stability of the copper sulfate resistance of mutant CN193Cur was verified in the laboratory,and its infectivity was determined by pathogenicity test in a jujube plantation with inoculation of spore by spraying to the jujube flowers and stab-wounding on the surface of unripe jujube fruits,together with the analysis of BOX-PCR finger printing patterns.[Result]Copper sulfate had highly inhibitory effect on A. alternata while cobalt chloride and silver nitrate were less inhibitive,and cycloheximide was not inhibitive. The initial concentration of copper sulfate was set at 1. 5 mg·mL -1 , which produced a mutation rate of 12%,and the final concentration of copper sulfate in this study was 4. 5 mg·mL -1 . Inoculation tests showed that the mutant CN193Cur had the same pathogenicity as did

  6. Barrier disrupting effects of alternaria alternata extract on bronchial epithelium from asthmatic donors.

    Directory of Open Access Journals (Sweden)

    Marina S Leino

    Full Text Available Sensitization and exposure to the allergenic fungus Alternaria alternata has been associated with increased risk of asthma and asthma exacerbations. The first cells to encounter inhaled allergens are epithelial cells at the airway mucosal surface. Epithelial barrier function has previously been reported to be defective in asthma. This study investigated the contribution of proteases from Alternaria alternata on epithelial barrier function and inflammatory responses and compared responses of in vitro cultures of differentiated bronchial epithelial cells derived from severely asthmatic donors with those from non-asthmatic controls. Polarised 16HBE cells or air-liquid interface (ALI bronchial epithelial cultures from non-asthmatic or severe asthmatic donors were challenged apically with extracts of Alternaria and changes in inflammatory cytokine release and transepithelial electrical resistance (TER were measured. Protease activity in Alternaria extracts was characterised and the effect of selectively inhibiting protease activity on epithelial responses was examined using protease inhibitors and heat-treatment. In 16HBE cells, Alternaria extracts stimulated release of IL-8 and TNFα, with concomitant reduction in TER; these effects were prevented by heat-treatment of the extracts. Examination of the effects of protease inhibitors suggested that serine proteases were the predominant class of proteases mediating these effects. ALI cultures from asthmatic donors exhibited a reduced IL-8 response to Alternaria relative to those from healthy controls, while neither responded with increased thymic stromal lymphopoietin (TSLP release. Only cultures from asthmatic donors were susceptible to the barrier-weakening effects of Alternaria. Therefore, the bronchial epithelium of severely asthmatic individuals may be more susceptible to the deleterious effects of Alternaria.

  7. Transcriptomics Analysis of Apple Leaves in Response to Alternaria alternata Apple Pathotype Infection

    Science.gov (United States)

    Zhu, Longming; Ni, Weichen; Liu, Shuai; Cai, Binhua; Xing, Han; Wang, Sanhong

    2017-01-01

    Alternaria blotch disease of apple (Malus × domestica Borkh.), caused by the apple pathotype of Alternaria alternata, is one of the most serious fungal diseases to affect apples. To develop an understanding of how apples respond to A. alternata apple pathotype (AAAP) infection, we examined the host transcript accumulation over the period between 0 and 72 h post AAAP inoculation. Large-scale gene expression analysis was conducted of the compatible interaction between “Starking Delicious” apple cultivar and AAAP using RNA-Seq and digital gene expression (DGE) profiling methods. Our results show that a total of 9080 differentially expressed genes (DEGs) were detected (>two-fold and FDR PRs) genes and phenylpropanoid/cyanoamino acid /flavonoid biosynthesis, were activated during this process. Our study also suggested that the cell wall defensive vulnerability and the down-regulation of most PRs and HSP70s in “Starking Delicious” following AAAP infection might interpret its susceptible to AAAP. PMID:28163714

  8. Mitogen-activated protein kinase signaling pathways of the tangerine pathotype of Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Kuang-Ren Chung

    2013-06-01

    Full Text Available Mitogen-activated protein kinase (MAPK- mediated signaling pathways have been known to have important functions in eukaryotic organisms. The mechanisms by which the filamentous fungus Alternaria alternata senses and responds to environmental signals have begun to be elucidated. Available data indicate that A. alternata utilizes the Fus3, Hog1 and Slt2 MAPK-mediated signaling pathways, either separately or in a cooperative manner, for conidia formation, resistance to oxidative and osmotic stress, and pathogenesis to citrus. This review provides an overview of our current knowledge of MAPK signaling pathways, in conjunction with the two-component histidine kinase and the Skn7 response regulator, in the tangerine pathotype of A. alternata.

  9. PHYTOCHEMICAL SCREENING AND IN-VITRO ANTIFUNGAL INVESTIGATION OF PARTHENIUM HYSTEROPHORUS EXTRACTS AGAINST ALTERNARIA ALTERNATA

    Directory of Open Access Journals (Sweden)

    Singh Padma

    2013-07-01

    Full Text Available The extensive use of fungicides are polluting the environment and giving rise to undesirable biological effects on animal and human beings. Therefore use of plant extracts as biological control agents is being popularized in recent years. Alternaria alternata is reported for causing foliage disease in several important vegetables and crops. In an approach towards the development of eco friendly antifungal compound for controlling plant diseases caused by Alternaria alternata different extracts of Parthenium hysterophorus were tested for their antifungal potential. Parthenium hysterophorus is considered as an obnoxious weed, growing on waste land. The four different solvent extracts viz., aqueous, methanol, acetone and ethanol extracts of leaves of Parthenium hysterophorus was evaluated from antifungal potential against four different isolates of Alternaria alternata isolated from potato (Solanum tuberosum, onion (Allium cepa, tomato (Lycopersicon esculentum and mustard (Brassica compestris by food poison technique. The ethanolic extract showed complete inhibition against the four isolates i.e. 100 % followed by acetone and methanol extracts which was approximately 96 % and 76 % respectively, while aqueous extract do not showed any antifungal activity. Thus the result showed that the ethanolic extract was the best extract to be used. The phytochemical analysis revealed the presence of alkaloid, glycoside, steroid, saponin in varying concentration in different extracts which might be the cause of antifungal potential. The present study supports the use of leaf extract of Parthenium hysterophorus as biofungicides for the disease caused by Alternaria alternata. This will help to save the environment from chemical hazards as most of the synthetic fungicide constitute mercury, zinc etc which are toxic for nature.

  10. Scopoletin is a phytoalexin against Alternaria alternata in wild tobacco dependent on jasmonate signalling.

    Science.gov (United States)

    Sun, Huanhuan; Wang, Lei; Zhang, Baoqin; Ma, Junhong; Hettenhausen, Christian; Cao, Guoyan; Sun, Guiling; Wu, Jianqiang; Wu, Jinsong

    2014-08-01

    Alternaria alternata (tobacco pathotype) is a necrotrophic fungus causing severe losses in Nicotiana species by infection of mature leaves. Similar to what has been observed in cultivated tobacco, N. tabacum, young leaves of wild tobacco, N. attenuata, were more resistant to A. alternata than mature leaves, and this was correlated with stronger blue fluorescence induced after infection. However, the nature of the fluorescence-emitting compound, its role in defence, and its regulation were not clear. Silencing feruloyl-CoA 6'-hydroxylase 1 (F6'H1), the gene encoding the key enzyme for scopoletin biosynthesis, by virus-induced gene silencing (VIGS) revealed that the blue fluorescence was mainly emitted by scopoletin and its β-glycoside form, scopolin. Further analysis showed that scopoletin exhibited strong antifungal activity against A. alternata in vitro and in vivo. Importantly, jasmonic acid (JA) levels were highly elicited in young leaves but much less in mature leaves after infection; and fungus-elicited scopoletin was absent in JA-deficient plants, but was largely restored with methyl jasmonate treatments. Consistent with this, plants strongly impaired in JA biosynthesis and perception were highly susceptible to A. alternata in the same way scopoletin/scopolin-depleted VIGS F6'H1 plants. Furthermore, silencing MYC2, a master regulator of most JA responses, reduced A. alternata-induced NaF6'H1 transcripts and scopoletin. Thus, it is concluded that JA signalling is activated in N. attenuata leaves after infection, which subsequently regulates scopoletin biosynthesis for the defence against A. alternata partly through MYC2, and higher levels of scopoletin accumulated in young leaves account for their strong resistance. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. Screening of Antagonistic Bacteria from Phyllosphere towards Tobacco Brown Spot Fungus Alternaria alternata

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chengsheng; KONG Fanyu; LI Duochuan; WANG Jing; WANG Fenglong

    2006-01-01

    The possibility of employing antagonistic bacteria for the control of tobacco brown spot was studied. Approximately 136 strains of bacteria were isolated from phyllospheres of tobacco and 9 of these possessed high levels of antagonistic properties. They significantly reduced brown spot in detached tobacco leaves when artificially inoculated with Alternaria alternata. Culture filtrate of the most effective bacterial isolate which designated as Tpb88 was shown to be very efficient in inhibiting mycelial growth of A alternata in dual cultures. Culture filtrate of Tpb88 inhibited germination and germ tube elongation of A alternata. The results showed that the culture filtrate directly inhibited spore germination of A. alternata, especially during the first hours of the paired cultivation. The rate of antagonistic activity of culture filtrate of Tpb88 depended on its concentration in the mixture. The greatest inhibition of spore germination was ob served at the highest concentration of filtrate (filtrate to fungal spores inocula mixed in proportion 1: 50). These suggest that the hypothetic mechanism of Tpb88 against tobacco brown spot is to produce antagonistic substances.

  12. Plant extracts and essential oils on the control of Alternaria alternata , Alternaria dauci and on the germination and emergence of carrot seeds ( Daucus carota L.

    Directory of Open Access Journals (Sweden)

    Cristina Batista de Lima

    2016-05-01

    Full Text Available ABSTRACT: The present study aims to investigate garlic, pepper and coriander plant extract as well as neem and orange peel essential oil effective ness to control Alternaria alternata and Alternaria dauci and their efficiency during carrot seeds germination and emergence. A completely randomized design was used in three different experiments. The first experiment evaluated the effect of plant extracts and essential oils on the incidence of A. alternata and A. dauci . It was done by means of a factorial design applied to five treatments (garlic, pepper, coriander, and neem and orange peel essential oils at three concentrations (10, 20 and 30%.They also evaluated the controls untreated and with fungicide (Thiram.The second experiment evaluated the effect of the treatment at30% concentration on the germination and emergence of seedlings assessed on trays, and in the third experiment, the presence of A. alternata and A. dauci on the pericarp, endosperm and on the embryo. A. alternata showed higher incidence than A. dauci. The garlic extract and the orange essential oil showed the potential to control A. dauci and A. alternata, because their lower concentrations were able to sufficiently reduce the incidence of these fungi and because they do not affect carrot seeds germination and emergence. A. alternata conidia were found on the embryo (8%, pericarp (17% and endosperm (31%.

  13. Effects of {gamma}-radiation on the fungus Alternaria alternata in artificially inoculated cereal samples

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, R. [Departamento de Microbiologia, Instituto de Ciencias Biomedicas II, Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 1374, CEP 05508-900 Sao Paulo (Brazil)], E-mail: raquelbraghini@yahoo.com.br; Pozzi, C.R. [Instituto de Zootecnia, Rua Heitor Penteado 56, CEP 13460-000, Nova Odessa, Sao Paulo (Brazil); Aquino, S. [Instituto Adolfo Lutz, Av. Dr. Arnaldo, 355 , CEP 01246-902, Sao Paulo (Brazil); Rocha, L.O.; Correa, B. [Departamento de Microbiologia, Instituto de Ciencias Biomedicas II, Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 1374, CEP 05508-900 Sao Paulo (Brazil)

    2009-09-15

    The objective of this study was to evaluate the effects of different {gamma}-radiation doses on the growth of Alternaria alternata in artificially inoculated cereal samples. Seeds and grains were divided into four groups: Control Group (not irradiated), and Groups 1, 2 and 3, inoculated with an A. alternata spore suspension (1x10{sup 6} spores/mL) and exposed to 2, 5 and 10 kGy, respectively. Serial dilutions of the samples were prepared and seeded on DRBC (dichloran rose bengal chloramphenicol agar) and DCMA (dichloran chloramphenicol malt extract agar) media, after which the number of colony-forming units per gram was determined in each group. In addition, fungal morphology after irradiation was analyzed by scanning electron microscopy (SEM). The results showed that ionizing radiation at a dose of 5 kGy was effective in reducing the growth of A. alternata. However, a dose of 10 kGy was necessary to inhibit fungal growth completely. SEM made it possible to visualize structural alterations induced by the different {gamma}-radiation doses used.

  14. Sensitivities of baseline isolates and boscalid-resistant mutants of Alternaria alternata from pistachio to fluopyram, penthiopyrad, and fluxapyroxad

    NARCIS (Netherlands)

    Avenot, H.F.; Biggelaar, van den H.; Morgan, D.P.; Moral, J.; Joosten, M.H.A.J.; Michailides, T.J.

    2014-01-01

    Resistance of Alternaria alternata to boscalid, the first succinate dehydrogenase inhibitor (SDHI) fungicide labeled on pistachio, has become a common occurrence in California pistachio orchards and affects the performance of this fungicide. In this study, we established the baseline sensitivities o

  15. Alternaria

    NARCIS (Netherlands)

    Wenneker, M.

    2015-01-01

    The genus Alternaria consists of approximately 250 species and has a worldwide distribution. As plant pathogens Alternaria spp. infect a diversity of plants. Several different cultivated crops are affected, causing severe damage and crop losses. Alternaria leaf blotch and associated premature leaf d

  16. Alternaria

    NARCIS (Netherlands)

    Wenneker, M.

    2015-01-01

    The genus Alternaria consists of approximately 250 species and has a worldwide distribution. As plant pathogens Alternaria spp. infect a diversity of plants. Several different cultivated crops are affected, causing severe damage and crop losses. Alternaria leaf blotch and associated premature leaf

  17. Laboratory and Field Evaluation of Lupo Compound Miroemulsion(LCM) against Alternaria alternata in Tobacco

    Institute of Scientific and Technical Information of China (English)

    Lu; Jinqing; Dai; Yi; Li; Xiaoshuang; Liang; Huan; Cai; Junlong; Li; Qiang; Guo; Shengnan

    2014-01-01

    [Objective]The paper was to study effect of Lupo compound microemulsion( LCW) on Alternaria alternata. [Method]The activity of spore germination and mycelial growth was investigated by filter paper method and mycelial growth rate method,and field test was also conducted to determine the effect of LCW on tobacco plants. [Result]LCW could inhibit spore germination and mycelial growth of A. alternate. The higher concentration led to more severe reduction of sporulation and heavier inhibition against mycelial growth. When LCW was diluted into 200 times,inhibition rate of sporulation reached 91. 23%,and the inhibition rate of mycelial growth reached 93. 50%. Field test also proved that LCW had significant inhibitory effect on tobacco brown spot disease. [Conclusion]The study provided the reference for using botanical pesticide to control A. alternate in fields.

  18. Effects of methyl jasmonate and gums formed in stone fruit trees on in vitro ethylene production by mycelium of verticillium dahliae and alternaria alternata

    National Research Council Canada - National Science Library

    Elżbieta Węgrzynowicz-Lesiak; Anna Jarecka Boncela; Justyna Góraj; Marian Saniewski

    2013-01-01

    .... In this study, we describe the effect of methyl jasmonate (JA-Me) and gums formed in stone fruit trees on the growth and in vitro ethylene production by mycelium of Verticillium dahliae and Alternaria alternata...

  19. Discoloured seeds of amaranth plant infected by Alternaria alternata: physiological, histopathological alterations and fungal secondary metabolites associated or registered

    Directory of Open Access Journals (Sweden)

    Noelting María Cristina

    2016-07-01

    Full Text Available In the present study the aspects of discolouration that could influence both the production and consumption of amaranth were analyzed with the objectives to identify the presence of Alternaria alternata on seeds, to analyze possible changes in the anatomy of seed tissues and to detect the presence of fungal secondary metabolites. Component plating, histopathological and mycological analyses on discoloured seeds allowed i location of propagules of A. alternata in all seminal components; ii observation of hypertrophies in perisperm and embryo and iii determination of several fungal secondary metabolites, mainly high concentrations of tenuazonic acid. To our knowledge, the information presented in this paper, related to physiological, histopathological changes and fungal secondary metabolites on discoloured seeds of (Amaranthus mantegazzianus syn. A. caudatus subsp. mantegazzianus (Pass Hanelt affected by A. alternata, is the first worldwide record.

  20. Thymus vulgaris essential oil and thymol against Alternaria alternata (Fr.) Keissler: effects on growth, viability, early infection and cellular mode of action.

    Science.gov (United States)

    Perina, Fabiano J; Amaral, Douglas C; Fernandes, Rafael S; Labory, Claudia Rg; Teixeira, Glauco A; Alves, Eduardo

    2015-10-01

    In initial assays, Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant-pathogenic fungi and has reduced the fungal diseases to levels comparable with commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of TEO and its major compound thymol (TOH) at the cellular level using an ultrastructure approach. TEO from leaves and TOH had minimum inhibitory concentrations (MICs) of 500 and 250 µg mL(-1) respectively against A. alternata; under the same conditions, MIC for a commercial fungicide was 1250 µg mL(-1) . Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, reduced fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive-curative commercial fungicides used as pattern control. These findings suggest that TOH was responsible for the antifungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by Alternaria alternata. © 2014 Society of Chemical Industry.

  1. Comparison of methodologies for conidia production by Alternaria alternata from citrus Comparação de metodologias para produção de conídios por Alternaria alternata do citros

    Directory of Open Access Journals (Sweden)

    Daniel D. C. Carvalho

    2008-12-01

    Full Text Available Conidia production is a problem in the study of Alternaria alternata from citrus. Thus, this study aimed to compare existing methodologies for conidial production of A. alternata isolated from Ponkan tangerine (2 isolates, Cravo lemon (1 isolate, Pêra orange (2 isolates and Murcott tangor (1 isolate. The methodologies used were conidia production with 12 and 24 hours under white fluorescent light, evaluation with 24 and 48 hours after applying fungal mycelium stress technique, cold stress followed by injury of mycelium and evaluation with 24 hours, using healthy vegetable tissue and the use of black fluorescent near ultraviolet (NUV lamp. Satisfactory result was obtained with A. alternata isolate from Murcott tangor, with the production of 2.8 x 10(5 conidia mL-1, when fungal mycelium was stressed (Petri dish with 66.66% of fungi growth and subsequently 24 h of growth. The use of white light (24 h and black fluorescent NUV lamp also induced expressive conidia production by one isolate of Ponkan tangerine, which produced 17.2 x 10(5 and 10.1 x 10(5 conidia mL-1 and another of Murcott tangor, which produced 13.9 x 10(5 and 10.1 x 10(5 conidia mL-1, respectively. The remaining methodologies analyzed in this study were not able to induce conidia production in satisfactory quantity. The use of both mycelium stress technique and white light (24 h and black fluorescent NUV lamp allowed the production of enough quantities of conidia to be used in vitro (detection of fungitoxic substancesand in vivo (pathogenicity testassays, respectively.A produção de conídios consiste em problema no estudo de Alternaria alternata do citros. Assim, este estudo objetivou comparar metodologias existentes para a produção de conídios de A. alternata por dois isolados de tangerina Ponkan, um de limão Cravo, dois de laranja Pêra e um de tangor Murcott. As metodologias empregadas foram a produção de conídios com 12 e 24 horas sob luz branca, avaliação com 24 e 48

  2. [Antifungal effect of phenolic and carotenoids extracts from chiltepin (Capsicum annum var. glabriusculum) on Alternaria alternata and Fusarium oxysporum].

    Science.gov (United States)

    Rodriguez-Maturino, Alfonso; Troncoso-Rojas, Rosalba; Sánchez-Estrada, Alberto; González-Mendoza, Daniel; Ruiz-Sanchez, Esau; Zamora-Bustillos, Roberto; Ceceña-Duran, Carlos; Grimaldo-Juarez, Onecimo; Aviles-Marin, Mónica

    2015-01-01

    The effect of phenolic and carotenoid extracts from chiltepin fruits on mycelial growth and the inhibition of conidial germination of Alternaria alternata and Fusarium oxysporum were investigated in the present work. Phenolic extracts inhibited mycelial growth of A.alternata by 38.46%, and significantly reduced conidial germination on the fifth day after treatment to 92% in relation to control. No significant changes were observed in the inhibition of mycelial growth in Fusarium oxysporum; however, the number of germinated conidia was reduced, showing 85% inhibition five days after treatment in relation to control. Moreover, carotenoid extracts showed 38.5% inhibition of mycelial growth and 85.3% inhibition of conidial germination of A.alternata, five days after treatment. Carotenoid extracts showed less inhibition of mycelial growth (20.3%) in F.oxysporum, with respect to A.alternata; while there was greater inhibition of conidial germination (96%) on the fifth day after treatment. Phenolic and carotenoid extracts from chiltepin may be a promising alternative as a natural fungicide against fungi of agricultural importance. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. The Alternaria genomes database: a comprehensive resource for a fungal genus comprised of saprophytes, plant pathogens, and allergenic species.

    Science.gov (United States)

    Dang, Ha X; Pryor, Barry; Peever, Tobin; Lawrence, Christopher B

    2015-03-25

    Alternaria is considered one of the most common saprophytic fungal genera on the planet. It is comprised of many species that exhibit a necrotrophic phytopathogenic lifestyle. Several species are clinically associated with allergic respiratory disorders although rarely found to cause invasive infections in humans. Finally, Alternaria spp. are among the most well known producers of diverse fungal secondary metabolites, especially toxins. We have recently sequenced and annotated the genomes of 25 Alternaria spp. including but not limited to many necrotrophic plant pathogens such as A. brassicicola (a pathogen of Brassicaceous crops like cabbage and canola) and A. solani (a major pathogen of Solanaceous plants like potato and tomato), and several saprophytes that cause allergy in human such as A. alternata isolates. These genomes were annotated and compared. Multiple genetic differences were found in the context of plant and human pathogenicity, notably the pro-inflammatory potential of A. alternata. The Alternaria genomes database was built to provide a public platform to access the whole genome sequences, genome annotations, and comparative genomics data of these species. Genome annotation and comparison were performed using a pipeline that integrated multiple computational and comparative genomics tools. Alternaria genome sequences together with their annotation and comparison data were ported to Ensembl database schemas using a self-developed tool (EnsImport). Collectively, data are currently hosted using a customized installation of the Ensembl genome browser platform. Recent efforts in fungal genome sequencing have facilitated the studies of the molecular basis of fungal pathogenicity as a whole system. The Alternaria genomes database provides a comprehensive resource of genomics and comparative data of an important saprophytic and plant/human pathogenic fungal genus. The database will be updated regularly with new genomes when they become available. The

  4. Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit.

    Science.gov (United States)

    Fagundes, Cristiane; Pérez-Gago, María B; Monteiro, Alcilene R; Palou, Lluís

    2013-09-16

    The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot.

  5. Characterisation of Alternaria alternata manganese-dependent superoxide dismutase, a cross-reactive allergen homologue to Asp f 6.

    Science.gov (United States)

    Gabriel, Marta F; Postigo, Idoia; Gutiérrez-Rodríguez, Antonio; Suñén, Ester; Guisantes, Jorge; Tomaz, Cândida T; Martínez, Jorge

    2015-07-01

    It is well known that Alternaria alternata presents a significant level of allergenic cross-reactivity with several other phylogenetically related and non-related allergenic moulds. To improve the molecular diagnosis, the identification and characterisation of all clinically relevant allergens, including both species-specific and cross-reacting proteins, is required. In this study we report the molecular and immunological characterisation of the A. alternata manganese-dependent superoxide dismutase (Alt a MnSOD) and its cross-reactivity with Asp f 6, a diagnostic marker allergen in allergic bronchopulmonary aspergillosis (ABPA). The cDNA coding for Alt a MnSOD sequence was isolated by RACE and PCR. Alt a MnSOD is a protein of 191 amino acids that presented significant homology and potential cross-reactive epitopes with Asp f 6. The recombinant protein was produced in Escherichia coli and the immunoreactivity was evaluated in patient sera. Immunoblotting analyses showed that seven of sixty-one A. alternata-sensitised patient sera and two ABPA patient sera reacted with the recombinant Alt a MnSOD. The native counterpart contained in both A. alternata and Aspergillus fumigatus extracts inhibited IgE binding to the recombinant molecule. The allergen was named Alt a 14 by the official Allergen nomenclature subcommittee. Thus, Alt a 14 is a relevant allergen in A. alternata sensitisation that may be used to improve diagnostic procedures. Evidence of cross-reactivity between Asp f 6 and Alt a 14-recognition by ABPA patient sera suggest the existence of an Alt a 14-mediated mechanism that, similar to Asp f 6, may be related to the pathogenesis of ABPA. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Large-spored Alternaria pathogens in section Porri disentangled

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

    2014-01-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e

  7. Large-spored Alternaria pathogens in section Porri disentangled

    NARCIS (Netherlands)

    Woudenberg, J.H.C.; Truter, M.; Groenewald, J.Z.; Crous, P.W.

    2014-01-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e

  8. Alternaria alternata as a new fungal enzyme system for the release of phenolic acids from wheat and triticale brans.

    Science.gov (United States)

    Xiao, Zhizhuang; Bergeron, Hélène; Lau, Peter C K

    2012-05-01

    This study describes the release of antioxidant ferulic acid from wheat and triticale brans by mixtures of extracellular enzymes produced in culture by a strain FC007 of Alternaria alternata, a dark mold originally isolated from Canadian wood log. The genus of the mold was confirmed as Alternaria by 18S ribosomal DNA characterization. Enzyme activities for feruloyl esterase (FAE) and polysaccharide hydrolyzing enzymes were measured, and conditions for release of ferulic acid and reducing sugars from the mentioned brans were evaluated. The highest level of FAE activity (89 ± 7 mU ml(-1) fermentation culture) was obtained on the fifth day of fermentation on wheat bran as growth substrate. Depending on biomass and processing condition, up to 91.2 or 72.3% of the ferulic acid was released from wheat bran and triticale bran, respectively, indicating the proficiency of A. alternata extracellular enzymes in plant cell wall deconstruction. The apparent high extraction of ferulic acid from wheat and triticale brans represents a potential advantage of using a whole fungal cell enzyme complement over yields reported previously through an artificial assembly of cloned FAE with a particular xylanase in a cocktail format.

  9. Environmental Factors Affecting Production, Release, and Field Populations of Conidia of Alternaria alternata, the Cause of Brown Spot of Citrus.

    Science.gov (United States)

    Timmer, L W; Solel, Z; Gottwald, T R; Ibañez, A M; Zitko, S E

    1998-11-01

    ABSTRACT Alternaria brown spot, caused by Alternaria alternata pv. citri, affects many tangerines and their hybrids, causing loss of immature leaves and fruit and reducing the marketability of the remaining fruit. Conidial production of A. alternata was greatest on mature leaves moistened and maintained at near 100% relative humidity (RH) for 24 h, whereas leaves that had been soaked or maintained at moderate RH produced few conidia. Conidial release from filter paper cultures and infected leaves was studied in a computer-controlled environmental chamber. Release of large numbers of conidia was triggered from both substrates by sudden drops in RH or by simulated rainfall events. Vibration induced release of low numbers of conidia, but red/infrared irradiation had no effect. In field studies from 1994 to 1996, air sampling with a 7-day recording volumetric spore trap indicated that conidia were present throughout the year with periodic large peaks. The number of conidia captured was not closely related to rainfall amounts or average wind speed, but was weakly related to the duration of leaf wetness. Likewise, disease severity on trap plants placed in the field weekly during 1995 to 1996 was not closely related to conidial numbers or rainfall amounts, but was weakly related to leaf wetness duration. Sufficient inoculum appears to be available to allow infection to occur throughout the year whenever susceptible host tissue and moisture are available.

  10. Effects of temperature and incubation period on production of toxic metabolites by Alternaria radicina and A. alternata

    Directory of Open Access Journals (Sweden)

    Krystyna Tylkowska

    2012-12-01

    Full Text Available The production of toxic metabolites by four isolates of Alternaria radicina and two isolates of A. alternata in rice grains and carrot discs at 1, 10 and 20°C was investigated. Incubation lasted 21 and 35 days or 14 and 28 days for rice grains and carrot discs, respectively. Accumulation of toxins in inoculated carrot roots stored for 24 weeks and in inoculated dried carrots stored for 48 weeks was also determined. It was found that A. radicina produced radicinin (RAD and epi-radicinol (epi-ROH, whereas tenuazonic acid (TeA, altertoxin I (ATX I, alternariol (AOH and alternariol methyl ether (AME were produced by A. alternata. Although the isolates tested were capable of producing toxins in rice grains at 1°C, none of them was detected in carrot discs. Accumulation of epi-ROH was observed in carrot roots stored for 24 weeks, whereas decreased amounts of RAD and epi-ROH were observed in dried carrots stored for 48 weeks. No A. alternata toxins were detected in stored carrot roots, whereas trace amounts of AOH were recorded in dried carrots after 32 and 48 weeks of storage.

  11. EXPLORATION OF SUITABLE SOLID MEDIA FOR MASS MULTIPLICATION OF Cochliobolus lunatus AND Alternaria alternata USED AS MYCOHERBICIDE FOR WEED MANAGEMENT (BARNYARD GRASS IN RICE

    Directory of Open Access Journals (Sweden)

    Jyothi G

    2013-09-01

    Full Text Available Fungal pathogens viz. Cochliobolus lunatus and Alternaria alternata were isolated from barnyard grass ( Echinochloa crusgalli and their pathogenicity was re - confirmed on same weed through various bioassays using spore suspension of both pathogens under green house conditi ons. For development of formulations of these mycoherbicide, large biomass is required and it is essential to find cheaper growth media to reduce the cost of the product. For this purpose, various solid substrates such as wheat and its bran, rice and its bran, broken sorghum and E. crusgalli seeds supplemented with yeast extract and molasses were used for mass multiplication of these weed pathogens. Among six substrates tested, rice supplemented with molasses (10g/L and yeast extract (3.0g/L produced high est conidia for both mycoherbicide after 14 days with 12h photoperiod at 25 0 C. The pathogenicity test with conidia obtained from both pathogens was conducted on 5 leaf stage of E. crusgalli and rice under glass house conditions. The results revealed that 100% mortality of the target weed within 14 days after treatment (DAT and no effect on rice.

  12. 一种快速、特异性检测小麦中链格孢菌(Alternaria alternata)的巢式 PCR 方法%A Rapid and Specific Nest-PCR Method for Detection of Alternaria alternata in Wheat

    Institute of Scientific and Technical Information of China (English)

    秦召; 李巧云; 段宗彪; 姜玉梅; 牛吉山

    2014-01-01

    为建立检测小麦中链格孢菌(Alternaria alternata )的方法,从河南省小麦黑胚籽粒上分离得到7个优势 A.alternata 病原菌株,对其 rDNA 的内部转录间隔区序列(ITS)进行测序,序列比较表明,分离到的病原菌株与 GenBank 公布的 A.alternata 的 ITS 区序列一致性达到99%~100%。根据 Alternaria 属菌株(A.alternata、A.tenuis、A.tenuissima)和麦类根腐离蠕孢菌(Bipolaris sorokiniana )的 ITS 序列比对结果,设计出1对 A.alternata 特异性引物 Aa1F/Aa1R。利用多种河南省小麦的主要病原真菌对该引物的特异性进行验证,只有在 A.alternata 中能特异性地扩增出1条443 bp 的 DNA 片段。以真菌通用引物 ITS1/ITS4为外侧引物、特异性引物Aa1F/Aa1R 为内侧引物进行巢式 PCR 扩增,能检测到 A.alternata DNA 的最低质量浓度为50 pg/μL。因此,建立的巢式 PCR 方法能够快速、特异地检测小麦中的 A.alternata。%The aim of this study was to establish a method for detection of Alternaria alternata in wheat.Seven dominating isolates of A.alternata from wheat black point grains in Henan province were collected,and then their internal transcribed spacer(ITS)regions in rDNA were sequenced, and the sequence analysis showed that the ITS sequences were highly similar among isolates of A.alternata isolated in this study and in GenBank by 99%-100%.According to the comparative result of ITS sequences of Alternaria spp.(A.alternate,A.tenuis,A.tenuissima)and Bipolaris sorokiniana,a pair of primers,namely Aa1F and Aa1R,were designed.Specificity of the primers was tested with several major fungal pathogens of wheat in Henan province,and a 443 bp specific DNA fragment could be amplified only from A.alternata.A rapid and specific nest-PCR method for detection of A.alternata in wheat was established with fungal universal primers ITS1/ITS4 as the outer primers and Aa1F/Aa1R as the inner primers

  13. Identification of Alternaria alternata mycotoxins by LC-SPE-NMR and their cytotoxic effects to soybean (Glycine max) cell suspension culture

    OpenAIRE

    Edson Rodrigues-Filho; Cristina Daolio; Bernd Schneider; De Souza, Gezimar D.; Axel Mithöfer

    2013-01-01

    This present work describes the application of liquid chromatograpy-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1), alternariol (2), 3'-hydroxyalternariol monomethyl ether (3), and alternariol monomethyl ether (4), were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max)...

  14. PCR技术在链格孢霉鉴定中的应用%Usefulness of PCR Technique in Identification of Alternaria Alternata Allergen Extracts

    Institute of Scientific and Technical Information of China (English)

    曹乃清; 张宏誉

    2009-01-01

    目的 应用PER技术对链格孢霉进行鉴定,以期获得制备链格孢霉变应原制剂的纯菌种.方法 采用空气曝皿收获链格孢霉菌种并进行培养,应用PER技术对其进行鉴定.结果 经空气曝皿、形态学鉴定为链格孢霉菌株的PER产物经1.5%琼脂糖凝胶电泳分析,紫外灯下鉴定扩增所得条带约580 bp;测序结果经Blast比对,544个碱基中543个能够与链格孢霉26s rDNA的545个碱基比对上,缺失1个,不能识别1个,相符率达99%.结论 证实待检真菌为链格孢霉.%Objective To produe the allergen extracts with Alternaria alternarta while were identified by PCR technique. Methods Alternaria alternata was collected from air and cultured under 26℃, identified by PCR technique. Result The fungus that was collected from air and identified as A lternaria alternata by morphology, its 26srDNA was amplified by PCR, resulting a 580 bp band, after sequencing, under microscope there were 543 bases those could be identical and consistent to the Alternaria alternata data from intemet based on the result of blast comparison, corresponding rate is 99%. Conclusion We succeeded in collecting and producing Alternaria alternata.

  15. Resposta de diferentes genótipos de tangerinas e seus híbridos à inoculação in vitro e in vivo de Alternaria alternata Response of different tangerine varieties and hybrids to in vitro and in vivo inoculation of Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Fernando Alves Azevedo

    2010-09-01

    Full Text Available A severidade da mancha-marrom de alternária nos pomares brasileiros de tangerinas tem causado sérias preocupações aos citricultores, devido aos prejuízos em plantios comerciais de variedades suscetíveis, como a tangerina Ponkan e o tangor Murcott. Para avaliar a resposta de diferentes genótipos ao fungo, foram realizadas inoculações de Alternaria alternata in vitro e in vivo, em 54 diferentes genótipos de tangerinas e seus híbridos, selecionados no Banco Ativo de Germoplasma de Citros do Centro APTA Citros Sylvio Moreira, do Instituto Agronômico, em Cordeirópolis-SP, visando a encontrar variedades resistentes. Para isso, inicialmente, testes de patogenicidade foram realizados com dez isolados de A. alternata para a seleção dos mais agressivos. Posteriormente, foram realizadas inoculações em folhas destacadas e em plântulas e, aos dois (in vitro e três (in vivo dias após, fez-se a contagem do número de lesões/folha e a estimativa da severidade da doença com auxílio de escala diagramática (in vivo. A maior parte dos genótipos apresentou sintomas da doença, porém com diferentes graus de suscetibilidade. Genótipos como a tangerina Sul da África e o tangelo Orlando foram os mais suscetíveis. Por outro lado, o grupo das satsumas e mexericas, assim como algumas tangerinas mostraram-se resistentes, indicando novas opções para a citricultura nacional.The confirmation of a new disease in the Brazilian tangerine orchards, the alternaria brown spot, has been concerning citrus growers because of the serious damages to commercial crops of susceptible varieties, such as Ponkan tangerine and Murcott tangor. In this research, in vitro and in vivo inoculations of Alternaria alternata fungus were held in 54 different varieties of the tangerine group selected from the Citrus Germoplasm Bank of Centro APTA Citros Sylvio Moreira, Instituto Agronomico, Cordeirópolis, State of São Paulo, Brazil, aiming to find varieties with more

  16. Large-spored Alternaria pathogens in section Porri disentangled.

    Science.gov (United States)

    Woudenberg, J H C; Truter, M; Groenewald, J Z; Crous, P W

    2014-09-01

    The omnipresent fungal genus Alternaria was recently divided into 24 sections based on molecular and morphological data. Alternaria sect. Porri is the largest section, containing almost all Alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens (e.g. Alternaria porri, A. solani and A. tomatophila). We constructed a multi-gene phylogeny on parts of the ITS, GAPDH, RPB2, TEF1 and Alt a 1 gene regions, which, supplemented with morphological and cultural studies, forms the basis for species recognition in sect. Porri. Our data reveal 63 species, of which 10 are newly described in sect. Porri, and 27 species names are synonymised. The three known Alternaria pathogens causing early blight on tomato all cluster in one clade, and are synonymised under the older name, A. linariae. Alternaria protenta, a species formerly only known as pathogen on Helianthus annuus, is also reported to cause early blight of potato, together with A. solani and A. grandis. Two clades with isolates causing purple blotch of onion are confirmed as A. allii and A. porri, but the two species cannot adequately be distinguished based on the number of beaks and branches as suggested previously. This is also found among the pathogens of Passifloraceae, which are reduced from four to three species. In addition to the known pathogen of sweet potato, A. bataticola, three more species are delineated of which two are newly described. A new Alternaria section is also described, comprising two large-spored Alternaria species with concatenate conidia.

  17. Decolorization and biodegradation of congo red dye by a novel white rot fungus Alternaria alternata CMERI F6.

    Science.gov (United States)

    Chakraborty, Samayita; Basak, Bikram; Dutta, Subhasish; Bhunia, Biswanath; Dey, Apurba

    2013-11-01

    A novel white rot fungus Alternaria alternata CMERI F6 decolorized 99.99% of 600 mg/L congo red within 48 h in yeast extract-glucose medium at 25 °C, pH 5 and 150 rpm. Physicochemical parameters like carbon and nitrogen sources, temperature, pH and aeration were optimized to develop faster decolorization process. Dye decolorization rate was maximal (20.21 mg/L h) at 25 °C, pH 5, 150 rpm and 800 mg/L dye, giving 78% final decolorization efficiency. Scanning electron microscopy and X-ray Diffraction analysis revealed that the fungus become amorphous after dye adsorption. HPLC and FTIR analysis of the extracted metabolites suggested that the decolorization occurred through biosorption and biodegradation. Thermogravimetric analysis (TGA), differential thermal analysis (DTA) and acid-alkali and 70% ethanol treatment revealed the efficient dye retention capability of the fungus. The foregoing results justify the applicability of the strain in removal of congo red from textile wastewaters and their safe disposal.

  18. Structure identification for compound I separated and purified from taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011)

    Institute of Scientific and Technical Information of China (English)

    XIANG Yong; LIU Jun; LU An-guo; CUI Jing-xia

    2003-01-01

    Endophytic fungi are widely found in almost all kinds of plants. Many endophytic fungi can produce some physiological active compounds, which are same to or analog to those isolated from their hosts. Producing physiological active compounds through microbial fermentation can give a new way to resolve resource limitation and to find out alternative source. Through the methods of organic solvent extraction, thin layer chromatography (TLC) and column chromatography, compound I was isolated, purified from the liquid fermentation metabolites of the taxoids-produced endophytic fungi (Alternaria. alternata var. taxi 1011 Y. Xiang et LU An-guo) that was screened from the bark of Taxus. cuspidata Sieb.et Zucc.. Compound I was identified as one kind of taxoids type III, based on the analyzing results by using the methods of ultraviolet spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). This study provides a completed method for separation and purification of the endophytic fungi as well as structure identification of its fermentation metabolite

  19. Comparative evaluation of biochemical changes in tomato (Lycopersicon esculentum Mill. infected by Alternaria alternata and its toxic metabolites (TeA, AOH and AME

    Directory of Open Access Journals (Sweden)

    Mukesh Meena

    2016-09-01

    Full Text Available In the present study, we have evaluated the comparative biochemical defense response generated against Alternaria alternata and its purified toxins viz. alternariol (AOH, alternariol monomethyl ether (AME and tenuazonic acid (TeA. The necrotic lesions developed due to treatment with toxins were almost similar as those produced by pathogen, indicating the crucial role of these toxins in plant pathogenesis. An oxidative burst reaction characterized by the rapid and transient production of a large amount of reactive oxygen species (ROS occurs following the pathogen infection/toxin exposure. The maximum concentration of H2O2 produced was reported in pathogen infected samples (22.2-fold at 24 h post inoculation followed by TeA (18.2-fold, AOH (15.9-fold, and AME (14.1-fold in treated tissues. DAB staining predicted the possible sites of H2O2 accumulation while the extent of cell death were measured by Evans blue dye. The extent of lipid peroxidation and MDA content was higher (15.8-fold at 48 h in the sample of inoculated leaves of pathogen, when compared to control. The cellular damages were observed as increased MDA content and reduced chlorophyll. The activities of antioxidative defense enzymes increased in both pathogen infected as well as toxin treated samples. SOD, activity was 5.9- fold higher at 72 h post inoculation in leaves followed by TeA (5.0-fold, AOH (4.1-fold and AME (2.3-fold treated leaves than control. Catalase activity was found to be increased upto 48 h post inoculation and maximum in pathogen challenged samples followed by other toxins. The native PAGE results showed the variations in the intensities of isozyme (SOD and CAT bands in the pathogen infected and toxin treated samples. APx and GR activities followed the similar trend to scavenge the excess H2O2. The reduction in CAT activities after 48 h post inoculation demonstrate that the biochemical defense programming shown by the host against the pathogen is not well efficient

  20. Influence of water activity and temperature on growth and mycotoxin production by Alternaria alternata on irradiated soya beans.

    Science.gov (United States)

    Oviedo, Maria Silvina; Ramirez, Maria Laura; Barros, Germán Gustavo; Chulze, Sofia Noemi

    2011-09-15

    The aim of this study was to determine the effects of water activity (a(w)) (0.99-0.90), temperature (15, 25 and 30°C) and their interactions on growth and alternariol (AOH) and alternariol monomethyl ether (AME) production by Alternaria alternata on irradiated soya beans. Maximum growth rates were obtained at 0.980 a(w) and 25°C. Minimum a(w) level for growth was dependent on temperature. Both strains were able to grow at the lowest a(w) assayed (0.90). Maximum amount of AOH was produced at 0.98 a(w) but at different temperatures, 15 and 25°C, for the strains RC 21 and RC 39 respectively. Maximum AME production was obtained at 0.98 a(w) and 30°C for both strains. The concentration range of both toxins varied considerably depending on a(w) and temperature interactions. The two metabolites were produced over the temperature range 15 to 30°C and a(w) range 0.99 to 0.96. The limiting a(w) for detectable mycotoxin production is slightly greater than that for growth. Two-dimensional profiles of a(w)× temperature were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soya bean. Knowledge of AOH and AME production under marginal or sub-optimal temperature and a(w) conditions for growth can be important since improper storage conditions accompanied by elevated temperature and moisture content in the grain can favour further mycotoxin production and lead to reduction in grain quality. This could present a hazard if the grain is used for human consumption or animal feedstuff. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Identification of Alternaria alternata mycotoxins by LC-SPE-NMR and their cytotoxic effects to soybean (Glycine max) cell suspension culture.

    Science.gov (United States)

    de Souza, Gezimar D; Mithöfer, Axel; Daolio, Cristina; Schneider, Bernd; Rodrigues-Filho, Edson

    2013-02-26

    This present work describes the application of liquid chromatography-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1), alternariol (2), 3'-hydroxyalternariol monomethyl ether (3), and alternariol monomethyl ether (4), were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max) cell cultures as a model. EC(50) values which range from 0.11 (± 0.02) to 4.69 (± 0.47) μM showed the high cytotoxicity of these compounds.

  2. Identification of Alternaria alternata Mycotoxins by LC-SPE-NMR and Their Cytotoxic Effects to Soybean (Glycine max Cell Suspension Culture

    Directory of Open Access Journals (Sweden)

    Edson Rodrigues-Filho

    2013-02-01

    Full Text Available This present work describes the application of liquid chromatograpy-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1, alternariol (2, 3'-hydroxyalternariol monomethyl ether (3, and alternariol monomethyl ether (4, were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max cell cultures as a model. EC50 values which range from 0.11 (±0.02 to 4.69 (±0.47 μM showed the high cytotoxicity of these compounds.

  3. Alternaria tenuissima, A. alternata y Fusarium oxysporum Hongos Causantes de la Pudrición del Florete de Brócoli

    OpenAIRE

    María de Lourdes Fraire-Cordero; Daniel Nieto-Ángel; Elizabeth Cárdenas-Soriano; Gabriel Gutiérrez-Alonso; Rafael Bujanos-Muñiz; Humberto Vaquera-Huerta

    2010-01-01

    Durante los meses de julio-octubre del 2005 y 2006, se observaron manchas necróticas circulares, café oscuras en floretes de brócoli en Guanajuato, México. Se colectaron floretes de brócoli con síntomas y del tejido sintomático se aislaron Alternaria tenuissima, A. alternata y Fusarium oxysporum, los cuales fueron identificados morfológica y molecularmente. Las pruebas de patogenicidad mostraron que los tres hongos son agentes causales de la pudrición o manchado del florete de brócoli. Los pr...

  4. Antibacterial effect of an extract of the endophytic fungus Alternaria alternata and its cytotoxic activity on MCF-7 and MDA MB-231 tumour cell lines

    Directory of Open Access Journals (Sweden)

    EZHIL ARIVUDAINAMBI U.S.

    2014-06-01

    Full Text Available There is a growing need for new and effective antimicrobial agents to treat life-threatening diseases. Fungal endophytes are receiving increasing attention by natural product chemists due to the diverse and structurally unprecedented compounds, which make them interesting candidates for drug discovery. The present study evaluates the antibacterial activity of ethyl acetate extract of the endophytic fungus Alternaria alternata VN3 on multi-resistant clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa, as well as its cytotoxicity on MCF-7 and MDA MB-231 tumour cell lines of breast cancer. The maximum inhibition zone of 21.4±0.07 mm and 21.5±0.25 mm was observed for S. aureus strain 10 and P. aeruginosa strain 2, respectively. The ethyl acetate extract showed minimal inhibitory concentration ranging from 100 to 900 μg/ml for S. aureus and P. aeruginosa. Further, the ethyl acetate extract of A. alternata VN3 exhibited moderate anticancer activity against MCF-7 and MDA MB-231 cell lines. At 30 μg/ml the cell viability was decreased to 75.5% and 71.8% for MCF-7 and MDA MB-231 cells, respectively. These results clearly indicate that the metabolites of A. alternata VN3 are a potential source for production of new drugs.

  5. Effects of gamma irradiation on the fungus Alternaria alternata and on mycotoxins Alternariol and Alternariol monomethyl ether in artificially contaminated cereal samples;Efeitos da radiacao gama no fungo Alternaria alternata e nas micotoxinas Alternariol e Alternariol monometil eter em amostras de cereais artificialmente contaminadas

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, Raquel

    2009-07-01

    The present study aimed to evaluate the effects of different gamma irradiation doses on the growth of Alternaria alternata and on production of mycotoxins Alternariol (AOH) and Alternariol Monomethyl Ether (AME) in cereal samples. The results showed a significant reduction in the number of CFU/g in rice grains and sunflower seeds, which were proportional to radiation dose used. However, in corn and wheat grains was observed an increase in the number of CFU/g with the increase of gamma irradiation. The radiation doses used resulted in a reduction of AOH levels. In rice and corn grains, the production of AOH was highest in the group irradiated with 5 kGy. Similar result was obtained with relation to AME. Scanning electron microscopy made it possible to visualize structural alterations on A. alternata induced by the different g-radiation doses used. Analysis of irradiated AOH and AME toxins standards did not show any alteration comparing to the control group. (author)

  6. Tomato resistance to Alternaria stem canker : localization in host genotypes and functional expression compared to non-host resistance

    NARCIS (Netherlands)

    Witsenboer, H.M.A.; Griend, E.G. van de; Tiersma, J.B.; Nijkamp, H.J.J.; Hille, J.

    1989-01-01

    The Alternaria stem canker resistance locus (Asc-locus), involved in resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici and in insensitivity to host-specific toxins (AAL-toxins) produced by the pathogen, was genetically mapped on the tomato genome. Susceptibility and resistanc

  7. Pathogenic, morphological and molecular characteristics of Alternaria Tenuissima from soybean

    OpenAIRE

    Jasnić Stevan M.; Marjanović Žaklina S.; Vidić Miloš B.; Bagi Ferenc F.; Budakov Dragana B.; Pavlović Snežana Đ.; Stojšin Vera B.

    2011-01-01

    During 2008 and 2009 phytopathological isolations were done from soybean plants and seed samples from several localities in Serbia. A total of 19 isolates of Alternaria spp. were isolated, 13 from the seed and 3 from both leaf and stem. In order to determine and characterize isolates, cultural, morphological, molecular and pathogenic characteristics were thoroughly investigated. The slowest growth of the examined isolates was noted on Malt agar (MA) with average colony diameter of 42.9 ...

  8. Pathogenic, morphological and molecular characteristics of Alternaria Tenuissima from soybean

    Directory of Open Access Journals (Sweden)

    Jasnić Stevan M.

    2011-01-01

    Full Text Available During 2008 and 2009 phytopathological isolations were done from soybean plants and seed samples from several localities in Serbia. A total of 19 isolates of Alternaria spp. were isolated, 13 from the seed and 3 from both leaf and stem. In order to determine and characterize isolates, cultural, morphological, molecular and pathogenic characteristics were thoroughly investigated. The slowest growth of the examined isolates was noted on Malt agar (MA with average colony diameter of 42.9 mm after 7 days of incubation. On other two media (V8 and PCA, colony growth was uniform and faster, with average diameter of 66.8 mm and 66.1 mm, respectively. Isolates of fungi form unbranched or poorly branched conidial chains on short unbranched conidiophores. Conidia are dark in colour, multicellular with transverse and longitudinal septae. They are of different size regarding the place of formation in the chain. Based on these characteristics, the tested isolates were determined as Alternaria tenuissima. Molecular identification with sequencing of ITS1-5.8S-ITS2 rDNA verified that investigated isolates belong to Alternaria tenuissima group. Pathogenicity test proved that all isolates were more or less virulent to soybean seed (12.5% to 40% of rotten seeds, while pathogenicity on plants was poorly expressed.

  9. Toxin production by Alternaria alternata in tomatoes and apples stored under various conditions and quantitation of the toxins by high-performance liquid chromatography.

    Science.gov (United States)

    Ozcelik, S; Ozcelik, N; Beuchat, L R

    1990-12-01

    Alternaria alternata strain 8442-3 was inoculated into tomatoes (Lycopersicon esculentum Mill.) and Red Delicious cultivar apples (Malus domestica Borkh.). Half of the lots of each fruit were shrink-wrapped in high-density polyethylene film. Wrapped and unwrapped fruits were incubated under darkness at 4, 15 and 25 degrees C for up to 5 weeks. A high-performance liquid chromatography method was developed to quantitate tenuazonic acid (TeA), alternariol (AOH), alternariol methyl ether (AME), and altenuene (ALT). Shrink-wrapping retarded, but did not completely inhibit growth in tomatoes for 3-7 days. Concentrations of up to 120.6 mg of AOH and 63.7 mg of AME per 100 g of tissue were produced in unwrapped tomatoes stored at 15 degrees C for 4 weeks; 19.0 mg of ALT per 100 g of tomato tissue was produced after 3 weeks at 25 degrees C. AOH, AME and ALT were also produced in unwrapped tomatoes stored at 4 degrees C; however, no TeA was detected in decayed tomatoes, regardless of type of wrapping or storage temperature. Shrink-wrapping resulted in decreased production of AOH, AME, and ALT. Alternaria toxins were not detected in apples stored at 4 and 15 degrees C. The highest concentration of AOH produced (48.8 mg per 100 g of tissue) was in unwrapped apples stored at 25 degrees C for 2 weeks; 12.3 mg per 100 g of tissue of shrink-wrapped apples was detected after 5 weeks of storage at 25 degrees C, while ALT reached 5.7 mg per 100 g after 4 weeks. TeA was not detected in apples infected with A. alternata.

  10. Chilling stress--the key predisposing factor for causing Alternaria alternata infection and leading to cotton (Gossypium hirsutum L. leaf senescence.

    Directory of Open Access Journals (Sweden)

    Jingqing Zhao

    Full Text Available Leaf senescence plays a vital role in nutrient recycling and overall capacity to assimilate carbon dioxide. Cotton premature leaf senescence, often accompanied with unexpected short-term low temperature, has been occurring with an increasing frequency in many cotton-growing areas and causes serious reduction in yield and quality of cotton. The key factors for causing and promoting cotton premature leaf senescence are still unclear. In this case, the relationship between the pre-chilling stress and Alternaria alternata infection for causing cotton leaf senescence was investigated under precisely controlled laboratory conditions with four to five leaves stage cotton plants. The results showed short-term chilling stress could cause a certain degree of physiological impairment to cotton leaves, which could be recovered to normal levels in 2-4 days when the chilling stresses were removed. When these chilling stress injured leaves were further inoculated with A. alternata, the pronounced appearance and development of leaf spot disease, and eventually the pronounced symptoms of leaf senescence, occurred on these cotton leaves. The onset of cotton leaf senescence at this condition was also reflected in various physiological indexes such as irreversible increase in malondialdehyde (MDA content and electrolyte leakage, irreversible decrease in soluble protein content and chlorophyll content, and irreversible damage in leaves' photosynthesis ability. The presented results demonstrated that chilling stress acted as the key predisposing factor for causing A. alternata infection and leading to cotton leaf senescence. It could be expected that the understanding of the key factors causing and promoting cotton leaf senescence would be helpful for taking appropriate management steps to prevent cotton premature leaf senescence.

  11. Characterization of mutations in the iron-sulphur subunit of succinate dehydrogenase correlating with Boscalid resistance in Alternaria alternata from California pistachio.

    Science.gov (United States)

    Avenot, H F; Sellam, A; Karaoglanidis, G; Michailides, T J

    2008-06-01

    Thirty-eight isolates of Alternaria alternata from pistachio orchards with a history of Pristine (pyraclostrobin + boscalid) applications and displaying high levels of resistance to boscalid fungicide (mean EC(50) values >500 microg/ml) were identified following mycelial growth tests. A cross-resistance study revealed that the same isolates were also resistant to carboxin, a known inhibitor of succinate dehydrogenase (Sdh). To determine the genetic basis of boscalid resistance in A. alternata the entire iron sulphur gene (AaSdhB) was isolated from a fungicide-sensitive isolate. The deduced amino-acid sequence showed high similarity with iron sulphur proteins (Ip) from other organisms. Comparison of AaSdhB full sequences from sensitive and resistant isolates revealed that a highly conserved histidine residue (codon CAC in sensitive isolates) was converted to either tyrosine (codon TAC, type I mutants) or arginine (codon CGC, type II mutants) at position 277. In other fungal species this residue is involved in carboxamide resistance. In this study, 10 and 5 mutants were of type I and type II respectively, while 23 other resistant isolates (type III mutants) had no mutation in the histidine codon. The point mutation detected in type I mutants was used to design a pair of allele-specific polymerase chain reaction (PCR) primers to facilitate rapid detection. A PCR-restriction fragment length polymorphism (RFLP) assay in which amplified gene fragments were digested with AciI was successfully employed for the diagnosis of type II mutants. The relevance of these modifications in A. alternata AaSdhB sequence in conferring boscalid resistance is discussed.

  12. Efecto antifúngico de extractos fenólicos y de carotenoides de chiltepín (Capsicum annum var. glabriusculum en Alternaria alternata y Fusarium oxysporum

    Directory of Open Access Journals (Sweden)

    Alfonso Rodriguez-Maturino

    2015-03-01

    Full Text Available En el presente estudio se evaluó el efecto de extractos fenólicos y de carotenoides procedentes de frutos de chiltepín sobre el crecimiento micelial y la germinación de conidios de Alternaria alternata y Fusarium oxysporum, 2 importantes hongos causantes de podredumbres en frutas y hortalizas. Los extractos fenólicos presentaron una inhibición en el crecimiento micelial de A. alternata del 38,46 %, y redujeron significativamente la germinación de conidios al quinto día después del tratamiento al 92 % en relación al control. No se observaron cambios significativos en el crecimiento micelial de F. oxysporum, pero sí se redujo significativamente al 85 % en relación al control, el número de conidios germinados a los 5 días de tratamiento. Los extractos de carotenoides mostraron una inhibición del 38,5 % en el crecimiento micelial y del 85,3 % en la germinación de conidios de A. alternata, 5 días después del tratamiento. Frente a F. oxysporum, dichos extractos presentaron menor inhibición del crecimiento micelial (20,3 %, mientras que hubo una mayor inhibición en la germinación de conidios (96 %. Los extractos fenólicos y de carotenoides de chiltepín pueden ser una alternativa promisoria de importancia agrícola como fungicidas naturales.

  13. FTIR spectroscopic evaluation of changes in the cellular biochemical composition of the phytopathogenic fungus Alternaria alternata induced by extracts of some Greek medicinal and aromatic plants

    Science.gov (United States)

    Skotti, Efstathia; Kountouri, Sophia; Bouchagier, Pavlos; Tsitsigiannis, Dimitrios I.; Polissiou, Moschos; Tarantilis, Petros A.

    2014-06-01

    In this study, the biological activity of aquatic extracts of selected Greek medicinal and aromatic plants to the phytopathogenic fungus Alternaria alternata was investigated. Lamiaceae species (Hyssopus officinalis L., Melissa officinalis L., Origanum dictamnus L., Origanum vulgare L. and Salvia officinalis L.) were found to enhance significantly the mycelium growth whereas Crocus sativus appears to inhibit it slightly. M. officinalis and S. officinalis caused the highest stimulation in mycelium growth (+97%) and conidia production (+65%) respectively. In order to further investigate the bioactivity of plant extracts to A. alternata, we employed Fourier Transform Infrared Spectroscopy (FTIR). Differences of original spectra were assigned mainly to amides of proteins. The second derivative transformation of spectra revealed changes in spectral regions corresponding to absorptions of the major cellular constituents such as cell membrane and proteins. Principal component analysis of the second derivative transformed spectra confirmed that fatty acids of the cell membranes, amides of proteins and polysaccharides of the cell wall had the major contribution to data variation. FTIR band area ratios were found to correlate with fungal mycelium growth.

  14. Solvent Effects on the Ultrastructure and Chemical Composition of Cuticular Wax and Its Potential Bioactive Role Against Alternaria alternata in Pingguoli Pear

    Institute of Scientific and Technical Information of China (English)

    CHEN Song-jiang; LI Yong-cai; BI Yang; YIN Yan; GE Yong-hong; WANG Yi

    2014-01-01

    Effects of different polarity solvents on the ultrastructure and chemical composition of cuticular wax in Pingguoli pear as well as their bioactive role against Alternaria alternate were studied and the results showed that the highest wax content was extracted with chloroform, and its wax content was up to 322.2 µg cm-2. Long-chain fatty acids predominated in menthol extracts and n-alkanes were predominant in wax extracted with ether, chloroform and n-hexane. Pingguoli pear fruit surface was covered by a smooth and amorphous wax layer with small, scattered crystal. The morphology of recrystallized wax in vitro after removal with different solvents was not similar to that of the intact fruit surface. Removal of cuticular wax with various solvents signiifcantly enhanced A. alternata infection, except for wax removed by methanol. The solvent extracts of methanol and chloroform stimulated the spore germination and mycelium growth of A. alternata, but the ether and n-hexane extracts showed antifungal activity.

  15. Assessment of protein silver nanoparticles toxicity against pathogenic Alternaria solani.

    Science.gov (United States)

    Abdel-Hafez, Sobhy I I; Nafady, Nivien A; Abdel-Rahim, Ismail R; Shaltout, Abeer M; Daròs, José-Antonio; Mohamed, Mohamed A

    2016-12-01

    Mycogenic synthesis of silver nanoparticles (AgNPs) was carried out in the present investigation using an aqueous extract of endophytic non-pathogenic Alternaria solani F10 (KT721914). The mycosynthesized AgNPs were characterized by means of spectroscopic and microscopic techniques. The surface plasmon resonance found at 430 nm confirmed the formation of stable AgNPs for several weeks at room temperature. Also, the results revealed the formation of spherical and monodispersed AgNPs with an average size of 14.8 ± 1.2 nm. The FT-IR spectrum suggested that the fungal extracellular proteins and secondary metabolites had the role in Ag reduction and AgNPs capping of which protein Ag nanoconjugates were formed. Furthermore, the mycosynthesized AgNPs exhibited potent antifungal activity against different pathogenic isolates of the same Alternaria solani fungus, the causal pathogen of tomato early blight disease. The antifungal efficiency of the AgNPs at 1, 5 and 10 ppm were evaluated for 8 days after incubation by measuring the inhibition rate of fungal radial growth. The results were further supported by investigating fungal hyphae morphology alteration by scanning and transmission electron microscopy. Treated fungal hyphae showed formation of pits and pores. Also, the mycosynthesized AgNPs were able to pass and distribute throughout the fungal cell area and interact with the cell components.

  16. Efeito do meio de cultura, temperatura, fotoperíodo e fungicidas no crescimento micelial e no controle de Alternaria alternata f. sp. citri, causador da mancha marrom do tangor murcote

    OpenAIRE

    Colturato,Adimara Bentivoglio

    2006-01-01

    A mancha marrom de alternaria, causada pela Alternaria alternata f. sp. citri, afeta o tangor murcote causando lesões em folhas, ramos e frutos, acarretando em desfolha e manchas que depreciam o fruto comercialmente. Os objetivos deste trabalho foram verificar o efeito do meio de cultura no isolamento, da temperatura e do fotoperíodo no crescimento micelial do patógeno, avaliar a sensibilidade do patógeno à fungicidas in vitro e estabelecer o melhor produto e dose para o controle da doença no...

  17. Impact of water activity and temperature on growth and alternariol and alternariol monomethyl ether production of Alternaria alternata isolated from soybean.

    Science.gov (United States)

    Oviedo, M S; Ramirez, M L; Barros, G G; Chulze, S N

    2010-02-01

    The objective of this study was to determine the effect of water activity (a(w); 0.995, 0.98, 0.96, 0.94, 0.92, and 0.90), temperature (5, 18, 25, and 30 degrees C), incubation time (7 to 35 days), and their interactions on mycelial growth and alternariol (AOH) and alternariol monomethyl ether (AME) production. Two Alternaria alternata strains isolated from soybeans in Argentina were grown on 2% soybean extract agar. Maximum growth rates were obtained at the highest a(w) (0.995) and 25 degrees C, with growth decreasing as the water availability of the medium was reduced. Maximum amount of AOH was produced at 0.98 a(w) and 25 degrees C for both strains. Maximum AME production was obtained for both strains at 30 degrees C but different a(w) values, 0.92 and 0.94, for the strains RC 21 and RC 39, respectively. The concentrations of both toxins varied considerably depending on the a(w) and temperature interactions assayed. The two metabolites were produced from 5 to 30 degrees C and at a(w) values of 0.92 to 0.995. Although at 5 and 18 degrees C little mycotoxin was produced at a(w) lower than 0.94. Two-dimensional profiles of a(w) by temperature interactions were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soybeans. All the conditions of a(w) and temperature that resulted in maximum production of both toxins are those found during soybean development in the field. Thus, field conditions are likely to be conducive to optimum A. alternata growth and toxin production.

  18. Blocking the QB-binding site of photosystem II by tenuazonic acid, a non-host-specific toxin of Alternaria alternata, activates singlet oxygen-mediated and EXECUTER-dependent signalling in Arabidopsis.

    Science.gov (United States)

    Chen, Shiguo; Kim, Chanhong; Lee, Je Min; Lee, Hyun-Ah; Fei, Zhangjun; Wang, Liangsheng; Apel, Klaus

    2015-06-01

    Necrotrophic fungal pathogens produce toxic compounds that induce cell death in infected plants. Often, the primary targets of these toxins and the way a plant responds to them are not known. In the present work, the effect of tenuazonic acid (TeA), a non-host-specific toxin of Alternaria alternata, on Arabidopsis thaliana has been analysed. TeA blocks the QB -binding site at the acceptor side of photosystem II (PSII). As a result, charge recombination at the reaction centre (RC) of PSII is expected to enhance the formation of the excited triplet state of the RC chlorophyll that promotes generation of singlet oxygen ((1)O₂). (1)O₂ activates a signalling pathway that depends on the two EXECUTER (EX) proteins EX1 and EX2 and triggers a programmed cell death response. In seedlings treated with TeA at half-inhibition concentration (1)O₂-mediated and EX-dependent signalling is activated as indicated by the rapid and transient up-regulation of (1)O₂-responsive genes in wild type, and its suppression in ex1/ex2 mutants. Lesion formation occurs when seedlings are exposed to higher concentrations of TeA for a longer period of time. Under these conditions, the programmed cell death response triggered by (1)O₂-mediated and EX-dependent signalling is superimposed by other events that also contribute to lesion formation.

  19. Genome-wide identification and expression analysis of the apple ASR gene family in response to Alternaria alternata f. sp. mali.

    Science.gov (United States)

    Huang, Kaihui; Zhong, Yan; Li, Yingjun; Zheng, Dan; Cheng, Zong-Ming

    2016-10-01

    The ABA/water stress/ripening-induced (ASR) gene family exists universally in higher plants, and many ASR genes are up-regulated during periods of environmental stress and fruit ripening. Although a considerable amount of research has been performed investigating ASR gene response to abiotic stresses, relatively little is known about their roles in response to biotic stresses. In this report, we identified five ASR genes in apple (Malus × domestica) and explored their phylogenetic relationship, duplication events, and selective pressure. Five apple ASR genes (Md-ASR) were divided into two clades based on phylogenetic analysis. Species-specific duplication was detected in M. domestica ASR genes. Leaves of 'Golden delicious' and 'Starking' were infected with Alternaria alternata f. sp. mali, which causes apple blotch disease, and examined for the expression of the ASR genes in lesion areas during the first 72 h after inoculation. Md-ASR genes showed different expression patterns at different sampling times in 'Golden delicious' and 'Starking'. The activities of stress-related enzymes, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia lyase (PAL), and polyphenoloxidase (PPO), and the content of malondialdehyde (MDA) were also measured in different stages of disease development in two cultivars. The ASR gene expression patterns and theses physiological indexes for disease resistance suggested that Md-ASR genes are involved in biotic stress responses in apple.

  20. Characterization and Comparison of the CPK Gene Family in the Apple (Malus × domestica) and Other Rosaceae Species and Its Response to Alternaria alternata Infection.

    Science.gov (United States)

    Wei, Menghan; Wang, Sanhong; Dong, Hui; Cai, Binhua; Tao, Jianmin

    2016-01-01

    As one of the Ca2+ sensors, calcium-dependent protein kinase (CPK) plays vital roles in immune and stress signaling, growth and development, and hormone responses, etc. Recently, the whole genome of apple (Malus × domestica), pear (Pyrus communis), peach (Prunus persica), plum (Prunus mume) and strawberry (Fragaria vesca) in Rosaceae family has been fully sequenced. However, little is known about the CPK gene family in these Rosaceae species. In this study, 123 CPK genes were identified from five Rosaceae species, including 37 apple CPKs, 37 pear CPKs, 17 peach CPKs, 16 strawberry CPKs, and 16 plum CPKs. Based on the phylogenetic tree topology and structural characteristics, we divided the CPK gene family into 4 distinct subfamilies: Group I, II, III, and IV. Whole-genome duplication (WGD) or segmental duplication played vital roles in the expansion of the CPK in these Rosaceae species. Most of segmental duplication pairs in peach and plum may have arisen from the γ triplication (~140 million years ago [MYA]), while in apple genome, many duplicated genes may have been derived from a recent WGD (30~45 MYA). Purifying selection also played a critical role in the function evolution of CPK family genes. Expression of apple CPK genes in response to apple pathotype of Alternaria alternata was verified by analysis of quantitative real-time RT-PCR (qPCR). Expression data demonstrated that CPK genes in apple might have evolved independently in different biological contexts. The analysis of evolution history and expression profile laid a foundation for further examining the function and complexity of the CPK gene family in Rosaceae.

  1. Characterization and Comparison of the CPK Gene Family in the Apple (Malus × domestica and Other Rosaceae Species and Its Response to Alternaria alternata Infection.

    Directory of Open Access Journals (Sweden)

    Menghan Wei

    Full Text Available As one of the Ca2+ sensors, calcium-dependent protein kinase (CPK plays vital roles in immune and stress signaling, growth and development, and hormone responses, etc. Recently, the whole genome of apple (Malus × domestica, pear (Pyrus communis, peach (Prunus persica, plum (Prunus mume and strawberry (Fragaria vesca in Rosaceae family has been fully sequenced. However, little is known about the CPK gene family in these Rosaceae species. In this study, 123 CPK genes were identified from five Rosaceae species, including 37 apple CPKs, 37 pear CPKs, 17 peach CPKs, 16 strawberry CPKs, and 16 plum CPKs. Based on the phylogenetic tree topology and structural characteristics, we divided the CPK gene family into 4 distinct subfamilies: Group I, II, III, and IV. Whole-genome duplication (WGD or segmental duplication played vital roles in the expansion of the CPK in these Rosaceae species. Most of segmental duplication pairs in peach and plum may have arisen from the γ triplication (~140 million years ago [MYA], while in apple genome, many duplicated genes may have been derived from a recent WGD (30~45 MYA. Purifying selection also played a critical role in the function evolution of CPK family genes. Expression of apple CPK genes in response to apple pathotype of Alternaria alternata was verified by analysis of quantitative real-time RT-PCR (qPCR. Expression data demonstrated that CPK genes in apple might have evolved independently in different biological contexts. The analysis of evolution history and expression profile laid a foundation for further examining the function and complexity of the CPK gene family in Rosaceae.

  2. Characterization and Pathogenicity of Alternaria burnsii from Seeds of Cucurbita maxima (Cucurbitaceae) in Bangladesh.

    Science.gov (United States)

    Paul, Narayan Chandra; Deng, Jian Xin; Lee, Hyang Burm; Yu, Seung-Hun

    2015-12-01

    In the course of survey of endophytic fungi from Bangladesh pumpkin seeds in 2011~2012, two strains (CNU111042 and CNU111043) with similar colony characteristics were isolated and characterized by their morphology and by molecular phylogenetic analysis of the internal transcribed spacer, glyceraldehydes-3-phosphate dehydrogenase (gpd), and Alternaria allergen a1 (Alt a1) sequences. Phylogenetic analysis of all three sequences and their combined dataset revealed that the fungus formed a subclade within the A. alternata clade, matching A. burnsi and showing differences with its other closely related Alternaria species, such as A. longipes, A. tomato, and A. tomaticola. Long ellipsoid, obclavate or ovoid beakless conidia, shorter and thinner conidial size (16~60 [90] × 6.5~14 [~16] µm) distinguish this fungus from other related species. These isolates showed more transverse septation (2~11) and less longitudinal septation (0~3) than did other related species. Moreover, the isolate did not produce any diffusible pigment on media. Therefore, our results reveal that the newly recorded fungus from a new host, Cucurbita maxima, is Alternaria burnsii Uppal, Patel & Kamat.

  3. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives.

    Science.gov (United States)

    Brun, Sophie; Madrid, Hugo; Gerrits Van Den Ende, Bert; Andersen, Birgitte; Marinach-Patrice, Carine; Mazier, Dominique; De Hoog, G Sybren

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphologically similar taxa. This study aimed to assess if strains of four closely-related plant pathogens, i.e., accurately Alternaria dauci (ten strains), Alternaria porri (six), Alternaria solani (ten), and Alternaria tomatophila (ten) could be identified using multilocus phylogenetic analysis and Matrix-Assisted Laser Desorption Ionisation Time of Flight (MALDI-TOF) profiling of proteins. Phylogenetic analyses were performed on three loci, i.e., the internal transcribed spacer (ITS) region of rRNA, and the glyceraldehyde-3-phosphate dehydrogenase (gpd) and Alternaria major antigen (Alt a 1) genes. Phylogenetic trees based on ITS sequences did not differentiate strains of A. solani, A. tomatophila, and A. porri, but these three species formed a clade separate from strains of A. dauci. The resolution improved in trees based on gpd and Alt a 1, which distinguished strains of the four species as separate clades. However, none provided significant bootstrap support for all four species, which could only be achieved when results for the three loci were combined. MALDI-TOF-based dendrograms showed three major clusters. The first comprised all A. dauci strains, the second included five strains of A. porri and one of A. solani, and the third included all strains of A. tomatophila, as well as all but one strain of A. solani, and one strain of A. porri. Thus, this study shows the usefulness of MALDI-TOF mass spectrometry as a promising tool for identification of these four species of Alternaria which are closely-related plant pathogens. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Restyling Alternaria

    NARCIS (Netherlands)

    Woudenberg, J.H.C.

    2015-01-01

    The omnipresent dematiaceous hyphomycete genus Alternaria is associated with a wide variety of substrates including seeds, plants, agricultural products, humans, soil and even the atmosphere. It includes saprophytic, endophytic and pathogenic species, among which multiple plant pathogens, post-harve

  5. Restyling Alternaria

    NARCIS (Netherlands)

    Woudenberg, J.H.C.

    2015-01-01

    The omnipresent dematiaceous hyphomycete genus Alternaria is associated with a wide variety of substrates including seeds, plants, agricultural products, humans, soil and even the atmosphere. It includes saprophytic, endophytic and pathogenic species, among which multiple plant pathogens,

  6. A Virulence-Reducing Mutation in the Postharvest Citrus Pathogen Alternaria citri.

    Science.gov (United States)

    Katoh, H; Isshiki, A; Masunaka, A; Yamamoto, H; Akimitsu, K

    2006-09-01

    ABSTRACT Alternaria citri causes Alternaria black rot, a postharvest fruit disease, on a broad range of citrus cultivars. We previously described that an endopolygalacturonase minus mutant of A. citri caused significantly less black rot in citrus fruit. To search for other essential factors causing symptoms in addition to endopolygalacturonase, a random mutation analysis of pathogenicity was performed using restriction enzyme-mediated integration. Three isolates among 1,694 transformants of A. citri had a loss in pathogenicity in a citrus peel assay, and one of these three mutants was a histidine auxotroph. Gene AcIGPD that encodes imidazole glycerol phosphate dehydratase, the sixth enzyme in the histidine biosynthetic pathway, was cloned, and the mutant containing the disrupted target gene, AcIGPD, caused less black rot.

  7. Characterization of Citrus-Associated Alternaria Species in Mediterranean Areas

    Science.gov (United States)

    Garganese, Francesca; Schena, Leonardo; Siciliano, Ilenia; Prigigallo, Maria Isabella; Spadaro, Davide; De Grassi, Anna; Ippolito, Antonio

    2016-01-01

    Alternaria brown spot is one of the most important diseases of tangerines and their hybrids worldwide. Recently, outbreaks in Mediterranean areas related to susceptible cultivars, refocused attention on the disease. Twenty representatives were selected from a collection of 180 isolates of Alternaria spp. from citrus leaves and fruit. They were characterized along with reference strains of Alternaria spp. Micro- and macroscopic characteristics separated most Alternaria isolates into six morphotypes referable to A. alternata (5) and A. arborescens (1). Phylogenetic analyses, based on endopolygalacturonase (endopg) and internal transcribed spacer (ITS), confirmed this finding. Moreover, a five-gene phylogeny including two anonymous genomics regions (OPA 1–3 and OPA 2–1), and the beta-tubulin gene (ß-tub), produced a further clustering of A. alternata into three clades. This analysis suggested the existence of intra-species molecular variability. Investigated isolates showed different levels of virulence on leaves and fruit. In particular, the pathogenicity on fruit seemed to be correlated with the tissue of isolation and the clade. The toxigenic behavior of Alternaria isolates was also investigated, with tenuazonic acid (TeA) being the most abundant mycotoxin (0.2–20 mg/L). Isolates also synthesized the mycotoxins alternariol (AOH), its derivate alternariol monomethyl ether (AME), and altenuene (ALT), although to a lesser extent. AME production significantly varied among the six morphotypes. The expression of pksJ/pksH, biosynthetic genes of AOH/AME, was not correlated with actual toxin production, but it was significantly different between the two genotypes and among the four clades. Finally, ten isolates proved to express the biosynthetic genes of ACTT1 phytotoxin, and thus to be included in the Alternaria pathotype tangerine. A significant correlation between pathogenicity on leaves and ACTT1 gene expression was recorded. The latter was significantly

  8. Screening for the Isolates of Thrichoderma Viride Against Alternaria Alternata and Its Antagonistic Mechanism%木霉拮抗烟草赤星病菌菌株的筛选及拮抗机制

    Institute of Scientific and Technical Information of China (English)

    王革; 周晓罡; 方敦煌; 天飞

    2000-01-01

    利用诱捕法从土壤中分离得到18株木霉(Trichoderma sps.)菌株,采用对峙法从中测定、筛选出一株对烟草赤星病菌(Alternaria alternata)具有极强拮抗作用的菌株(Tv-1).光学显微镜及透射电镜观察结果表明,Tv-1菌株的拮抗机制主要为生长竞争、寄生作用以及产生抗菌素类物质使病菌菌丝消解,表现为Tv-1菌株菌丝生长迅速;能附着、缠绕于病菌菌丝上,并产生吸器侵入菌丝;同时还能分泌使病菌菌丝原生质浓缩、断裂、消解的物质.

  9. Efeito do óleo essencial de pimenta longa (Piper hispidinervum C. DC e do emulsificante Tween® 80 sobre o crescimento micelial de Alternaria alternata (Fungi: Hyphomycetes The effect of Long-pepper essential oil (Piper hispidinervum C. DC. and of Tween®; 80 emulsifier on the mycelial growth of Alternaria alternate (Fungi: Hyphomycetes

    Directory of Open Access Journals (Sweden)

    Fabiane Reis Nascimento

    2008-01-01

    Full Text Available Este trabalho objetivou avaliar o efeito do óleo essencial de folhas de pimenta longa (Piper hispidinervum C. DC, sobre o crescimento micelial de Alternaria alternata e a análise da influência da concentração do emulsificante Tween® 80 no controle deste fitopatógeno. O óleo essencial foi obtido pela técnica "arraste a vapor d'água", utilizando-se aparelho de Clevenger modificado, e posteriormente submetido, à análise por cromatografia em fase gasosa acoplada a espectrômetro de massas CG-EM a CG. Para os ensaios biológicos, o método foi o bioanalítico in vitro observando-se o crescimento ou inibição do micélio de A. alternata no meio de cultura BDA na presença de diferentes concentrações do óleo essencial (0, 100, 250, 500 e 1000 mgL-1 sob diferentes concentrações de Tween® 80. Adotou-se esquema fatorial com quatro repetições, em delineamento inteiramente casualizado (DIC. Observou-se que o óleo essencial de pimenta longa apresentou inibição sobre o crescimento micelial do fungo A. alternataem todas as concentrações analisadas, sendo que na concentração de 1000 mgL-1 esta inibição foi de 100% , e a porcentagem de emulsificante (Tween® 80, influenciou na atividade fungitóxica das concentrações de 250 mgL -1 e 500 mgL -1 do óleo essencial.The object of this work was to evaluate the effectof essential oils from Long-pepper leaves Piper hispidinervum on the mycelial growth of Alternaria alternata and to analyze the influence of emulsifier Tween® 80 concentration in the control of this phytopathogen. The essential oil was obtained by steam stream distillation, using a modified Clevenger apparatus, and the chemical composition was analyzed by gas chromatography coupled to mass spectroscopy GC-MS and GC. For biological tests, the bioanalytical in vitro method was used, observing the growth or inhibition of such phytopathogen in BDA culture media, in the presence of different essential oil concentrations (0, 100

  10. Pathogenic mycoflora on carrot seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.

  11. Pathogenic mycoflora on carrot seeds

    OpenAIRE

    Bogdan Nowicki

    2013-01-01

    Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.

  12. Overexpression of citrus polygalacturonase-inhibiting protein in citrus black rot pathogen Alternaria citri.

    Science.gov (United States)

    Katoh, Hiroshi; Nalumpang, Sarunya; Yamamoto, Hiroyuki; Akimitsu, Kazuya

    2007-05-01

    The rough lemon (Citrus jambhiri) gene encoding polygalacturonase-inhibiting protein (RlemPGIPA) was overexpressed in the pathogenic fungus Alternaria citri. The overexpression mutant AcOPI6 retained the ability to utilize pectin as a sole carbon source, and the overexpression of polygalacturonase-inhibiting protein did not have any effect on the growth of AcOPI6 in potato dextrose and pectin medium. The pathogenicity of AcOPI6 to cause a black rot symptom in citrus fruits was also unchanged. Polygalacturonase-inhibiting protein was secreted together with endopolygalacturonase into culture filtrates of AcOPI6, and oligogalacturonides were digested from polygalacturonic acid by both proteins in the culture filtrates. The reaction mixture containing oligogalacturonides possessed activity for induction of defense-related gene, RlemLOX, in rough lemon leaves.

  13. Role of mannitol metabolism in the pathogenicity of the necrotrophic fungus Alternaria brassicicola

    Directory of Open Access Journals (Sweden)

    Benoit eCalmes

    2013-05-01

    Full Text Available In this study, the physiological functions of fungal mannitol metabolism in the pathogenicity and protection against environmental stresses were investigated in the necrotrophic fungus Alternaria brassicicola. Mannitol metabolism was examined during infection of Brassica oleracea leaves by sequential HPLC quantification of the major soluble carbohydrates and expression analysis of genes encoding two proteins of mannitol metabolism, i.e. a mannitol dehydrogenase (AbMdh, and a mannitol-1-phosphate dehydrogenase (AbMpd. Knockout mutants deficient for AbMdh or AbMpd and a double mutant lacking both enzyme activities were constructed. Their capacity to cope with various oxidative and drought stresses and their pathogenic behaviour were evaluated. Metabolic and gene expression profiling indicated an increase in mannitol production during plant infection. Depending on the mutants, distinct pathogenic processes, such as leaf and silique colonization, sporulation, survival on seeds, were impaired by comparison to the wild-type. This pathogenic alteration could be partly explained by the differential susceptibilities of mutants to oxidative and drought stresses. These results highlight the importance of mannitol metabolism with respect to the ability of A. brassicicola to efficiently accomplish key steps of its pathogenic life cycle.

  14. Phytotoxin solanapyrone A produced by Ascochyta rabiei and Alternaria solani is nonessential for pathogenicity, but likely plays ecological roles

    Science.gov (United States)

    Ascochyta rabiei and Alternaria solani, causal agents of chickpea and potato blights respectively, produce the same phytotoxin solanapyrone A (SolA).The toxicity of SolA to plants has been documented, but its role in pathogenicity has not been investigated. In this study, we generated solanapyrone-d...

  15. Screening of Antagonistic Bacterium to Alternaria alternata (Fries) Keissler%烟草赤星病拮抗菌的筛选

    Institute of Scientific and Technical Information of China (English)

    周棱波; 黎定军; 陈武; 罗坤

    2011-01-01

    Eighty-six strains were isolated and selected from the healthy tobacco leaves collected from Liuyang area of Hunan Province by using confront culture method, in which the B17 showed the strongest antagonism to Alternaria alternala (Fries) Keissler with inhibition rate of 72.1% . Through physiological and biochemical experiments and morphologic observation, the B17 was identified as Bacillus brevis. The control efficacy tests of in vitro culture and green house culture for B17 zymotic fluid showed that the B17 zymotic fluid can obviously reduce the incidence of disease. In pot experiment, the control efficacy of the B17 zymotic fluid reached 71.2%.%采用对峙培养法从湖南浏阳地区烟田采摘的健康烟叶中筛选分离出86株菌株,其中B17菌株对烟草赤星病菌拮抗作用最强,抑制率为72.1%.通过生理生化实验和形态观察,初步鉴定B17菌株为短芽孢杆菌.在B17菌株发酵液的离体防效和温室栽培防效试验中,发酵液可以明显的减轻病害的发生,盆栽试验中,其防效为71.2%.

  16. 三种化学物质诱导观赏百合对黑斑病抗性的研究%Resistance of ornamental lily against Alternaria alternata induced by three chemicals

    Institute of Scientific and Technical Information of China (English)

    梁巧兰; 魏列新; 徐秉良; 师桂英

    2011-01-01

    [Objective] The induced resistance effect of salicylic acid (SA), nanometer silicon and ammonium oxalate for lily to Alternaria alternata were evaluated so as to provide the basis for control of lily diseases. [Method]The inhibitory bioactivity and the induced resistance of ornamental lily to A. alternata elicited by three chemicals were tested. [Result] The inhibitory effects of salicylic acid (SA), nanomcter silicon and ammonium oxalate to A. alternata were very weak, and the rates of inhibition were less than 5.43%. When treated at the concentration 100 μg/mL, 50 μg/mL and 25 μg/mL of nanometer silicon, the induced resistance to lily leaves reached 55.55%, 60.69% and 48.57%, respectively. The enzyme activity of β-1,3-glucosan reached the maximum in one day when lily leaves were treated by SA, while the enzyme activity of POD induced by nanometer silicon and PAL induced by ammonium oxalate reached the maximum in five days, which were 3.95, 2.10 and 1.15 times as those of control, respectively. The enzyme activity of β-1,3-glucosan, POD and PAL enzyme of lily leaves were higher than that of the control when lily leaves were treated with 50 μg/mL of the three chemicals and then inoculated with A. alternata. The induced resistance to lily leaves elicited by the three chemicals after seven days reached 35.38%, 43.55% and 31.07%, respectively. After fourteen days, the induced resistance to lily leaves was decreased significantly, compared with that elicited by the three chemicals after seven days. [Conclusion] Salicylic acid (SA), nanometer silicon and ammonium oxalate had induced resistance effects to lily to some extent, among which, nanometer silicon had the best effect of over 48%.%[目的]确定水杨酸、纳米硅、草酸按等3种化学物质对观赏百合黑斑病抗病性的诱导效果,为百合生长期病害的防治提供理论依据.[方法]测定3种化学物质对现赏百合黑斑病菌的抑菌活性和诱导

  17. Cultural, Morphological and Pathogenic Characterization of Alternaria porri Causing Purple Blotch of Onion

    Directory of Open Access Journals (Sweden)

    Sayed Mohammad MOHSIN

    2016-06-01

    Full Text Available Twenty seven (27 isolates of Alternaria porri were isolated from diseased leaf samples collected from different onion growing regions of Bangladesh and characterized for cultural, morphological and pathogenic variabilities. A. porri colonies colony colour ranged between light to dark olivacious and grayish white with irregular, regular with concentric ring and regular without concentric ring shape. Margin of colonies were entire, irregular and wavy with effuse, fluffy and velvety texture. Isolates impregnated media with colour ranged between grey to brown on the reverse of the plates. Growth rate of isolates ranged between 2.433 and 3.950 mm/day with fast growth in isolate DSTR 02 and least in MMBH. Morphological variation in conidia production was between 7.720×103 to 47.02×103 per mm2 with sporulation time 3.33 to 11.00 days. The conidial shape was straight to curve with light to deep brown colour. The number of horizontal and vertical separation in the conidia ranged from 3.00 to 6.00 × 1.00 to 2.00 with size from 11.20 to 39.20 × 4.76 to 11.43 µm. In pathogenicity test isolates also exhibited variations in size of the lesions (2.77 to 7.55 mm produced on onion leaves. The results demonstrate existence of considerable variation in cultural, morphological, and pathogenic characters of A. porri isolates prevalent in Bangladesh environment.

  18. Fungal-specific transcription factor AbPf2 activates pathogenicity in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Ohm, Robin A.; Grigoriev, Igor V.; Srivastava, Akhil

    2012-12-03

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. To identify molecular determinants of pathogenicity, we created non-pathogenic mutants of a transcription factor-encoding gene, AbPf2. The frequency and timing of germination and appressorium formation on host plants were similar between the non-pathogenic abpf2 mutants and wild-type A. brassicicola. The mutants were also similar in vitro to wild-type A. brassicicola in terms of vegetative growth, conidium production, and responses to a phytoalexin, reactive oxygen species and osmolites. The hyphae of the mutants grew slowly but did not cause disease symptoms on the surface of host plants. Transcripts of the AbPf2 gene increased exponentially soon after wild-type conidia contacted their host plants . A small amount of AbPf2 protein, as monitored using GFP fusions, was present in young, mature conidia. The protein level decreased during saprophytic growth, but increased and was located primarily in fungal nuclei during pathogenesis. Levels of the proteins and transcripts sharply decreased following colonization of host tissues beyond the initial infection site. When expression of the transcription factor was induced in the wild-type during early pathogenesis, 106 fungal genes were also induced in the wild-type but not in the abpf2 mutants. Notably, 33 of the 106 genes encoded secreted proteins, including eight putative effector proteins. Plants inoculated with abpf2 mutants expressed higher levels of genes associated with photosynthesis, the pentose phosphate pathway and primary metabolism, but lower levels of defense-related genes. Our results suggest that AbPf2 is an important regulator of pathogenesis, but does not affect other cellular processes in A. brassicicola.

  19. Preliminary study on three pathogens with potential biological control in Barnyard grass (Echinochloa crus galli)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ More than 10 species of pathogenic fungi were isolated from the naturally infected leaves of barnyard grass (Echinochloa crus-galli) in paddy. After preliminary bioassaying, it was found that the Alternaria alternata (Fr.) keissler(AA), Exserohilum monoceras (EM),and "99-10" were three potential agents for biological control of barnyard grass.

  20. RESISTÊNCIA DE TOMATEIRO (Lycopersicon esculentum AO PATÓGENO Alternaria solani RESISTANCE OF TOMATO (Lycopersicon esculentum TO Alternaria solani PATHOGEN

    Directory of Open Access Journals (Sweden)

    Wilson Ferreira de Oliveira

    2007-09-01

    resistant were F1 hibrid Hawaii 7998 x Monense and Rotam 4. The genotypes Ohio 4013 and the F1 Hawaii 7998 x Monense hibrid were the ones that more stood out for resistance to these pathogen and could be suitable for future breeding programs.

    KEY-WORDS: Tomato; resistance; Alternaria solani.

  1. Action of the Metabolite Produced by Streptomyces cacaoi Strain 182-2 on Alternaria alternata%可可链霉菌182-2活性代谢产物对烟草赤星病菌的作用

    Institute of Scientific and Technical Information of China (English)

    高芬; 吴元华; 王梦亮

    2013-01-01

    [目的]明确可可链霉菌(Streptomyces cacaoi)182-2的活性代谢产物--KA08对烟草赤星病菌(Alternariaalternata)的抑菌活性及其机理,为后续农用抗生素产品开发和应用提供科学依据。[方法]采用菌丝湿重法和培养皿中萌发法,测定KA08对烟草赤星病菌菌丝生长和孢子萌发的抑制作用;采用电导率法和紫外吸收法测定其对细胞膜渗透性、麦角甾醇含量、脂质过氧化程度、可溶性蛋白含量的影响。[结果]KA08对烟草赤星病菌菌丝生长和孢子萌发均有强烈的抑制作用,同时,还可造成菌丝节间缩短、扭曲,芽管顶端膨大,并产生大量囊状膨大物。处理24 h时,对孢子萌发的抑菌中浓度为177.53µg·mL-1。抑菌机理研究发现KA08能导致菌丝体内电解质泄漏,细胞膜上麦角甾醇含量显著降低,脂质过氧化产物-丙二醛含量明显升高,并显著抑制菌丝体内蛋白质含量。[结论]农抗KA08对烟草赤星病菌具有显著抑制作用,主要通过抑制菌丝细胞膜上麦角甾醇合成,引发细胞膜脂质过氧化而使病菌细胞膜受损、通透性增加,从而导致菌丝生长受阻。细胞膜是KA08的主要作用位点之一。%[Objective] The objective of this study is to understand the antifungal activity and mechanism of KA08 produced by Streptomyces cacaoi strain 182-2 against Alternaria alternata so as to provide a scientific basis for further product development and application.[Method]Estimation of mycelia wet weight and spore germination in petri dish method were used to test the inhibitory effect of KA08 on mycelia growth and spore germination. Electrical conductivity method was used to test the permeability of pathogen plasma membrane, and the ultraviolet absorption method was employed to detect the content of ergosterol, MDA and soluble protein.[Result]KA08 had a remarkable inhibition effect on mycelia growth and spore germination. It

  2. Efficiency and cost of chemical control of alternaria brown spot

    OpenAIRE

    Adimara Bentivoglio Colturato; Tatiana Paulossi; Wilson Story Venâncio; Edson Luiz Furtado

    2009-01-01

    A mancha de alternaria, causada por Alternaria alternata f. sp. citri, afeta tangelos Minneola, tangerinas Dancy, tangores Murcote e, menos freqüentemente, tangelos Orlando, tangerinas Novas, Lees e Sunburst. Esta doença causa desfolha grave, queda de frutos e manchas nas frutas. O objetivo deste trabalho foi estabelecer o melhor fungicida e a melhor dose para o controle da mancha marrom de alternaria. O delineamento experimental foi de parcelas subdivididas em blocos, com 10 tratamentos prin...

  3. Effect of Alternaria solani exudates on resistant and susceptible potato cultivars from two different pathogen isolates

    Science.gov (United States)

    The resistance phenotypes of two potato cultivars to two isolates of Alternaria solani, causal agent of early blight, were studied under greenhouse conditions. The two isolates contain varying degrees of aggressiveness on both susceptible and resistant phenotypes of potatoes. A bioassay was used to ...

  4. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives

    DEFF Research Database (Denmark)

    Brun, Sophie; Madrid, Hugo; Gerrits Van Den Ende, Bert

    2013-01-01

    -Assisted Laser Desorption Ionisation Time of Flight (MALDI-TOF) profiling of proteins. Phylogenetic analyses were performed on three loci, i.e., the internal transcribed spacer (ITS) region of rRNA, and the glyceraldehyde-3-phosphate dehydrogenase (gpd) and Alternaria major antigen (Alt a 1) genes. Phylogenetic...

  5. Tomato early blight (Alternaria solani): the pathogen, genetics and breeding for resistance

    NARCIS (Netherlands)

    Chaerani, R.; Voorrips, R.E.

    2006-01-01

    Alternaria solani causes diseases on foliage (early blight), basal stems of seedlings (collar rot), stems of adult plants (stem lesions), and fruits (fruit rot) of tomato. Early blight is the most destructive of these diseases and hence receives considerable attention in breeding. For over 60 years,

  6. Multilocus phylogeny and MALDI-TOF analysis of the plant pathogenic species Alternaria dauci and relatives

    NARCIS (Netherlands)

    Brun, S.; Madrid, H.; Gerritis van den Ende, B.; Andersen, B.; Marinach-Patrice, C.; Mazier, D.; de Hoog, G.S.

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphol

  7. Analysis of genetic and pathogenic variation among Alternaria solani in a potato production region

    Science.gov (United States)

    A two-year survey was conducted in a potato production region to investigate the genetic variability within naturally infecting populations of Alternaria solani, the cause of early blight in potato, and between species A. solani and A. dauci. Genetic diversity among 151 isolates was assessed using s...

  8. Tomato early blight (Alternaria solani): the pathogen, genetics and breeding for resistance

    OpenAIRE

    Chaerani, R.; Voorrips, R. E.

    2006-01-01

    Alternaria solani causes diseases on foliage (early blight), basal stems of seedlings (collar rot), stems of adult plants (stem lesions), and fruits (fruit rot) of tomato. Early blight is the most destructive of these diseases and hence receives considerable attention in breeding. For over 60 years, breeding for early blight resistance has been practiced, but the development of cultivars with high levels of resistance has been hampered by the lack of sources of strong resistance in the cultiv...

  9. Characterisation of Alternaria species-groups associated with core rot of apples in South Africa

    DEFF Research Database (Denmark)

    Serdani, M.; Kang, J.C.; Andersen, Birgitte

    2002-01-01

    Alternaria core rot of red apple cultivars is a serious post-harvest disease in South Africa. Thirty isolates of Alternaria spp. previously isolated from apple, together with reference isolates of A. alternata and A. infectoria, were characterised and grouped according to their sporulation patterns...... and conidial morphology. Isolates were identified as belonging to A. arborescens, A. infectoria and A. tenuissima species-groups. The isolates were also analysed for production of mycotoxins and other secondary metabolites and their cultural characteristics on DRYES medium were recorded. Apple fruit were...... the other species-groups, as all isolates had a distinction of 35 base pair insertions and 6 base pair deletions in the ITS regions. The results obtained in the present study showed that the major pathogens associated with core rot disease of Top Red apples in South Africa belong to the A. tenuissima...

  10. 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...

  11. Fungal-specific transcription factor AbPf2 activates pathogenicity in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Ohm, Robin A. [US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA; Grigoriev, Igor V. [US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA; Srivastava, Akhil [Plant and Environmental Protection Sciences, University of Hawaii at Manoa, 3190 Maile Way, St John 317, Honolulu, HI, 96822, USA

    2013-05-24

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. To identify molecular determinants of pathogenicity, we created non-pathogenic mutants of a transcription factor-encoding gene, AbPf2. The frequency and timing of germination and appressorium formation on host plants were similar between the non-pathogenic abpf2 mutants and wild-type A. brassicicola. The mutants were also similar in vitro to wild-type A. brassicicola in terms of vegetative growth, conidium production, and responses to a phytoalexin, reactive oxygen species and osmolites. The hyphae of the mutants grew slowly but did not cause disease symptoms on the surface of host plants. Transcripts of the AbPf2 gene increased exponentially soon after wild-type conidia contacted their host plants . A small amount of AbPf2 protein, as monitored using GFP fusions, was present in young, mature conidia. The protein level decreased during saprophytic growth, but increased and was located primarily in fungal nuclei during pathogenesis. Levels of the proteins and transcripts sharply decreased following colonization of host tissues beyond the initial infection site. When expression of the transcription factor was induced in the wild-type during early pathogenesis, 106 fungal genes were also induced in the wild-type but not in the abpf2 mutants. Notably, 33 of the 106 genes encoded secreted proteins, including eight putative effector proteins. Plants inoculated with abpf2 mutants expressed higher levels of genes associated with photosynthesis, the pentose phosphate pathway and primary metabolism, but lower levels of defense-related genes. Our results suggest that AbPf2 is an important regulator of pathogenesis, but does not affect other cellular processes in A. brassicicola.

  12. Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.

    Science.gov (United States)

    Kim, Wonyong; Park, Chung-Min; Park, Jeong-Jin; Akamatsu, Hajime O; Peever, Tobin L; Xian, Ming; Gang, David R; Vandemark, George; Chen, Weidong

    2015-04-01

    Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here, we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both Ascochyta rabiei and Alternaria solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound, prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of Ascochyta rabiei and Alternaria solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity.

  13. 抗菌肽和几丁质酶基因提高烟草对黑胫病菌和赤星病菌的抗性研究%Overexpression of antimicrobial peptide genes and a chitinase gene in transgenic tobacco enhances resistance to Phytophthora parasitica var. nicotianae and Alternaria alternata

    Institute of Scientific and Technical Information of China (English)

    罗小英; 曾雪嘉; 肖月华; 罗明; 杨星勇; 裴炎

    2005-01-01

    通过农杆菌介导法将加信号肽修饰的人工合成杂合抗菌肽CEMA基因(SPCEMA),苜蓿防御素基因(AFP),苦瓜几丁质酶基因(CHI)以及SPCEMA-CHI、AFP-CHI、AFP-SPCEMA双价基因导入本明烟(Nicotiana benthamiana),并对转基因烟草T0和T1代进行了抗病性检测,比较了不同转基因植株的抗病效果.研究结果表明,转基因烟草对黑胫病菌(Phytophthora parasitica var.nicotianae)、赤星病菌(Alternaria alternata)的抗性均强于非转基因烟草,病情指数差异达极显著水平,其中转AFP-CHI双价基因烟草具有较强的抗性,与单价转基因烟草的抗性差异达显著水平.但各单价转基因以及双价转基因烟草之间对上述病菌并未表现出显著的抗病性差异.结果表明植物源的抗菌肽基因与几丁质酶基因在抗植物真菌病害中具有协同增效作用.

  14. Liquid Chromatographic Determination of Alternaria Toxins in Carrots

    NARCIS (Netherlands)

    Solfrizzo, M.; Girolamo, De A.; Vitti, C.; Bulk, van den R.W.

    2004-01-01

    A liquid chromatographic (LC) method was developed for the determination of Alternaria radicina and A. alternata toxins in carrots. Toxins were extracted from carrot with an acidified mixture of water¿methanol¿acetonitrile. The filtered extract was divided in 2 parts that were purified by

  15. AGGRESSIVENESS AND MORPHOLOGICAL VARIABILITY OF SMALL SPORE Alternaria SPECIES ISOLATED FROM ALGERIA

    Directory of Open Access Journals (Sweden)

    Nabahat Bessadat

    2014-05-01

    Full Text Available Natural epidemics of blight disease are strongly influenced by environmental conditions, even though several diseases appears every year in north western of Algeria which can cause complete loss of the crop when the infection is severe. The fungi which are frequently associated with leaf blight, stem blight and apical fruit rot of Solanaceae family are Alternaria arborescens, A. alternata and A. tenuissima. These fungi were identified on morphological characteristics. For that, eighty one small spore strains belonging to the A. alternata section were assessed for disease symptoms, percent disease incidence (PDI and area under the diseases progress curve (AUDPC on three different tomato cultivars. Among the tested fungal isolates, it revealed that PDI of the isolates were changed according to the cultivar and the highest blight disease incidence was found in A. tenuissima strain 164 (96% in Saint Pierre, 59% in Cherry tomato and 69% in Rio Grande, it was followed be A. alternata strain 156 (90% in Saint Pierre, 82% in cherry tomato and 46% in Rio Grande and A. arborescens strain 65 (49% in Saint Pierre, 85% in cherry tomato and 63,15% in Rio Grande. According to the aggressiveness component of the isolates, the classical behavior of the cultivars was confirmed, and Saint Pierre and Rio Grande cultivars were found susceptible with a slightly higher mean of AUDPC (413.72 and 390.48 respectively but Cherry tomato cultivar was found to be resistant with the lowest AUDPC mean 227.18 ± 166.10. Based upon results of present study, it was concluded that a complex of small spore Alternaria species and isolates found on Solanaceae lesions are not equally pathogenic but majority of A. tenuissima isolates are not the part of this complex.

  16. Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds

    Directory of Open Access Journals (Sweden)

    Sharma Bechan

    2009-03-01

    Full Text Available Abstract Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz, against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 μg/ml of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100% of spore germination in both the moulds. At 100 μg/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 μg/ml of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 μg/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata.

  17. Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds.

    Science.gov (United States)

    Mishra, Ajay K; Mishra, Amita; Kehri, H K; Sharma, Bechan; Pandey, Abhay K

    2009-03-07

    Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz), against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. The lowest test concentration (50 microg/ml) of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100%) of spore germination in both the moulds. At 100 microg/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 microg/ml) of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 microg/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata.

  18. First report of QoI resistance in Alternaria spp. infecting sugar beet (Beta vulgaris) in Michigan, USA

    Science.gov (United States)

    Alternaria leaf spot (ALS) of sugar beet is caused by Alternaria spp. in the A. alternata species complex. ALS is common wherever sugar beet is grown, but historically has been a minor issue for sugar beet production in the USA with damage usually not affecting crop yield significantly. Occurrence o...

  19. 烟草赤星病菌代谢产物诱导的烟草BY-2细胞ROS爆发和ATP损耗%ROS Burst and ATP Depletion in Tobacco BY-2 Cells Induced by Metabolic Products of Alternaria alternata

    Institute of Scientific and Technical Information of China (English)

    程丹丹; 孙学娟; 高辉远; 杨程; 张立涛; 孟庆伟

    2011-01-01

    [目的]探讨赤星病菌代谢产物(metabolic product s of AIternaria alternata,MP)对烟草BY-2细胞活性氧(reactive oxygen species,ROS)产生和ATP含量的影响以及产生这种影响的原因.[方法]用10%MP处理烟草BY-2细胞,用氧电极检测不同MP处理时间后,烟草BY-2细胞呼吸速率和呼吸途径的变化,同时分析BY-2细胞内BO产生和ATP含量等的变化.[结果]MP处理导致了烟草BY-2细胞HO爆发和ATP含量下降,此外,MP处理也导致了烟草BY-2细胞总呼吸速率、细胞色素途径(cytochrome pathway)和交替氧化酶途径(AOX)的下降,并且造成线粒体通透转换孔道(permeability transition pore,PTP)开放和细胞色素c释放.[结论]MP对BY-2细胞呼吸速率和细胞色素途径的抑制不可避免地导致胞内ATP含量下降,此外MP诱导的烟草BY-2细胞氧化磷酸化的解偶联作用是MP导致胞内ATP含量下降的另一重要原因.而MP对AOX途径的抑制则是诱导胞内ROS爆发的重要原因.%[Objective] The objective of this study is to explore the effect of the Alternaria alternata metabolic products (MP) on changes of reactive oxygen species (ROS) production and ATP content in the tobacco BY-2 cells. [ Method] 10% MP was used to treat tobacco BY-2 cells, and Oxytherm oxygen electrode was used to study the effects of MP on the reparation rate and reparation pathway in the tobacco BY-2 cells. The changes of ROS production and ATP content in tobacco BY-2 cells was also studied. [ Result] Treatment with the MP led to remarkable overproduction of ROS, rapid depletion of ATP, significant declines in respiration, in cytochrome pathway and in alternative oxidase pathway (AOX). The treatment with MP also resulted in uncoupling of oxidative phosphorylation, opening of the permeability transition pore (PTP) and release of cytochrome c from mitochondria to cytoplasm in tobacco BY-2 cells. [Conclusion] The inhibition of respiration and cytochrome pathway inevitably result in ATP

  20. Multilocus phylogeny and MALDI-TOF analysis of the plant-pathogenic species Alternaria dauci and relatives

    NARCIS (Netherlands)

    Brun, S.; Madrid, H.; Gerrits van den Ende, A.H.G.; Andersen, B.; Marinach-Patrice, C.; Mazier, D.; de Hoog, G.S.

    2013-01-01

    The genus Alternaria includes numerous phytopathogenic species, many of which are economically relevant. Traditionally, identification has been based on morphology, but is often hampered by the tendency of some strains to become sterile in culture and by the existence of species-complexes of morphol

  1. Arabidopsis Elongator subunit 2 positively contributes to resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola.

    Science.gov (United States)

    Wang, Chenggang; Ding, Yezhang; Yao, Jin; Zhang, Yanping; Sun, Yijun; Colee, James; Mou, Zhonglin

    2015-09-01

    The evolutionarily conserved Elongator complex functions in diverse biological processes including salicylic acid-mediated immune response. However, how Elongator functions in jasmonic acid (JA)/ethylene (ET)-mediated defense is unknown. Here, we show that Elongator is required for full induction of the JA/ET defense pathway marker gene PLANT DEFENSIN1.2 (PDF1.2) and for resistance to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola. A loss-of-function mutation in the Arabidopsis Elongator subunit 2 (ELP2) alters B. cinerea-induced transcriptome reprogramming. Interestingly, in elp2, expression of WRKY33, OCTADECANOID-RESPONSIVE ARABIDOPSIS AP2/ERF59 (ORA59), and PDF1.2 is inhibited, whereas transcription of MYC2 and its target genes is enhanced. However, overexpression of WRKY33 or ORA59 and mutation of MYC2 fail to restore PDF1.2 expression and B. cinerea resistance in elp2, suggesting that ELP2 is required for induction of not only WRKY33 and ORA59 but also PDF1.2. Moreover, elp2 is as susceptible as coronatine-insensitive1 (coi1) and ethylene-insensitive2 (ein2) to B. cinerea, indicating that ELP2 is an important player in B. cinerea resistance. Further analysis of the lesion sizes on the double mutants elp2 coi1 and elp2 ein2 and the corresponding single mutants revealed that the function of ELP2 overlaps with COI1 and is additive to EIN2 for B. cinerea resistance. Finally, basal histone acetylation levels in the coding regions of WRKY33, ORA59, and PDF1.2 are reduced in elp2 and a functional ELP2-GFP fusion protein binds to the chromatin of these genes, suggesting that constitutive ELP2-mediated histone acetylation may be required for full activation of the WRKY33/ORA59/PDF1.2 transcriptional cascade.

  2. Metabolites from Alternaria Fungi and Their Bioactivities

    Directory of Open Access Journals (Sweden)

    Ligang Zhou

    2013-05-01

    Full Text Available Alternaria is a cosmopolitan fungal genus widely distributing in soil and organic matter. It includes saprophytic, endophytic and pathogenic species. At least 268 metabolites from Alternaria fungi have been reported in the past few decades. They mainly include nitrogen-containing metabolites, steroids, terpenoids, pyranones, quinones, and phenolics. This review aims to briefly summarize the structurally different metabolites produced by Alternaria fungi, as well as their occurrences, biological activities and functions. Some considerations related to synthesis, biosynthesis, production and applications of the metabolites from Alternaria fungi are also discussed.

  3. Mycosynthesis of iron nanoparticles by Alternaria alternata and its ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-04-08

    Apr 8, 2015 ... their special physical and chemical characteristics, they showed unusual ..... FeCl3 resulted in the particles with the smallest Z- average diameter ... reactive oxygen species generation and the Fenton reaction. Oxidative stress ...

  4. Automated and unbiased image analyses as tools in phenotypic classification of small-spored Alternaria species

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Hansen, Michael Edberg; Smedsgaard, Jørn

    2005-01-01

    For more than 25 years, controversy has surrounded the characterization and differentiation of small-spored Alternaria spp. And, therefore, the application of names of several species that are involved in the pathology of diseases related to host-specific toxin production. The name A. alternata o...

  5. 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.

  6. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis) Ciferri

    Science.gov (United States)

    Nanda, Satyabrata; Chand, Subodh Kumar; Mandal, Purander; Tripathy, Pradyumna; Joshi, Raj Kumar

    2016-01-01

    Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ‘CBT-Ac77’ and cultivar ‘Arka Kalyan’ were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur) in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001). All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India. PMID:27904458

  7. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis Ciferri

    Directory of Open Access Journals (Sweden)

    Satyabrata Nanda

    2016-12-01

    Full Text Available Purple blotch, caused by Alternaria porri (Ellis Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ‘CBT-Ac77’ and cultivar ‘Arka Kalyan’ were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001. All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India.

  8. Detection of Alternaria fungal contamination in cereal grains by a polymerase chain reaction-based assay.

    Science.gov (United States)

    Zur, Gideon; Shimoni, Eyal; Hallerman, Eric; Kashi, Yechezkel

    2002-09-01

    Alternaria sp. are important fungal contaminants of grain products; they secrete four structural classes of compounds that are toxic or carcinogenic to plants and animals and cause considerable economic losses to growers and the food-processing industry. Alternaria toxins have been detected by high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay, and other techniques. Here, we report the development of a polymerase chain reaction (PCR)-based method for the detection of Alternaria DNA. PCR primers were designed to anneal to the ITS1 and ITS2 regions of the 5.8S rDNA gene of Alternaria alternata or Alternaria solani but not to other microbial or plant DNA. We compared the sensitivity of PCR in detecting Alternaria DNA, that of the HPLC method in detecting Alternaria alternariol and alternariol methyl ether toxins, and that of the morphological examination of mycelia and conidia in experimentally infested corn samples. The sensitivity of toxin detection for HPLC was above the level of contamination in a set of commercially obtained grain samples, resulting in negative scores for all samples, while the PCR-based method and mold growth plating followed by morphological identification of Alternaria gave parallel, positive results for 8 of 10 samples. The PCR assay required just 8 h, enabling the rapid and simultaneous testing of many samples at a low cost. PCR-based evidence for the presence of Alternaria DNA followed by positive assay results for Alternaria toxins would support the rejection of a shipment of grain.

  9. Induction of protection against the necrotrophic pathogens Phytophthora citrophthora and Alternaria solani in Lycopersicon esculentum Mill. by a novel synthetic glycoside combined with amines.

    Science.gov (United States)

    Flors, Víctor; Miralles, M Carmen; González-Bosch, Carmen; Carda, Miguel; García-Agustín, Pilar

    2003-04-01

    1,2,3,4-tetra-O-acetyl-6-ethyladipate-beta- D-glucopyranose (TOGE), a glycoside derivative of adipic acid monoethyl ester and 1,2,3,4-tetra-O-acetyl-beta- D-glucopyranose, was synthesized and the resistance-inducing activity shown by TOGE-1 (TOGE plus furfurylamine) and TOGE-2 (TOGE plus 1,3-diaminepropane) was assayed. TOGE-1 and TOGE-2 protected tomato plants against two different fungal pathogens Phytophthora citrophthora and Alternaria solani. Foliar treatments at very low concentrations (2.5 mg l(-1) TOGE, 0.5 mg l(-1) amine) clearly reduced the disease incidence for both pathogens. TOGE-2 application was the most effective on intact plants as well as on detached leaves, reducing fungal growth by more than 46% with respect to control plants. On the other hand TOGE-1 treatment reduced fungal advance by 21%. These results demonstrate a high protective effect against fungal infections for both chemicals. A possible direct antimicrobial effect was discounted due to the weak activity observed in vitro against these pathogens at the low concentrations used in plants. TOGE-2 treatment clearly activates resistance against both pathogens and improves the protective effect previously shown by FGA mixture (adipic acid monoethyl ester, 1,2,3,4-tetra-O-acetyl-beta- D-glucopyranose and furfurylamine) [V. Flors et al. (2001) J Agric Food Chem 49:2569-2575]. The obtained results indicate that TOGE-1 and TOGE-2 act as resistance inducers. Although their mode of action is still unknown, pre-challenge studies have demonstrated the induction of the phenylpropanoid pathway and antioxidant activities. Both chemicals have demonstrated a beneficial effect on plant development, increasing chlorophyll and protein contents, photosynthetic rate and water-use efficiency. The improvement of plant growth and development produced by these treatments suggests crop tolerance to these chemicals, although effective formulations that are safe to humans must be developed before this technology can

  10. Variety of plant pathogens of ornamental shrubs of the genus Rosa L.

    Directory of Open Access Journals (Sweden)

    Marchenko Alla Borisovna

    2015-12-01

    In the Ukraine’s forest-steppe environment, over the years of research, the most common disease among different representatives of the genus Rosa L. is Diplocarpon rosae FA Wolf, about 52.7%. Diseases caused by Sphaerotheca pannosa var. rosae Woron account for 28.3%: Coniothyrium wernsdorffiae Laubert―19.2%; Botrytis cinerea Pers.―16.9%; Phragmidium mucronatum (Pers. Schltdl., Phragmidium tuberculatum Müll. Hal., Nectria cinnabarina (Tode Fr.―from 7.2 to 6.7%. Pathogens Alternaria alternata (Fr. Keissl., Alternaria tenuissima (Kunze Wiltshire, Fusarium oxysporum Schltdl., Fusarium solani (Mart. Sacc., Phytophthora cactorum J. Schröt., Verticillium dahliae Kleb., Verticillium albo-atrum Reinke Berthold are less common―5%.

  11. 阿魏精油对果蔬采后病原菌的抑制作用%Inhibitory Effect of Ferula Essential Oil on Postharvest Pathogens of Fruits and Vegetables

    Institute of Scientific and Technical Information of China (English)

    王春娟; 谢慧琴; 杨德松

    2012-01-01

    蒸馏法提取阿魏精油并测定其对果蔬采后的致病真菌灰霉菌(Botrytis cinerea)、链格孢菌(Alternaria alternata)、青霉菌(Penicillium citrinum)、炭疽病菌(Colletotrichum gloeosporiodes)的体外抑菌活性.结果表明,阿魏精油对供试的4种致病真菌有抑制作用.抑制率随阿魏精油浓度的增加而提高,随处理时间延长抑制作用也有所加强,但加强幅度不大.阿魏精油对病原菌48 h EC50从小到大依次为炭疽病菌、青霉菌、灰霉菌、链格孢菌.%The ferula essential oil was extracted by distillation, and the inhibitory effects to Botrytis cinerea, Alternaria alternate , Penicillium citrinum and Colletotrichum gloeosporiodes were determined. The results showed that ferula essential oil had strong inhibitory effects on the four postharvest pathogens, and inhibition rates increased with the increasing of the concentration of ferula oils and treating time. After 48 h treatments of the ferula essential oils on the four pathogens, the order of EC50 is Colletotrichum gloeosporiodes < Penicillium citrinum < Botrytis cinerea < Alternaria alternata.

  12. Alternaria in aardappel

    NARCIS (Netherlands)

    Spits, H.G.

    2005-01-01

    De laatste jaren komt een aantasting door Alternaria in aardappel steeds vaker voor. Door een aantasting sterft het gewas vervroegd af. Dit heeft opbrengstderving tot gevolg. Ook kunnen de geoogste knollen aangetast worden. De oorzaak, dat Alternaria de laatste jaren vaker voorkomt dan voorheen is,

  13. Expression of ß-1,3-glucanase and ß-1,4-glucanase in two potato cultivars following challenge by the fungal pathogen Alternaria solani

    Science.gov (United States)

    Early blight of potato, caused by Alternaria solani, is a ubiquitous disease in many countries around the world. We have previously found that variation in resistance phenotypes exist between two different Iranian cultivars of potato. Cultivar ‘Diamond’ is more resistant to multiple isolates of A. s...

  14. Antifungal Activity of Essential Oils from Some Medicinal Plants of Iran against Alternaria alternate

    Directory of Open Access Journals (Sweden)

    I. Hadizadeh

    2009-01-01

    Full Text Available Problem statement: Increasing public concern over the level of pesticide residues in food especially fresh produce has built up adequate pressure for scientists to look for less hazardous and environmentally safer compounds for controlling post harvest diseases. Essential oils as registered food grade materials have the potential to be applied as alternative anti-fungal treatments for fresh fruits and vegetables. Approach: We present in this study, the identification of the essential oils with antifungal activity from some medicinal plants of Iran (nettle (Urtica dioica L., thyme (Thymus vulgaris L., eucalyptus (Eucalyptus spp., Rue (Ruta graveolens L. and common yarrow (Achillea millefolium L., and their potential application as "generally regarded as safe" antifungal compounds against Alternaria alternate on tomato as a model pathosystem. Results: Both the nettle and the thyme oils exhibited antifungal activity against A. alternata. The thyme oil exhibited a lower degree of inhibition 68.5 and 74.8% at 1500 and 2000 ppm, respectively. Spore germination and germ tube elongation of the pathogens in potato dextrose broth was strongly reduced in the presence of 1500 ppm of the nettle oil. The same concentration of this oil reduced the percentage of decayed tomatoes. The experiments on reducing the development of natural tomato rot gave similar results. Conclusions: Application of essential oils for postharvest disease control of fresh produce, as a novel emerging alternative to hazardous anti-fungal treatments will allow a safer and environmentally more acceptable management of postharvest diseases.

  15. Identification of A. arborescens, A. grandis, and A. protenta as new members of the European Alternaria population on potato.

    Science.gov (United States)

    Landschoot, Sofie; Vandecasteele, Michiel; De Baets, Bernard; Höfte, Monica; Audenaert, Kris; Haesaert, Geert

    2017-02-01

    Alternaria species, primarily the small-spored Alternaria alternata and the large-spored Alternaria solani, are considered a serious threat to potato cultivation. To develop control strategies, it is important to gain insight into the Alternaria population. Based on the sequence analyses of the internal transcribed spacer region (ITS) and the glyceraldehyde-3-phosphate dehydrogenase gene, the small-spored and large-spored Alternaria isolates could be separated from each other. Sequence analyses of the calmodulin gene and the RNA polymerase second largest subunit showed that besides A. solani also A. grandis and A. protenta were present in the large-spored Alternaria population. Sequence analyses of the Alternaria major allergen gene Alt a 1 and the elongation factor-α revealed that both A. alternata and species belonging to the Alternaria arborescens species complex were present in the small-spored Alternaria population. Furthermore, according to the histone h3 sequence the members of the A. arborescens species complex could be subdivided into two groups. Concerning the fitness, it was concluded that the mycelium growth rate of the large-spored isolates was significantly lower compared to the growth rate of the small-spored isolates. In contrast, the spore-germinating capacity and early growth of the large-spored isolates was greater compared to those of the small-spored isolates. Within the groups of small-spored and large-spored isolates there were no significant differences in fitness between the species. Copyright © 2016 British Mycological Society. All rights reserved.

  16. Fungicidal activity of silver nanoparticles against Alternaria brassicicola

    Science.gov (United States)

    Gupta, Deepika; Chauhan, Pratima

    2016-04-01

    This work highlighted the fungicidal properties of silver nanoparticles against Alternaria brassicicola. Alternaria brassicicola causes Black spot of Cauliflower, radish, cabbage, kale which results in sever agricultural loss. We treat the synthesised silver nanoparticles (AgNPs) of 10, 25, 50, 100 and 110 ppm concentrations against Alternaria brassicicola on PDA containing Petri dish. We calculated inhibitory rate (%) in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. Treatment with 100ppm AgNPs resulted in maximum inhibition of Alternaria brassicicola i.e.92.2%. 110ppm of AgNPS also shows the same result, therefore 100ppm AgNPs was treated as optimize concentration. AgNPs effectively inhibited the growth of a Alternaria brassicicola, which suggests that AgNPs could be used as fungicide in plant disease management. Further research and development are necessary to translate this technology into plant disease management strategies.

  17. Specific Antibodies for the Detection of Alternaria Allergens and the Identification of Cross-Reactive Antigens in Other Fungi

    Science.gov (United States)

    Twaroch, Teresa E.; Curin, Mirela; Sterflinger, Katja; Focke-Tejkl, Margit; Swoboda, Ines; Valenta, Rudolf

    2017-01-01

    Background The mould Alternaria alternata is an important source of respiratory allergens. A. alternata extracts show great variations regarding allergenic potency. The aim of this study was to generate antibody probes specific for important Alternaria allergens and to use them to study allergen expression, depending on different culture conditions, as well as to search for cross-reactive allergens in other mould species. Methods Synthetic peptides from antigenic regions of A. alternata allergens (Alt a 1, Alt a 2, Alt a 3, Alt a 6 and Alt a 8) were used to raise highly specific rabbit antibodies. These antibodies and IgE from allergic patients were used to detect allergens by immunoblotting in extracts of 4 A. alternata strains grown under varying culturing conditions, in commercial skin-prick extracts and in closely (Cladosporium herbarum and Aureobasidium pullulans) or distantly related (Aspergillus niger and Penicillium chrysogenum) mould species. Results There was a wide variation of expression of the individual A. Alternata allergens, depending on the strain and culture conditions, but the antibody probes allowed us to distinguish strains and culture conditions with low and high allergen expression. In the commercial skin-prick solutions, varying levels of Alt a 1 were found, but no other allergens were detectable. Alt a 1 was identified as species-specific A. Alternata allergen, whereas Alt a 3, 6- and Alt a 8-cross-reactive antigens were found in C. herbarum and/or A. pullulans. Conclusions and Clinical Relevance Peptide-specific antibodies are useful to analyze diagnostic and therapeutic mould extracts, to study the presence of A. Alternata allergens in biological samples and to search for cross-reactive allergens in other mould species. PMID:27780168

  18. Alternaria in Food: Ecophysiology, Mycotoxin Production and Toxicology.

    Science.gov (United States)

    Lee, Hyang Burm; Patriarca, Andrea; Magan, Naresh

    2015-06-01

    Alternaria species are common saprophytes or pathogens of a wide range of plants pre- and post-harvest. This review considers the relative importance of Alternaria species, their ecology, competitiveness, production of mycotoxins and the prevalence of the predominant mycotoxins in different food products. The available toxicity data on these toxins and the potential future impacts of Alternaria species and their toxicity in food products pre- and post-harvest are discussed. The growth of Alternaria species is influenced by interacting abiotic factors, especially water activity (aw), temperature and pH. The boundary conditions which allow growth and toxin production have been identified in relation to different matrices including cereal grain, sorghum, cottonseed, tomato, and soya beans. The competitiveness of Alternaria species is related to their water stress tolerance, hydrolytic enzyme production and ability to produce mycotoxins. The relationship between A. tenuissima and other phyllosphere fungi has been examined and the relative competitiveness determined using both an Index of Dominance (ID) and the Niche Overlap Index (NOI) based on carbon-utilisation patterns. The toxicology of some of the Alternaria mycotoxins have been studied; however, some data are still lacking. The isolation of Alternaria toxins in different food products including processed products is reviewed. The future implications of Alternaria colonization/infection and the role of their mycotoxins in food production chains pre- and post-harvest are discussed.

  19. Evaluation of the Efficacy of Different Fungicide for the Management of Alternaria Leaf Spot Disease of Chilli

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Yadav

    2015-03-01

    Full Text Available Alternaria leaf spot of chilli caused by Alternaria alternate is an important disease affecting chilly production areas in India. The disease is primarily controlled through the use of fungicidal seed treatments. In this study, different fungicides viz. Captol, Captan, Ziram, Captofol, Thiram, Indofill Z 78 and Indofill Z 45 were assessed for their ability to reduce the growth of Alternaria alternata under laboratory conditions. Maximum inhibition (100% was achieved by Captol and capton followed by captofol (89.5 % while 0.1 % dose given. This paper reports the efficacy of fungicides that can be used under field conditions to control alternaria leaf spot in tropical regions and demonstrates the use of a method of application that could significantly improve the efficacy of disease control.

  20. Beheersing van Alternaria in aardappel

    NARCIS (Netherlands)

    Spits, H.G.

    2007-01-01

    De laatste jaren komt Alternaria in aardappel meer voor. In 2004 waren er vooral problemen in het Zuidwesten van Nederland. Ook werden hier verschillende partijen waargenomen met knolaantasting. Voor 2004 was knolaantasting door Alternaria in Nederland uiterst zeldzaam. Omdat Alternaria zelden probl

  1. Identification and antifungal activity of an actinomycete strain against Alternaria spp.

    Directory of Open Access Journals (Sweden)

    Fen Gao

    2014-10-01

    Full Text Available Alternaria alternata (Fries Keissler is a phytopathogenic fungus responsible for tobacco brown spot disease. This study aims to evaluate the antifungal activity of strain 163 against A. alternata and clarify its taxonomic status. The evaluation of the antifungal activity of strain 163 and its bacteria-free filtrate of fermentation broth was done through measuring the diameters of inhibition zones, and testing the antimicrobial spectrum and the inhibition effect on mycelial growth in vitro. The biocontrol activity of the bacteria-free filtrate in vivo was evaluated by using detached tobacco leaves method and assaying the inhibition rate to disease incidence in growth chamber. A polyphasic approach was taken in the identification of strain 163. The bacterial strain 163 showed inhibitory effect in vitro against A. alternata. The bacteria-free filtrate of the strain 163 fermentation broth showed a 56.7% inhibition rate in a detached leaf assay. In growth chamber conditions, it showed greater biocontrol activity when applied before plants being inoculated with A. alternata than after, the inhibition rate being 46.05%. Investigations into the morphological, cultural, physiological and biochemical properties of strain 163 found it to be most similar to Streptomyces microflavus. Its classification into cell wall type I and sugar type C further confirmed its Streptomyces characteristics. Construction of a phylogenetic tree based on 16S rDNA verified that strain 163 was most closely related to Streptomyces microflavus. From polyphasic taxonomical analysis, strain 163 was found to be identical to S. microflavus.

  2. 河北鸭梨病果上链格孢分离系的形态及分子特性研究%Morphological and molecular characterization of Alternaria isolates on fruits of Pyrus bretschneideri Rehd. "Ya Li"

    Institute of Scientific and Technical Information of China (English)

    孙霞; 张天宇

    2008-01-01

    A total of 123 Alternaria isolates were obtained from roting fruits of Pyrus bretschneideri "Ya Li" collected in Hebei Province, China. The isolates, according to morphological characteristics of conidia and sporulation patterns, were segregated into four groups: A. alternata group, A. tenuissima group, A. yaliinficiens group and Alternaria sp. group. Molecular characteristics of part of the isolates were determined using random amplified polymorphism DNA (RAPD) analysis. Based on cluster analysis of RAPD data, large- and small-spored Alternaria spp. were evidently distinguished, and the small-spored species can form five clusters that fundamentally paralleled the morphological groupings.

  3. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Directory of Open Access Journals (Sweden)

    José Cuenca

    Full Text Available Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR to map a genome region linked to Alternaria brown spot (ABS resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  4. Genetically based location from triploid populations and gene ontology of a 3.3-mb genome region linked to Alternaria brown spot resistance in citrus reveal clusters of resistance genes.

    Science.gov (United States)

    Cuenca, José; Aleza, Pablo; Vicent, Antonio; Brunel, Dominique; Ollitrault, Patrick; Navarro, Luis

    2013-01-01

    Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR) to map a genome region linked to Alternaria brown spot (ABS) resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids.

  5. Genetically Based Location from Triploid Populations and Gene Ontology of a 3.3-Mb Genome Region Linked to Alternaria Brown Spot Resistance in Citrus Reveal Clusters of Resistance Genes

    Science.gov (United States)

    Cuenca, José; Aleza, Pablo; Vicent, Antonio; Brunel, Dominique; Ollitrault, Patrick; Navarro, Luis

    2013-01-01

    Genetic analysis of phenotypical traits and marker-trait association in polyploid species is generally considered as a challenge. In the present work, different approaches were combined taking advantage of the particular genetic structures of 2n gametes resulting from second division restitution (SDR) to map a genome region linked to Alternaria brown spot (ABS) resistance in triploid citrus progeny. ABS in citrus is a serious disease caused by the tangerine pathotype of the fungus Alternaria alternata. This pathogen produces ACT-toxin, which induces necrotic lesions on fruit and young leaves, defoliation and fruit drop in susceptible genotypes. It is a strong concern for triploid breeding programs aiming to produce seedless mandarin cultivars. The monolocus dominant inheritance of susceptibility, proposed on the basis of diploid population studies, was corroborated in triploid progeny. Bulk segregant analysis coupled with genome scan using a large set of genetically mapped SNP markers and targeted genetic mapping by half tetrad analysis, using SSR and SNP markers, allowed locating a 3.3 Mb genomic region linked to ABS resistance near the centromere of chromosome III. Clusters of resistance genes were identified by gene ontology analysis of this genomic region. Some of these genes are good candidates to control the dominant susceptibility to the ACT-toxin. SSR and SNP markers were developed for efficient early marker-assisted selection of ABS resistant hybrids. PMID:24116149

  6. Association of IL-4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma.

    Science.gov (United States)

    Knutsen, Alan P; Vijay, Hari M; Kariuki, Barbara; Santiago, Luis A; Graff, Ralph; Wofford, Jonathan D; Shah, Maulik R

    2010-03-18

    Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked Alternaria sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying Alternaria sensitivity and asthma, in these studies we examined T cell responses to Alternaria antigens, HLA Class II restriction and HLA-DQ protection in children with severe asthma. Sixty children with Alternaria-sensitive moderate-severe asthma were compared to 49 children with Alternaria-sensitive mild asthma. We examined HLA-DR and HLA-DQ frequencies in Alternaria-sensitive asthmatic by HLA typing. To determine ratios of Th1/Th2 Alternaria-specific T-cells, cultures were stimulated in media alone, Alternaria alternata extract and Alt a1. Sensitivity to IL-4 stimulation was measured by up-regulation of CD23 on B cells. Children with Alternaria-sensitive moderate-severe asthma trended to have increased sensitivities to Cladosporium (46% versus 35%), to Aspergillus (43% versus 28%), and significantly increased sensitivities to trees (78% versus 57%) and to weeds (68% versus 48%). The IL-4RA ile75val polymorphism was significantly increased in Alternaria-sensitive moderate-severe asthmatics, 83% (0.627 allele frequency) compared to Alternaria-sensitive mild asthmatics, 57% (0.388 allele frequency). This was associated with increased sensitivity to IL-4 stimulation measured by significantly increased IL-4 stimulated CD23 expression on CD19+ and CD86+CD19+ B cells of Alternaria-sensitive moderate-severe asthmatics. IL-5 and IL-13 synthesis was significantly increased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics to Alternaria extract and Alt a1 stimulation. The frequency of HLA-DQB1*03 allele was significantly decreased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics, 39

  7. Association of IL-4RA single nucleotide polymorphisms, HLA-DR and HLA-DQ in children with Alternaria-sensitive moderate-severe asthma

    Directory of Open Access Journals (Sweden)

    Santiago Luis A

    2010-03-01

    Full Text Available Abstract Background Asthma afflicts 6% to 8% of the United States population, and severe asthma represents approximately 10% of asthmatic patients. Several epidemiologic studies in the United States and Europe have linked Alternaria sensitivity to both persistence and severity of asthma. In order to begin to understand genetic risk factors underlying Alternaria sensitivity and asthma, in these studies we examined T cell responses to Alternaria antigens, HLA Class II restriction and HLA-DQ protection in children with severe asthma. Methods Sixty children with Alternaria-sensitive moderate-severe asthma were compared to 49 children with Alternaria-sensitive mild asthma. We examined HLA-DR and HLA-DQ frequencies in Alternaria-sensitive asthmatic by HLA typing. To determine ratios of Th1/Th2 Alternaria-specific T-cells, cultures were stimulated in media alone, Alternaria alternata extract and Alt a1. Sensitivity to IL-4 stimulation was measured by up-regulation of CD23 on B cells. Results Children with Alternaria-sensitive moderate-severe asthma trended to have increased sensitivities to Cladosporium (46% versus 35%, to Aspergillus (43% versus 28%, and significantly increased sensitivities to trees (78% versus 57% and to weeds (68% versus 48%. The IL-4RA ile75val polymorphism was significantly increased in Alternaria-sensitive moderate-severe asthmatics, 83% (0.627 allele frequency compared to Alternaria-sensitive mild asthmatics, 57% (0.388 allele frequency. This was associated with increased sensitivity to IL-4 stimulation measured by significantly increased IL-4 stimulated CD23 expression on CD19+ and CD86+CD19+ B cells of Alternaria-sensitive moderate-severe asthmatics. IL-5 and IL-13 synthesis was significantly increased in Alternaria-sensitive moderate-severe asthmatics compared to mild asthmatics to Alternaria extract and Alt a1 stimulation. The frequency of HLA-DQB1*03 allele was significantly decreased in Alternaria-sensitive moderate

  8. 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

  9. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea

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    Jian Xin Deng

    2015-03-01

    Full Text Available In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.

  10. Occurrence of Leaf Blight on Cosmos Caused by Alternaria cosmosa in Korea.

    Science.gov (United States)

    Deng, Jian Xin; Lee, Ji Hye; Paul, Narayan Chandra; Cho, Hye Sun; Lee, Hyang Burm; Yu, Seung Hun

    2015-03-01

    In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.

  11. 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.

  12. Pathogens present on vegetative organs and seeds of white mustard (Sinapis alba L. and chinese mustad (Brassica juncea L.

    Directory of Open Access Journals (Sweden)

    Barbara Majchrzak

    2013-12-01

    Full Text Available The research was conducted in the years 1999-2001. The aim of the research was to determine the health condition of overground parts and seeds of white niuslard (Sinapis alba L. cv. Metex and chinese mustard (Brassica juncea L. cv. Małopolska. In all the years of the research alternaria blight was found on the leaves of white mustard which injury index ranged from 5,6% in 2001 to 17,6% in 200O. The most dangerous disease of chinese mustard also was alternaria blight and its symptoms were found on leaves and siliques. The strongest infection of leaves was in 2000 (50% and the weakest in 2001 (6,7%. In all the years of the research siliques were rather weak infected (50-8,89%. Besides powdery mildew was found on chinese mustard which injury index ranged from 0,3% in 1999 to 32,3% in 2000. Intensity of diseases was affected generally by the weather conditions. From the seeds of white mustard and chinese mustard were isolated respectively 263 and 137 colonies. Alternaria alternata was the most numerous species which makes respectively 60,9% and 42,3% isolates. Among the fungi pathogenic for white and chinese mustard were also isolated: A. brassicae, Botrytis cinerea and Rhizoctonia solami.

  13. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M.

    2008-01-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species...

  14. The use of tissue culture and in vitro mutagenesis for the improvement resistance to Alternaria solani in irish potato (Solanum tuberosum L. var. Desirée

    Directory of Open Access Journals (Sweden)

    Novisel Veitía

    2001-01-01

    Full Text Available Two phases of work were carried out with the objective of obtaining somaclons in Irish Potato (Solanum tuberosum L. that present a superior behavior with respect to the variety Desirée against the early blight disease caused by Alternaria solani (Sor. and A. alternata (Fr. Keissler. In the first phase, the aspects related to the pathogen, the incubation time and the method of application of the filtered culture on the vitroplants were studied the immersion of the roots as the effective method of inoculation. The biological effectiveness of the different concentrations of the filtrate on the vitroplants of the variety Desirée (susceptible and the specie Solanum chacoense (resistant was checked, taking the dilution of 1:3 v/v as the effective for the selection. A scale was elaborated to evaluate the intensity of the damages caused by the filtrate and a selection scheme was established for the genetic improvement of the variety Desirée. The second phase had as its objective the massive inoculation with the filtered culture of the fungus 1 000 somaclons were obtained from the irradiated calli with gamma radiation. Forty-five somaclons presented levels of affectation inferior to that of the original variety. The behavior of the somaclons selected in vitro was evaluated in the greenhouse against the disease and six somaclons presented levels of affectation inferior to that of the original variety. Key words: culture filtrate, early blight, , in vitro selection

  15. First report of Alternaria alternata causing leaf spot on Ruth's golden aster (Pityopsis ruthii) in Tennessee

    Science.gov (United States)

    Ruth’s golden aster, Pityopsis ruthii (Small), is an endangered, herbaceous perennial plant that is only endemic to small sections of the Hiwassee and Ocoee Rivers, in Polk County, Tennessee. In July 2015, a greenhouse grown plant exhibited symptoms of disease that included elongated brown lesions o...

  16. Alternaria alternata, causal agent of dead (dormant) flower bud disease of pear

    NARCIS (Netherlands)

    Wenneker, M.; Tjou-Tam-Sin, L.T.; Bruggen, van A.S.; Vink, P.

    2006-01-01

    Dead (dormant) flower buds of pear are an important phenomenon in pear production in the Netherlands. Vigourous or unbalanced tree growth and Pseudomonas syringae pv. syringae are mentioned as likely causes of dead flower buds. Several tree growth control treatments including ethephon, Regalis (Proh

  17. COLONIZATION OF GRAPE BERRIES BY REPRESENTATIVES OF THE GENUS ALTERNARIA AND THEIR OCCURRENCE IN THE STUM

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    Zuzana Mašková

    2013-02-01

    Full Text Available The aim of the study was to analyze the mycobiota occurring on the grapes originating from Slovak wine-growing regions. The main focus was to discover the presence of the representatives of the genus Alternaria on/in grape berries and in the stum.Using the direct method of placing grape berries on the culture medium was analyzed their total and endogenous (after superficial sterilization mycobiota. Plate dilution method was used for stum mycobiota determination. Alternaria spp. colonized grapeson the surface and inside with anisolation frequency (Fr of 100%. Moreover, 100% of the stum samples were positive for the presence of this genus. Their relative density (RD was 44.9% (unsterilized grapes, 57.9% (sterilized grapes and 6.35% (stum. In all the areas analysed we recorded 4 species-groups: A. alternata, A. arborescens, A. infectoria and A. tenuissima. With the highest Fr and RD occurredA. tenuissima species-group, followed by A. alternata and A. arborescens species-groups. All of them are potential producers of mycotoxins as alternariol, alternariol monomethylether, tenuazonic acid, altertoxin I, II and III.

  18. Eficiência e custo do controle químico da mancha de alternaria em tangor murcote Efficiency and cost of chemical control of alternaria brown spot

    Directory of Open Access Journals (Sweden)

    Adimara Bentivoglio Colturato

    2009-09-01

    Full Text Available A mancha de alternaria, causada por Alternaria alternata f. sp. citri, afeta tangelos Minneola, tangerinas Dancy, tangores Murcote e, menos freqüentemente, tangelos Orlando, tangerinas Novas, Lees e Sunburst. Esta doença causa desfolha grave, queda de frutos e manchas nas frutas. O objetivo deste trabalho foi estabelecer o melhor fungicida e a melhor dose para o controle da mancha marrom de alternaria. O delineamento experimental foi de parcelas subdivididas em blocos, com 10 tratamentos principais e 3 doses (subparcelas, com 5 repetições. Foram feitas 5 aplicações, com intervalo de 15 dias. Os tratamentos foram: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + tebuconazole (2 aplicações seguido de 3 aplicações de mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + propineb (2 aplicações seguido de 3 aplicações de oxicloreto de cobre, oxicloreto de cobre + óleo e testemunha. Simultaneamente foram feitas avaliações de incidência e número de lesões por folha. Ao surgimento dos frutos foram avaliadas a incidência em frutos e a produtividade em Kg/ha. Todos os tratamentos foram superiores à testemunha quanto a produtividade. Entre os produtos utilizados o tratamento com trifloxystrobin + propiconazole foi rentável comparando-se custo e produtividade.Alternaria brown spot, caused by Alternaria alternata sp. citri, attacks with more intensity the Tangelos Minneola, tangerine Dancy, and Murcotts, and with less intensity the tangelos Orlando and the tangerinas Novas, Lees and Sunburst. This disease causes severe defoliation and drop or necrotic spots in the fruits. The aim of this work was to evaluated the chemical control of brown spot, and to define the most appropriate dosage of fungicide to control it. The experimental design was split-spot, with ten treatments and 3 doses of fungicides, with five replicates, the fungicides were: azoxystrobin, pyraclostrobin, trifloxystrobin

  19. 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.

  20. Characterization of small-spored Alternaria from Argentinean crops through a polyphasic approach

    DEFF Research Database (Denmark)

    da Cruz Cabral, Lucía; Rodriguero, Marcela; Stenglein, Sebastián

    2017-01-01

    exporter of agricultural products, so it is essential to thoroughly understand the physiological behaviour of this pathogen in a food safety context. Thus, the objective of this work was to characterize small-spored Alternaria spp. obtained from tomato fruits, pepper fruits, wheat grains and blueberries...... at species level through classical morphology or modern molecular techniques does not seem to be a useful tool to predict toxicological risk in food matrices. The detection of any small-spored Alternaria from Section Alternaria (D.P. Lawr., Gannibal, Peever & B.M. Pryor 2013) in food implies a potential...

  1. 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.

  2. Alternaria in aardappel: een Europees alternatief

    NARCIS (Netherlands)

    Schepers, H.T.A.M.; Evenhuis, A.

    2010-01-01

    Vroeger kwam Alternaria in Nederland op beperkte schaal voor, tegenwoordig komt Alternaria algemeen voor en kan het in sommige rassen en jaren flink schade veroorzaken. In dit artikel wordt daarom ingegaan op verschillende aspecten van Alternaria in aardappel: symptomen, factoren die aantasting beïn

  3. Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens.

    Science.gov (United States)

    Grasso, Valeria; Palermo, Simona; Sierotzki, Helge; Garibaldi, Angelo; Gisi, Ulrich

    2006-06-01

    The cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria solani Sorauer, A alternata (Fr) Keissl and Plasmopara viticola (Berk & Curt) Berlese & de Toni. The sequenced fragment included the two hot spot regions in which mutations conferring resistance to QoI fungicides may occur. The cyt b gene structure of these pathogens was compared with that of other species from public databases, including the strobilurin-producing fungus Mycena galopoda (Pers) P Kumm, Saccharomyces cerevisiae Meyer ex Hansen, Venturia inaequalis (Cooke) Winter and Mycosphaerella fijiensis Morelet. In all rust species, as well as in A solani, resistance to QoI fungicides caused by the mutation G143A has never been reported. A type I intron was observed directly after the codon for glycine at position 143 in these species. This intron was absent in pathogens such as A alternata, Blumeria graminis (DC) Speer, Pyricularia grisea Sacc, Mycosphaerella graminicola (Fuckel) J Schröt, M fijiensis, V inaequalis and P viticola, in which resistance to QoI fungicides has occurred and the glycine is replaced by alanine at position 143 in the resistant genotype. The present authors predict that a nucleotide substitution in codon 143 would prevent splicing of the intron, leading to a deficient cytochrome b, which is lethal. As a consequence, the evolution of resistance to QoI fungicides based on G143A is not likely to evolve in pathogens carrying an intron directly after this codon.

  4. Production of the Allergenic Protein Alt a 1 by Alternaria Isolates from Working Environments

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    Justyna Skóra

    2015-02-01

    Full Text Available The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather present within the working environment stimulate or inhibit Alt a 1 production (ELISA test. Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%–16% frequency in the air. The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103–6.528 ng/mL than a ATCC strain (0.551–0.975 ng/mL. It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein.

  5. Antifungal metabolites (monorden, monocillins I, II, III) from Colletotrichum graminicola, a systemic vascular pathogen of maize.

    Science.gov (United States)

    Wicklow, Donald T; Jordan, Annalisa M; Gloer, James B

    2009-12-01

    Colletotrichum graminicola is a systemic vascular pathogen that causes anthracnose stalk rot and leaf blight of maize. In the course of an effort to explore the potential presence and roles of C. graminicola metabolites in maize, ethyl acetate extracts of solid substrate fermentations of several C. graminicola isolates from Michigan and Illinois were found to be active against Aspergillus flavus and Fusarium verticillioides, both mycotoxin-producing seed-infecting fungal pathogens. Chemical investigations of the extract of one such isolate (NRRL 47511) led to the isolation of known metabolites monorden (also known as radicicol) and monocillins I-III as major components. Monorden and monocillin I displayed in vitro activity against the stalk- and ear-rot pathogen Stenocarpella maydis while only the most abundant metabolite (monorden) showed activity against foliar pathogens Alternaria alternata, Bipolaris zeicola, and Curvularia lunata. Using LC-HRESITOFMS, monorden was detected in steam-sterilized maize stalks and stalk residues inoculated with C. graminicola but not in the necrotic stalk tissues of wound-inoculated plants grown in an environmental chamber. Monorden and monocillin I can bind and inhibit plant Hsp90, a chaperone of R-proteins. It is hypothesized that monorden and monocillins could support the C. graminicola disease cycle by disrupting maize plant defenses and by excluding other fungi from necrotic tissues and crop residues. This is the first report of natural products from C. graminicola, as well as the production of monorden and monocillins by a pathogen of cereals.

  6. Sensitivity of four Yeasts to Fungicides and CO2 Concentrations and Their Antagonistic Ability in Combination with Fungicide to pathogenic Fungi in vitro

    Institute of Scientific and Technical Information of China (English)

    TIAN Shi-ping; YAO Hong-jie; QIN Guo-zheng; XU Yong; FENG Xiao-yuan

    2004-01-01

    The yeasts Cryptococcus laurentii,Trichosporon pullulans,Rhodotorula glutinis and Trichosporon sp.were used to investigate their sensitivity to four fungicides and different concentrations of CO2,as well as their antagonistic ability to Penicilliumexpansum and Alternaria alternata in vitro when applied with fungicide.There were significant differences in sensitivity to the fungicides among the different yeasts(P = 0.05).R.glutinis was more sensitive to Deccocil,Iprodione and Stroby as compared to other yeasts.Combination antagonistic yeasts with fungicide could more significantly enhance biocontrol ability of the yeasts against the pathogenic fungi in vitro(P = 0.05).C.laurentii was the most effective antagonist among the four yeasts and could completely control spore germination of P.expansum and A.alternata when combined with Stroby at the concentration of 100 μL L-1.The yeasts,except R.glutinis,could grow well on nutrient yeast dextrose agar (NYDA) after 8 d incubation even at 20% CO2 concentration at 25℃.Particularly Trichosporon sp.showeda better adaptability to low temperature as compared to other antagonists.

  7. The effect of cytosolic extract of Alternaria aternata fungus on Monocyte-derived dendritic cell maturation and T-lymphocyte polarization in the presence of myelin basic protein

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    Loghmanni A

    2013-03-01

    Full Text Available Background: Multiple Sclerosis (MS is an autoimmune disease with impairment in function of central nervous system. Macrophages and dendritic cells play important roles in alleviating or progression of the disease. These cells can cause inflammation and damage to the myelin of nerve cells by realizing of harmful substances when these cells get matured. We studied the effect of Alternaria alternata extract on maturation of monocyte- derived dendritic cell (modc and T-cell responses in the presence of Myelin Basic Protein (MBP as a laboratory model of multiple sclerosis (MS. The purpose of this study is suitable dendritic cells production for usage in MS immunotherapy.Methods: For this study plastic adherent monocytes were cultured with granulocyte/ macrophage- colony stimulating factor (GM-CSF and interleukin -4 for converting these cells to modc and pulsed with MBP and matured in the presence of monocyte-conditioned medium (MCM in control group and MCM + Alternaria alternata extract in treatment groups. Anti-CD14, anti-CD83, anti-human leukocyte antigen-DR (anti HLA-DR monoclonal antibody were carried out for phenotyping. Autologos T cell responses and cytokine production were evaluated.Results: The results showed that the expression of CD14 decreased and CD83, HLA-DR increased in treatment groups in comparison with control groups. The production amount of IL-10 overcame IL-12 and in T cell the production of cytokines, IL-17 and Interferon-γ (IFN-γ decreased and IL-4 was increased (P<0.05. These effects escalated with increasing of dosage from 50 to 100 (mg/ml (P<0.001.Conclusion: Alternaria alternata extract can cause maturation of MBP-pulsed modc and skewing of T- lymphocyte toward Th2 and thereby can evolve into a new strategy in immunotherapy of MS.

  8. Ergosterol concentration and variability in genotype-by-pathogen interaction for grain mold resistance in sorghum.

    Science.gov (United States)

    Mpofu, Leo T; McLaren, Neal W

    2014-08-01

    A lack of understanding of host-by-pathogen relations can hinder the success of breeding for resistance to a major disease. Fungal strain pathogenicity has to be understood from the virulence it can cause on susceptible genotypes and host resistance indicates which genotypes have resistance genes. Where the two worlds meet lies the place where researchers match the prevalent pathogen in the area of production with resistant varieties. This paper uses ergosterol concentration analysis as a measure of fungal biomass accumulation to assess levels of resistance in host genotypes. 11 sorghum genotypes were inoculated with 5 strains of fungi that are known to be associated with grain mold disease of sorghum. The resulting interaction was analyzed using GGE Biplot analysis and Cluster analysis which showed that none of the genotypes were resistant to Phoma sorghina and Curvularia lunata. Three genotypes were resistant to Fusarium thapsinum. One fungal strain (Alternaria alternata) does not contribute any significant damage in the grain mold disease. Fusarium graminearum causes very little grain mold disease. There was no correlation between the fungal strains. Visual scoring did not correlate with ergosterol accumulation. Resistance to grain mold in sorghum is shown to be due to vertical or specific resistance genes. Sorghum breeders should, therefore, identify predominant fungal strains in their localities and then locate and tag these resistance genes in their germplasm and pyramid them in commercial varieties.

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

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    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.

  10. Potencial de pseudomonas spp. fluorescentes para biocontrole de alternaria ricini em mamoneira Potential of fluorescent pseudomonas spp. For biological control of alternaria ricini on castorbean

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    Francisco de A.G. da Silva

    1998-06-01

    Full Text Available The potential of fluorescent Pseudomonas spp. to control Alternaria leaf spot on castorbean, caused by Alternaria ricini, was studied under greenhouse conditions. Two periods for antagonist applications were tested: 48h before and simultaneously to the pathogen inoculation. Among the antagonists tested JA4 and BJ22 were the most effectives showing disease severity reduction of 20.9% and 17.8% respectively, when applied simultaneously. The effect of Pseudomonas spp. on the micelial growth and sporulation was also studied throughout three different methods (funel, streak and celophane. Inhibition of micelial growth and sporulation was observed. There was no correlation between in vitro and in vivo data. Antibiosis was showed as a mode of action for Pseudomonas spp. in relation to Alternaria ricini. Ultrastructural studies confirmed the inhibition of spore germination by the bacteria.

  11. Subcutaneous phaeohyphomycosis due to Alternaria infectoria in a renal transplant patient: surgical treatment with no long-term relapse.

    Science.gov (United States)

    Salido-Vallejo, Rafael; Linares-Sicilia, María José; Garnacho-Saucedo, Gloria; Sánchez-Frías, Marina; Solís-Cuesta, Francisco; Gené, Josepa; Moreno-Giménez, José Carlos

    2014-01-01

    Phaeohyphomycosis can be caused by a number of different species, being the most common Alternaria alternata and Alternaria infectoria. The biggest risk factor for the development of the infection is immunosuppression. We present the case of a 64-year-old male renal transplant patient who came to hospital for presenting a tumour in the Achilles region which had been gradually growing in size. A skin biopsy was taken for histological study and culture of fungi and mycobacteria. Blood tests and imaging studies were performed. Histopathology study and cultures identified A. infectoria as the causal agent. Imaging studies ruled out internal foci of infection. The lesion was surgically removed with no signs of recurrence after 24 months of follow-up. There are no treatment guidelines at present for cutaneous and subcutaneous Alternaria spp. infections. Various systemic antifungals have been used, either in combination with surgical removal or alone, with varying results. Surgery alone could be useful in the treatment of solitary, localised lesions in transplant patients in whom there are difficulties in controlling immunosuppression. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  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. Studies on Alternaria allergens. I. Isolation of allergens from Alternaria tenuis and Alternaria solani.

    Science.gov (United States)

    Vijay, H M; Huang, H; Young, N M; Bernstein, I L

    1979-01-01

    Extracts of Alternaria tenuis and Alternaria solani were separated into dialyzable (molecular weight less than 10,000) and non-dialyzable forms. The latter was further fractionated by gel filtration through Sephadex G-100 followed by ion-exchange chromatography on DEAE-cellulose. The dialyzable material was fractionated by gel filtration through Sephadex G-50. The allergenic activities of the fractions obtained from the A. tenuis extract was measured in vitro by the radioallergosorbent test assay and the allergenic potency was measured by radioallergosorbent test inhibition assay. Allergenic activity was detected in most of the non-dialyzable fractions, the majority of the activity being in the last G-100 fraction (MW approximately 20,000) which was predominantly protein in nature. The same component may be responsible for the activity found in the dialyzate and its first G-50 fraction since the immunodiffusion studies indicated that the last G-100 fraction has antigenic components in common with those of the first G-50 fraction. In addition, cross-reactions between A. tenuis and A. solani extracts show that the two species share common antigenic determinants.

  14. Arbuscular mycorrhiza reduces susceptibility of tomato to Alternaria solani.

    Science.gov (United States)

    Fritz, Maendy; Jakobsen, Iver; Lyngkjaer, Michael Foged; Thordal-Christensen, Hans; Pons-Kühnemann, Jörn

    2006-09-01

    Mycorrhiza frequently leads to the control of root pathogens, but appears to have the opposite effect on leaf pathogens. In this study, we studied mycorrhizal effects on the development of early blight in tomato (Solanum lycopersicum) caused by the necrotrophic fungus Alternaria solani. Alternaria-induced necrosis and chlorosis of all leaves were studied in mycorrhizal and non-mycorrhizal plants over time course and at different soil P levels. Mycorrhizal tomato plants had significantly less A. solani symptoms than non-mycorrhizal plants, but neither plant growth nor phosphate uptake was enhanced by mycorrhizas. An increased P supply had no effect on disease severity in non-mycorrhizal plants, but led to a higher disease severity in mycorrhizal plants. This was parallel to a P-supply-induced reduction in mycorrhiza formation. The protective effect of mycorrhizas towards development of A. solani has some parallels to induced systemic resistance, mediated by rhizobacteria: both biocontrol agents are root-associated organisms and both are effective against necrotrophic pathogens. The possible mechanisms involved are discussed.

  15. 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.

  16. Chemosensitization of plant pathogenic fungi to agricultural fungicides.

    Directory of Open Access Journals (Sweden)

    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.

  17. Pathogenicity of Alternaria tenuissima HZ-1 to broadleaf weeds and its safety on crops%极细链格孢菌HZ-1对阔叶杂草的致病性及对作物的安全性评价

    Institute of Scientific and Technical Information of China (English)

    朱海霞; 马永强; 程亮; 郭青云

    2016-01-01

    采用形态学结合分子鉴定的方法,对生防潜力菌株HZ-1进行分类学鉴定,通过菌株发酵液致病性测定,评价该菌株对5种阔叶杂草的除草活性,采用盆栽生测法评价其对青海省主栽作物的安全性.结果表明,HZ-1为极细链格孢菌(Alternaria tenuissima),菌株发酵液对猪秧秧(Galium aparine)、刺儿菜[Cephalano-plos setosum(Willd.)Kitam]、藜(Chenopodium album)、冬葵(Malva crispa)、酸模叶蓼(Polygonum lapathifolium L.)表现出不同程度的致病作用,尤其对猪秧秧、藜致病效果最为突出.安全性评价结果显示,该菌株除对春油菜有轻微影响外,对春小麦、蚕豆、豌豆和青稞4种作物相对安全.综上,HZ-1可作为防除猪殃殃、藜等阔叶杂草生物除草剂的候选菌株.%Strain HZ-1 was identified through morphology observation and sequence analysis. The herbicidal activity of HZ-1 against 5 broadleaf weeds was evaluated by the pathogenicity of fermentation broth, and its safety to major crops in Qinghai was tested by pot bioassay. It was shown that strain HZ-1 was identified as Alternaria tenuissima. The fermentation broth of strain HZ-1 exhibited varied pathogenicity to Galium aparine, Cephalanoplos setosum ( Willd. ) Kitam, Chenopodium album, Malva crispa, Polygonum lapathifolium, and within these 4 species, the pathogenicity to Galium aparine and Chenopodium album was more severe. Strain HZ-1 was safe to major crops ex-cept spring rape. In general, strain HZ-1 was candidate of microbial herbicide against broadleaf weeds such as Gali-um aparine and Chenopodium album.

  18. Research on the Separation of Two Pathogens Causing Hemp Stem Disease and Its Impacts on the Soil Environment%大麻茎腐病菌的分离及其对土壤环境影响的研究

    Institute of Scientific and Technical Information of China (English)

    郑楠; 宋宪友; 张利国; 房郁妍; 殷博

    2013-01-01

    In this article, two strains of pathogenic fungi (DN1 and DN2) were separated from le-sion site of hemp. Through morphological identification, DN1 and DN2 were initial identificated as Alternaria and Verticillium of feuteromycotina subphylum separately. Two strains could grow nor-mally when the pH value ranged from 4 to 14. It indicated that both all have the very strong adapt-ability to the environment. The effect of hemp on soil pH value was determined by pot experiment, and the results showed that hemp could repair alkaline soil.%  从病变部位分离出两株病真菌DN1和DN2,通过菌丝及孢子形态的观察,初步确定其分别为半知菌亚门链格孢属(Alternaria alternata)及轮枝孢属(M.Verticillium).在pH值4~14之间,两株菌都能正常生长,对环境的适应能力较强.通过盆栽试验确定大麻对土壤pH的影响,结果表明大麻能修复弱碱性土壤.

  19. Antimicrobial activity of pyrrocidines from Acremonium zeae against endophytes and pathogens of maize.

    Science.gov (United States)

    Wicklow, Donald T; Poling, Stephen M

    2009-01-01

    Acremonium zeae produces pyrrocidines A and B, which are polyketide-amino acid-derived antibiotics, and is recognized as a seedborne protective endophyte of maize which augments host defenses against microbial pathogens causing seedling blights and stalk rots. Pyrrocidine A displayed significant in vitro activity against Aspergillus flavus and Fusarium verticillioides in assays performed using conidia as inoculum, with pyrrocidine A being more active than B. In equivalent assays performed with conidia or hyphal cells as inoculum, pyrrocidine A revealed potent activity against major stalk and ear rot pathogens of maize, including F. graminearum, Nigrospora oryzae, Stenocarpella (Diplodia) maydis, and Rhizoctonia zeae. Pyrrocidine A displayed significant activity against seed-rotting saprophytes A. flavus and Eupenicillium ochrosalmoneum, as well as seed-infecting colonists of the phylloplane Alternaria alternata, Cladosporium cladosporioides, and Curvularia lunata, which produces a damaging leaf spot disease. Protective endophytes, including mycoparasites which grow asymptomatically within healthy maize tissues, show little sensitivity to pyrrocidines. Pyrrocidine A also exhibited potent activity against Clavibacter michiganense subsp. nebraskense, causal agent of Goss's bacterial wilt of maize, and Bacillus mojaviense and Pseudomonas fluorescens, maize endophytes applied as biocontrol agents, but were ineffective against the wilt-producing bacterium Pantoea stewartii.

  20. Green Fluorescent Detection of Fungal Colonization and Endopolygalacturonase Gene Expression in the Interaction of Alternaria citri with Citrus.

    Science.gov (United States)

    Isshiki, A; Ohtani, K; Kyo, M; Yamamoto, H; Akimitsu, K

    2003-07-01

    ABSTRACT Alternaria citri, a postharvest pathogen, produces endopolygalacturonase (endoPG) and causes black rot on citrus fruit. We previously described that an endoPG-disrupted mutant of Alternaria citri was significantly reduced in its ability to macerate plant tissue and cause black rot symptoms on citrus. In order to investigate colonization of citrus fruit tissues by Alternaria citri, pTEFEGFP carrying a green fluorescent protein (GFP) gene was introduced into wild-type Alternaria citri and its endoPG-disrupted mutant (M60). Green fluorescence was observed in spores, germ tubes, appressoria, and infection hyphae of transformants G1 (derived from wild type) and GM4 (derived from M60). Hyphae of G1 but not GM4 vertically penetrated the peel, but the hyphae of both G1 and GM4 spread equally in the juice sac area of citrus fruit. Green fluorescence of Alternaria citri transformant EPG7 carrying a GFP gene under control of the endoPG gene promoter of Alternaria citri was induced by pectin in the peel during the infection stage, but repressed completely in the juice sac area, likely by carbon catabolite repression by sugars in the juice.

  1. 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...

  2. Enhancement of the citrus immune system provides effective resistance against Alternaria brown spot disease.

    Science.gov (United States)

    Llorens, Eugenio; Fernández-Crespo, Emma; Vicedo, Begonya; Lapeña, Leonor; García-Agustín, Pilar

    2013-01-15

    In addition to basal defense mechanisms, plants are able to develop enhanced defense mechanisms such as induced resistance (IR) upon appropriate stimulation. We recently described the means by which several carboxylic acids protect Arabidopsis and tomato plants against fungi. In this work, we demonstrate the effectiveness of hexanoic acid (Hx) in the control of Alternaria brown spot (ABS) disease via enhancement of the immune system of Fortune mandarin. The application of 1mM Hx in irrigation water to 2-year-old Fortune plants clearly reduced the incidence of the disease and led to smaller lesions. We observed that several of the most important mechanisms involved in induced resistance were affected by Hx application. Our results demonstrate enhanced callose deposition in infected plants treated with Hx, which suggests an Hx priming mechanism. Plants treated with the callose inhibitor 2-DDG were more susceptible to the fungus. Moreover, polygalacturonase-inhibiting protein (PGIP) gene expression was rapidly and significantly upregulated in treated plants. However, treatment with Hx decreased the levels of reactive oxygen species (ROS) in infected plants. Hormonal and gene analyses revealed that the jasmonic acid (JA) pathway was activated due to a greater accumulation of 12-oxo-phytodienoic acid (OPDA) and JA along with a rapid accumulation of JA-isoleucine (JA-Ile). Furthermore, we observed a more rapid accumulation of abscisic acid (ABA), which could act as a positive regulator of callose deposition. Thus, our results support the hypothesis that both enhanced physical barriers and the JA signaling pathway are involved in hexanoic acid-induced resistance (Hx-IR) to Alternaria alternata.

  3. 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.

  4. Nonhost-specific phytotoxicity of the polyketide-derived toxin solanapyrone A produced by Ascochyta rabiei and Alternaria solani

    Science.gov (United States)

    Solanapyrone A is a polyketide-derived metabolite produced by Ascochyta rabiei and Alternaria solani, which are the most destructive necrotrophic pathogens of chickpea and potato/tomato, respectively. They belong to the Order Pleosporales within the Class Dothideomycetes, but are phylogenetically di...

  5. Infectopyrone, a potential mycotoxin from Alternaria infectoria

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Perry, N.B.; Andersen, Birgitte

    2003-01-01

    A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an alpha-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria ...

  6. Infectopyrone, a potential mycotoxin from Alternaria infectoria

    DEFF Research Database (Denmark)

    Larsen, Thomas Ostenfeld; Perry, N.B.; Andersen, Birgitte

    2003-01-01

    A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an alpha-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria ...

  7. COMPARISON OF OCCURRENCE AND TOXINOGENITY OF ALTERNARIA SPP. ISOLATED FROM SAMPLES OF CONVENTIONAL AND NEW CROSSBRED WHEAT OF SLOVAK ORIGIN

    Directory of Open Access Journals (Sweden)

    Soňa Felšöciová

    2012-02-01

    Full Text Available The aim of this study was to compare the results of mycological and mycotoxicological analysis of two types of Slovak wheat samples, focusing on Alternaria genus. A total of 21 samples of conventional wheat grains and 3 samples of the new crossbred wheat were investigated for exogenous and endogenous mycobiota. The exogenous mycobiota was determined by using plate dilution method and the endogenous mycobiota by the method of direct placing of superficially sterilized grains on agar plates. Toxinogenity of selected isolates was analysed by means of thin layer chromatography. The obtained results of this study show a high isolation frequency of Alternaria isolates in samples of conventional as well as new crossbred wheat. A total of 4 species-groups of the genus Alternaria were isolated from conventional wheat (A. alternata, A. arborescens, A. infectoria, A. tenuissima and 3 species-groups from new crossbred wheat (A. arborescens, A. infectoria, A. tenuissima. A. tenuissima species-group was isolated within the endogenous mycobiota from all samples of conventional and new crossbred wheat. Species-group with the second highest isolation frequency in all tested samples was A. infectoria. The highest relative density in all samples belongs to A. infectoria and A. tenuissima species-groups. Selected strains isolated from both types of wheat were tested for production of altenuene, alternariol monomethylether and alternariol. In neither case of A. infectoria species-group isolates was confirmed the production of tested mycotoxins. The highest toxinogenity (100% was observed in strains of A. arborescens and A. tenuissima.

  8. Plasma-Based Degradation of Mycotoxins Produced by Fusarium, Aspergillus and Alternaria Species

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    Lars ten Bosch

    2017-03-01

    Full Text Available The efficacy of cold atmospheric pressure plasma (CAPP with ambient air as working gas for the degradation of selected mycotoxins was studied. Deoxynivalenol, zearalenone, enniatins, fumonisin B1, and T2 toxin produced by Fusarium spp., sterigmatocystin produced by Aspergillus spp. and AAL toxin produced by Alternaria alternata were used. The kinetics of the decay of mycotoxins exposed to plasma discharge was monitored. All pure mycotoxins exposed to CAPP were degraded almost completely within 60 s. Degradation rates varied with mycotoxin structure: fumonisin B1 and structurally related AAL toxin were degraded most rapidly while sterigmatocystin exhibited the highest resistance to degradation. As compared to pure compounds, the degradation rates of mycotoxins embedded in extracts of fungal cultures on rice were reduced to a varying extent. Our results show that CAPP efficiently degrades pure mycotoxins, the degradation rates vary with mycotoxin structure, and the presence of matrix slows down yet does not prevent the degradation. CAPP appears promising for the decontamination of food commodities with mycotoxins confined to or enriched on surfaces such as cereal grains.

  9. 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.

  10. Mycotoxin Production in Liquid Culture and on Plants Infected with Alternaria spp. Isolated from Rocket and Cabbage

    Science.gov (United States)

    Siciliano, Ilenia; Ortu, Giuseppe; Gilardi, Giovanna; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions. PMID:25751147

  11. Mycotoxin Production in Liquid Culture and on Plants Infected with Alternaria spp. Isolated from Rocket and Cabbage

    Directory of Open Access Journals (Sweden)

    Ilenia Siciliano

    2015-03-01

    Full Text Available Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower. A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.

  12. Mycotoxin production in liquid culture and on plants infected with Alternaria spp. isolated from rocket and cabbage.

    Science.gov (United States)

    Siciliano, Ilenia; Ortu, Giuseppe; Gilardi, Giovanna; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-03-05

    Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.

  13. Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants

    Institute of Scientific and Technical Information of China (English)

    Fa-zhong YANG; Li LI; Bin YANG

    2012-01-01

    The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation.However,the effects of Alternaria toxins on insects have just begun to be investigated.Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study.At a concentration of 50.0 μg/ml,the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P≥0.079),and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P≤0.001).However,this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml (P≥0.096).Therefore,the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids,demonstrating that the resistance mechanism triggered by the Altemaria toxin in the rose plant may also be used by the plant to defend itself against insects.Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants.The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P≤0.014).This result showed that the toxin-induced resistance related to the volatile changes of host plants.

  14. [Seasonal variation in the content of spores of the genus Alternaria Nees ex Fr. in the air of the city of Córdoba (Spain)].

    Science.gov (United States)

    Nogales Moncada, M T; Domínguez Vilches, E; Galán Soldevilla, C; Ruiz de Clavijo Jiménez, E

    1986-01-01

    The spore concentrations of Alternaria, a genera of microfungi widely considered as allergenic by different authors (Caplin & Haynes, Gravesen, Gregory, Larsen, Petersen & Sandberg), have been investigated in the atmosphere of Córdoba (Spain) during the period of April, 1983 to March, 1985 by means of the volumetric (Andersen sampler) and gravimetric (Durham based) methods, taking samples three times a day in culture media (Agar-Malt extract 2%) and incubating them for 5-7 days. The objectives of the work have been the establishment of seasonal variation patterns, as well as the possible correlations with the climatological factors. The results show that the different species of Alternaria detected are among the most important components in the aeromycoflora of the town, only exceeded by Cladosporium ssp., yeasts and Mycelia sterilia. In fact we found 3,283 colonies of Alternaria through the gravimetric method and 572 through the volumetric method, representing a 4.28% and 0.59% respectively of the total developed colonies during the sample period. The seasonal variations in air spore concentrations of Alternaria have also been studied monthly following the methods indicated above. It was found that January is always the month with less incidence of spores, with some days free of spores. May was the month with a maximum spores incidence during the first year of study, while this was delayed until june in the second year. This delay was probably due to the prolonged rainy season during the last spring. By establishing positive groups, A. alternata was found to be the most frequent species, with seven months during the period 1984-1985 exceeding the figure of 150 colonies per month.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Fungi isolated from Stewartia pseudocamellia Max. seeds and their pathogenesis

    Directory of Open Access Journals (Sweden)

    Halina Kurzawińska

    2012-12-01

    Full Text Available The aim of studies was to determine typical composition of fungi occurring on seeds of Stewartia pseudocamellia.The studies conducted on 100 disinfected and 100 nondisinfected seeds of these plants.Isolates of Alternaria alternata, Fusarium oxysporum, Cylindrocarpon radicicola and Rhizoctonia solani were characterized by pathogenicity towards the investigated Stewartia pseudocamellia. In the laboratory experiment, 204 isolations of microorganisms were obtained that belonged to 20 species and form of fungi and bacteria. Among fungi there were both of parasite (Alternaria alternata, Botrytis cinerea, Fusarium spp., Rhizoctonia solani and typical saprophytic (Cladosporium spp., Penicillium spp., Aspergillus spp., Epicoccum spp., Mucor spp.. The dominant fungus on seeds was Alternaria alternata. Among the investigated isolates only one isolate (R4 Rhizoctonia solani, was strongly pathogenic, isolates (A1 Alternaria alternata were weakly pathogenic to seedlings of Stewartia pseudocamellia.

  16. EVALUATION OF DISEASE RESISTANCE POTENTIAL OF SEVEN POTATO GENOTYPES AGAINST EARLY BLIGHT CAUSED BY Alternaria tenuissima UNDER GREENHOUSE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mirkarimi

    2013-07-01

    Full Text Available Early blight of potato was caused by various species of genus Alternaria, the disease has a prominent role in reducing crop yields in most of the countries, especially in Iran. Various studies has been conducted for the finding out the information regarding the diversity of pathogen and estimation of damage caused by genus Alternaria tenuissima in Iran, but the information regarding the resistance against this fungal pathogen in various genotype of potatoes are in scarcity. Seven isolates of potato were obtained from the National Plant Gene Bank of Iran. Amongst these seven, on the basis of mean comparison curve progress Cosmos was recognized as the most sensitive genetic samples while the samples Armida was reported as a most resistant to the disease. Other cultivars showed different levels of resistance against this pathogen.

  17. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Directory of Open Access Journals (Sweden)

    Yelko Rodríguez-Carrasco

    2016-11-01

    Full Text Available Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH, alternariol monomethyl ether (AME, and tentoxin (TEN are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC tandem mass spectrometry (MS/MS detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr and intermediate reproducibility (RSDR were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g.

  18. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Science.gov (United States)

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Juan, Cristina

    2016-01-01

    Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH), alternariol monomethyl ether (AME), and tentoxin (TEN) are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC) tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME) combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL) by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr) and intermediate reproducibility (RSDR) were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g). PMID:27845716

  19. Presence of adhesive vesicles in the mycoherbicide Alternaria helianthi

    Science.gov (United States)

    Alternaria helianthi conidia have been shown to cause disease on common cocklebur. Conidia were applied to slides made hydrophobic by coating with dimethyldicholorosilane (mimics leaf surface), then rinsed and treated with FITC-Con A to stain the adhesive material. Alternaria helianthi coni...

  20. Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192

    Institute of Scientific and Technical Information of China (English)

    SUN Hong; GAO Shushan; LI Xiaoming; LI Chunshun; WANG Bingui

    2013-01-01

    A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN-192,an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa,resulted in the isolation of nine known secondary metabolites,including four indole-diterpenoids:penijanthine A (1),paspaline (2),paspalinine (3),and penitrem A (4); three tricycloaltemarene derivatives:tricycloalternarene 3a (5),tricycloaltemarene lb (6),and tricycloalternarene 2b (7); and two altemariol congeners:djalonensone (8) and altemariol (9).The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature.The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum,with inhibition zone diameters of 8 and 9 mm,respectively,at 100 μ.g/disk.To the best of our knowledge,this is the first report on the secondary metabolites of mangrove-derived Alternaria tenuissima and also the first report of the isolation of indole-diterpenoids from fungal genus Alternaria.

  1. Alternethanoxins A and B, polycyclic ethanones produced by Alternaria sonchi , potential mycoherbicides for Sonchus arvensis biocontrol.

    Science.gov (United States)

    Evidente, Antonio; Punzo, Biancavaleria; Andolfi, Anna; Berestetskiy, Alexander; Motta, Andrea

    2009-08-12

    Alternaria sonchi is a fungal pathogen isolated from Sonchus arvensis and proposed as a biocontrol agent of this noxious perennial weed. Different phytotoxic metabolites were isolated from solid culture of the fungus. Two new polycyclic ethanones, named alternethanoxins A and B, were characterized using essentially spectroscopic and chemical methods. Tested by leaf disk-puncture assay on the fungal host plant and a number of nonhost plants, alternethanoxins A and B were shown to be phytotoxic, whereas they did not possess antimicrobial activity tested at 100 microg/disk. Hence, alternethanoxins A and B have potential as nonselective natural herbicides. Some structure-activity relationship observations were also made.

  2. First Record of Alternaria simsimi Causing Leaf Spot on Sesame (Sesamum indicum L.) in Korea.

    Science.gov (United States)

    Choi, Young Phil; Paul, Narayan Chandra; Lee, Hyang Burm; Yu, Seung Hun

    2014-12-01

    Leaf spot disease was observed in sesame (Sesamum indicum L.) during 2009 and 2010 in Korea. The pathogen was identified as Alternaria simsimi based on morphological and cultural characteristics. The morphological identification was well supported by phylogenetic analysis of the ribosomal DNA-internal transcribed spacer region. A. simsimi isolates caused spot symptoms on leaves and stems of sesame plants 2 wk after artificial inoculation, which were similar to those observed in the field. This is the first record of leaf spot disease in Korea caused by A. simsimi.

  3. Phytotoxic effects of metabolites from Alternaria euphorbiicola against its host plant Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    Eduardo Vinícius Vieira Varejão

    2013-01-01

    Full Text Available A bioassay-guided fractionation of culture filtrates of the fungus Alternaria euphorbiicola, a pathogen of the weed Euphorbia heterophylla, led to the isolation of anhydromevalonolactone (1, tyrosol (2, (R-( - -mevalonolactone (3, and cycloglycylproline (4. When tested on the punctured leaves of the host plant, these compounds produced bleached lesions with dark brown margins at concentrations as low as 80 µM. When tested on the leaves of other relevant weeds, only cycloglycylproline showed selective activity against E. heterophylla. This is the first report on the isolation of phytotoxins from A. euphorbiicola and on the phytotoxicity of anhydromevalonolactone, (R-( - -mevalonolactone, and cycloglycylproline.

  4. Abscisic acid enhances resistance to Alternaria solani in tomato seedlings.

    Science.gov (United States)

    Song, Weiwei; Ma, Xinrong; Tan, Hong; Zhou, Jinyan

    2011-07-01

    The plant hormone abscisic acid (ABA) is an important regulator in many aspects of plant growth and development, as well as stress resistance. Here, we investigated the effects of exogenous ABA application on the interaction between tomato (Solanum lycopersicon L.) and Alternaria solani (early blight). Foliar spraying of 7.58 μM ABA was effective in reducing disease severity in tomato plants. Previously, increased activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were observed in exogenous ABA-treated tomato leaves. Moreover, these enzyme activities were maintained at higher levels in ABA-pretreated and A. solani challenged tomato plants. Tomato defense genes, such as PR1, β-1, 3-glucanase (GLU), PPO, POD, and superoxide dismutase (SOD), were rapidly and significantly up-regulated by exogenous ABA treatment. Furthermore, a subsequent challenge of ABA-pretreated plants with the pathogen A. solani resulted in higher expression of defense genes, compared to water-treated or A. solani inoculated plants. Therefore, our results suggest that exogenous ABA could enhance disease resistance against A. solani infection in tomato through the activation of defense genes and via the enhancement of defense-related enzymatic activities.

  5. Evaluation of Alternaria mycotoxins in strawberries: quantification and storage condition.

    Science.gov (United States)

    Juan, Cristina; Oueslati, Souheib; Mañes, Jordi

    2016-05-01

    Alternariol (AOH), alternariol methyl ether (AME) and tentoxin (TEN) are Alternaria mycotoxins produced by the most common post-harvest pathogens of fruits. The production of these metabolites depends on several environmental factors, mainly temperature, water activity, pH and the technological treatments that have been applied to the product. In this study, the occurrence of AOH, AME and TEN was evaluated in strawberries samples stored at different temperatures ranges (at 22 ± 2 or 6 ± 2°C) and different periods (up to 1 month) simulating the current practice of consumer's storage conditions. Sample extraction was performed using a liquid-liquid extraction method prior to LC-MS/MS analysis. AOH was the most prevalent mycotoxins with a 42% at strawberries stored at (22 ± 2)°C and 37% stored at (6 ± 2)°C. The highest AOH levels were found in samples conserved at (22 ± 2)°C ranging between 26 and 752 ng g(-1). AME levels ranged between 11 and 137 ng g(-)(1), which were found mainly in stored samples at (6 ± 2)°C for more than 28 days. None sample presented levels of TEN in either of the studied conditions.

  6. Cloning and functional analysis of three genes encoding polygalacturonase-inhibiting proteins from Capsicum annuum and transgenic CaPGIP1 in tobacco in relation to increased resistance to two fungal pathogens.

    Science.gov (United States)

    Wang, Xiuju; Zhu, Xiaoping; Tooley, Paul; Zhang, Xiuguo

    2013-03-01

    Polygalacturonase-inhibiting proteins (PGIPs) are plant cell wall glycoproteins that can inhibit fungal endopolygalacturonases (PGs). The PGIPs directly reduce the aggressive potential of PGs. Here, we isolated and functionally characterized three members of the pepper (Capsicum annuum) PGIP gene family. Each was up-regulated at a different time following stimulation of the pepper leaves by Phytophthora capcisi and abiotic stresses including salicylic acid, methyl jasmonate, abscisic acid, wounding and cold treatment. Purified recombinant proteins individually inhibited activity of PGs produced by Alternaria alternata and Colletotrichum nicotianae, respectively, and virus-induced gene silencing in pepper conferred enhanced susceptibility to P. capsici. Because three PGIP genes acted similarily in conferring resistance to infection by P. capsici, and because individually purified proteins showed consistent inhibition against PG activity of both pathogens, CaPGIP1 was selected for manipulating transgenic tobacco. The crude proteins from transgenic tobacco exhibited distinct enhanced resistance to PG activity of both fungi. Moreover, the transgenic tobacco showed effective resistance to infection and a significant reduction in the number of infection sites, number of lesions and average size of lesions in the leaves. All results suggest that CaPGIPs may be involved in plant defense response and play an important role in a plant's resistance to disease.

  7. 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.

  8. Molecular diversity and evolutionary processes of Alternaria solani in Brazil inferred using genealogical and coalescent approaches.

    Science.gov (United States)

    Lourenço, Valdir; Moya, Andrés; González-Candelas, Fernando; Carbone, Ignazio; Maffia, Luiz A; Mizubuti, Eduardo S G

    2009-06-01

    Alternaria spp. form a heterogeneous group of saprophytic and plant-pathogenic fungi widespread in temperate and tropical regions. However, the relationship between evolutionary processes and genetic diversity with epidemics is unknown for several plant-pathogenic Alternaria spp. The interaction of Alternaria solani populations with potato and tomato plants is an interesting case study for addressing questions related to molecular evolution of an asexual fungus. Gene genealogies based on the coalescent process were used to infer evolutionary processes that shape the A. solani population. Sequences of the rDNA internal transcribed spacer (ITS) region and the genes which encode the allergenic protein alt a 1 (Alt a 1) and glyceraldehyde-3-phosphate dehydrogenase (Gpd) were used to estimate haplotype and nucleotide diversity as well as for the coalescent analyses. The highest number of parsimony informative sites (n = 14), nucleotide diversity (0.007), and the average number of nucleotide differences (3.20) were obtained for Alt a 1. Although the highest number of haplotypes (n = 7) was generated for ITS, haplotype diversity was the lowest (0.148) for this region. Recombination was not detected. Subdivision was inferred from populations associated with hosts but there was no evidence of geographic subdivision, and gene flow is occurring among subpopulations. In the analysis of the Alt a 1, balancing selection and population expansion or purifying selection could have occurred in A. solani subpopulations associated with potato and tomato plants, respectively. There is strong evidence that the subpopulation of A. solani that causes early blight in potato is genetically distinct from the subpopulation that causes early blight in tomato. The population of A. solani is clonal, and gene flow and mutation are the main evolutionary processes shaping its genetic structure.

  9. Mutation breeding in sunflower for resistance to alternaria leaf spot

    OpenAIRE

    de Marcelo Oliveira F.; Tulmann Augusto Neto; Regina Leite M.V.B.C.; Vania Castiglioni B.R.; Arias C.A.A.

    2004-01-01

    Genetic variability for resistance to Alternarla leaf spot disease (Alternaria helianthi) can be induced by radiation or chemical mutagens. The objectives of this study were to create genetic variability in cultivated sunflower and to select lines resistant to Alternaria leaf spot. In the first experiment, sunflower seeds of the genotype HA BR 104 were irradiated with 150 and 165 Gy of gamma rays. Seeds were sown in the field at the Embrapa Soybean experimental station, in Londrina, PR, Brazi...

  10. Genetic and physical analysis of a YAC contig spanning the fungal disease resistance locus Asc of tomato (Lycopersicon esculentum)

    NARCIS (Netherlands)

    Mesbah, L.A.; Kneppers, T.J.A.; Takken, F.L.W.; Laurent, P.; Hille, J.; Nijkamp, H.J.J.

    1998-01-01

    The Alternaria stem canker disease of tomato is caused by the necrotrophic fungal pathogen Alternaria alternata f. sp. lycopersici (AAL). The fungus produces AAL toxins that kill the plant tissue. Resistance to the fungus segregates as a single locus, called Asc, and has been genetically mapped on c

  11. Studies on the cost-effective management of Alternaria blight of rapeseed-mustard (Brassica spp.

    Directory of Open Access Journals (Sweden)

    M.M. Khan

    2007-08-01

    Full Text Available Three systemic fungicides: Topsin-M (Thiophanate methyl, 70%WP, Ridomil MZ (Mancozeb, 64% + Metalaxyl, 8%WP, and Bavistin (Carbendazim, 50%WP alone and in combination with four non-systemic fungicides Captaf (Captan, 50%WP, Indofil M-45 (Mancozeb, 75%WP, Indofil Z-78 (Zineb, 75%WP, and Thiram (Thiram, 75%WP were evaluated both in vitro and in vivo for their effectiveness to manage Alternaria blight of rapeseedmustard caused by Alternaria brassicae. A pure culture of the pathogenic fungus was applied in the field at 2 g colonized sorghum seeds kg-1 soil. All the fungicides were evaluated for their efficacy at various concentrations, 50, 100, 150, 200 and 500 ppm, and were sprayed in the field at 0.2% a.i. l-1. All fungicides significantly reduced the severity of the disease but Ridomil MZ was most effective. Topsin-M at a concentration of 500 ppm was the most effective in reducing radial growth of the pathogenic fungi (74.2%. Ridomil MZ reduced disease severity by 32% and was followed in effectiveness by the combination Bavistin+Captaf (26.5%. Maximum yield was obtained in plots sprayed with Bavistin+Captaf (1198 kg ha-1 followed by Bavistin+Indofil Z-78 (1172 kg ha-1. It was worth noting that the highest net profit as well as the highest cost-benefit ratio was obtained with Bavistin+Indofil Z-78 (1:3.2, followed by Bavistin+Captaf (1:1.3.

  12. Comparative evaluation of long-term storage techniques on viability and virulence of Alternaria solani

    Directory of Open Access Journals (Sweden)

    M.C. Ravikumar

    2016-07-01

    Full Text Available The study was conducted to test the viability and pathogenicity of different forms of Alternaria solani inoculum stored at different conditions and time intervals for a period of 16 months. The aim was to confirm the survival period of pathogen in soil and to determine the simplest method to maintain inoculum in laboratory for further studies. The cultures stored at 5 °C for 2, 4, 8 and 16 months were pathogenic, while cultures stored at room temperature turned non-pathogenic after 4 months. All 6 successive sub-cultures retained viability and virulence. All the target-spots stored at 5 °C were viable after all time intervals as tested by culturing and subsequent spray of harvested mycelial suspension, but at the room temperature (RT, 16 months old inoculum lost viability and virulence. The powdered tissue samples of target-spots stored at 5 °C were found pathogenic by spray method after all the intervals of the time but, at RT 16 month old sample lost virulence. In inoculation by soil splashing, powdered tissue stored in paper bag at 5 °C retained pathogenicity till 8 months, while at RT, the inoculum stored in paper bags and the inoculum mixed in soil lost pathogenicity after 4 months.

  13. Biochemical evaluation of resistance responses of potato to different isolates of Alternaria solani.

    Science.gov (United States)

    Shahbazi, Hadis; Aminian, Heshmatollah; Sahebani, Navazollah; Halterman, Dennis A

    2010-05-01

    The resistance phenotypes of nine potato cultivars to five isolates of Alternaria solani, causal agent of early blight, were studied after inoculation and growth under greenhouse conditions. We identified potato cultivars with both susceptible and resistant phenotypes as well as A. solani isolates with varying degrees of aggressiveness. Two potato cultivars and two pathogen isolates were selected for biochemical analysis of phenol production and peroxidase activity after inoculation. Phenol compounds were evaluated 2, 4, 6, and 8 days after inoculation, while peroxidase activities were monitored daily for 10 days. Native polyacrylamide electrophoresis was used to identify one protein with peroxidase activity in extracts taken 6 days after inoculation. Significantly higher peroxidase activity as well as total phenol content in potato was correlated with resistance in the Iranian potato cultivar Diamond. Variability of responses within the same cultivar to different isolates of A. solani suggests genotypic diversity between isolates that results in phenotypic diversity for pathogen aggressiveness.

  14. A polyphasic approach to the taxonomy of the Alternaria infectoria species-group

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Sørensen, Jens Laurids; Nielsen, Kristian Fog;

    2009-01-01

    morphologically identifiable as belonging to the A. infectoria species-group together with 12 strains belonging to closely related species: Alternaria malorum (syn. Cladosporium malorum), Chalastospora cetera (syn. Alternaria cetera) and Embellisia abundans. Morphological examination separated the 51 strains...

  15. Screening of Plant Extracts with Bioactivity to Alternaria alternata%抗烟草赤星病的植物源粗提物筛选

    Institute of Scientific and Technical Information of China (English)

    王少南; 杨立军; 杨小军; 成洪山

    2005-01-01

    为筛选对烟草赤星病有较高抗性的植物源提取物,进行了从10个科植物中以不同提取方法提取的12种粗提物对烟草赤星病室内孢子萌发和田间小区防治试验.结果表明:胡椒科的山鸡椒(Litsea cubeba)果实的水蒸气粗提物、菊科的牛蒡(Arctium lappa)种子的石油醚提取物和桃金娘科的丁子香(Syzygiumaromaticum)花的水蒸气粗提取物可明显抑制烟草赤星病菌孢子萌发,具有相对较好的田间防治效果.

  16. Effect of climate change on Alternaria leaf spot of rocket salad and black spot of basil under controlled environment.

    Science.gov (United States)

    Pugliese, M; Cogliati, E; Gullino, M L; Garibaldi, A

    2012-01-01

    Plant responses to elevated CO2 and temperature have been much studied in recent years, but effects of climate change on pathological responses are still largely unknown. The pathosystems rocket (Eruca vesicaria subsp. sativa)--Alternaria leaf spot (Alternaria japonica) and basil (Ocimum basilicum)--black spot (Colletotrichum gloeosporioides) were chosen as models to assess the potential impact of increased CO2 and temperature on disease incidence and severity under controlled environment. Potted plants were grown in phytotrons under 4 different simulated climatic conditions: (1) standard temperature (ranging from 18 degrees to 22 degrees C) and standard CO2 concentration (400 ppm); (2) standard temperature and elevated CO2 concentration (800 ppm); (3) elevated temperature (ranging from 22 degrees to 26 degrees C, 4 degrees C higher than standard) and standard CO2 concentration; (4) elevated temperature and CO2 concentration. Each plant was inoculated with a spore suspension containing 1 x 10(5) cfu/ml of the pathogen. Disease incidence and severity were assessed 14 days after inoculation. Increasing CO2 to 800 ppm showed a clear increment in the percentage of Alternaria leaf spot on rocket leaves compared to standard conditions. Basil plants grown at 800 ppm of CO2 showed increased black spot symptoms compared to 400 ppm. Disease incidence and severity were always influenced by the combination of rising CO2 and increased temperature, compared to standard conditions (400 ppm of CO2 - 22 degrees C). Considering the rising concentrations of CO2 and global temperature, we can assume that this could increase the severity of Alternaria japonica on rocket and Colletotrichum gloeosporioides on basil.

  17. Alternaria-aantasting van aardappelknollen : evaluatie 2004/2005

    NARCIS (Netherlands)

    Schepers, H.T.A.M.; Remijn, J.F.A.; Goorden, P.

    2005-01-01

    In de eerste maanden van 2005 werden diverse aardappeltelers geconfronteerd met veel Alternaria in de knollen. Door zowel DLV Plant, PPO-AGV als Cebeco Agrochemie zijn met name in het Zuid Westen monsters van aardappelen met problemen opgestuurd naar diverse laboratoria waaronder Plant Research Inte

  18. Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila.

    Science.gov (United States)

    Andersen, Birgitte; Dongo, Anita; Pryor, Barry M

    2008-02-01

    Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin I, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila.

  19. In silico prediction and characterization of secondary metabolite biosynthetic gene clusters in the wheat pathogen Zymoseptoria tritici.

    Science.gov (United States)

    Cairns, Timothy; Meyer, Vera

    2017-08-17

    Fungal pathogens of plants produce diverse repertoires of secondary metabolites, which have functions ranging from iron acquisition, defense against immune perturbation, to toxic assaults on the host. The wheat pathogen Zymoseptoria tritici causes Septoria tritici blotch, a foliar disease which is a significant threat to global food security. Currently, there is limited knowledge of the secondary metabolite arsenal produced by Z. tritici, which significantly restricts mechanistic understanding of infection. In this study, we analyzed the genome of Z. tritici isolate IP0323 to identify putative secondary metabolite biosynthetic gene clusters, and used comparative genomics to predict their encoded products. We identified 32 putative secondary metabolite clusters. These were physically enriched at subtelomeric regions, which may facilitate diversification of cognate products by rapid gene rearrangement or mutations. Comparative genomics revealed a four gene cluster with significant similarity to the ferrichrome-A biosynthetic locus of the maize pathogen Ustilago maydis, suggesting this siderophore is deployed by Z. tritici to acquire iron. The Z. tritici genome also contains several isoprenoid biosynthetic gene clusters, including one with high similarity to a carotenoid/opsin producing locus in several fungi. Furthermore, we identify putative phytotoxin biosynthetic clusters, suggesting Z. tritici can produce an epipolythiodioxopiperazine, and a polyketide and non-ribosomal peptide with predicted structural similarities to fumonisin and the Alternaria alternata AM-toxin, respectively. Interrogation of an existing transcriptional dataset suggests stage specific deployment of numerous predicted loci during infection, indicating an important role of these secondary metabolites in Z. tritici disease. We were able to assign putative biosynthetic products to numerous clusters based on conservation amongst other fungi. However, analysis of the majority of secondary

  20. Use of differents potato somaclons for evaluating the resistance to Alternaria solani Sorauer by artificial inoculation in field condition

    Directory of Open Access Journals (Sweden)

    Michel Leiva-Mora

    2001-04-01

    Full Text Available The use of plant pathogens, for the genetic improving programs is an important matter to guarantee its success. Utilization of phytopathogenic isolates from natural source, let us to employ rapid screening in some important genotypes. In this work it was used a mycelium homogenizated of Alternaria solani Sor (strain IBP-As-4, with a relative concentration of 1.7x105 ufc ml-1. The inoculum was applied by spraying to the somaclons (obtained by mutagenic and in vitro selection with culture filtrated of the fungus, also to the susceptible (Desireé and resistant (Solanum chacoense cultivars, respectively. The first symptoms appeared after seventh day of inoculation. The behavior between somaclons and testers in the final evaluation were different. Solanum chacoense was the most resistant genotype, the somaclons IBP-93 and IBP-38 were more susceptible than Desireé. The somaclons IBP-27 reached a similar affectation score respect to Solanum chacoense. The rest of the somaclons had an intermediate performance. It was proved the important of using of pathogenic strains of Alternaria solani Sor, for making selection where the natural inoculum source it is weak. Key words: genetic, improvement, selection, Solanum tuberosum L.

  1. Two new compounds from an endophytic fungus Alternaria solani.

    Science.gov (United States)

    Ai, Hong-Lian; Zhang, Li-Mei; Chen, Yan-Ping; Zi, Shu-Hui; Xiang, Hong; Zhao, Da-Ke; Shen, Yong

    2012-01-01

    Two new secondary metabolites, named 7-dehydroxyl-zinniol (1) and 20-hydroxyl-ergosta-4,6,8(14),22-tetraen-3-one (2), were isolated from the culture of Alternaria solani, an endophytic fungal strain residing in the roots of Aconitum transsectum. Their structures were elucidated on the basis of comprehensive spectroscopic analyses including IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR. Biological activity tests indicated that compound 1 showed moderate anti-HBV activity.

  2. Emerging Fusarium and Alternaria Mycotoxins: Occurrence, Toxicity and Toxicokinetics

    Directory of Open Access Journals (Sweden)

    Sophie Fraeyman

    2017-07-01

    Full Text Available Emerging Fusarium and Alternaria mycotoxins gain more and more interest due to their frequent contamination of food and feed, although in vivo toxicity and toxicokinetic data are limited. Whereas the Fusarium mycotoxins beauvericin, moniliformin and enniatins particularly contaminate grain and grain-based products, Alternaria mycotoxins are also detected in fruits, vegetables and wines. Although contamination levels are usually low (µg/kg range, higher contamination levels of enniatins and tenuazonic acid may occasionally occur. In vitro studies suggest genotoxic effects of enniatins A, A1 and B1, beauvericin, moniliformin, alternariol, alternariol monomethyl ether, altertoxins and stemphyltoxin-III. Furthermore, in vitro studies suggest immunomodulating effects of most emerging toxins and a reproductive health hazard of alternariol, beauvericin and enniatin B. More in vivo toxicity data on the individual and combined effects of these contaminants on reproductive and immune system in both humans and animals is needed to update the risk evaluation by the European Food Safety Authority. Taking into account new occurrence data for tenuazonic acid, the complete oral bioavailability, the low total body clearance in pigs and broiler chickens and the limited toxicity data, a health risk cannot be completely excluded. Besides, some less known Alternaria toxins, especially the genotoxic altertoxins and stemphyltoxin III, should be incorporated in risk evaluation as well.

  3. Emerging Fusarium and Alternaria Mycotoxins: Occurrence, Toxicity and Toxicokinetics.

    Science.gov (United States)

    Fraeyman, Sophie; Croubels, Siska; Devreese, Mathias; Antonissen, Gunther

    2017-07-18

    Emerging Fusarium and Alternaria mycotoxins gain more and more interest due to their frequent contamination of food and feed, although in vivo toxicity and toxicokinetic data are limited. Whereas the Fusarium mycotoxins beauvericin, moniliformin and enniatins particularly contaminate grain and grain-based products, Alternaria mycotoxins are also detected in fruits, vegetables and wines. Although contamination levels are usually low (µg/kg range), higher contamination levels of enniatins and tenuazonic acid may occasionally occur. In vitro studies suggest genotoxic effects of enniatins A, A1 and B1, beauvericin, moniliformin, alternariol, alternariol monomethyl ether, altertoxins and stemphyltoxin-III. Furthermore, in vitro studies suggest immunomodulating effects of most emerging toxins and a reproductive health hazard of alternariol, beauvericin and enniatin B. More in vivo toxicity data on the individual and combined effects of these contaminants on reproductive and immune system in both humans and animals is needed to update the risk evaluation by the European Food Safety Authority. Taking into account new occurrence data for tenuazonic acid, the complete oral bioavailability, the low total body clearance in pigs and broiler chickens and the limited toxicity data, a health risk cannot be completely excluded. Besides, some less known Alternaria toxins, especially the genotoxic altertoxins and stemphyltoxin III, should be incorporated in risk evaluation as well.

  4. Isolation and characterization of microsatellite markers from the phytopathogenic fungus Alternaria dauci.

    Science.gov (United States)

    Benichou, Soumaya; Dongo, Anita; Henni, Djamel Eddine; Peltier, Didier; Simoneau, Philippe

    2009-01-01

    Eleven polymorphic microsatellite markers were isolated from the necrotrophic phytopathogenic fungus Alternaria dauci based on enriched genomic libraries. In order to assess allelic variability, the microsatellite loci were analysed in a collection of 43 isolates. The number of detected alleles in 11 loci ranged from two to 24 (mean 10.4). Test of cross-species amplification and sequencing of the resulting amplicons showed that some of these microsatellites could be used in different species such as Alternaria solani, Alternaria bataticola and Alternaria zinniae. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

  5. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  6. Characterization of Alternaria strains from Argentinean blueberry, tomato, walnut and wheat

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Nielsen, Kristian Fog; Fernández Pinto, Virginia

    2015-01-01

    Alternaria species have the ability to produce a variety of secondary metabolite, which plays important roles in food safety. Argentina is the second largest exporter of fresh and processed food products to Europe, however, fewstudies on Alternaria mycotoxins and other bioactive secondary...

  7. 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.

  8. Novel chemotaxonomic markers of the Alternaria infectoria species-group

    DEFF Research Database (Denmark)

    Christensen, K.B.; Van Klink, J.W.; Weavers, R.T.;

    2005-01-01

    Two new structurally related metabolites, novae-zelandin A (1) and novae-zelandin B (2), as well as the novel metabolite 4Z-infectopyrone (3) were purified from extracts of filamentous fungi belonging to the Alternaria infectoria species-group. The structures were elucidated by a combination of 1...... and 2D NMR spectroscopic data and MS data. 1-3 are important chemotaxonomic markers of the A. infectoria species-group and exhibit structures similar to those of known biologically active compounds, suggesting that they could be potential phytotoxins....

  9. Two new zinniol-related phytotoxins from Alternaria solani.

    Science.gov (United States)

    Moreno-Escobar, Jorge; Puc-Carrillo, Alejandra; Cáceres-Farfán, Mirbella; Peña-Rodríguez, Luis M; Gamboa-Angulo, M Marcela

    2005-09-01

    Bioassay-guided purification of the organic crude extract of Alternaria solani resulted in the isolation of three metabolites responsible for causing necrosis on potato leaves. These phytotoxins were identified as 2-(2",3"-dimethyl-but-1-enyl)-zinniol (1), 8-zinniol methyl ether (2). and 8-zinniol methyl ether based on their spectroscopic data (IR, MS, 1H and 13CNMR). Metabolites 1 and 2 have been identified as new phytotoxins structurally related to zinniol (4). Additionally, 5-(3',3'-dimethylallyloxy)-7-methoxy-6-methyl-phthalide and 8-zinniol-2-(phenyl)-ethyl ether (3) were also isolated during the purification process.

  10. Mapping Resistance to Alternaria cucumerina in Cucumis melo.

    Science.gov (United States)

    Daley, James; Branham, Sandra; Levi, Amnon; Hassell, Richard; Wechter, Patrick

    2017-04-01

    Infection with Alternaria cucumerina causes Alternaria leaf blight (ALB), a disease characterized by lesion formation on leaves, leading to substantial yield and quality losses in Cucumis melo (melon). Although fungicides are effective against ALB, reduction in the frequency of application would be economically and environmentally beneficial. Resistant melon lines have been identified but the genetic basis of this resistance has not been determined. A saturated melon genetic map was constructed with markers developed through genotyping by sequencing of a recombinant inbred line population (F6 to F10; n = 82) derived from single-seed descent of a F2 population from a cross between the ALB-resistant parent MR-1 and the ALB-susceptible parent Ananas Yokneum. The population was evaluated for A. cucumerina resistance with an augmented block greenhouse study using inoculation with the wounded-leaf method. Multiple quantitative trait loci (QTL) mapping identified two QTL that explained 33.9% of variation in lesion area. Several candidate genes within range of these QTL were identified using the C. melo v3.5 genome. Markers linked to these QTL will be used to accelerate efforts to breed melon cultivars resistant to ALB.

  11. Inhibition of spore germination of Alternaria tenuis by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Couey, H.M.

    1962-08-01

    As a part of a continuing study of SO/sub 2/ fumigation of table grapes, the effect of SO/sub 2/ on spores of an isolate of A. tenuis Auct. causing decay of table grapes was determined. The amount of SO/sub 2/ required to inhibit completely spore germination depended on availability of moisture and the temperature. At 20/sup 0/C, wet spores required 20-min exposure to 100 ppm SO/sub 2/ to prevent germination, but spores equilibrated at 90% relative humidity (RH) required 10-min exposure to 1000 ppm SO/sub 2/. Dry spores at 60% RH were unaffected by a 20-min exposure to 4000 ppm SO/sub 2/. Increasing the temperature in the range 5-20/sup 0/C increased effectiveness of the SO/sub 2/ treatment. A comparison of Alternaria with Botrytis cinerea Fr. (studied earlier) showed that wet spores of these organisms were about equally sensitive to SO/sub 2/, but that dry Alternaria spores were more resistant to SO/sub 2/ than dry Botrytis spores under comparable conditions.

  12. Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

    Science.gov (United States)

    Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

    2015-12-28

    The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis.

  13. Incidence and distribution of seed-borne fungi associated with wheat in Markazi Province, Iran

    National Research Council Canada - National Science Library

    Masomeh Hajihasani

    2012-01-01

    ... including Tilletia laevis, Tilletia tritici, Ustilago tritici, Fusarium graminearum, Fusarium culmorum, Microdochium nivale, Bipolaris sorokiniana, Alternaria alternata, Curvularia sp., Aspergil...

  14. Aislamiento, identificación y pruebas in vitro de cepas autóctonas de Bacillus subtilis como agente de biocontrol de Alternaria spp en Brassica oleracea var.italica.

    OpenAIRE

    Ñacato Suntaxi, Carolina Aracely; Valencia Gordón, María Fernanda

    2016-01-01

    There is an increasing consumer demand for quality food, a concept which mainly involves the availability of disease-free products and harmful to human health chemical waste, which is why the need for new options for sustainable management arises broccoli crop against the causative pathogen damage in inflorescence. The disease caused by the phytopathogenic fungus Alternaria spp is a major cause of damage to broccoli cultivars. Field sampling and laboratory investigations w...

  15. Airborne Alternaria and Cladosporium species and relationship with meteorological conditions in Eskisehir City, Turkey.

    Science.gov (United States)

    Erkara, Ismuhan Potoglu; Asan, Ahmet; Yilmaz, Veysel; Pehlivan, Sevil; Okten, Suzan Sarica

    2008-09-01

    Alternaria and Cladosporium, known as the most allergenic spores were first collected by means of Durham gravimetric sampler from Eskisehir atmosphere from January 1, 2000 to December 31, 2001. The daily, monthly and annual variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 10.231 spores belonging to Cladosporium and Alternaria genera were recorded. Of these spores, 5,103 were identified in 2000 and 5,128 in 2001. While 63.09% of the total spores were those of Cladosporium, 36.91% were of Alternaria. Relationships between airborne fungal spore presence and meteorological conditions were statistically investigated. A Shapiro-Wilk test revealed that the airborne Cladosporium and Alternaria spores differed from a normal distribution. Thus, a Friedmann test was performed followed by a Pearson Correlation Analysis. The effects of rainfall, temperature and wind speed on Cladosporium and Alternaria numbers were non-significant according to the sites and months (p > 0.05), but the effects of relative humidity on Cladosporium and Alternaria numbers were significant (p < 0.01). Spore concentrations reached to their highest levels in May 2001.

  16. Priming by Hexanoic Acid Induce Activation of Mevalonic and Linolenic Pathways and Promotes the Emission of Plant Volatiles

    OpenAIRE

    Eugenio eLlorens; Gemma eCamañes; Leonor eLapeña; Pilar eGarcía-Agustín

    2016-01-01

    Hexanoic acid is a short natural monocarboxylic acid present in some fruits and plants. Previous studies reported that soil drench application of this acid induces effective resistance in tomato plants against Botrytis cinerea and Pseudomonas syringae and in citrus against Alternaria alternata and Xanthomonas citri. In this work, we performed an in deep study of the metabolic changes produced in citrus by the application of hexanoic acid in response to the challenge pathogen Alternaria altern...

  17. Chemical constituents of marine mangrove-derived endophytic fungus Alternaria tenuissima EN-192

    Science.gov (United States)

    Sun, Hong; Gao, Shushan; Li, Xiaoming; Li, Chunshun; Wang, Bingui

    2013-03-01

    A chemical investigation of the ethyl acetate extract of the fermentation broth of Alternaria tenuissima EN-192, an endophytic fungus obtained from the stems of the marine mangrove plant Rhizophora stylosa, resulted in the isolation of nine known secondary metabolites, including four indole-diterpenoids: penijanthine A ( 1), paspaline ( 2), paspalinine ( 3), and penitrem A ( 4); three tricycloalternarene derivatives: tricycloalternarene 3a ( 5), tricycloalternarene 1b ( 6), and tricycloalternarene 2b ( 7); and two alternariol congeners: djalonensone ( 8) and alternariol ( 9). The chemical structures of these metabolites were characterized through a combination of detailed spectroscopic analyses and their comparison with reports from the literature. The inhibitory activities of each isolated compound against four bacteria were evaluated and compounds 5 and 8 displayed moderate activity against the aquaculture pathogenic bacterium Vibrio anguillarum, with inhibition zone diameters of 8 and 9 mm, respectively, at 100 μg/disk. To the best of our knowledge, this is the first report on the secondary metabolites of mangrove-derived A lternaria tenuissima and also the first report of the isolation of indole-diterpenoids from fungal genus A lternaria.

  18. Variability among Alternaria solani isolates associated with early blight of tomato.

    Science.gov (United States)

    Varma, P Kishore; Singh, Sher; Gandhi, S K; Chaudhary, K

    2006-01-01

    Variability among isolates of Alternaria solani, the causal agent of early blight of tomato, from Northern and Southern parts of India was determined based on conidial morphology, pathogenicity tests and random amplified polymorphic DNA (RAPD) techniques. The isolates varied with respect to size of conidia and number of septa. The average size of conidia varied from 150-224.9 microm x 12.4-17.2 microm. The number of horizontal (4-14), vertical (0-3) and beak (0-8) septa also varied among the isolates. The test isolates differed in the virulence pattern on ten tomato genotypes under screen house conditions. Based on disease severity, test isolates were categorized into three main groups. Isolates RAS (Rohtak) and HAS-I (Hisar) were more virulent than all other isolates. None of the genotypes were completely resistant to all the test isolates. The analysis of RAPD profiles showed that there was a high level of genetic variability among the isolates of A. solani. The cluster analysis based on similarity coefficients separated the ten A. solani isolates into two major clusters. There was no evidence for geographical clustering of isolates with high levels of genetic similarity, suggesting that isolates are widely spread across India.

  19. Resistance to Alternaria solani in hybrids between a Solanum tuberosum haploid and S. raphanifolium.

    Science.gov (United States)

    Weber, B N; Jansky, S H

    2012-02-01

    Early blight of potato (Solanum tuberosum), caused by the foliar fungal pathogen Alternaria solani, is a major cause of economic loss in many potato-growing regions. Genetic resistance offers an opportunity to decrease fungicide usage while maintaining yield and quality. In this study, an early blight resistant clone of the diploid wild species S. raphanifolium was crossed as a male to a haploid (2n=2x) of cultivated potato. Hybrids were backcrossed to both parents. Eight families were created and evaluated for early blight resistance in the field. Families created by backcrossing to the wild species parent exhibited significantly lower relative area under the disease progress curve means than those from backcrossing to the cultivated parent, leading to the conclusion that S. raphanifolium contributes genes for early blight resistance. The mechanism of resistance in S. raphanifolium is unique because A. solani could not be recovered from lesions. Clones were identified with high levels of resistance and adaptation to the photoperiod of a temperate production region.

  20. A new species of Xorides Latreille (Hymenoptera, Ichneumonidae, Xoridinae parasitizing Pterolophia alternata (Coleoptera, Cerambycidae in Robinia pseudoacacia

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    Mao-Ling Sheng

    2012-11-01

    Full Text Available A new species is described, Xorides benxicus Sheng, sp. n., reared from the cerambycid twig-boring pest of Robinia pseudoacacia Linnaeus, Pterolophia alternata Gressitt 1938, in Benxi County, Liaoning Province, China. A key is given to the species similar to Xorides benxicus Sheng, namely X. asiasius Sheng & Hilszczański 2009, X. cinnabarius Sheng & Hilszczański 2009 and X. sapporensis (Uchida 1928.

  1. Survey of Major Diseases Occurred on Apple in NorthernGyeongbuk from 2013 to 2014

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    Wonsu Cheon

    2015-12-01

    Full Text Available During the period from 2013 to 2014, disease occurrences by various pathogens in apple cultivars have been investigated in northern Gyeongbuk province of Korea. Anthracnose, white rot, Alternaria leaf spot, Marssonina blotch, and bacterial shoot blight as major diseases have been observed. Pathogens isolated from the symptomatic plants were identified as Colletotrichum gloeosporioides for anthracnose, Botryosphaeria dothidea for white rot, Alternaria alternata for Alternaria leaf spot, Marssonina mali for Marssonina blotch, and Pseudomonas syringae pv. syringae for bacterial shoot blight. Of all diseases, the bacterial shoot blight has been severely increased in chronically infested fields in Gyeongbuk province.

  2. The Arabidopsis thaliana-Alternaria brassicicola pathosystem: A model interaction for investigating seed transmission of necrotrophic fungi.

    Science.gov (United States)

    Pochon, Stephanie; Terrasson, Emmanuel; Guillemette, Thomas; Iacomi-Vasilescu, Beatrice; Georgeault, Sonia; Juchaux, Marjorie; Berruyer, Romain; Debeaujon, Isabelle; Simoneau, Philippe; Campion, Claire

    2012-05-09

    Seed transmission constitutes a major component of the parasitic cycle for several fungal pathogens. However, very little is known concerning fungal or plant genetic factors that impact seed transmission and mechanisms underlying this key biological trait have yet to be clarified. Such lack of available data could be probably explained by the absence of suitable model pathosystem to study plant-fungus interactions during the plant reproductive phase. Here we report on setting up a new pathosystem that could facilitate the study of fungal seed transmission. Reproductive organs of Arabidopsis thaliana were inoculated with Alternaria brassicicola conidia. Parameters (floral vs fruit route, seed collection date, plant and silique developmental stages) that could influence the seed transmission efficiency were tested to define optimal seed infection conditions. Microscopic observations revealed that the fungus penetrates siliques through cellular junctions, replum and stomata, and into seed coats either directly or through cracks. The ability of the osmosensitive fungal mutant nik1Δ3 to transmit to A. thaliana seeds was analyzed. A significant decrease in seed transmission rate was observed compared to the wild-type parental strain, confirming that a functional osmoregulation pathway is required for efficient seed transmission of the fungus. Similarly, to test the role of flavonoids in seed coat protection against pathogens, a transparent testa Arabidopsis mutant (tt4-1) not producing any flavonoid was used as host plant. Unexpectedly, tt4-1 seeds were infected to a significantly lower extent than wild-type seeds, possibly due to over-accumulation of other antimicrobial metabolites. The Arabidopsis thaliana-Alternaria brassicicola pathosystem, that have been widely used to study plant-pathogen interactions during the vegetative phase, also proved to constitute a suitable model pathosystem for detailed analysis of plant-pathogen interactions during the reproductive

  3. The Arabidopsis thaliana-Alternaria brassicicola pathosystem: A model interaction for investigating seed transmission of necrotrophic fungi

    Directory of Open Access Journals (Sweden)

    Pochon Stephanie

    2012-05-01

    Full Text Available Abstract Background Seed transmission constitutes a major component of the parasitic cycle for several fungal pathogens. However, very little is known concerning fungal or plant genetic factors that impact seed transmission and mechanisms underlying this key biological trait have yet to be clarified. Such lack of available data could be probably explained by the absence of suitable model pathosystem to study plant-fungus interactions during the plant reproductive phase. Results Here we report on setting up a new pathosystem that could facilitate the study of fungal seed transmission. Reproductive organs of Arabidopsis thaliana were inoculated with Alternaria brassicicola conidia. Parameters (floral vs fruit route, seed collection date, plant and silique developmental stages that could influence the seed transmission efficiency were tested to define optimal seed infection conditions. Microscopic observations revealed that the fungus penetrates siliques through cellular junctions, replum and stomata, and into seed coats either directly or through cracks. The ability of the osmosensitive fungal mutant nik1Δ3 to transmit to A. thaliana seeds was analyzed. A significant decrease in seed transmission rate was observed compared to the wild-type parental strain, confirming that a functional osmoregulation pathway is required for efficient seed transmission of the fungus. Similarly, to test the role of flavonoids in seed coat protection against pathogens, a transparent testa Arabidopsis mutant (tt4-1 not producing any flavonoid was used as host plant. Unexpectedly, tt4-1 seeds were infected to a significantly lower extent than wild-type seeds, possibly due to over-accumulation of other antimicrobial metabolites. Conclusions The Arabidopsis thaliana-Alternaria brassicicola pathosystem, that have been widely used to study plant-pathogen interactions during the vegetative phase, also proved to constitute a suitable model pathosystem for detailed analysis

  4. CONTROLE DE ALTERNARIA SOLANI COM FUNGICIDAS NA CULTURA DO TOMATEIRO CONTROL OF ALTERNARIA SOLANI WITH FUNGICIDES IN TOMATO PLANTS

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    Fabrício Silva Coelho

    2011-06-01

    Full Text Available A pinta-preta, causada pelo fungo Alternaria solani, caracteriza-se por ser uma importante e destrutiva doença da cultura do tomate, sob condições de alta temperatura e umidade. Objetivou-se avaliar a eficiência de diferentes fungicidas no controle da Alternaria solani na cultura do tomateiro na região de Lavras (MG. O experimento foi desenvolvido na Universidade Federal de Lavras - Departamento de Agricultura, no período de novembro de 2004 a janeiro de 2005. O delineamento experimental foi o de blocos casualizados com 10 tratamentos e quatro repetições. Cada parcela composta por 12 plantas. As aplicações foram realizadas com um pulverizador costal manual (45 lbf/pol2, volume de aplicação de 800 L•ha-1, totalizando sete aplicações, com intervalos de sete dias. Foram realizadas cinco avaliações para a severidade foliar da doença com o uso de escala diagramática. Todos os fungicidas apresentaram potencial de controle da pinta-preta dentro das características inerentes ao seu grupo químico. Os melhores níveis de controle foram obtidos com os tratamentos Chlorothalonil 500 g•L-1 + Tetraconazole 20 g•L-1 (dosagem 200 mL•100 L-1, Chlorothalonil 400 g•L-1+ Oxicloreto de Cobre 420 g•kg-1 e Chlorothalonil 750 g•kg-1 + Tetraconazole 20 g•kg-1 (dosagem 150 g•100 L-1. Tetraconazole 100 g•L-1 proporcionou os menores níveis de controle.The early blight disease on tomato, caused by the fungus Alternaria solani, is referred to in importance due its destructive power, under conditions of high temperature and humidity. This study aimed to evaluate the effectiveness of various fungicides in your control in the region of Lavras-MG, Brazil. The experiment was conducted at the Federal University of Lavras, Department of Agriculture in the period from November 2004 to January 2005. The experimental design was randomized blocks with 10 treatments and four replications, each plot comprise 12 plants. The applications were made

  5. Antifungal Effect of the Aqueous and Ethanolic Avicennia marina Extracts on Alternaria citri and Penicillium digitatum

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    Behrooz Alizadeh Behbahani

    2016-02-01

    Full Text Available Background Plants have a great potential for producing new drugs of great benefit to mankind. There are many approaches to the search for new biologically active principles in higher plants. Objectives The aim of this study was to determine antifungal effect of the aqueous and ethanolic extracts of Avicennia marina on Penicillium digitatum and Alternaria citri in vitro. Materials and Methods In this experimental study, antimicrobial effects of extract were determined by screening antimicrobial activity and disk agar diffusion test in 20, 40, 60 and 80 mg/mL concentration of the extract against P. digitatum and A. citri. Minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC were determined by incorporating various concentrations of extracts in Sabouraud dextrose agar (SDA in tubes against P. digitatum and A. citri. The data were analyzed using one way analysis of variance (ANOVA using SPSS-17. Results The results indicate that extracts of A. marina mostly had been effective on P. digitatum and have the least impact on A. citri. The results show that the ethanol extract of mangrove leaf with antimicrobial activity method in 2 mg/mL, were inhibited the growth of P. digitatum and A. citri. In disk agar diffusion test the mentioned extract were shown inhibition effect on pathogen molds growth (P < 0.05. Conclusions Ethanolic extract compared to the aqueous extract was more effective and has a greater inhibition effect. The results of this study showed that the extract of A. marina has antifungal properties that justify their traditional use as medicinal plants.

  6. Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

    2012-05-01

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

  7. Expression analysis of chitinase upon challenge inoculation to Alternaria wounding and defense inducers in Brassica juncea

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    Sandhya Rawat

    2017-03-01

    Full Text Available Chitinases are the hydrolytic enzymes which belong to the pathogenesis-related (PR protein family and play an important role not only in plant defense but also in various abiotic stresses. However, only a limited number of chitinase genes have been characterised in B. juncea. In this study, we have characterised B. juncea class IV chitinase gene (accession no EF586206 in response to fungal infection, salicylic acid (SA, jasmonic acid (JA treatments and wounding. Gene expression studies revealed that the transcript levels of Bjchitinase (BjChp gene increases significantly both in local and distal tissues after Alternaria infection. Bjchitinase gene was also induced by jasmonic acid and wounding but moderately by salicylic acid. A 2.5 kb class IV chitinase promoter of this gene was isolated from B. juncea by Genome walking (accession no KF055403.1. In-silico analysis of this promoter revealed a number of conserved cis-regulatory elements related to defense, wounding and signalling molecules like SA, and JA. For validation, chitinase promoter was fused to the GUS gene, and the resultant construct was then introduced into Arabidopsis plants. Histochemical analysis of T2 transgenic Arabidopsis plants showed that higher GUS activity in leaves after fungal infection, wounding and JA treatment but weakly by SA. GUS activity was seen in meristematic tissues, young leaves, seeds and siliques. Finally investigation has led to the identification of a pathogen-inducible, developmentally regulated and organ-specific promoter. Present study revealed that Bjchitinase (BjChp promoter is induced during biotic and environmental stress and it can be used in developing finely tuned transgenics.

  8. Salicylic Acid Induces Resistance to Alternaria solani in Hydroponically Grown Tomato.

    Science.gov (United States)

    Spletzer, M E; Enyedi, A J

    1999-09-01

    ABSTRACT Alternaria solani is the causal agent of early blight disease in tomato and is responsible for significant economic losses sustained by tomato producers each year. Because salicylic acid (SA) is an important signal molecule that plays a critical role in plant defense against pathogen invasion, we investigated if the exogenous application of SA would activate systemic acquired resistance (SAR) against A. solani in tomato leaves. The addition of 200 muM SA to the root system significantly increased the endogenous SA content of leaves. Free SA levels increased 65-fold over basal levels to 5.85 mug g(-1) fresh weight (FW) after 48 h. This level of SA had no visible phytotoxic effects. Total SA content (free SA + SA-glucose conjugate) increased to 108 mug g(-1) FW after 48 h. Concomitant with elevated SA levels, expression of the tomato pathogenesis-related (PR)-1B gene was strongly induced within 24 h of the addition of 200 muM SA. PR-1B expression was still evident after 48 h; however, PR-1B induction was not observed in plants not receiving SA treatment. Challenge inoculation of SA-treated tomato plants using conidia of A. solani resulted in 83% fewer lesions per leaf and a 77% reduction in blighted leaf area as compared with control plants not receiving SA. Our data indicate that root feeding 200 muM SA to tomato plants can (i) significantly elevate foliar SA levels, (ii) induce PR-1B gene expression, and (iii) activate SAR that is effective against A. solani.

  9. Sensivity of Jordanian Isolates of Alternaria solani to Manchotane

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    K.I. Al-Mughrabi

    2004-04-01

    Full Text Available Early blight of potato, caused by Alternaria solani, poses a significant risk to potato crops worldwide. Fifty A. solani isolates representing a population were collected from the Jordan Valley, purified, and tested for their sensitivity to the fungicide mancothane. The isolates were tested against a series of concentrations of 0, 0.1, 1, 10, 100, and 1000 mg mancothane ml-1 in 5% sodium dodecyl sulfate (SDS. Some A. solani isolates tolerated up to 1000 mg mancothane ml-1. Isolates treated with the various concentrations were divided into 5 groups based on the percentage of A. solani growth achieved despite treatment: group 1 comprised isolates with mycelial growth of 0.1– 20.9%; group 2, 21–40.9%; group 3, 41–60.9%; group 4, 61–80.9%; and group 5, 81–100%. Ninety-seven percent of all isolates grew at 0.1 mg mancothane ml-1, 94% at 1 mg ml-1, 86% at 10 mg ml-1, 66% at 100 mg ml-1, and 16% at 1000 mg ml-1. Isolates appeared to be distributed normally at 10 mg mancothane ml-1. Eight isolates were highly resistant to mancothane and grew even at the highest test concentration. An A. solani population collected from potato fields in the Jordan Valley exhibited a moderate level of resistance to mancothane. Growers should be careful and vigilant when using this fungicide to control early blight.

  10. Effects of ozone on conidiophores and conidia of Alternaria solani

    Energy Technology Data Exchange (ETDEWEB)

    Rich, S.; Tomlinson, H.

    1968-04-01

    Ozone at 0.1 ppm for 4 hr or at 1.0 ppm for 2 hr stopped elongation of conidiophores of Alternaria solani, caused their apical cells to swell, and often collapsed the cell wall at their tips. These conidiophores began to elongate again when they were removed from ozone and exposed to light to prevent sporulation. Usually the collapsed end wall was sloughed, and the new cells often grew at an angle to the original axis of the conidiophore. Sometimes breaks appeared in the pigmented layers of the walls of the swollen cells. Ozone-damaged conidiophores, given the necessary dark period, sporulated normally. If sporulating cultures were exposed to 1.0 ppm ozone for 30 min, the conidia began to germinate while still attached to the conidiophores. Conidiophores treated with a subtoxic dose of a sulfhydryl-binding reagent (..cap alpha..-iodoacetamide) became more susceptible to ozone. Exposure to pure oxygen at either 1 or 4 atm pressure for 4 hr caused no visible damage to conidiophores of A. solani.

  11. Follicular cell differentiation in polytrophic ovaries of a moth midge, Tinearia alternata.

    Science.gov (United States)

    Mazurkiewicz, Marta; Kubrakiewicz, Janusz

    2008-01-01

    Dipteran ovaries consist of structural-functional units termed egg chambers. Each egg chamber is composed of a cluster of germ cells enveloped by a simple somatic follicular epithelium. With the progress of oogenesis, initially an almost uniform population of follicular cells (FCs) becomes diversified into a few subgroups, which significantly differ in their function and behaviour. From the extensive genetic and molecular studies on Drosophila it became evident that the mode of diversification of FCs and the interactions between distinct FC subpopulations and the germ-line cells are essential for a proper course of oogenesis and the generation of oocyte/embryo polarity. Recent comparative studies showed that major dipteran lineages may significantly differ in the mode of FC differentiation. The most essential difference occurs in the ability of the FCs to undertake migrations within the egg chamber. In contrast to long distance, invasive migrations characteristic of distinct FC subgroups in the egg chambers of the most derived flies (Brachycera), including Drosophila, the FCs in the ovaries of more ancestral Nematocera lack migratory activity and change their location only within the epithelial layer. Comparative analyses indicate that the FCs in the representatives of particular evolutionary lineages within Nematocera may differ in their behaviour during oogenesis. In this report we describe the FC differentiation pathway in the egg chambers of a moth midge, T. alternata (Psychodomorpha). Comparison with representatives of craneflies (Nematocera: Polyneura) showed that differences in the behaviour of FCs and in the number of FC subpopulations between Polyneura and Psychodomorpha, may depend on different oogenesis dynamics. In spite of the observed differences, some functional homologies between distinct subsets of the FCs in dipteran ovaries are postulated.

  12. Dehydrin-like proteins in the necrotrophic fungus Alternaria brassicicola have a role in plant pathogenesis and stress response.

    Science.gov (United States)

    Pochon, Stéphanie; Simoneau, Philippe; Pigné, Sandrine; Balidas, Samuel; Bataillé-Simoneau, Nelly; Campion, Claire; Jaspard, Emmanuel; Calmes, Benoît; Hamon, Bruno; Berruyer, Romain; Juchaux, Marjorie; Guillemette, Thomas

    2013-01-01

    In this study, the roles of fungal dehydrin-like proteins in pathogenicity and protection against environmental stresses were investigated in the necrotrophic seed-borne fungus Alternaria brassicicola. Three proteins (called AbDhn1, AbDhn2 and AbDhn3), harbouring the asparagine-proline-arginine (DPR) signature pattern and sharing the characteristic features of fungal dehydrin-like proteins, were identified in the A. brassicicola genome. The expression of these genes was induced in response to various stresses and found to be regulated by the AbHog1 mitogen-activated protein kinase (MAPK) pathway. A knock-out approach showed that dehydrin-like proteins have an impact mainly on oxidative stress tolerance and on conidial survival upon exposure to high and freezing temperatures. The subcellular localization revealed that AbDhn1 and AbDhn2 were associated with peroxisomes, which is consistent with a possible perturbation of protective mechanisms to counteract oxidative stress and maintain the redox balance in AbDhn mutants. Finally, we show that the double deletion mutant ΔΔabdhn1-abdhn2 was highly compromised in its pathogenicity. By comparison to the wild-type, this mutant exhibited lower aggressiveness on B. oleracea leaves and a reduced capacity to be transmitted to Arabidopsis seeds via siliques. The double mutant was also affected with respect to conidiation, another crucial step in the epidemiology of the disease.

  13. Dehydrin-like proteins in the necrotrophic fungus Alternaria brassicicola have a role in plant pathogenesis and stress response.

    Directory of Open Access Journals (Sweden)

    Stéphanie Pochon

    Full Text Available In this study, the roles of fungal dehydrin-like proteins in pathogenicity and protection against environmental stresses were investigated in the necrotrophic seed-borne fungus Alternaria brassicicola. Three proteins (called AbDhn1, AbDhn2 and AbDhn3, harbouring the asparagine-proline-arginine (DPR signature pattern and sharing the characteristic features of fungal dehydrin-like proteins, were identified in the A. brassicicola genome. The expression of these genes was induced in response to various stresses and found to be regulated by the AbHog1 mitogen-activated protein kinase (MAPK pathway. A knock-out approach showed that dehydrin-like proteins have an impact mainly on oxidative stress tolerance and on conidial survival upon exposure to high and freezing temperatures. The subcellular localization revealed that AbDhn1 and AbDhn2 were associated with peroxisomes, which is consistent with a possible perturbation of protective mechanisms to counteract oxidative stress and maintain the redox balance in AbDhn mutants. Finally, we show that the double deletion mutant ΔΔabdhn1-abdhn2 was highly compromised in its pathogenicity. By comparison to the wild-type, this mutant exhibited lower aggressiveness on B. oleracea leaves and a reduced capacity to be transmitted to Arabidopsis seeds via siliques. The double mutant was also affected with respect to conidiation, another crucial step in the epidemiology of the disease.

  14. A compatible interaction of Alternaria brassicicola with Arabidopsis thaliana ecotype DiG: evidence for a specific transcriptional signature

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    Gepstein Shimon

    2009-03-01

    Full Text Available Abstract Background The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG, which is considered sensitive to A. brassicicola. Results We show that the interaction has the characteristics of a compatible one, with expanding rather than limited lesions. To ask whether DiG is merely more sensitive to the pathogen or, rather, interacts in distinct manner, we identified genes whose regulation differs between Col-0 and DiG challenged with A. brassicicola. Suppression subtractive hybridization was used to identify differentially expressed genes, and their expression was verified using semi-quantitative PCR. We also tested a set of known defense-related genes for differential regulation in the two plant-pathogen interactions. Several known pathogenesis-related (PR genes are up-regulated in both interactions. PR1, and a monooxygenase gene identified in this study, MO1, are preferentially up-regulated in the compatible interaction. In contrast, GLIP1, which encodes a secreted lipase, and DIOX1, a pathogen-response related dioxygenase, are preferentially up-regulated in the incompatible interaction. Conclusion The results show that DiG is not only more susceptible, but demonstrate that its interaction with A. brassicicola has a specific transcriptional signature.

  15. Synergistic estrogenic effects of Fusarium and Alternaria mycotoxins in vitro.

    Science.gov (United States)

    Vejdovszky, Katharina; Hahn, Kathrin; Braun, Dominik; Warth, Benedikt; Marko, Doris

    2017-03-01

    Mycotoxins are toxic secondary metabolites formed by various fungal species that are found as natural contaminants in food. This very heterogeneous group of compounds triggers multiple toxic mechanisms, including endocrine disruptive potential. Current risk assessment of mycotoxins, as for most chemical substances, is based on the effects of single compounds. However, concern on a potential enhancement of risks by interactions of single substances in naturally occurring mixtures has greatly increased recently. In this study, the combinatory effects of three mycoestrogens were investigated in detail. This includes the endocrine disruptors zearalenone (ZEN) and α-zearalenol (α-ZEL) produced by Fusarium fungi and alternariol (AOH), a cytotoxic and estrogenic mycotoxin formed by Alternaria species. For evaluation of effects, estrogen-dependent activation of alkaline phosphatase (AlP) and cell proliferation were tested in the adenocarcinoma cell line Ishikawa. The estrogenic potential varied among the single substances. Half maximum effect concentrations (EC50) for AlP activation were evaluated for α-ZEL, ZEN and AOH as 37 pM, 562 pM and 995 nM, respectively. All three mycotoxins were found to act as partial agonists. The majority of binary combinations, even at very low concentrations in the case of α-ZEL, showed strong synergism in the AlP assay. These potentiating phenomena of mycotoxin mixtures highlight the urgent need to incorporate combinatory effects into future risk assessment, especially when endocrine disruptors are involved. To the best of our knowledge, this study presents the first investigation on synergistic effects of mycoestrogens.

  16. Cutaneous infection with Alternaria triticina in a Bilateral lung transplant recipient.

    Science.gov (United States)

    González-Vela, M C; Armesto, S; Unda-Villafuerte, F; Val-Bernal, J F

    2014-10-01

    We report the case of a 60-year-old man who was receiving immunosuppressive therapy for a bilateral lung transplant and presented with a crusted, violaceous plaque on the left hand. Based on histopathology and microbiological culture the patient was diagnosed with infection by Alternaria species. Treatment with itraconazole led to complete resolution of the skin lesion. Forty months later he developed four reddish, nodular, skin lesions on the left leg. Analysis of a biopsy from one of these lesions using histopathologic and molecular techniques identified a mold that shared 98% homology with a strain of Alternaria triticina. Alternaria species belong to a group of dematiaceous fungi that cause opportunistic infections in humans. The incidence of these infections is increasing, mainly in transplant centers. To the best of our knowledge, this is the first reported case of a human infection caused by A. triticina. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

  17. Alternaria and Fusarium in Norwegian grains of reduced quality - a matched pair sample study

    DEFF Research Database (Denmark)

    Kosiak, B.; Torp, M.; Skjerve, E.;

    2004-01-01

    The occurrence and geographic distribution of species belonging to the genera Alternaria and Fusarium in grains of reduced and of acceptable quality were studied post-harvest in 1997 and 1998. A total of 260 grain samples of wheat, barley and oats was analysed. The distribution of Alternaria...... and Fusarium spp. varied significantly in samples of reduced quality compared with acceptable samples. Alternaria spp. dominated in the acceptable samples with A. infectoria group as the most frequently isolated and most abundant species group of this genus while Fusarium spp. dominated in samples of reduced...... quality. The most frequently isolated Fusarium spp. from all samples were F avenaceum, E poae, F culmorum and E tricinctum. Other important toxigenic Fusarium spp. isolated were F graminearum and E equiseti. The infection levels of F graminearum and F culmorunt were significantly higher in the samples...

  18. Identification of Alternaria isolates from America soybean%美国大豆中链格孢的分离鉴定研究

    Institute of Scientific and Technical Information of China (English)

    冉俊祥; 肖杰文; 杨占臣; 刘月廉

    2011-01-01

    本文通过对美国进境大豆病害分离,共得到36个菌株,并对其中5株链格孢菌进行了形态学和分子生物学鉴定(其中2株),确认了它们分别是细极链格孢(Alternaria tenuissima(Kunze)Wiltshire)、樱桃链格孢(Alternaria cerasi Potebnia)、苘麻链格孢(Alternaria abutilonis(Speg.).Schwarze)、百日菊链格孢(Alternaria zinniae H.Pape)、落葵链格孢(Alternaria basellae T.Y.Zhang).本研究证实了美国大豆中链格孢菌的多样性,不仅充实了正在构建的大豆病害数据库和菌种资源库,也可为港口的植物检疫工作提供借鉴.%In this article, 36 separate strains from America soybean were obtained, and five Alternaria isolates were identified by morphological and molecular biology method, which are Alternaria tenuissima (Kunze) Wiltshire, Alternaria cerasi Potebnia, Alternaria abutilonis ( Speg. ) Schwarze, Alternaria zinniae H. Pape and Alternaria basellae T. Y. Zhang, respectively. It proved that Alternaria had rich diversity in America soybean , and it can not only enrich the soybean databank and strain resource , but also provide reference for plant quarantine.

  19. Development of a Semi-nested PCR-Based Method for Specific and Rapid Detection of Alternaria solani Causing Potato Early Blight in Soil.

    Science.gov (United States)

    Gu, Qing; Yang, Zhi-Hui; Zhao, Dong-Mei; Zhang, Dai; Wang, Qian; Ma, Li-Song; Zhu, Jie-Hua

    2017-09-01

    Early blight, caused by Alternaria solani, is one of the most devastating diseases of potato that causes severe yield loss worldwide. The infected potato debris existed in the soil serve as the initial infection sources for the next growing potato. Current identification of A. solani in soil relies primarily on cultural and morphological characteristics, which are time-consuming and inaccurate. In this study, a semi-nested PCR method was developed using primers based on internal transcribed spacer region that is specific to A. solani. 20 isolates including 6 Alternaria species and 10 other species of common potato pathogens were used to examine the specificity of the primers. The primer set ptAsQ-F/ptAs-R was highly specific to A. solani, as a product of 251 bp was amplified only from A. solani isolates and no amplification signal was observed from other tested species. The sensitivity of this method determined using A. solani genomic DNA was 10 fg. This PCR assay was also successfully employed to detect A. solani in soil with the detection sensitivity of one conidia spore in 0.5 g of soil. To the best of our knowledge, this is the first report of molecular detection of A. solani in soil, which provides a useful tool for early and rapid detection of early blight in soil before next growing season.

  20. 布替奈芬体外抗眼部致病真菌活性研究%Activity of butenafine against ocular pathogenic filamentous fungi in vitro

    Institute of Scientific and Technical Information of China (English)

    徐岩; 庞广仁; 赵东卿; 高传文; 周路坦; 孙声桃; 王丙亮; 陈祖基

    2010-01-01

    Objective To investigate antifungal activity of butenafine in comparison with that of natamycin, amphotericin B and fluconazole against ocular pathogenic filmentous fungi in vitro.Methods It was an experimental study.Susceptibility tests were performed against 260 isolates of ocular pathogenic filmentous fungi by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute (CLSI) M38-A document The isolates included Fusarium spp.(136) , Aspergillus spp.(98), Alternaria alternata (9), Curmdaria lunata (3), and unusual ocular pathogens (14).Final concentration ranged from 0.008 to 16.000 mg/L for butenafine, from 0.031 to 16.000 mg/L for amphotericin B and natamycin, and from 0.5 to 256.0 mg/L for fluconazole.Following incubation at 35 ℃ for 48 h, minimal inhibitory concentration (MIC) was determined according to the CLSI M38-A document For amphotericin B and natamycin, the MIC was defined as the lowest drug concentration that prevented any discernible growth.For butenafine and fluconazole, the MIC was defined as the lowest concentration in which an approximately 75% reduction compared to the growth of the control was observed.Candida parapsilosis ATCC22019 was used as quality control strains to validated the results.Mean MIC and MIC range, the MIC at which 50% of the isolates tested were inhibited (MIC_(50)) and the MIC at which 90% of the isolates tested were inhibited (MIC_(90)) , were provided for all the isolates tested by using descriptive statistical analysis with the statistical SPSS package (version 13.0).Results MIC_(90) of butenafine, natamycin, amphotericin B and fluconazole were 4,8,2 and 512 mg/L for Fusarium spp., respectively; 0.063, 32.000, 2.000 and 256.000 mg/L for Aspergillus spp., respectively; 0.5, 8.0, 2.0 and 128.0 mg/L for Alternaria alternat, respectively; 0.125, 2.000, 0.500 and 4.000 mg/L for Curvularia lunata, respectively; and 1,4,1 and 256 mg/L for unusual ocular

  1. Fungistatic activity of Zanthoxylum rhoifolium Lam. bark extracts against fungal plant pathogens and investigation on mechanism of action in Botrytis cinerea.

    Science.gov (United States)

    Carotenuto, Gennaro; Carrieri, Raffaele; Tarantino, Paola; Alfieri, Mariaevelina; Leone, Antonella; De Tommasi, Nunziatina; Lahoz, Ernesto

    2015-01-01

    Plant-derived compounds are emerging as an alternative choice to synthetic fungicides. Chloroform-methanol extract, obtained from the bark of Zanthoxylum rhoifolium, a member of Rutaceae, showed a fungistatic effect on Botrytis cinerea, Sclerotinia sclerotiorum, Alternaria alternata, Colletotrichum gloeosporioides and Clonostachys rosea, when added to the growth medium at different concentrations. A fraction obtained by gel separation and containing the alkaloid O-Methylcapaurine showed significant fungistatic effect against B. cinerea and S. sclerotiorum, two of the most destructive phytopathogenic fungi. The underlying mechanism of such an inhibition was further investigated in B. cinerea, a fungus highly prone to develop fungicide resistance, by analysing the expression levels of a set of genes (BcatrB, P450, CYP51 and TOR). O-Methylcapaurine inhibited the expression of all the analysed genes. In particular, the expression of BcatrB gene, encoding a membrane drug transporter involved in the resistance to a wide range of xenobiotic compounds, was strongly inhibited (91%).

  2. Overexpression of the tomato asc-1 gene mediates high insensitivity to AAL toxins and fumonisin B-1 in tomato hairy roots and confers resistance to Alternaria alternata f. sp lycopersici in Nicotiana umbratica plants

    NARCIS (Netherlands)

    Brandwagt, BF; Kneppers, TJA; Nijkamp, HJJ; Hille, J

    2002-01-01

    The sphinganine-analog mycotoxins (SAMs) fumonisin B-1 and AAL toxins are inhibitors of eukaryotic sphinganine N-acyltransferase in vitro. Treatment of eukaryotes with SAMs generally results in an accumulation of sphingoid base precursors and a depletion of complex sphingolipids. The asc,asc genotyp

  3. Overexpression of the Tomato Asc-1 Gene Mediates High Insensitivity to AAL Toxins and Fumonisin B1 in Tomato Hairy Roots and Confers Resistance to Alternaria alternata f. sp. lycopersici in Nicotiana umbratica Plants

    NARCIS (Netherlands)

    Brandwagt, Bas F.; Kneppers, Tarcies J.A.; Nijkamp, H. John J.; Hille, Jacques

    2002-01-01

    The sphinganine-analog mycotoxins (SAMs) fumonisin B1 and AAL toxins are inhibitors of eukaryotic sphinganine N-acyltransferase in vitro. Treatment of eukaryotes with SAMs generally results in an accumulation of sphingoid base precursors and a depletion of complex sphingolipids. The asc,asc genotype

  4. Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Mogensen, Jesper Mølgaard; Thrane, Ulf

    2009-01-01

    A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA whe...

  5. Meteorological and agricultural effects on airborne Alternaria and Cladosporium spores and clinical aspects in Valladolid (Spain).

    Science.gov (United States)

    Reyes, Estefanía Sánchez; de la Cruz, David Rodríguez; Merino, Ma Eugenia Sanchís; Sánchez, José Sánchez

    2009-01-01

    The aeropalynological monitoring was carried out from 1 February 2005-31 January 2007. The total number of spores collected during the main spore season (MSS) in 2005 was 4,500 for Alternaria and 93,744 in the case of Cladosporium, whereas in 2006 values were increased (8,385 for Alternaria and 150,144 for Cladosporium), reaching the maximum concentrations on 18 July and 17 June 2006 with 344 and 5,503 spores, respectively. The influence of the main meteorological parameters on spore concentrations was studied, resulting in a positive correlation with temperature. Rainfall, relative humidity and frequency of calms obtained negative correlations in the case of Alternaria, and positive for Cladosporium, the total daily hours of sunshine having an inverse influence on them. The intra-diurnal pattern was very similar for both genera, with a greater representation towards the central hours of the day and at night. Finally, some clinical aspects for the Alternaria spore type were analyzed, with a low percentage of sensitized patients though (9.5%). Only one patient showed positive skin test reaction to Cladosporium.

  6. Alternaria fungal dermatitis in a free-ranging javelina (Pecari tajacu).

    Science.gov (United States)

    Shender, Lisa A; Gerhold, Rick; Sanchez, Susan; Keel, M Kevin

    2011-07-01

    We report a javelina from Pinal County, Arizona, USA, with severe fungal dermatitis and cellulitis. Extreme emaciation and rostral disfiguration, including left-lateral displacement of the nasal planum, justified euthanasia. A pus-filled tract within the rostrum was observed. Histopathology revealed granulomatous inflammation with hyphae morphologically consistent with Alternaria sp. isolated by culture.

  7. A polyphasic approach for the characterization of endophytic Alternaria strains isolated from grapevines

    DEFF Research Database (Denmark)

    Polizzotto, Rachele; Andersen, Birgitte; Martini, Marta

    2012-01-01

    A polyphasic approach was set up and applied to characterize 20 fungal endophytes belonging to the genus Alternaria, recovered from grapevine in different Italian regions.Morphological, microscopical, molecular and chemical investigations were performed and the obtained results were combined in a...

  8. Biological control of Alternaria radicina in seed production of carrots with Ulocladium atrum

    NARCIS (Netherlands)

    Köhl, J.; Langerak, C.J.; Meekes, E.T.M.; Molhoek, W.M.L.

    2004-01-01

    Black rot of carrots is caused by seed-borne Alternaria radicina. Biological control of seed infestation by treatments applied to plants in flower during seed production with the fungal antagonist Ulocladium atrum was investigated in laboratory and field experiments resulting in a reduction of seed

  9. Assessment of early blight (Alternaria solani) resistance in tomato using a droplet inoculation method

    NARCIS (Netherlands)

    Chaerani, R.; Groenwold, R.; Stam, P.; Voorrips, R.E.

    2006-01-01

    A droplet inoculation method was used for evaluation of tomato resistance to early blight, a destructive foliar disease of tomato caused by Alternaria solani (Ellis and Martin) Sorauer. In this test method, leaflets are inoculated with small droplets of a spore suspension in either water or a 0.1% a

  10. QTL identification for early blight resistance (Alternaria solani) in a Solanum lycopersicum x S. arcanum cross.

    NARCIS (Netherlands)

    Chaerani, R.; Smulders, M.J.M.; Linden, van der C.G.; Vosman, B.; Stam, P.; Voorrips, R.E.

    2007-01-01

    Alternaria solani (Ellis and Martin) Sorauer, the causal agent of early blight (EB) disease, infects aerial parts of tomato at both seedling and adult plant stages. Resistant cultivars would facilitate a sustainable EB management. EB resistance is a quantitatively expressed character, a fact that ha

  11. Characterization of Alternaria isolates and reaction of potato genotypes to early blight

    Directory of Open Access Journals (Sweden)

    Thayssa Vilela Miguel Alvarenga

    Full Text Available ABSTRACT: Early blight is one of the most important fungal diseases of potato. The objective of this study was to evaluate the in vitro reaction of potato genotypes to the severity of early blight and compare the species Alternaria solani and Alternaria grandis , etiologic agents of disease, through the evaluation of physiological characteristics. Twenty-two genotypes of the Potato Breeding Program at UFLA, two cultivars, Aracy and Bintje, patterns of resistance and susceptibility, respectively were evaluated. For inoculation, three isolates of A. grandis and two isolates of A. solani were used. Plantlets obtained in vitro were inoculated with a 5mm diameter mycelial disk of isolates Alternaria spp. of. These were incubated in severity and classified according to the rating scale. Isolates of Alternaria spp. were evaluated for mycelial growth index (MGI and for formation of mycelial compatibility groups (MCG. The methodology for evaluating the in vitro reaction of genotypes to severity of early blight was efficient for both isolates. The isolates of A. solani and A. grandis were similar in their aggressiveness. The isolates of A. grandis MGI's had higher, and therefore mycelium grew faster when compared to those isolated from A. solani . The occurrence of mycelial compatibility among isolates of A. solani and A. grandis indicated the possible occurrence of parasexual cycle.

  12. Identification and characterization of cDNA sequences encoding the HIS3 and LEU2 genes of the fungus Alternaria tenuissima

    Institute of Scientific and Technical Information of China (English)

    Ying Wan; Xuli Wang; Yun Huang; Dewen Qiu; Linghuo Jiang

    2008-01-01

    Alternaria tenuissima is a fungus widely present in the environment and could cause diseases in plants and humans.In this study,through a yeast genetic approach,cDNA sequences were isolated and characterized for the AtHIS3 and AtLEU2 genes.AtHIS3 cDNA encodes a protein of 238 amino acids,while AtLEU2 cDNA encodes a protein of 363 amino acids.Based on the phylogenetic analysis of amino acid sequences of AtHis3p and AtLeu2p,A.tenuissima is closely related to the plant pathogenic fungus Phaeosphaeria nodorum.This study provides two genetic markers for studies of functions of genes regulating development,morphology,and virulence of A.tenuissima.

  13. Modification of primary and secondary metabolism of potato plants by nitrogen application differentially affects resistance to Phytophthora infestans and Alternaria solani.

    Science.gov (United States)

    Mittelstrass, K; Treutter, D; Plessl, M; Heller, W; Elstner, E F; Heiser, I

    2006-09-01

    Potato plants ( SOLANUM TUBEROSUM L. cv. Indira) were grown at two levels of N supply in the greenhouse. Plants supplied with 0.8 g N per plant (high N variant) showed significantly increased biomass as compared to plants without additional N fertilisation (low N variant). C/N ratio was lower and protein content was higher in leaves of the high N variant. The concentration of chlorogenic acids and flavonols was significantly lower in leaves from the high N variant. Whereas resistance to ALTERNARIA SOLANI increased when plants were supplied with additional nitrogen, these plants were more susceptible to PHYTOPHTHORA INFESTANS. After infection with both pathogens, we found a strong induction of p-coumaroylnoradrenaline and p-coumaroyloctopamine, which are identified for the first time in potato leaves and are discussed as resistance factors of other solanaceous plants.

  14. Transcriptional Responses of the Bdtf1-Deletion Mutant to the Phytoalexin Brassinin in the Necrotrophic Fungus Alternaria brassicicola

    Directory of Open Access Journals (Sweden)

    Yangrae Cho

    2014-07-01

    Full Text Available Brassica species produce the antifungal indolyl compounds brassinin and its derivatives, during microbial infection. The fungal pathogen Alternaria brassicicola detoxifies brassinin and possibly its derivatives. This ability is an important property for the successful infection of brassicaceous plants. Previously, we identified a transcription factor, Bdtf1, essential for the detoxification of brassinin and full virulence. To discover genes that encode putative brassinin-digesting enzymes, we compared gene expression profiles between a mutant strain of the transcription factor and wild-type A. brassicicola under two different experimental conditions. A total of 170 and 388 genes were expressed at higher levels in the mutants than the wild type during the infection of host plants and saprophytic growth in the presence of brassinin, respectively. In contrast, 93 and 560 genes were expressed, respectively, at lower levels in the mutant than the wild type under the two conditions. Fifteen of these genes were expressed at lower levels in the mutant than in the wild type under both conditions. These genes were assumed to be important for the detoxification of brassinin and included Bdtf1 and 10 putative enzymes. This list of genes provides a resource for the discovery of enzyme-coding genes important in the chemical modification of brassinin.

  15. Selection and differentiation of Bacillus spp. Antagonistic to Fusarium oxysporum f.sp. lycopersici and Alternaria solani infecting Tomato.

    Science.gov (United States)

    Shanmugam, Veerubommu; Atri, Kamini; Gupta, Samriti; Kanoujia, Nandina; Naruka, Digvijay Singh

    2011-03-01

    Antagonistic Bacillus spp. displaying in vitro production of siderophore, chitinase, and β-1,3-glucanase were identified from dual culture assays. In independent greenhouse studies, seed bacterization and soil application of Bacillus atrophaeus S2BC-2 challenge inoculated with Fusarium oxysporum f.sp. lycopersici (FOL) and Alternaria solani (AS) recorded low percent disease index of 25.3 and 28.7, respectively, over nonbacterised pathogen control (44.3 and 56.4). The low disease incidence corroborated with tomato growth promotion with high vigor index (8,041.2) and fresh plant weight (82.5 g) on challenge inoculation with FOL. Analysis of root and leaf samples in rhizobacterial treatment challenged with FOL and AS revealed maximum induction of chitinase (1.9 and 1.7 U/mg of protein, respectively) and β-1,3-glucanase (23.5 and 19.2 U/mg of protein, respectively). In native gel activity assays, the rhizobacterial treatment on challenge inoculation strongly expressed three high intensity PO isoforms along with one low intensity isoform. In studies on genetic diversity of the Bacillus strains by repetitive extragenomic palindromic-polymerase chain reaction (REP-PCR) and amplified rDNA restriction analysis (ARDRA) patterns, ARDRA was more highly discriminant than REP-PCR and allowed grouping of the strains and differentiation of the antagonistic strains from other isolates.

  16. Occurrence of root parsley pathogens inhabiting seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available The studies on root parsley pathogens inhabiting seeds were conducted during 1981-1988 and in 1993. Filter paper method with prefreezing and keeping under light was used. Each test sample comprised 500 seeds. Pathogenicity of collected fungal isolates was tested following two laboratory methods. 238 seed samples were studied. 18 fungal species were found but only 7 proved to be important pathogens of root parsley. The most common inhabitants of root parsley seeds were Alternaria spp. A.allernata occurred on 74,8% of seeds but only a few isolates showed to be slightly pathogenic while A.petroselini and A.radicina were higly pathogenic and inhabited 11,4 and 4,2% of seeds, respectively. The second group of important pathogens were species of Fusarium found on 3,9% of seeds. F.avenaceum dominated as it comprised 48% of Fusarium isolates, the next were as follow: F.culmorum - 20%, F.equiseti - 15%, F.solani - 8%, F.oxysporum - 7% and F.dimerum -2%. Some fungi like Botrytis cinerea, Septoria petroselini and Phoma spp. inhabited low number of seeds, respectively O,4; 0,5 and 0,8%, but they were highly pathogenic to root parsley. The fungi: Bipolaris sorokiniana, Drechslera biseptata, Stemphylium botryosum and Ulocludium consortiale showed slight pathogenicity. They were isolated from 3,8% of seeds.

  17. 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

  18. Monitoring and assessment of airborne Cladosporium Link and Alternaria Nées spores in Sivrihisar (Eskisehir), Turkey.

    Science.gov (United States)

    Erkara, Ismuhan Potoglu; Ilhan, Semra; Oner, Setenay

    2009-01-01

    The spores of Cladosporium spp. and Alternaria spp., commonly described as the most allergenic spores, were collected by means of Durham gravimetric sampler from the Sivrihisar (Eskisehir) atmosphere throughout 2005 to 2006. The weekly variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 6,198 spores belonging to Cladosporium spp. and Alternaria spp. were recorded. Of these spores, 2,969 were identified in 2005 and 3,229 in 2006. While 69.55% of the total spores were those of Cladosporium spp., 30.45% were Alternaria spp. Relationships between airborne fungal spore presence and weather conditions were examined statistically. A Shapiro-Wilk test revealed that the airborne spores of Cladosporium spp. and Alternaria spp. had a normal distribution. Following this, Chi-square test, t test and Pearson correlation analysis were performed. The effects of temperature and relative humidity on the spore numbers of Cladosporium spp. and Alternaria spp. were significant according to the month in which they were collected (p < 0.01). The spore concentrations of each species reached to their highest levels in June 2006.

  19. Overexpression of a Gene Encoding a Catabolite Repression Element in Alternaria citri Causes Severe Symptoms of Black Rot in Citrus Fruit.

    Science.gov (United States)

    Katoh, H; Ohtani, K; Yamamoto, H; Akimitsu, K

    2007-05-01

    ABSTRACT A gene (AcCreA) encoding a catabolite repression element (CreA) with (two zinc fingers of the Cys(2)His(2) type was isolated from the postharvest fungal pathogen Alternaria citri. The AcCreA overexpression mutant AcOEC2 of A. citri showed normal growth on pectin medium and on segments of peel or the juice sac area from citrus fruit. Production of endopolygalacturonase, an essential virulence factor of this pathogen, was similar in AcOEC2 and the wild type in pectin-containing media. However, addition of glucose to the medium showed that carbon catabolite repression of endopolygalacturonase gene (Acpg1) expression, as well as endopolygalacturonase production, was lost in AcOEC2. The wild-type strain of A. citri causes rot mainly in the central axis of citrus fruit without development of rotting in the juice sac area; however, AcOEC2 caused severe black rot symptoms in both the central axis and juice sac areas. These results indicate that AcCreA-mediated catabolite repression controls the virulence or infection of this pathogen, and that the wild-type A. citri does not cause symptoms in the juice sac area due to carbon catabolite repression by sugars in the juice of the juice sac area.

  20. Degradation of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking.

    Science.gov (United States)

    Siegel, David; Feist, Michael; Proske, Matthias; Koch, Matthias; Nehls, Irene

    2010-09-01

    The stability of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking was investigated by model experiments using a spiked wholemeal wheat flour matrix. For alternariol and alternariol monomethyl ether, but not for altenuene, degradation products, formed through a sequence of hydrolysis and decarboxylation, could be identified in pilot studies. The simultaneous quantification of alternariol, alternariol monomethyl ether, altenuene, and the degradation products was achieved by a newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) multimethod. The obtained quantitative data indicate that the Alternaria mycotoxins are barely degraded during wet baking, while significant degradation occurs upon dry baking, with the stability decreasing in the order alternariol monomethyl ether>alternariol>altenuene. The novel degradation products could be detected after the wet baking of flour spiked with alternariol and in a sample survey of 24 commercial cereal based baking products.

  1. [Aerobiological study of Alternaria and Cladosporium conidia in the atmosphere of Almeria (SE Spain)].

    Science.gov (United States)

    Sabariego Ruiz, Silvia; Díaz de la Guardia Guerrero, Consuelo; Alba Sánchez, Francisca

    2004-09-01

    This study analysed the seasonal and intradiurnal behaviour of fungal spores from Alternaria and Cladosporium on air samples collected in the city of Almeria (SE Spain), as well as the influence that meteorological parameters have on the concentration of these type of spores. Aerobiological sampling was made during four years (1998-2001) using a Hirst-type volumetric spore trap. Spores of Alternaria and Cladosporium were detected throughout the year, reaching the highest concentrations from May to October. The diurnal patterns of these taxons reflected a presence similar of spores during a 24 h period, with values horary close to 4% of total sampling daily. The correlations show a positive association with temperature, hours of sunshine and accumulate rainfall, but negative with daily rainfall.

  2. Altering Conidial Dispersal of Alternaria solani by Modifying Microclimate in Tomato Crop Canopy.

    Science.gov (United States)

    Jambhulkar, Prashant Prakash; Jambhulkar, Nitiprasad; Meghwal, Madanlal; Ameta, Gauri Shankar

    2016-12-01

    Early blight of tomato caused by Alternaria solani, is responsible for severe yield losses in tomato. The conidia survive on soil surface and old dry lower leaves of the plant and spread when suitable climatic conditions are available. Macroclimatic study reveals that highest inoculum concentration of Alternaria spores appeared in May 2012 to 2013 and lowest concentration during January 2012 to 2013. High night temperature positively correlated and significantly (P solani conidial density, tomato leaf damage and microclimatic parameters as compar to tomato alone (T). Tomato-marigold intercropping-plastic mulching treatment (T + M + P) showed 35-39% reduction in disease intensity as compared to tomato alone. When intercropped with tomato, marigold served as barrier to conidial movement and plastic mulching prevented evapotranspiration and reduced the canopy RH that resulted in less germination of A. solani spores. Marigold intercropping and plastic mulching served successfully as physical barrier against conidial dissemination to diminish significantly the tomato foliar damage produced by A. solani.

  3. Role of micronutrients in defense to white rust and Alternaria blight infecting Indian mustard.

    Science.gov (United States)

    Rathi, A S; Singh, Dhiraj; Avtar, Ram; Kumar, Pawan

    2015-03-01

    Field experiments were carried out at Oilseeds Research Area of CCS Haryana Agricultural University, Hisar during rabi, 2008-09 to 2011-12 to find out the possible role of soil application of different micronutrients alone and in combinations in defense to white rust and Alternaria blight diseases in Indian mustard [Brassica juncea (L.) Czern & Coss.]. Among the sole application of micronutrients, minimum disease severity of both white rust (35.0%) and Alternaria blight (31.8%) was observed when S @ 40 kg ha in the form of Gypsum was applied as basal dose in the soil. When Gypsum was supplemented with Borax @10 kg ha(-1) or with ZnSO4 @15 kg ha(-1) the level of tolerance seems to be improved for both the diseases as compared to the sole treatment of each nutrient, i.e., ZnSO4 @ 15 kg/ha, Borax @ 10 kg ha' and Gypsum @ 250 kg ha(-1). Furthermore, minimum disease severity of both white rust (31.3 %) and Alternaria blight (26.3 %) was observed with soil application of ZnSO4 @ 15 kg ha(-1) + Borax @ 10 kg ha(-1) + Gypsum @250 kg ha(-1) as basal dose as compared to the severity of white rust (43.6%) and Alternaria blight (38.6%) in untreated check. Significant increase in seed yield (1612 kg ha(-1)) was also recorded in above mentioned treatment as compared to the yield (1337 kg ha(-1)) in untreated check. These findings will also be helpful in maintaining soil health and minimizing the losses due to both the fungal diseases for eco-friendly sustainability of Indian mustard.

  4. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities

    Directory of Open Access Journals (Sweden)

    Jingfeng Lou

    2016-03-01

    Full Text Available Abstract One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 µg/mL and median inhibitory concentration (IC50 values ranging from 16.00 to 38.27 µg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 µg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 µg/mL and 74.62 µg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.

  5. Alternariol 9-methyl ether from the endophytic fungus Alternaria sp. Samif01 and its bioactivities.

    Science.gov (United States)

    Lou, Jingfeng; Yu, Ruiting; Wang, Xiaohan; Mao, Ziling; Fu, Linyun; Liu, Yang; Zhou, Ligang

    2016-01-01

    One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75μg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27μg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18μg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17μg/mL and 74.62μg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.

  6. Effects of meteorological factors on the levels of Alternaria spores on a potato crop

    Science.gov (United States)

    Escuredo, Olga; Seijo, Maria Carmen; Fernández-González, Maria; Iglesias, Isabel

    2011-03-01

    Alternaria solani Soraeur produces early blight in Solanum tuberosum L., leading to significant agricultural losses. The current study was carried out on the extensive potato crop situated in north-western of Spain during 2007, 2008 and 2009. In this area potato crops are the most important source of income. In this work we used a Hirst-type volumetric spore-trap for the aerobiological monitoring of Alternaria spores. The highest spore concentrations were recorded during the 2009 cycle (10,555 spores), and the lowest concentrations were recorded during the 2008 cycle (5,471 spores). Over the 3 years of study, the highest concentrations were registered during the last stage of the crop. The aim of the study was to observe the influence of meteorological factors on the concentration of Alternaria spores, which can lead to serious infection and early blight. Prediction of the stages during which a crop is particularly vulnerable to infection allows for adjustment of the application of fungicide and is of environmental and agricultural importance. For this reason, we tested three models (P-Days, DD and IWP) to predict the first treatment and decrease the negative effect that these spores have on potato crops. The parameter that showed the most significant correlation with spore concentrations was minimum temperature. We used ARIMA (autoregressive integrated model of running mean) time-series models to determine the forecast. We considered weather data as predictor variables and the concentration of spores on the previous day as the fixed variable.

  7. The role of meteorological factors in determining the annual variation of Alternaria and Cladosporium spores in the atmosphere of Palencia, 1990 1992

    Science.gov (United States)

    Herrero, B.; Fombella-Blanco, M. A.; Fernández-González, D.; Valencia-Barrera, R. M.

    1996-09-01

    A study was made of the daily content of Alternaria and Cladosporium spores in the atmosphere in Palencia city (Spain) for three consecutive years 1990 1992. Alternaria and Cladosporium represented 55% of the total identified spores, presenting an annual distributional pattern of which the maximum values were reached in summer. Multiple regression analyses showed a positive correlation between minimum temperature and Cladosporium spore concentrations, while for Alternaria there was a positive correlation with maximum temperature and a negative correlation with precipitation. Duncan's multiple range test among means of Alternaria data indicated that winds coming from a northeasterly direction were associated with significantly higher concentrations the spores.

  8. 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.

  9. Biocontrol Potential of Streptomyces hydrogenans Strain DH16 toward Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

    Science.gov (United States)

    Manhas, Rajesh K.; Kaur, Talwinder

    2016-01-01

    Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v) of S. hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10%) and streptomycete cells significantly improved seed germination (75–80%) and vigor index (1167–1538). Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers. PMID:28018402

  10. Biocontrol Potential of Streptomyces hydrogenans strain DH16 Towards Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

    Directory of Open Access Journals (Sweden)

    Rajesh Kumari Manhas

    2016-12-01

    Full Text Available Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v of Streptomyces hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10% and streptomycete cells significantly improved seed germination (75-80% and vigour index (1167-1538. Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers.

  11. Biocontrol Potential of Streptomyces hydrogenans Strain DH16 toward Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus.

    Science.gov (United States)

    Manhas, Rajesh K; Kaur, Talwinder

    2016-01-01

    Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v) of S. hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10%) and streptomycete cells significantly improved seed germination (75-80%) and vigor index (1167-1538). Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers.

  12. Sensitization to Alternaria and Cladosporium in patients with respiratory allergy and outdoor counts of mold spores in Ankara atmosphere, Turkey.

    Science.gov (United States)

    Bavbek, Sevim; Erkekol, Ferda Oner; Ceter, Talip; Mungan, Dilşad; Ozer, Faruk; Pinar, Münevver; Misirligil, Zeynep

    2006-08-01

    Sensitization to Alternaria and Cladosporium has been reported to be 3% to 30% in European countries. However, in Turkey, there is limited data about the prevalence of sensitization to these molds and the intensity of the two mold spores in Ankara atmosphere. This study was designed to evaluate the sensitization to Alternaria and Cladosporium in patients with respiratory allergy in Ankara and also the concentration of the two molds in Ankara atmosphere. Allergic rhinitis and asthma patients living in Ankara were included in the study. Demographic and diagnostic data of the patients were recorded. A skin prick test with extracts supplied by three different laboratories was used to evaluate the sensitization to Alternaria and Cladosporium. Mold spores were measured using a Burkard 7-day recording volumetric spore trap in Ankara atmosphere during a year. Overall sensitization to the two molds was found to be 14.8%, and isolated Alternaria or Cladosporiumsensitization was 3%. Considering the positive reaction to at least one of the three suppliers, the sensitization rate was 11.9% and 8.1% for Alternaria and Cladosporium, respectively. Cochran's Q homogenization test demonstrated that the positive and negative reaction were not homogeneous among three laboratories. The total number of mold spores in Ankara atmosphere was 429,264 spores/m3 of which 75.5% and 6% were constituted by Cladosporium and Alternaria, respectively. The prevalence of Cladosporium and Alternaria sensitization in respiratory allergy patients is quite similar to European countries; however, our data indicate that commercial mold extracts should be standardized to establish the real sensitization rates. Additionally, considering the great numbers of these mold spores in Ankara atmosphere, long-term follow-up studies are needed to evaluate the relationship between the mold load and sensitization patterns.

  13. Resposta diferencial das cultivares de algodoeiro a Alternaria macrospora Differential response of cotton cultivars to Alternaria macrospora

    Directory of Open Access Journals (Sweden)

    Yeshwant Ramchandra Mehta

    2006-06-01

    Full Text Available Estudou-se a resposta diferencial de 32 cultivares comerciais do algodoeiro a A. macrospora em casa de vegetação. A inoculação foi realizada em plântulas de 20-25 dias de idade com 25 repetições, utilizando-se o delineamento experimental de blocos ao acaso. As cultivares foram agrupadas através de análise de Scott & Knott. Resistência completa não foi encontrada, sendo que todas as cultivares foram suscetíveis. Houve diferença entre reação de plantas da mesma cultivar. Não obstante, quando algumas plantas das cvs. BRS Antares e Fibermax 986, que mostraram resistência, foram inoculadas com mistura de nove isolados escolhidos ao acaso, as mesmas mantiveram sua resistência a esta mistura. Trabalhos futuros deverão ser realizados para encontrar fontes de resistência a este patógeno em outras espécies de Gossypium.The differential response of 32 commercial cotton cultivars to A. macrospora was studied under greenhouse conditions. Twenty to twentyfive days old plants were inoculated in 25 repetitions in a randomized block design. The cultivars were grouped using the Scott & Knott analysis. Complete resistance was not found and all cultivars were susceptible to the pathogen. Differential reaction within the plants of the same cultivar was observed. However, when some resistant plants of cultivars BRS Antares and Fibermax 986 were inoculated using a mixture of nine randomly selected isolates of A. macrospora, the plants maintained their resistance. Further research is necessary to find sources of resistance to this pathogen in other species of Gossypium.

  14. Hourly predictive artificial neural network and multivariate regression tree models of Alternaria and Cladosporium spore concentrations in Szczecin (Poland)

    Science.gov (United States)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2009-11-01

    A study was made of the link between time of day, weather variables and the hourly content of certain fungal spores in the atmosphere of the city of Szczecin, Poland, in 2004-2007. Sampling was carried out with a Lanzoni 7-day-recording spore trap. The spores analysed belonged to the taxa Alternaria and Cladosporium. These spores were selected both for their allergenic capacity and for their high level presence in the atmosphere, particularly during summer. Spearman correlation coefficients between spore concentrations, meteorological parameters and time of day showed different indices depending on the taxon being analysed. Relative humidity (RH), air temperature, air pressure and clouds most strongly and significantly influenced the concentration of Alternaria spores. Cladosporium spores correlated less strongly and significantly than Alternaria. Multivariate regression tree analysis revealed that, at air pressures lower than 1,011 hPa the concentration of Alternaria spores was low. Under higher air pressure spore concentrations were higher, particularly when RH was lower than 36.5%. In the case of Cladosporium, under higher air pressure (>1,008 hPa), the spores analysed were more abundant, particularly after 0330 hours. In artificial neural networks, RH, air pressure and air temperature were the most important variables in the model for Alternaria spore concentration. For Cladosporium, clouds, time of day, air pressure, wind speed and dew point temperature were highly significant factors influencing spore concentration. The maximum abundance of Cladosporium spores in air fell between 1200 and 1700 hours.

  15. Conidia of Alternaria, allergy risk factor in Castilla-La Mancha Conidios de 'alternaria', factor de riesgo de alegria en Castilla-La Mancha

    Directory of Open Access Journals (Sweden)

    Silvia Sabariego Ruiz

    2007-12-01

    Full Text Available In this work study the seasonal behaviour of the conidia of Alternaria, as well as the main locations in the Castilla-La Mancha region where the levels of these conidia in the air may pose a risk of allergy for people who are sensitised to them. The study was conducted in 5 sampling stations belonging to the Castilla-La Mancha Aerobiological Network (Red Aerocam: Albacete, Ciudad Real, Cuenca, Guadalajara and Toledo, in 2008. The pollen traps and the sampling methodology used follow the guidelines of the Spanish Aerobiology Network (REA. Alternaria conidia are detected in the atmosphere of Castilla-La Mancha all year round, although the highest concentrations are obtained in May, June and July. The greatest annual concentrations are detected in the cities of Ciudad Real, Toledo y Guadalajara with 5.624 conidia, 4.527 conidia and 4.173 conidia respectively, followed by Albacete and Cuenca. Some locations sampled showed high maximum daily values on a considerable number of days: examples include the levels recorded in Ciudad Real on 20 March (722 conidia/m3, Toledo on 18 June (324 conidia/m3, and Guadalajara on 26 June (220 conidia/m3.En este trabajo se estudia el comportamiento estacional de los conidios de Alternaria en la atmósfera de Castilla-La Mancha, cuyo inte- rés se basa en que los niveles en el aire de estos conidios suponen un riesgo de alergia para las personas sensibilizadas a los mismos. El estudio se ha llevado a cabo en cinco estaciones de muestreo pertenecientes a la Red de Aerobiología de Castilla-La Mancha (Red Aerocam: Albacete, Ciudad Real, Cuenca, Guadalajara y Toledo, durante el año 2008. Los captadores utilizados y la metodología de muestreo siguen las directrices de la Red Española de Aerobiología (REA. Los conidios de Alternaria se detectan en la atmósfera de Castilla-La Mancha durante todo el año, aunque los meses de mayores concentraciones se obtienen en mayo, junio y julio. Ciudad Real, Toledo y Guadalajara

  16. A Research on Control ofAlternaria Panax Whetz by Different Chinese Herbal Medicines%不同中药材对三七黑斑病病原Alternaria panax Whetz抑制作用研究

    Institute of Scientific and Technical Information of China (English)

    陈昱君; 王勇; 刘云芝; 杨建忠; 朱云飞

    2012-01-01

    The paper studies the control ofAlternaria Panax ginseng (Alternaria Panax whetz) byusingdifferent Chinese herbal medicines through antibacterial experiment and field resistance identification, screens out Chinese herbal medicines that can be mixed plant with Panax notoginseng such as Herba Lycopi, Kaempferia galanga L, Radix Ophiopogonis, Rhizoma Polygonati Odorati the results could provide the scientific basis for biodiversity control ofPanax notoginseng black spot disease.%通过不同中药材对黑斑病病原Alternaria panax Whetz.室内抑菌试验研究及病原田间致病性鉴定,筛选出可与三七混种的中药材品种泽兰、山萘、麦冬、玉竹。

  17. Atividades amilolítica e pectinolítica de Alternaria solani e a relação com a agressividade em tomateiro Amilolytic and pectinolytic activities of Alternaria solani and aggressiveness in tomato plants

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Marchi

    2006-09-01

    Full Text Available As atividades amilolítica e pectinolítica de 45 isolados de Alternaria solani, provenientes de diferentes hospedeiros, foram estimadas por meio da difusão enzimática em meio sólido específico e mensuração do halo de degradação do substrato. Todos os isolados degradaram pectina. Apenas 17 isolados apresentaram atividade amilolítica, sendo nove isolados provenientes de batateira. Somente o isolado AS18 se destacou como bom produtor de ambas as enzimas. Uma vez que a atividade pectinolítica foi mais evidente, avaliou-se a influência de pectinases na agressividade de A. solani ao tomateiro. Para isso, cinco isolados (2 de berinjela, 2 de tomateiro e 1 de batateira contrastantes quanto à produção de pectinases foram selecionados para testes em folíolos destacados e plantas inteiras. Quatro isolados foram utilizados no teste em folíolos destacados (AS6, AS7, AS12 e AS26, e constatou-se haver variabilidade patogênica. A correlação obtida entre o tamanho das lesões e a atividade pectinolítica foi de r = 0,963 (P = 0,087. Cinco isolados (AS6, AS7, AS12, AS25 e AS26 foram inoculados em plantas inteiras de tomate. Os isolados não diferiram quanto ao número de lesões/cm² de área foliar, porém variaram em agressividade. Houve correlação (r = 0,916; P = 0,042 entre a atividade de pectinases e o índice de doença, sugerindo possível papel para as enzimas pécticas durante a infecção de A. solani em tomateiro. É provável que as diferenças no perfil enzimático dos isolados estejam associadas ao hospedeiro original de onde os mesmos foram obtidos. Os resultados reforçaram evidências de especificidade por hospedeiro em populações de A. solani.Amilolytic and pectinolytic activities of 45 isolates of Alternaria solani from distinct hosts were investigated. Enzyme secretion was evaluated in glucose-free medium amended with pectin or starch as carbon source. All isolates degraded pectin. Only 17 isolates had amilolytic

  18. Enhanced resistance to Phytophthora infestans and Alternaria solani in leaves and tubers, respectively, of potato plants with decreased activity of the plastidic ATP/ADP transporter.

    Science.gov (United States)

    Conrath, Uwe; Linke, Christoph; Jeblick, Wolfgang; Geigenberger, Peter; Quick, W Paul; Neuhaus, H Ekkehard

    2003-05-01

    Recently, it has been reported that tubers of transgenic potato ( Solanum tuberosum L.) plants with decreased activity of the plastidic ATP/ADP transporter (AATP1) contain less starch, despite having an increased glucose level [P. Geigenberger et al. (2001) Plant Physiol 125:1667-1678]. The metabolic alterations correlated with enhanced resistance to the bacterium Erwinia carotovora. Here it is shown that transgenic potato tubers, possessing less starch yet increased glucose levels due to the expression of a cytoplasm-localized yeast invertase, exhibit drastic susceptibility to E. carotovora. In addition, it is demonstrated that AATP1 anti-sense tubers show an increased capacity to ward off the pathogenic fungus Alternaria solani. In contrast to AATP1 anti-sense tubers, the corresponding leaf tissue does not show changes in carbohydrate accumulation. However, upon elicitor treatment, AATP1 anti-sense leaves possess an increased capacity to release H(2)O(2) and activate various defence-related genes, reactions that are associated with substantially delayed appearance of disease symptoms caused by Phytophthora infestans. Grafting experiments between AATP1 anti-sense plants and wild-type plants indicate the presence of a signal that is generated in AATP1 rootstocks and primes wild-type scions for potentiated activation of cellular defence responses in leaves. Together, the results suggest that (i) the enhanced pathogen tolerance of AATP1 anti-sense tubers is not due to "high sugar resistance", (ii) the increased disease resistance of AATP1 anti-sense tubers is effective against different types of pathogen and (iii) a systemic signal induced by antisensing the plastidic ATP/ADP transporter in potato tubers confers increased resistance to pathogens.

  19. CONTROL OF Alternaria porri (E11 CIF. AND TOXIC EFFECT OF CAPTAFOL SPRAYING IN GARLIC (Allium sativum L. CONTROLE DE Alternaria porri (E11 Cif. E EFEITO FITOTÓXICO DE CAPTAFOL EM PULVERIZAÇÃO NA CULTURA DO ALHO (Allium sativum L.

    Directory of Open Access Journals (Sweden)

    Iraídes Fernandes Carneiro

    2007-09-01

    Full Text Available

    The objective of the present work was to verify the effect of the different concentrations of the captafol fungicide (0, 50, 100, 200 and 400 g.i.a./100 l of water, in the control of Alternaria porri (E11 Cif. and their toxic effects on plants, in two cultivars of garlic (Lavinia and Centenário. The results show that, for the cultivars tested, the fungicide, in the concentrations utilized, didn’t control the pathogen, and it didn’t show fitotoxicity.

    Com o objetivo de verificar o efeito do Captafol no controle de Alternaria porri (E11 Cif. na cultura do alho, e seus efeitos fitotóxicos nesta A1iácea, foi instalado um experimento nas dependências da Escola de Agronomia da Universidade Federal de Goiás, em Goiânia. O delineamento experimental foi de blocos ao acaso com parcelas subdivididas utilizando-se as cultivares Lavinia e Centenário, submetidas a pulverizações com o fungicida nas seguintes concentrações: 0, 50, 100, 200 e 400 gramas do princípio ativo por 100 litros de água. Os resultados indicam que, para as duas cultivares utilizadas, o Captafol não controlou o patógeno, nem se mostrou fitotóxico.

  20. Natural occurrence of mycotoxins and toxigenic capacity of Alternaria strains from mouldy peppers

    DEFF Research Database (Denmark)

    da Cruz Cabral, Lucía; Terminiello, Laura; Fernández Pinto, Virginia

    2016-01-01

    Sweet pepper (Capsicum annuum) is an important crop cultivated worldwide, with Argentina being one of the major producers in South America. The fruit is susceptible to several fungal diseases, leading to severe economic losses for producers. In this study, Alternaria was found as the prevalent...... and alternariols. A total 32 out of 48 spoiled pepper fruits were contaminated with at least one of these metabolites. Half of the samples were positive for tenuazonic acid (range 8–11,422 μg/kg), while alternariol and its monomethyl ether were less frequently detected (21 and 29%, respectively) and at lower...

  1. Solanapyrones, Phytotoxins Produced by Alternaria solani: Biosynthesis and Isolation of Minor Components.

    Science.gov (United States)

    Oikawa, H; Yokota, T; Sakano, C; Suzuki, Y; Naya, A; Ichihara, A

    1998-01-01

    Two minor components of solanapyrones D and E, phytotoxins from Alternaria solani, were isolated. The absolute stereochemistry of D and the optical purity of solanapyrones A and D were determined by chemical transformation and measurement of the CD spectrum. In addition, complete signal assignment of the (1)H- and (13)C-NMR spectra of solanapyrones A and D, and their solution conformations were studied. Feeding experiments with various isotopically labeled acetates and methionine established the biosynthetic pathway of solanapyrones. The phytotoxicity of solanapyrones on lettuce seedlings is discussed.

  2. Chemical composition and fungicidal activity of the essential oil of Thymus vulgaris against Alternaria citri

    Directory of Open Access Journals (Sweden)

    Erica A. Soto Mendívil

    2006-01-01

    Full Text Available Se analizó químicamente el aceite esencial de tomillo (Thymus vulgaris L. por Cromatografía de Gases/Espectroscopia de Masas y se evaluó su actividad fungicida. Los principales constituyentes fueron borneol (28.4%, timol (16.6%, carvacrol metil eter (9.6%, camfeno (6.9%, α-humulene (6.4% y carvacrol (5.0%. Las pruebas de actividad fungicida (in vitro indicaron que la concentración de 1000ppm del aceite esencial de tomillo fue efectivo para inhibir a Alternaria citri, cuando se adicionó al medio de cultivo agar papa dextrosa

  3. Suitability of various plant derived gelling agents as agar substitute ...

    African Journals Online (AJOL)

    USER

    2012-06-05

    Jun 5, 2012 ... of three test fungi (Trichoderma harzianum, Alternaria alternata and Alternaria solani) as good as agar. Guar gum .... validate the available data and to look for additional cheap and .... A revised medium for rapid growth and.

  4. New cytotoxic compounds of endophytic fungus Alternaria sp. isolated from Broussonetia papyrifera (L.) Vent.

    Science.gov (United States)

    Zhang, Naidan; Zhang, Chunyan; Xiao, Xiao; Zhang, Qiaoyan; Huang, Baokang

    2016-04-01

    From the ethyl acetate extract of a culture of the endophytic fungus Alternaria species G7 in Broussonetia papyrifera, a new compound altertoxin IV (1) together with nine known compounds were isolated and identified by means of bioassay-guided fractionation. The structures of these compounds were established on the basis of spectroscopic methods, among which the absolute configuration of compound 1, a new tetrahydroperylenone derivative, was determined by means of X-Ray Crystallographic analysis. The isolated compounds were subjected to cytotoxic activity against three human cancer cell lines (A549, MG-63, and SMMC-7721). Compound 2 showed significant cytotoxic activities against tested cell lines, with IC50 values of 1.47, 2.11 and 7.34 μg/mL, respectively. Additionally, compound 4 also exhibited significant cytotoxic activities against cell lines MG-63 and SMMC-7721, with IC50 values of 0.53 and 2.92 μg/mL. Endophytic fungi Alternaria from B. papyrifera might be promising sources of natural bioactive and novel metabolites.

  5. Altering Conidial Dispersal of Alternaria solani by Modifying Microclimate in Tomato Crop Canopy

    Directory of Open Access Journals (Sweden)

    Prashant Prakash Jambhulkar

    2016-12-01

    Full Text Available Early blight of tomato caused by Alternaria solani, is responsible for severe yield losses in tomato. The conidia survive on soil surface and old dry lower leaves of the plant and spread when suitable climatic conditions are available. Macroclimatic study reveals that highest inoculum concentration of Alternaria spores appeared in May 2012 to 2013 and lowest concentration during January 2012 to 2013. High night temperature positively correlated and significantly (P < 0.01 involved in conidial spore dispersal and low relative humidity (RH displayed significant (P < 0.05 but negative correlation with conidial dispersal. The objective of the study was to modify microclimatic conditions of tomato crop canopy which may hamper conidial dispersal and reduce disease severity. We evaluated effect of marigold intercropping and plastic mulching singly and in consortia on A. solani conidial density, tomato leaf damage and microclimatic parameters as compar to tomato alone (T. Tomato-marigold intercropping–plastic mulching treatment (T + M + P showed 35–39% reduction in disease intensity as compared to tomato alone. When intercropped with tomato, marigold served as barrier to conidial movement and plastic mulching prevented evapotranspiration and reduced the canopy RH that resulted in less germination of A. solani spores. Marigold intercropping and plastic mulching served successfully as physical barrier against conidial dissemination to diminish significantly the tomato foliar damage produced by A. solani.

  6. 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.

  7. 链格孢菌毒素能诱导中国月季产生抗蚜活性的细交链孢菌酮酸%Alternaria toxin-induced resistance in rose plants against rose aphid (Macrosiphum rosivorum):effect of tenuazonic acid

    Institute of Scientific and Technical Information of China (English)

    Fa-zhong YANG; Bin YANG; Bei-bei LI; Chun XIAO

    2015-01-01

      结论:(1)链格孢菌粗毒素和对照品 TeA均能使中国月季植株产生对月季长管蚜的系统诱导抗性,显著降低月季长管蚜对中国月季的危害;(2)链格孢菌粗毒素中的主要抗蚜活性成分是 TeA, TeA有望成为中国月季上具有抗蚜活性的先导化合物;(3)粗毒素和对照品 TeA对蚜虫和植物均无伤害作用,但能激活植物对虫害的诱导抗性(ISR)和系统获得性抗性(SAR),可直接证实二者间存在着寄主植物介导的间接的病虫互作关系。%Many different types of toxins are produced by the fungus, Alternaria alternata (Fr.) Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography (HPLC) analyses demon-strated that tenuazonic acid (TeA) was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60%15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060μg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component

  8. Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

    NARCIS (Netherlands)

    Koch, E.; Schmitt, A.; Stephan, D.; Kromphardt, C.; Jahn, M.; Krauthausen, H.J.; Forsberg, G.; Werner, S.; Amein, T.; Wright, S.A.I.; Tinivella, F.; Gullino, M.L.; Roberts, S.J.; Wolf, van der J.M.; Groot, S.P.C.

    2010-01-01

    The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Contr

  9. The Asc locus for resistance to Alternaria stem canker in tomato does not encode the enzyme aspartate carbamoyltransferase

    NARCIS (Netherlands)

    Overduin, Bert; Hogenhout, Saskia A.; Biezen, Erik A. van der; Haring, Michel A.; Nijkamp, H. John J.; Hille, Jacques

    1993-01-01

    The fungal disease resistance locus Alternaria stem canker (Asc) in tomato has been suggested to encode the enzyme aspartate carbamoyltransferase (ACTase). To test this hypothesis a segment of the tomato ACTase gene was amplified by the polymerase chain reaction (PCR) using degenerate primers. The P

  10. Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in Alternaria solani

    Science.gov (United States)

    Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight, therefore, the application of fungicides is a primary means of achieving disease control. Previo...

  11. A Zinc-Finger-Family Transcription Factor, AbVf19, Is Required for the Induction of a Gene Subset Important for Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Akhil [Univ. of Hawaii, Manoa, HI (United States); Ohm, Robin A. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Oxiles, Lindsay [Univ. of Hawaii, Manoa, HI (United States); Brooks, Fred [Univ. of Hawaii, Manoa, HI (United States); Lawrence, Christopher B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Cho, Yangrae [Univ. of Hawaii, Manoa, HI (United States)

    2011-10-26

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen with a broad host range within the family Brassicaceae. It produces secondary metabolites that marginally affect virulence. Cell wall degrading enzymes (CDWE) have been considered important for pathogenesis but none of them individually have been identified as significant virulence factors in A. brassicicola. In this study, knockout mutants of a gene, AbVf19, were created and produced considerably smaller lesions than the wild type on inoculated host plants. The presence of tandem zinc-finger domains in the predicted amino acid sequence and nuclear localization of AbVf19- reporter protein suggested that it was a transcription factor. Gene expression comparisons using RNA-seq identified 74 genes being downregulated in the mutant during a late stage of infection. Among the 74 downregulated genes, 28 were putative CWDE genes. These were hydrolytic enzyme genes that composed a small fraction of genes within each family of cellulases, pectinases, cutinases, and proteinases. The mutants grew slower than the wild type on an axenic medium with pectin as a major carbon source. This study demonstrated the existence and the importance of a transcription factor that regulates a suite of genes that are important for decomposing and utilizing plant material during the late stage of plant infection.

  12. Fine Mapping for Identification of Citrus Alternaria Brown Spot Candidate Resistance Genes and Development of New SNP Markers for Marker-Assisted Selection

    Science.gov (United States)

    Cuenca, Jose; Aleza, Pablo; Garcia-Lor, Andres; Ollitrault, Patrick; Navarro, Luis

    2016-01-01

    Alternaria brown spot (ABS) is a serious disease affecting susceptible citrus genotypes, which is a strong concern regarding citrus breeding programs. Resistance is conferred by a recessive locus (ABSr) previously located by our group within a 3.3 Mb genome region near the centromere in chromosome III. This work addresses fine-linkage mapping of this region for identifying candidate resistance genes and develops new molecular markers for ABS-resistance effective marker-assisted selection (MAS). Markers closely linked to ABSr locus were used for fine mapping using a 268-segregating diploid progeny derived from a heterozygous susceptible × resistant cross. Fine mapping limited the genomic region containing the ABSr resistance gene to 366 kb, flanked by markers at 0.4 and 0.7 cM. This region contains nine genes related to pathogen resistance. Among them, eight are resistance (R) gene homologs, with two of them harboring a serine/threonine protein kinase domain. These two genes along with a gene encoding a S-adenosyl-L-methionine-dependent-methyltransferase protein, should be considered as strong candidates for ABS-resistance. Moreover, the closest SNP was genotyped in 40 citrus varieties, revealing very high association with the resistant/susceptible phenotype. This new marker is currently used in our citrus breeding program for ABS-resistant parent and cultivar selection, at diploid, triploid and tetraploid level. PMID:28066498

  13. Characterization of rhizosphere bacteria for control of phytopathogenic fungi of tomato.

    Science.gov (United States)

    Pastor, Nicolás; Carlier, Evelin; Andrés, Javier; Rosas, Susana B; Rovera, Marisa

    2012-03-01

    Fluorescent Pseudomonas spp., isolated from rhizosphere soil of tomato and pepper plants, were evaluated in vitro as potential antagonists of fungal pathogens. Strains were characterized using the API 20NE biochemical system, and tested against the causal agents of stem canker and leaf blight (Alternaria alternata f. sp. lycopersici), southern blight (Sclerotium rolfsii Sacc.), and root rot (Fusarium solani). To this end, dual culture antagonism assays were carried out on 25% Tryptic Soy Agar, King B medium, and Potato Dextrose Agar to determine the effect of the strains on mycelial growth of the pathogens. The effect of two concentrations of FeCl(3) on antagonism against Alternaria alternata f. sp. lycopersici was also tested. In addition, strains were screened for ability to produce exoenzymes and siderophores. Finally, the selected Pseudomonas strain, PCI2, was evaluated for effect on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotium rolfsii Sacc., under growth chamber conditions. All strains significantly inhibited Alternaria alternata f. sp. lycopersici, particularly in 25% TSA medium. Antagonistic effect on Sclerotium rolfsii Sacc. and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strains produced cellulase or chitinase. Growth chamber studies resulted in significant increases in plant stand as well as in root dry weight. PCI2 was able to establish and survive in tomato plants rhizosphere after 40 days following planting of bacterized seeds. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Serine protease identification (in vitro) and molecular structure predictions (in silico) from a phytopathogenic fungus, Alternaria solani.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Chandrasekar, Raman; Sa, Tongmin; Sathiyabama, Muthukrishnan

    2014-07-01

    Serine proteases are involved in an enormous number of biological processes. The present study aims at characterizing three-dimensional (3D) molecular architecture of serine proteases from early blight pathogen, Alternaria solani that are hypothesized to be markers of phytopathogenicity. A serine protease was purified to homogeneity and MALDI-TOF-MS/MS analysis revealed that protease produced by A. solani belongs to alkaline serine proteases (AsP). AsP is made up of 403 amino acid residues with molecular weight of 42.1 kDa (Isoelectric point - 6.51) and its molecular formula was C1859 H2930 N516 O595 S4 . AsP structure model was built based on its comparative homology with serine protease using the program, MODELER. AsP had 16 β-sheets and 10 α-helices, with Ser(350) (G347-G357), Asp(158) (D158-H169), and His(193) (H193-G203) in separate turn/coil structures. Biological metal binding region situated near 6th-helix and His(193) residue is responsible for metal binding site. Also, calcium ion (Ca(2+)) is coordinated by the carboxyl groups of Lys(84), Ile(85), Lys(86), Asp(87), Phe(88), Ala(89), Ala(90) (K84-A90) for first Ca(2+) binding site and carbonyl oxygen atom of Lys(244), Gly(245), Arg(246), Thr(247), Lys(248), Lys(249), and Ala(250) (K244-A250), for second Ca(2+) binding site. Moreover, Ramachandran plot analysis of protein residues falling into most favored secondary structures were determined (83.3%). The predicted molecular 3D structural model was further verified using PROCHECK, ERRAT, and VADAR servers to confirm the geometry and stereo-chemical parameters of the molecular structural design. The functional analysis of AsP 3D molecular structure predictions familiar in the current study may provide a new perspective in the understanding and identification of antifungal protease inhibitor designing. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Three New Resveratrol Derivatives from the Mangrove Endophytic Fungus Alternaria sp.

    Directory of Open Access Journals (Sweden)

    Jinhua Wang

    2014-05-01

    Full Text Available Three new resveratrol derivatives, namely, resveratrodehydes A–C (1–3, were isolated from the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. All compounds showed broad-spectrum inhibitory activities against three human cancer cell lines including human breast MDA-MB-435, human liver HepG2, and human colon HCT-116 by MTT assay (IC50 < 50 μM. Among them, compounds 1 and 2 both exhibited marked cytotoxic activities against MDA-MB-435 and HCT-116 cell lines (IC50 < 10 μM. Additionally, compounds 1 and 3 showed moderate antioxidant activity by DPPH radical scavenging assay.

  16. First Report of Foliar Blight on Dendropanax morbifera Caused by Alternaria panax.

    Science.gov (United States)

    Deng, Jian Xin; Kim, Chang Sun; Oh, Eun Sung; Yu, Seung Hun

    2010-12-01

    Leaf spot and blight disease was observed on two-year-old seedlings of Dendropanax morbifera (Korean name: Hwangchil tree) during July of 2008 in Jindo Island, Korea. Symptoms included yellow-brown to dark brown irregularly enlarged spots frequently located along the veins of leaves. The lesions were often surrounded by chlorotic haloes. Severe leaf blight and subsequent defoliation occurred when conditions favored disease outbreak. The causal organism of the disease was identified as Alternaria panax based on morphological characteristics and sequence analysis of the internal transcribed spacer region of rDNA. A. panax isolates induced leaf spots and blight symptoms not only on D. morbifera but also on the other members of Araliaceae tested. This is the first report of foliar blight caused by A. panax on D. morbifera.

  17. Conidios de 'alternaria', factor de riesgo de alegria en Castilla-La Mancha

    Directory of Open Access Journals (Sweden)

    Silvia Sabariego Ruiz

    2007-12-01

    Full Text Available En este trabajo se estudia el comportamiento estacional de los conidios de Alternaria en la atmósfera de Castilla-La Mancha, cuyo inte- rés se basa en que los niveles en el aire de estos conidios suponen un riesgo de alergia para las personas sensibilizadas a los mismos. El estudio se ha llevado a cabo en cinco estaciones de muestreo pertenecientes a la Red de Aerobiología de Castilla-La Mancha (Red Aerocam: Albacete, Ciudad Real, Cuenca, Guadalajara y Toledo, durante el año 2008. Los captadores utilizados y la metodología de muestreo siguen las directrices de la Red Española de Aerobiología (REA. Los conidios de Alternaria se detectan en la atmósfera de Castilla-La Mancha durante todo el año, aunque los meses de mayores concentraciones se obtienen en mayo, junio y julio. Ciudad Real, Toledo y Guadalajara son las ciudades en las que se detecta una mayor concentración anual, con 5.624 conidios, 4.527 conidios y 4.173 conidios, respectivamente, seguidas de Albacete y de Cuenca. En algunas de las localidades muestreadas, los valores máximos diarios han sido elevados en un importante número de días, destacamos los registrados en Ciudad Real el 20 de marzo (722 conidios/m3, en Toledo el 18 de junio (324 conidios/m3 y en Guadalajara el 26 de junio (220 conidios/m3.

  18. Substrates and enzyme activities related to biotransformation of resveratrol from phenylalanine by Alternaria sp. MG1.

    Science.gov (United States)

    Zhang, Jinhua; Shi, Junling; Liu, Yanlin

    2013-12-01

    To identify the substrates and enzymes related to resveratrol biosynthesis in Alternaria sp. MG1, different substrates were used to produce resveratrol, and their influence on resveratrol production was analyzed using high performance liquid chromatography (HPLC). Formation of resveratrol and related intermediates was identified using mass spectrum. During the biotransformation, activities of related enzymes, including phenylalanine ammonia-lyase (PAL), trans-cinnamate 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL), were analyzed and tracked. The reaction system contained 100 mL 0.2 mol/L phosphate buffer (pH 6.5), 120 g/L Alternaria sp. MG1 cells, 0.1 g/L MgSO₄, and 0.2 g/L CaSO₄ and different substrates according to the experimental design. The biotransformation was carried out for 21 h at 28 °C and 120 rpm. Resveratrol formation was identified when phenylalanine, tyrosine, cinnamic acid, and p-coumaric acid were separately used as the only substrate. Accumulation of cinnamic acid, p-coumaric acid, and resveratrol and the activities of PAL, C4H, and 4CL were identified and changed in different trends during transformation with phenylalanine as the only substrate. The addition of carbohydrates and the increase of phenylalanine concentration promoted resveratrol production and yielded the highest value (4.57 μg/L) when 2 g/L glucose, 1 g/L cyclodextrin, and phenylalanine (4.7 mmol/L) were used simultaneously.

  19. Yield loss assessment due to Alternaria blight and its management in linseed.

    Science.gov (United States)

    Singh, R B; Singh, H K; Parmar, Arpita

    2014-04-01

    Field experiments were conducted during 2010-11 and 2011-12 to assess the yield losses due to Alternaria blight disease caused by Alternaria lini and A. linicola in recently released cultivars and their management with the integration of Trichoderma viride, fungicides and plant extract. Disease severity on leaves varied from 41.07% (Parvati) to 65.01% (Chambal) while bud damage per cent ranged between 23.56% (Shekhar) to 46.12% (T-397), respectively in different cultivars. Maximum yield loss of 58.44% was recorded in cultivar Neelum followed by Parvati (55.56%), Meera (55.56%) and Chambal (51.72%), respectively while minimum loss was recorded in Kiran (19.99%) and Jeevan (22.22%). Minimum mean disease severity (19.47%) with maximum disease control (69.74%) was recorded with the treatment: seed treatment (ST) with vitavax power (2 g kg(-1) seed) + 2 foliar sprays (FS) of Saaf (a mixture of carbendazim+mancozeb) 0.2% followed by ST with Trichoderma viride (4g kg(-1) seed) + 2 FS of Saaf (0.2%). Minimum bud damage (13.75%) with maximum control (60.94%) was recorded with treatment of ST with vitavax power+2 FS of propiconazole (0.2%). Maximum mean seed yield (1440 kg ha(-1)) with maximum net return (Rs. 15352/ha) and benefit cost ratio (1:11.04) was obtained with treatment ST with vitavax power + 2 FS of Neem leaf extract followed by treatment ST with vitavax power+2 FS of Saaf (1378 kg ha(-1)).

  20. 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.

  1. Alternaria-Induced Release of IL-18 from Damaged Airway Epithelial Cells: n NF-kB Dependent Mechanism of Th2 Differentiation?

    OpenAIRE

    2012-01-01

    BACKGROUND: A series of epidemiologic studies have identified the fungus Alternaria as a major risk factor for asthma. The airway epithelium plays a critical role in the pathogenesis of allergic asthma. These reports suggest that activated airway epithelial cells can produce cytokines such as IL-25, TSLP and IL-33 that induce Th2 phenotype. However the epithelium-derived products that mediate the pro-asthma effects of Alternaria are not well characterized. We hypothesized that exposure of the...

  2. Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase-inhibiting fungicides in Alternaria solani.

    Science.gov (United States)

    Mallik, I; Arabiat, S; Pasche, J S; Bolton, M D; Patel, J S; Gudmestad, N C

    2014-01-01

    Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight; therefore, the application of fungicides is the primary means of achieving disease control. Previous work in our laboratory reported resistance to the succinate dehydrogenase-inhibiting (SDHI) fungicide boscalid in this plant pathogen with a concomitant loss of disease control. Two phenotypes were detected, one in which A. solani isolates were moderately resistant to boscalid, the other in which isolates were highly resistant to the fungicide. Resistance in other fungal plant pathogens to SDHI fungicides is known to occur due to amino acid exchanges in the soluble subunit succinate dehydrogenase B (SdhB), C (SdhC), and D (SdhD) proteins. In this study, the AsSdhB, AsSdhC, and AsSdhD genes were analyzed and compared in sensitive (50% effective concentration [EC50] resistant (EC50 = 5.1 to 20 μg ml(-1)), highly resistant (EC50 = 20.1 to 100 μg ml(-1)), and very highly resistant (EC50 > 100 μg ml(-1)) A. solani isolates. In total, five mutations were detected, two in each of the AsSdhB and AsSdhD genes and one in the AsSdhC gene. The sequencing of AsSdhB elucidated point mutations cytosine (C) to thymine (T) at nucleotide 990 and adenine (A) to guanine (G) at nucleotide 991, leading to an exchange from histidine to tyrosine (H278Y) or arginine (H278R), respectively, at codon 278. The H278R exchange was detected in 4 of 10 A. solani isolates moderately resistant to boscalid, exhibiting EC50 values of 6 to 8 μg ml(-1). Further genetic analysis also confirmed this mutation in isolates with high and very high EC50 values for boscalid of 28 to 500 μg ml(-1). Subsequent sequencing of AsSdhC and AsSdhD genes confirmed the presence of additional mutations from A to G at nucleotide position 490 in AsSdhC and at nucleotide position 398 in the AsSdhD, conferring H134R and H

  3. 两种中药提取物对番茄灰霉病菌和番茄早疫病菌的抑制活性研究%Antifungal Activity of Botanical Extracts against Botrytis cinerea and Alternaria solani

    Institute of Scientific and Technical Information of China (English)

    毕亚玲; 王波; 黄保宏; 张文同; 张轶辉

    2011-01-01

    [Objective] The antifungal activity of the extracts from,Atractylodes macracephal Koidz and Pulsatilla chinensis Bunge Regel,against Botrytis cinerea and Alternaria solani were studied under the condition of laboratory,in order to develop and utilize these two plants.[Method] The mycelium growth rate test was applied to measure the antifungal activities of extracts against fungi.[Result] the extracts of all the two plants showed strong antifungal activity against the target pathogenic fungi,especially the antifungal activity of the extract from Pulsatilla chinensis Bunge Regel was stronger and more stable.The inhibition rate to the mycelium growth of Botrytis cinerea was 80.25%.At the same concentration,the extract from Atractylodes macracephal Koidz showed little inhibition to Botrytis cinerea and Alternaria solani.The petrolelum ether extract of Atractylodes macracephal Koidz showed stronger antifungal activities and the EC50 was 5.31 mg/ml,and the n-butanol extract of Pulsatilla chinensis Bunge Regel showed stronger antifungal activities and the EC50 was 2.93 mg/ml.[Conclusion] The extracts from Pulsatilla chinensis Bunge Regel showed the stronger antifungal activity against Botrytis cinerea and Alternaria solani.%[目的]研究白术和白头翁2种中药提取物的杀菌活性,为其在植物源农药上的开发利用奠定基础。[方法]采用菌丝生长速率法,研究了白术和白头翁2种植物提取物对番茄灰霉病菌和番茄早疫病菌的抗菌活性。[结果]供试2种中药提取物对番茄灰霉病菌和番茄早疫病菌均具有较好的抗菌活性,其中白头翁提取物的抗菌活性最好,72h白头翁正丁醇提取物对番茄灰霉病菌的抑制率达80.25%;白术石油醚提取物对番茄灰霉病菌的抗菌活性较好,EC50为5.31mg/ml,白头翁正丁醇提取物的抗菌活性较强,EC50为2.93mg/ml。[结论]白头

  4. Effects of chemical treatments on infestation of Alternaria spp. and Fusarium spp. in correlation with technological wheat quality

    Directory of Open Access Journals (Sweden)

    Vučković Jovana N.

    2011-01-01

    Full Text Available In this study, the time of infestation by fungi from genus Alternaria spp. and Fusarium spp. was investigated in different stages of wheat maturity (milk, waxy, and technological maturity; the effects of different fungicides on the yield, technological properties, and content of mycotoxin DON were studied also. The results showed that Alternaria spp. attacked spike and kernel in f lowering and end-f lowering stage, as it was already known for Fusarium species. Fungicide treatment increases the yield up to 20%, test weight by 3.7%, and thousand-kernel weight up to 19.1%. High content of mycotoxin DON, above tolerable limits, was detected only in the treatment with fungicide Caramba and in untreated control.

  5. Pathogen intelligence

    Science.gov (United States)

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  6. Bio-priming of seeds: A potential tool in the integrated management of alternaria blight of sunflower

    OpenAIRE

    Rao M.S.L.; Kulkarni S; Lingaraju S.; Nadaf H.L.

    2009-01-01

    Of the different integrated seed treatment options tested for the management of Alternaria blight of sunflower, highest benefit was obtained in the seed treatment with Carbendazim+Iprodione (Quintal) at 0.3% in water along with hexaconazole foliar spray (0.1%) followed by seed treatment with Pseudomonas fluorescens (0.8%) in jelly+hexaconazole foliar spray. Efficacy of Pseudomonas fluorescens as seed dresser can be enhanced by bio-priming the sunflower seeds for the effective and eco-friendly...

  7. Fluctuation range of the concentration of airborne Alternaria conidiospores sampled at different geographical locations in Poland (2010–2011

    Directory of Open Access Journals (Sweden)

    Idalia Kasprzyk

    2013-04-01

    Full Text Available Knowledge of seasonal and diurnal fluctuations of allergenic and phytopathogenic fungal spores in the air and the determination of the influence of weather and environmental parameters on spore concentrations are of great practical use in control of both human and animal health as well as plant diseases. The aim of this study was to evaluate the dynamics of the occurrence of Alternaria spores in the air at three sites located in different geographical regions of Poland. The study was done from 15 April to 30 September in 2010–2011 in Rzeszów (Carpathian Foothills, south-east Poland, Lublin (Lublin Upland, central east, and Poznań (central west; the distance between the experimental sites ranged from 138 to 441 km. To assess the concentration of Alternaria spores, the volumetric method was used. In both years, the highest concentration of spores was observed in Poznań and the lowest in Rzeszów. In 2010 the annual total, monthly total and maximum spore concentration were higher than in 2011 at all monitoring sites. The greatest concentration of Alternaria spores was recorded in August, followed by July. High spore concentrations were also noted at the beginning of September. The differences in daily concentrations, average concentrations and cumulative numbers of spores were statistically significant. The reasons for this can be related not only to weather parameters, which is often raised in the literature, but also to the type of landscape. Landscape and geo-botanical conditions of Great Poland and Carpathian Foothills greatly differ. In both years, the highest number of Alternaria spores was found in Poznań – the city with the highest urbanization factor and the capital of the region with large-scale farming, connected with the intensification of agricultural practices.

  8. Spotlight on the Underdogs—An Analysis of Underrepresented Alternaria Mycotoxins Formed Depending on Varying Substrate, Time and Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Theresa Zwickel

    2016-11-01

    Full Text Available Alternaria (A. is a genus of widespread fungi capable of producing numerous, possibly health-endangering Alternaria toxins (ATs, which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 °C, 25 °C, substrate (rice, wheat kernels and incubation time (4, 7, and 14 days on the production of thirteen ATs and three sulfoconjugated ATs by three different Alternaria isolates from the species groups A. tenuissima and A. infectoria was determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 °C and with increasing incubation time all toxins were formed in high amounts by the two A. tenuissima strains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to the A. tenuissima strains, the A. infectoria strain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions.

  9. Analysis of the predicting variables for daily and weekly fluctuations of two airborne fungal spores: Alternaria and Cladosporium

    Science.gov (United States)

    Recio, Marta; del Mar Trigo, María; Docampo, Silvia; Melgar, Marta; García-Sánchez, José; Bootello, Lourdes; Cabezudo, Baltasar

    2012-11-01

    Alternaria and Cladosporium are two fungal taxa whose spores (conidia) are included frequently in aerobiological studies of outdoor environments. Both spore types are present in the atmosphere of Malaga (Spain) throughout almost the entire year, although they reach their highest concentrations during spring and autumn. To establish predicting variables for daily and weekly fluctuations, Spearman's correlations and stepwise multiple regressions between spore concentrations (measured using a volumetric 7-day recorder) and meteorological variables were made with results obtained for both spore types in 1996 and 1997. Correlations and regressions were also made between the different taxa and their concentrations in different years. Significant and positive correlation coefficients were always obtained between spore concentrations of both taxa, followed by temperature, their concentrations in different years, sunshine hours and relative humidity (this last in a negative sense). For the two spore types we obtained higher correlation and regression coefficients using weekly data. We showed different regression models using weekly values. From the results and a practical point of view, it was concluded that weekly values of the atmospheric concentration of Alternaria spores can be predicted from the maximum temperature expected and its concentrations in the years sampled. As regards the atmospheric concentration of Cladoposrium spores, the weekly values can be predicted based on the concentration of Alternaria spores, thus saving the time and effort that would otherwise be employed in counting them by optical microscopy.

  10. Green Chemistry Approach for the Synthesis of Gold Nanoparticles Using the Fungus Alternaria sp.

    Science.gov (United States)

    Dhanasekar, Naresh Niranjan; Rahul, Ganga Ravindran; Narayanan, Kannan Badri; Raman, Gurusamy; Sakthivel, Natarajan

    2015-07-01

    The synthesis of gold nanoparticles has gained tremendous attention owing to their immense applications in the field of biomedical sciences. Although several chemical procedures are used for the synthesis of nanoparticles, the release of toxic and hazardous by-products restricts their use in biomedical applications. In the present investigation, gold nanoparticles were synthesized biologically using the culture filtrate of the filamentous fungus Alternaria sp. The culture filtrate of the fungus was exposed to three different concentrations of chloroaurate ions. In all cases, the gold ions were reduced to Au(0), leading to the formation of stable gold nanoparticles of variable sizes and shapes. UV-Vis spectroscopy analysis confirmed the formation of nanoparticles by reduction of Au(3+) to Au(0). TEM analysis revealed the presence of spherical, rod, square, pentagonal, and hexagonal morphologies for 1 mM chloroaurate solution. However, quasi-spherical and spherical nanoparticles/heart-like morphologies with size range of about 7-13 and 15-18 nm were observed for lower molar concentrations of 0.3 and 0.5 mM gold chloride solution, respectively. The XRD spectrum revealed the face-centered cubic crystals of synthesized gold nanoparticles. FT-IR spectroscopy analysis confirmed the presence of aromatic primary amines, and the additional SPR bands at 290 and 230 nm further suggested that the presence of amino acids such as tryptophan/tyrosine or phenylalanine acts as the capping agent on the synthesized mycogenic gold nanoparticles.

  11. Changes in concentration of Alternaria and Cladosporium spores during summer storms

    Science.gov (United States)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2013-09-01

    Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004-2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms.

  12. Grouping sunflower genotypes for yield, oil content, and reaction to Alternaria leaf spot using GGE biplot

    Directory of Open Access Journals (Sweden)

    Regina Maria Villas Bôas de Campos Leite

    2015-08-01

    Full Text Available Abstract:The objective of this work was to evaluate the suitability of the multivariate method of principal component analysis (PCA using the GGE biplot software for grouping sunflower genotypes for their reaction to Alternaria leaf spot disease (Alternariaster helianthi, and for their yield and oil content. Sixty-nine genotypes were evaluated for disease severity in the field, at the R3 growth stage, in seven growing seasons, in Londrina, in the state of Paraná, Brazil, using a diagrammatic scale developed for this disease. Yield and oil content were also evaluated. Data were standardized using the software Statistica, and GGE biplot was used for PCA and graphical display of data. The first two principal components explained 77.9% of the total variation. According to the polygonal biplot using the first two principal components and three response variables, the genotypes were divided into seven sectors. Genotypes located on sectors 1 and 2 showed high yield and high oil content, respectively, and those located on sector 7 showed tolerance to the disease and high yield, despite the high disease severity. The principal component analysis using GGE biplot is an efficient method for grouping sunflower genotypes based on the studied variables.

  13. Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.

    Science.gov (United States)

    Wittek, Finni; Kanawati, Basem; Wenig, Marion; Hoffmann, Thomas; Franz-Oberdorf, Katrin; Schwab, Wilfried; Schmitt-Kopplin, Philippe; Vlot, A Corina

    2015-08-01

    Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.

  14. QTL identification for early blight resistance (Alternaria solani) in a Solanum lycopersicum x S. arcanum cross.

    Science.gov (United States)

    Chaerani, R; Smulders, M J M; van der Linden, C G; Vosman, B; Stam, P; Voorrips, R E

    2007-02-01

    Alternaria solani (Ellis and Martin) Sorauer, the causal agent of early blight (EB) disease, infects aerial parts of tomato at both seedling and adult plant stages. Resistant cultivars would facilitate a sustainable EB management. EB resistance is a quantitatively expressed character, a fact that has hampered effective breeding. In order to identify and estimate the effect of genes conditioning resistance to EB, a quantitative trait loci (QTL) mapping study was performed in F2 and F3 populations derived from the cross between the susceptible Solanum lycopersicum (syn. Lycopersicon esculentum) cv. 'Solentos' and the resistant Solanum arcanum (syn. Lycopersicon peruvianum) LA2157 and genotyped with AFLP, microsatellite and SNP markers. Two evaluation criteria of resistance were used: measurements of EB lesion growth on the F2 plants in glasshouse tests and visual ratings of EB severity on foliage of the F3 lines in a field test. A total of six QTL regions were mapped on chromosomes 1, 2, 5-7, and 9 with LOD scores ranging from 3.4 to 17.5. Three EB QTL also confer resistance to stem lesions in the field, which has not been reported before. All QTL displayed significant additive gene action; in some cases a dominance effect was found. Additive x additive epistatic interactions were detected between one pair of QTL. For two QTL, the susceptible parent contributed resistance alleles to both EB and stem lesion resistance. Three of the QTL showed an effect in all tests despite methodological and environmental differences.

  15. Synthesis of N-substituted phthalimides and their antifungal activity against Alternaria solani and Botrytis cinerea.

    Science.gov (United States)

    Pan, Le; Li, Xiuzhuang; Gong, Chengwen; Jin, Hui; Qin, Bo

    2016-06-01

    As organosulfur and organophosphorus agents, phaltane and phosmet are facing great challenges for the environmental contamination, mammalian toxicity and increasing resistance with long term use. It is efficient and meaningful to develop phthalimide-based alternatives with non-sulfur and non-phosphorus groups. A series of N-substituted phthalimides were synthesized and their antifungal activity against two disastrous phytopathogenic fungi, Alternaria solani and Botrytis cinerea was evaluated in vitro. Most of them showed significant antifungal activity against both of fungi, or either of them selectively. N-vinylphthalimide (4) and 8-[4-(phthalimide-2-yl) butyloxy] quinoline (13) were identified as the most promising candidates against B. cinerea and A. solani with the IC50 values of 7.92 μg/mL and 10.85 μg/mL respectively. The brief structure-activity relationships have revealed that vinyl, quinolyl, bromide alkyl and benzyl substitutions were appropriate substituents and coupling functional moieties indirectly with optimum alkyl chain was efficient to prepare phthalimides related fungicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. acetylcholinesterase inhibitory potential and insecticidal activity of an endophytic Alternaria sp. from Ricinus communis.

    Science.gov (United States)

    Singh, Bahaderjeet; Thakur, Abhinay; Kaur, Sanehdeep; Chadha, B S; Kaur, Amarjeet

    2012-11-01

    Keeping in view the vast potential of endophytic fungi to produce bioactive molecules, this study aimed at isolating and screening endophytes for the production of acetylcholinesterase inhibitors. Fifty-four endophytic fungi were isolated from Ricinus communis and screened for their AChE inhibitory activity using Ellman's colorimetric assay method. Six isolates were found to possess AChE inhibitory activity with maximum inhibition of 78 % being evinced by culture Cas1 which was identified to be Alternaria sp. on the basis of molecular as well as microscopic methods. Optimization of inhibitor production was carried out using one factor at a time approach. Maximum production of inhibitor was obtained on potato dextrose broth after 10 days incubation. The IC(50) of the chloroform extract was observed to be 40 μg/ml. The extract was purified on silica gel and eluted stepwise with a gradient of chloroform/methanol. The insecticidal potential of the extract was evaluated by feeding the larvae of Spodoptera litura on diet containing varying concentrations of the extract. It was observed that with increase in the concentration of the extract, mortality of the larvae increased. The culture has the potential of being exploited in medicine as well as a biocontrol agent.

  17. Effects of ozone on growth, lipid metabolism, and sporulation of fungi. [Colletotrichum lindemuthianum; Alternaria oleraceae

    Energy Technology Data Exchange (ETDEWEB)

    Treshow, M.; Harner, F.M.; Price, H.E.; Kormelink, J.R.

    1969-09-01

    Fumigations with ozone at concentrations of 10 pphm or more for 4 hr repeated daily for 4 days suppressed radial growth and spore production of Colletotrichum lindemuthianum, the most sensitive species studied. Neither radial nor mass growth of Alternaria oleraceae, a more tolerant species, was inhibited by 60 pphm ozone, although spore production was significantly accelerated. Since ozone did not affect spore viability, the inoculum potential was greatly enhanced. Histological effects of ozone included loss of pigmentation in C. lindemuthianum and abundant formation of light-refractive globules in the hyphae. Chemical analyses of mycelial mats showed an average 28% decrease in neutral lipid content of ozone-fumigated cultures. No differences were detectable in fatty acid composition of fumigated cultures. While some lipids may have leaked into the substrate, it was suspected that ozone penetrated into vital sites within the cell-oxidizing sulfhydryl groups, thereby suppressing lipid synthesis. The actual degree of suppression in fumigated hyphae may have been greater than indicated, since much of the mycelia analyzed grew within the substrate and was not directly subjected to ozone. 14 references.

  18. Transplastomic Nicotiana benthamiana plants expressing multiple defence genes encoding protease inhibitors and chitinase display broad-spectrum resistance against insects, pathogens and abiotic stresses.

    Science.gov (United States)

    Chen, Peng-Jen; Senthilkumar, Rajendran; Jane, Wann-Neng; He, Yong; Tian, Zhihong; Yeh, Kai-Wun

    2014-05-01

    Plastid engineering provides several advantages for the next generation of transgenic technology, including the convenient use of transgene stacking and the generation of high expression levels of foreign proteins. With the goal of generating transplastomic plants with multiresistance against both phytopathogens and insects, a construct containing a monocistronic patterned gene stack was transformed into Nicotiana benthamiana plastids harbouring sweet potato sporamin, taro cystatin and chitinase from Paecilomyces javanicus. Transplastomic lines were screened and characterized by Southern/Northern/Western blot analysis for the confirmation of transgene integration and respective expression level. Immunogold localization analyses confirmed the high level of accumulation proteins that were specifically expressed in leaf and root plastids. Subsequent functional bioassays confirmed that the gene stacks conferred a high level of resistance against both insects and phytopathogens. Specifically, larva of Spodoptera litura and Spodoptera exigua either died or exhibited growth retardation after ingesting transplastomic plant leaves. In addition, the inhibitory effects on both leaf spot diseases caused by Alternaria alternata and soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum were markedly observed. Moreover, tolerance to abiotic stresses such as salt/osmotic stress was highly enhanced. The results confirmed that the simultaneous expression of sporamin, cystatin and chitinase conferred a broad spectrum of resistance. Conversely, the expression of single transgenes was not capable of conferring such resistance. To the best of our knowledge, this is the first study to demonstrate an efficacious stacked combination of plastid-expressed defence genes which resulted in an engineered tolerance to various abiotic and biotic stresses.

  19. Pathogen Sensors

    Directory of Open Access Journals (Sweden)

    Joseph Irudayaraj

    2009-10-01

    Full Text Available The development of sensors for detecting foodborne pathogens has been motivated by the need to produce safe foods and to provide better healthcare. However, in the more recent times, these needs have been expanded to encompass issues relating to biosecurity, detection of plant and soil pathogens, microbial communities, and the environment. The range of technologies that currently flood the sensor market encompass PCR and microarray-based methods, an assortment of optical sensors (including bioluminescence and fluorescence, in addition to biosensor-based approaches that include piezoelectric, potentiometric, amperometric, and conductometric sensors to name a few. More recently, nanosensors have come into limelight, as a more sensitive and portable alternative, with some commercial success. However, key issues affecting the sensor community is the lack of standardization of the testing protocols and portability, among other desirable elements, which include timeliness, cost-effectiveness, user-friendliness, sensitivity and specificity. [...

  20. 贡柑黑腐病病原菌的分子鉴定%Pathogen Identification of Black Rot of Gonggan

    Institute of Scientific and Technical Information of China (English)

    覃旭; 邓明学; 阳廷密; 谭有龙; 张素英; 门友均; 唐明丽; 张戈壁

    2012-01-01

    Black rot of gonggan citrus was a new disease occurred in recent years. This disease caused rapid withering of young shoot tips, massive abscission of young leaves, resulting in reduced yield. In this study, the pathogen of this disease was isolated, and identified by analysis of the rDNA-ITS sequence. The results showed that the pathogen was an Alternaria fungus. The sequence of its rDNA-ITS shared a 99% of identity with those of Alternaria brassicae (Berk ) Sacc. And Alternaria citri Ellis $- Everhart deposited in GenBank. The pathogen was finally identified as A. Citri based on the morphological characteristics and sequence of rDNA-ITS.%贡柑黑腐病是近年来在贡柑上发生的一种新型病害,该病害可导致嫩梢快速枯死,大量嫩叶脱落,严重影响树势和产量.本研究从病区采集发病枝叶,对贡柑黑腐病病原菌进行分离、纯化,并采用rDNA-ITS序列分析技术对其进行分子鉴定.结果表明,贡柑黑腐病病原菌为链格孢属Alternaria Nees真菌,rDNA-ITS序列与GenBank中芸薹链格孢菌A.brassicae (Berk.) Sacc.和柑桔链格孢菌A.citri Ellis et Everhart的ITS序列的同源性为99%.结合形态学特征,推断该病原菌为柑桔链格孢菌.

  1. 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.

  2. The Secondary Metabolites of the Crinoid(Comanthina schlegeli) Epipsymbiosis Fungus Alternaria brassicae 93%海百合 Comanthina schlegeli 共附生真菌Alternaria brassicae 93次级代谢产物研究

    Institute of Scientific and Technical Information of China (English)

    李永芳; 王宏维; 许佳怡; 李静; 刘岚

    2015-01-01

    利用硅胶、Sephadex LH -20凝胶柱层析和高效液相色谱(HPLC)等方法对采自湛江海百合共附生真菌 Alternaria brassicae 93的次级代谢产物进行分离纯化,根据化合物的理化性质、波谱数据以及与文献数据对照的方法确定化合物的结构。从海百合共生真菌 Alternaria brassicae 93的次级代谢产物中分离得到5个化合物,分别鉴定为 clavatol (1)、3R,14S-ochratoxin A (2)、3R,14S-ochratoxin B (3)、chaetoquadrin F (4)、ent-cyclo-echinulin (5)。化合物1,2,3,4,5,均为首次从海洋真菌中得到。%Secondary metabolities of the crinoid epipsymbiosis fungus Altermaria brassicae 93 from South China Sea were studied.The metabolities of Alternaria brassicae 93 were isolated by silica gel column chromatography,Sephadex LH -20 gel column chromatography and HPLC,the structures of compounds were eventually identified and confirmed on the basis of physicochemical properties,spectral data and compared with the published spectral information.Five compounds were isolated from marine fungi for the first time and their structures were identified as clavatol (1),3R,14S-ochratoxin A (2),3R,14S-ochratoxin B (3),chaetoquadrin F (4)and ent-cycloechinulin (5).

  3. Chemical and morphological segregation of Alternaria arborescens, A-infectoria and A-tenuissima species-groups

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Krøger, Elisabeth; Roberts, R.G.

    2002-01-01

    belonging to the genus Alternaria were examined. They were grown under standardised conditions and subjected to morphological and chemical examination. All isolates were grouped according to their three-dimensional sporulation pattern on potato carrot agar and their colony colour on dichloran rose bengal....... tenuissima species-groups with only a few metabolites in common. None of the 35 A. infectoria species-group isolates produced any known metabolites and all had white or greyish white colonies on DRYES. The A. arborescens species-group and the A. tenuissima species-group, shared most of the known metabolites...

  4. Potencial antifúngico de extratos de plantas e de basidiomicetos nativos sobre Colletotrichum acutatum, Alternaria solani e Sclerotium rolfsii

    OpenAIRE

    Ricardo José Domingues; Maria Cláudia Marx Young; Jesus Guerino Töfoli; Dácio Roberto Matheus

    2011-01-01

    O emprego de fungicidas na agricultura, principalmente quando utilizados de forma inadequada, tem provocado danos tanto ao homem como ao ambiente. O presente trabalho teve por objetivo o estudo in vitro da eficácia de extratos de três plantas e de dois basidiomicetos nativos do Brasil no controle dos fungos Alternaria solani e Colletotrichum acutatum, causadores de graves prejuízos às culturas de tomate e morango, respectivamente, além de Sclerotium rolfsii, considerado como patógeno polífago...

  5. 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

  6. A critical role of autophagy in plant resistance to necrotrophic fungal pathogens.

    Science.gov (United States)

    Lai, Zhibing; Wang, Fei; Zheng, Zuyu; Fan, Baofang; Chen, Zhixiang

    2011-06-01

    Autophagy is a pathway for degradation of cytoplasmic components. In plants, autophagy plays an important role in nutrient recycling during nitrogen or carbon starvation, and in responses to abiotic stress. Autophagy also regulates age- and immunity-related programmed cell death, which is important in plant defense against biotrophic pathogens. Here we show that autophagy plays a critical role in plant resistance to necrotrophic pathogens. ATG18a, a critical autophagy protein in Arabidopsis, interacts with WRKY33, a transcription factor that is required for resistance to necrotrophic pathogens. Expression of autophagy genes and formation of autophagosomes are induced in Arabidopsis by the necrotrophic fungal pathogen Botrytis cinerea. Induction of ATG18a and autophagy by B. cinerea was compromised in the wrky33 mutant, which is highly susceptible to necrotrophic pathogens. Arabidopsis mutants defective in autophagy exhibit enhanced susceptibility to the necrotrophic fungal pathogens B. cinerea and Alternaria brassicicola based on increased pathogen growth in the mutants. The hypersusceptibility of the autophagy mutants was associated with reduced expression of the jasmonate-regulated PFD1.2 gene, accelerated development of senescence-like chlorotic symptoms, and increased protein degradation in infected plant tissues. These results strongly suggest that autophagy cooperates with jasmonate- and WRKY33-mediated signaling pathways in the regulation of plant defense responses to necrotrophic pathogens.

  7. Antifungal activity of medicinal plant extracts against phytopathogenic fungus Alternaria spp Actividad antifúngica de extractos de plantas medicinales contra el hongo fitopatógeno Alternaria spp

    Directory of Open Access Journals (Sweden)

    Paola Díaz Dellavalle

    2011-06-01

    Full Text Available The aim of the study was to evaluate the antifungal activity of extracts of 10 plant species used in traditional Uruguayan medicine against the phytopathogenic fungus Alternaria spp. The plants were selected on the basis of their reported ethnobotanical uses. Aqueous, saline buffer and acid extracts of different plant species were screened in vitro for their antifungal activity against Alternaria spp. For the antifungal evaluation we used a microspectrophotometric assay. Minimal inhibitory concentration (MIC and minimum fungicidal concentration (MFC of the extracts were determined. Three solvents were assayed on different tissues of the plants and among the 29 evaluated extracts, 31% of the extracts inhibited growth, similar to the effects of a chemical fungicide. Acid extracts of the plants were more effective than the aqueous or buffer extracts against Alternaria spp. The MIC values of the extracts were determined ranging between 1.25 and 25 µg mL-1. The MFC values of the extracts ranged between 1.25 µg mL-1 (Rosmarinus officinalis L. and 10 µg mL-1 (Cynara scolymus L.. MICs and MFCs values obtained from leaves (Salvia officinalis L. and R. officinalis and seeds extracts (Salvia sclarea L. were quite comparable to values obtained with the conventional fungicide captan (2.5 µg mL-1. The extracts of Salvia sclarea, S. officinalis and R. officinalis could be considered as potential sources of antifungal compounds for treating diseases in plants. These extracts showed maximum activity, even at very low concentrations, and the same fungicide effects as chemical fungicide. We conclude from this that these extracts exhibit amazing fungicidal properties that support their traditional use as antiseptics.El objetivo de este trabajo fue evaluar la actividad antifúngica de extractos vegetales de 10 especies utilizadas en la medicina tradicional uruguaya contra el hongo fitopatógeno Alternaria spp. Las plantas fueron seleccionadas en base a usos

  8. [Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng].

    Science.gov (United States)

    Chen, Chang-Qing; Li, Tong; Li, Xin-Lian; Jiang, Yun; Tian, Lei; Xu, Peng

    2014-05-01

    To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG.

  9. Isolation and identification of the pathogens of jujube (Zizyphus jujuba cv. Huping) fruit Shrink disease in Shanxi%山西壶瓶枣缩果病病原茵分离和鉴定

    Institute of Scientific and Technical Information of China (English)

    徐祥彬; 赖童飞; 景云飞; 徐勇; 田世平

    2009-01-01

    2005~2008年山两壶瓶枣缩果病害发生严重,造成了巨大的经济损失.本文利用真菌ITS rDNA和细菌16S rDNA基因的通用引物,分别对分离白山西晋中的罹病壶瓶枣果实表而寄生真菌和细菌基因组DNA进行PCR扩增,将扩增产物进行核苷酸序列测定,在GenBank数据库进行Megablast同源性分析.确定壶瓶枣果实的主要寄生菌是细极链格孢菌(Alternaria alternata)、白囊耙齿菌(Irpex lacteus)、青霉菌(Penicillium expansum)、芽枝孢菌(Cladosporium tenuissimum)4种真菌和枯草芽孢杆菌(Bacillus subtilis)、巨大芽孢杆菌(B.megaterium)、短小芽孢朴菌(B.pumilus)、多粘类芽孢杆菌(Paenibacillus polymyxa)4种细菌.回接试验证明链格孢菌、青霉菌、芽枝孢菌是壶瓶枣果实主要的致病真菌,而所分离的细菌没有致病性.

  10. 几种真菌对3种常见冷季型草坪草的致病性测定%Pathogenicity of ten fungi affecting three common cool-season turfgrasses of China

    Institute of Scientific and Technical Information of China (English)

    李春杰; 南志标; 崔嵩; 胡玉骄; 李东明; 李强; 李悦; 李舟

    2003-01-01

    以我国北方常见的冷季型草坪草高羊茅(Festuca arundinacea)、多年生黑麦草(Lolium perenne)和草地早熟禾(Poa pratensis)为材料,将细交链孢(Alternaria alternata)、根腐离蠕孢(Bipolaris sorokiniana)、枝孢(Cladosporium herbarum)、新月弯孢(Curvularia lunata)、德氏霉(Drechslera sp.)、燕麦镰孢(Fusari-um avenaceum)、锐顶镰孢(F.acuminatum)、尖镰孢(F.oxysporum),腐皮镰孢(F.solani)和粉红粘帚霉(Gliocldium roseum)10种分离自草坪草的真菌接种,进行离体叶片的致病性测定.结果表明:细交链孢、根腐离蠕孢、德氏霉、腐皮镰孢、粉红粘帚霉和枝孢对高羊茅具有明显的致病性;根腐离蠕孢、燕麦镰孢和锐顶镰孢对黑麦草有明显的致病性;而仅根腐离蠕孢对早熟禾有较明显的致病性.

  11. A Preliminary Study on Pathogenic Bacteria of Mango Stem-end Rot in Hainan Province%海南省杧果蒂腐病病原菌的初步研究

    Institute of Scientific and Technical Information of China (English)

    邓泽明; 胡美姣; 白菊仙; 杨凤珍

    2002-01-01

    @@ (木,亡)果蒂腐病是世界(木,亡)果产地仅次于炭疽病的重要采后病害.该病使果实在贮运期间严重腐烂.据报道,引起果蒂腐病的病原菌有多种.广东省农业科学院植物保护研究所王璧生等认为,引起广东果蒂腐病的病原菌主要有Dothiorella dominicana Pet.et Cif.、Botryodiplodia theobromae Pat.(又名Diplodia natalensis Pole-Evans、Lasiodiplodia theobromae)和Phomopsis mangiferae Ahmad. 国外报道引起该病的病原菌更为复杂,除上述3种外,还有Dothiorella mangiferae、D.‘long'、D.aromatica、Cytosphaera mangiferae、Pestalotipsis sp. 、Phomopsis citri、Phloeospora rhodina 、Nattrassia mangiferae 、Botrytis sp.、Alternaria alternata 亦可引起果蒂腐病.

  12. Occurrence of Cladosporium spp. and Alternaria spp. spores in Western, Northern and Central-Eastern Poland in 2004-2006 and relation to some meteorological factors

    Science.gov (United States)

    Grinn-Gofroń, Agnieszka; Rapiejko, Piotr

    2009-08-01

    The concentration of airborne spores of Cladosporium spp. and Alternaria spp. has been investigated at three monitoring stations situated along the west-north and central-east transect in Poland (Szczecin, Olsztyn, Warszawa,) i.e. from a height of 100 m to 149 m above sea level. The aerobiological monitoring of fungal spores was performed by means of three Lanzoni volumetric spore traps. Cladosporium spp. spores were dominant at all the stations. The highest Cladosporium spp. and Alternaria spp. numbers of spores were observed at all the cities in July and August. Statistically significant correlations have been found between the Cladosporium spp. and Alternaria spp. concentration in the air and the mean air temperature, amount of precipitation, air pressure and relative air humidity. The spore count of Cladosporium spp. and Alternaria spp. is determined by the diversity of local flora and weather conditions, especially by the air temperature. The identification of factors, which influence and shape spore concentrations, may significantly improve the current methods of allergy prevention.

  13. Isolation, characterization and molecular three-dimensional structural predictions of metalloprotease from a phytopathogenic fungus, Alternaria solani (Ell. and Mart.) Sor.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Chandrasekar, Raman; Chun, Se-Chul; Sathiyabama, Muthukrishnan

    2016-08-01

    The present study aims at isolation, identification, characterization and prediction of three-dimensional molecular architecture of a proteolytic enzyme from the early blight pathogen, Alternaria solani which are hypothesized to be a marker of phytopathogenicity. Maximum enzyme production by A. solani was observed in Czapex's Dox broth amended with 2% (w/v) casein than other inducer amendments. Results indicate that the enzyme remained highly active in a pH range of 7.0-10.0 and a temperature range of 45-50°C. The enzyme was strongly inhibited by EDTA, whereas phenylmethylsulfonyl fluoride and monovalent cations (Na(+), K(+)) had little effect. Metal ions such as MgSO4, CaCl2, KCl at 10 mM concentration showed a stimulatory effect (>85%) on protease activity. Matrix-assisted laser desorption and ionization time of flight/mass spectrometry analysis of partially purified enzyme revealed the presence of protease belonging to a keratinolytic protein (metalloprotease) of exopeptidase nature. Putative A. solani keratinolytic enzyme (AsK) is made up of 216 amino acid residues with molecular weight (MW) 24.5 kDa, having a molecular formula of C1094H1704N290O342S4. Ramachandran plot analysis of the protein residues falling into the most favored secondary structures was observed at 84.2%. The major protein structural blocks, 2-β-sheets, and 9-α-helices have a greater tendency to be conserved during the evolutionary process than do mere sequences of amino acids. Besides, AsK, model prediction showed the presence of a Zinc atom at helix regions (Helix 3, 6, 7: His(57), His(130), His(169), and Cys(123)). Thus, it can be concluded that the major proteinases of AsK are divalent cation-requiring metalloproteinases and make them potential targets of protease inhibitors designing. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Eco-friendly PEG-based controlled release nano-formulations of Mancozeb: Synthesis and bioefficacy evaluation against phytopathogenic fungi Alternaria solani and Sclerotium rolfsii.

    Science.gov (United States)

    Majumder, Sujan; Shakil, Najam A; Kumar, Jitendra; Banerjee, Tirthankar; Sinha, Parimal; Singh, Braj B; Garg, Parul

    2016-12-01

    Controlled release (CR) nano-formulations of Mancozeb (manganese-zinc double salt of N,N-bisdithiocarbamic acid), a protective fungicide, have been prepared using laboratory-synthesized poly(ethylene glycols) (PEGs)-based functionalized amphiphilic copolymers without using any surfactants or external additives. The release kinetics of the developed Mancozeb CR formulations were studied and compared with that of commercially available 42% suspension concentrate and 75% wettable powder. Maximum amount of Mancozeb was released on 42nd day for PEG-600 and octyl chain, PEG-1000 and octyl chain, and PEG-600 and hexadecyl chain, on 35th day for PEG-1000 and hexadecyl chain, on 28th day for PEG-1500 and octyl chain, PEG-2000 and octyl chain, PEG-1500 and hexadecyl chain, and PEG-2000 and hexadecyl chain in comparison to both commercial formulations (15th day). The diffusion exponent (n value) of Mancozeb in water ranged from 0.42 to 0.62 in tested formulations. The half-release (t1/2) values ranged from 17.35 to 35.14 days, and the period of optimum availability of Mancozeb ranged from 18.54 to 35.42 days. Further, the in vitro bioefficacy evaluation of developed formulations was done against plant pathogenic fungi Alternaria solani and Sclerotium rolfsii by poison food technique. Effective dose for 50% inhibition in mgL(-1) (ED50) values of developed formulations varied from 1.31 to 2.79 mg L(-1) for A. solani, and 1.60 to 3.14 mg L(-1) for S. rolfsii. The present methodology is simple, economical, and eco-friendly for the development of environment-friendly CR formulations of Mancozeb. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, the maximum amount of active ingredient remains available for a reasonable period after application. In addition, the developed CR formulations were found to be suitable for fungicidal applications, allowing use

  15. Alternaria-induced release of IL-18 from damaged airway epithelial cells: an NF-κB dependent mechanism of Th2 differentiation?

    Directory of Open Access Journals (Sweden)

    Hiroki Murai

    Full Text Available BACKGROUND: A series of epidemiologic studies have identified the fungus Alternaria as a major risk factor for asthma. The airway epithelium plays a critical role in the pathogenesis of allergic asthma. These reports suggest that activated airway epithelial cells can produce cytokines such as IL-25, TSLP and IL-33 that induce Th2 phenotype. However the epithelium-derived products that mediate the pro-asthma effects of Alternaria are not well characterized. We hypothesized that exposure of the airway epithelium to Alternaria releasing cytokines that can induce Th2 differentiation. METHODOLOGY/PRINCIPAL FINDING: We used ELISA to measure human and mouse cytokines. Alternaria extract (ALT-E induced rapid release of IL-18, but not IL-4, IL-9, IL-13, IL-25, IL-33, or TSLP from cultured normal human bronchial epithelial cells; and in the BAL fluids of naïve mice after challenge with ALT-E. Both microscopic and FACS indicated that this release was associated with necrosis of epithelial cells. ALT-E induced much greater IL-18 release compared to 19 major outdoor allergens. Culture of naïve CD4 cells with rmIL-18 induced Th2 differentiation in the absence of IL-4 and STAT6, and this effect was abrogated by disrupting NF- κB p50 or with a NEMO binding peptide inhibitor. CONCLUSION/SIGNIFICANCE: Rapid and specific release of IL-18 from Alternaria-exposed damaged airway epithelial cells can directly initiate Th2 differentiation of naïve CD4(+ T-cells via a unique NF-κB dependent pathway.

  16. The dynamics of the fungal aerospores Alternaria sp. and Cladosporium sp. in Parisian atmospheric air, in France

    Science.gov (United States)

    Brezoczki, V. M.

    2016-08-01

    The bioallergens occurring naturally in the atmospheric air are microorganisms, pollen grains, plant seeds, leaf and stem scrap, or their protein molecules. The presence of various airborne fungal spores determines a high allergenic potential for public health. This effect is due to the high number of produced spores, which under favourable meteorological conditions (dry weather and wind) reach the surrounding air. This paper traces the dynamics of two types of fungi, Alternaria sp and Cladosporium sp, fungi which can be found outdoors, in the surrounding air, as well as indoors, inside houses (especially the conidia of Cladosporium sp). The effects of these fungal spores on human health are varies, ranging from seasonal allergies (hay fever, rhinitis, sinusitis etc.) to sever afflictions of the respiratory system, onset of asthma, disfunctionalities of the nervous systems, of the immune system, zymoses etc. The monitoring of the dynamics of the aerospores Alternaria sp and Cladosporium sp was carried out between 2010 and 2013, over a period of 42 weeks during one calendar year, from February to the end of September, in the surrounding air in the French capital, Paris. The regional and global climate and meteorological conditions are directly involved in the occurrence and development of fungi colonies, the transportation and dispersion of fungal spores in the atmospheric air, as well as in the creation of the environment required for the interaction of chemical and biological components in the air. Knowledge of the dynamics of the studied fungal aerospores, coupled with climate and meteorological changes, offers a series of information on the magnitude of the allergenic potential these airborne spores can determine. Legal regulations in this domain set the allergen risk threshold for the Alternaria sp aerospores at 3500 ÷ 7000 spores/m3 air/week, and for the Cladosporium sp aerospores at 56,000 spores/m3 air/week. Besides these regulations there exist a series of

  17. Effect of sulfur fertilization on the sanitary state of plants of the family Brassicaceae

    Directory of Open Access Journals (Sweden)

    Tomasz P. Kurowski

    2012-12-01

    Full Text Available The experiment was carried out in the years 2006-2008 in Bałcyny (N=53°35'49"; E=19°51'20". The aim of this study was to determine the effect of sulfur fertilization on the sanitary state of spring oilseed rape, winter oilseed rape, white mustard and Chinese mustard as well as on the species composition of fungi colonizing their seeds. Sulfur fertilization had a beneficial effect on the health of Brassicaceae plants infested by Alternaria blight, grey mould, Sclerotinia stem rot, Phoma stem canker and Verticillium wilt, but it had a varying effect on the occurrence of powdery mildew. Alternaria alternata and Penicillium spp. were isolated most frequently from Brassicaceae seeds. In general, more fungi (including pathogenic to Brassicaceae were isolated from the seeds of plants grown in non-sulfur fertilized plots. Pathogens occurred primarily on the seed surface, and their number decreased after surface disinfection of seeds.

  18. Emerging Pathogens Initiative (EPI)

    Data.gov (United States)

    Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

  19. Importancia del género Alternaria como productor de micotoxinas y agente causal de enfermedades humanas The importance of genus Alternaria in mycotoxins production and human diseases

    Directory of Open Access Journals (Sweden)

    M. Á. Pavón Moreno

    2012-12-01

    Full Text Available Alternaría es un género fúngico muy común, donde se incluyen numerosas especies saprofitas, endofíticas y patógenas ampliamente distribuidas en el suelo y la materia orgánica en descomposición. Incluye especies patógenas que pueden invadir los cultivos vegetales antes y después de la recolección y es responsable de considerables pérdidas económicas, debido a que reduce el rendimiento de las cosechas y produce alteraciones en los vegetales durante su almacenamiento. Las especies del género Alternaría sintetizan más de 70 metabolitos secundarios tóxicos para las plantas (fitotoxinas, algunos de los cuales afectan también a personas y animales, por lo que se consideran micotoxinas. La exposición a las toxinas de Alternaría spp. se ha relacionado con la aparición de efectos adversos para la salud en personas y animales y, en muchos casos, se ha demostrado que tienen capacidad genotóxica, mutagénica, carcinogénica y citotóxica. Las micotoxinas de Alternaría spp. se han aislado de frutas (manzana, pera, melón, albaricoque, uvas, uvas pasas, fresa, aceituna, cítricos e higos desecados, hortalizas (tomate, pimiento y zanahoria y tubérculos (patata, así como de numerosos alimentos procesados elaborados con materias primas contaminadas (zumos, conservas, salsas, etc.. Además, determinadas especies de Alternaría están implicadas en infecciones y alergias humanas, hasta el punto de que Alternaría se considera uno de los principales géneros fúngicos causantes de alergias.Alternaría is a cosmopolitan fungal genus that includes saprophytic, endophytic and pathogenic species, widely distributed in soil and organic matter in decomposition. Plant pathogenic species affect cereals, vegetables and fruit crops in the field and during storage. Alternaría spp. contamination is responsible for some of the world's most devastating plant diseases, causing serious reduction of crop yields and considerable economic losses. Alternar

  20. ANTIMICROBIAL ACTIVITY OF ROSA CANINA FLOWERS AGAINST SELECTED MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Katarína Rovná

    2015-02-01

    Full Text Available Rosa canina flowers were screened against various plant pathogenic microbial strains to study the antimicrobial properties of the plant. Ethanolic and methanolic extracts of flowers were screened applying agar well diffusion method against two Gram-negative bacteria including Escherichia coli CCM 3988 and Pseudomonas aeruginosa CCM 1960 and three microscopic filamentous fungi strains Aspergillus niger, Fusarium culmorum and Alternaria alternata, respectively. The best antimicrobial effect of ethanolic extract of Rosa canina flowers was found against Pseudomonas aeruginosa and the best antimicrobial effect of methanolic extract of Rosa canina flowers was found against Escherichia coli.

  1. Communities of fungi in grain from several generations of triticale

    Directory of Open Access Journals (Sweden)

    Jacek Kwiatkowski

    2012-12-01

    Full Text Available An assessment of health status of winter triticale grain obtained from a longterm reproduction experiment was performed in 1993-1994. Grain from six generations of triticale was examined each year. In both years of the study, the most frequently isolated fungus was Alternaria alternata. The number of isolated pathogens as well as the total extent of grain infestation by fungi depended on the weather conditions during the vegetative growth of triticale plants. There was no correlation between the generations of triticale and fungal infestation of triticale grain.

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

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2014-08-01

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

  3. EPIDEMIOLOGICAL ASPECTS OF LEAF BLIGHT OF CARROT (Daucus carota L. CAUSED BY Alternaria dauci (KÜHN GROVES & SKOLKO: SURVIVAL OF Alternaria dauci IN VEGETAL RESIDUES OF CARROT (Daucus carota L. CROP ASPECTOS EPIDEMIOLÓGICOS DA QUEIMA DAS FOLHAS DA CENOURA (Daucus carota L. CAUSADA POR Alternaria dauci (Kühn GROVES & SKOLKO: Sobrevivência de Alternaria dauci (Kühn Groves & SKOLKO em restos culturais da cenoura (Daucus carota L.

    Directory of Open Access Journals (Sweden)

    Geraldo Martins Chaves

    2007-09-01

    Full Text Available

    The spore viability of Alternaria dauci (Kühn Groves & Skolko in carrot (Daucus carota L. debris which were kept at different levels of temperature and relative humidity, without light, was studied. The temperature levels tested were 8, 16, 24 and 32°C, and the relative humidity levels 3, 18, 51, 73 and 100%. The treatments were different combinations of these levels. Humidity was the more important factor in preserving the fungus spore ability to germinate and its infectivity. Under conditions of high relative humidity and temperatures of 24 and 32°C, the spores rapidly lost their viability. This did not happen when the relative humidity was equal to, or below, 51%. The survival of fungus mycelium on carrot petioles was studied in non-treated organic soil, at different humidity levels, at three different depths, during a period of 120 days. Soil humidity was the factor of major significance in the persistence of the mycelium, followed by depths and time factors. In petioles kept at depths of 10 and 20 cm in humid soil, the survival was greatly reduced, while survival was markedly higher in those kept at the surface of dry soil. The effect of humidity on the viability of mycelium was studied also under soiless condition. Petioles were maintained in relative humidity controlled chamber, at 24°C. In saturated atmosphere (100% humidity, the mycelium viability was lost in less than 20 days. It was concluded that both, the conidial and mycelial form of Alternaria dauci are quite sensitive to high humidity levels.

    Estudou-se a sobrevivência das formas conidial e miceliana de Alternaria dauci, respectivamente, sobre folhas necrosadas e pecíolos de cenoura, sob diferentes condições mesológicas. Os esporos do fungo sobre conidióforos em folhas necrosadas de cenoura foram mantidos por 120 dias sob condi

  4. StCDPK5 confers resistance to late blight pathogen but increases susceptibility to early blight pathogen in potato via reactive oxygen species burst.

    Science.gov (United States)

    Kobayashi, Michie; Yoshioka, Miki; Asai, Shuta; Nomura, Hironari; Kuchimura, Kazuo; Mori, Hitoshi; Doke, Noriyuki; Yoshioka, Hirofumi

    2012-10-01

    • Potato (Solanum tuberosum) calcium-dependent protein kinase (StCDPK5) has been shown to phosphorylate the N-terminal region of plasma membrane RBOH (respiratory burst oxidase homolog) proteins, and participate in StRBOHB-mediated reactive oxygen species (ROS) burst. The constitutively active form, StCDPK5VK, provides a useful tool for gain-of-function analysis of RBOH in defense responses. • StCDPK5- and StCDPK5VK-green fluorescent protein fusion proteins were predominantly targeted to the plasma membrane, and conditional expression of StCDPK5VK activated StRBOHA-D. The interaction was confirmed by bimolecular fluorescence complementation assay. We generated transgenic potato plants containing StCDPK5VK under the control of a pathogen-inducible promoter to investigate the role of ROS burst on defense responses to blight pathogens. • Virulent isolates of the late blight pathogen Phytophthora infestans and the early blight pathogen Alternaria solani induced hypersensitive response-like cell death accompanied by ROS production at the infection sites of transgenic plants. Transgenic plants showed resistance to the near-obligate hemibiotrophic pathogen P. infestans and, by contrast, increased susceptibility to the necrotrophic pathogen A. solani. • These results indicate that RBOH-dependent ROS contribute to basal defense against near-obligate pathogens, but have a negative role in resistance or have a positive role in expansion of disease lesions caused by necrotrophic pathogens. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  5. Antagonistic Activities of Volatiles from Four Strains of Bacillus spp. and Paenibacillus spp. Against Soil-Borne Plant Pathogens

    Institute of Scientific and Technical Information of China (English)

    LIU Wei-wei; MU Wei; ZHU Bing-yu; DU You-chen; LIU Feng

    2008-01-01

    The four effective antagonistic Bacillus strains,isolated from the rhizosphere soil of cucumber in a greenhouse,produced antifungal volatiles.These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants,induced the mycelial morphological abnormalities,and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates.Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension.An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi,including Ascochyta citrullina,Alternaria solani,Alternaria brassicae,and so on.Interactions mediated by microbial volatiles could be widespread in soils,and volatiles may play an important role in reducing disease levels.A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa (BMP-11),Bacillus subtilis (BL02),and Bacillus pumilus (BSH-4 and ZB 13).Through headspace sampling and GC-MS analysis,a rich profile was found from B.subtilis and overlapping volatile patterns could be found among the different species.Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.

  6. Sobrevivência saprofítica de Alternaria brassicicola e manejo de restos foliares de brócolos Saprophytic survival of Alternaria brassicicola and management of broccoli leaf debris

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Martins Peruch

    2007-02-01

    Full Text Available A sobrevivência saprofítica do fungo Alternaria brassicicola foi investigada em restos foliares de brócolos (Brassica oleracea var. italica, em diferentes profundidades de incorporação no solo, períodos do ano e sistemas de manejo do solo. Os restos foliares infectados pelo patógeno foram distribuídos em parcelas no campo, na superfície do solo e nas profundidades de 5 e 10cm. Periodicamente, os restos foliares foram coletados e a concentração de conídios quantificada, sendo obtida a longevidade da esporulação e a taxa de extinção da esporulação. Foi verificada maior longevidade da esporulação nos restos foliares no período com temperaturas amenas, maior umidade relativa do ar e menor precipitação pluvial. Menor esporulação ocorreu quando os restos culturais foram incorporados a 10cm de profundidade. Quando comparados os sistemas de manejo convencional e orgânico, houve diferença na taxa de extinção da esporulação do patógeno quando a fonte de inóculo foi depositada nas profundidades de 5 e 10cm, sendo superior no solo sob manejo convencional, enquanto na superfície do solo não houve diferença. O manejo da alternariose em brócolos na região do estudo pode ser realizado pela incorporação dos restos foliares infectados no solo, à profundidade mínima de 10cm, visando a um intervalo mínimo de 60 dias entre cultivos de brássicas.The saprophytic survival of the fungus Alternaria brassicicola was investigated in leaf debris of broccoli (Brassica oleracea var. italica, at different depths of soil incorporation, periods of the year, and systems of soil management. Infected leaf debris were distributed in field plots, at the soil surface and at depths of 5 and 10cm. Periodically, the debris in the bags were collected and conidia concentrations were quantified for longevity of spore production and extinction rate. Higher spore production longevity was observed on leaf debris in the period with lower temperatures

  7. Microarray analyses during early stage of the tomato/Alternaria solani interaction

    Directory of Open Access Journals (Sweden)

    Priti Upadhyay

    2015-12-01

    Full Text Available Tomato early blight is an important threat and it has capacity to reduce the production in all major tomato producing areas. Molecular mechanism underlying the resistance against this is not well known. Therefore we studied this system to search the possible mechanism of resistance, which includes pathogenesis related protein, and pathways and transcription factors, which are responsible for resistance against this pathogen using affymetrix gene chip for tomato. Their differential expressions have enhanced the biochemical and other related products, which have, direct or indirect role in stopping the penetration of mycelia in the host plant.

  8. Microarray analyses during early stage of the tomato/Alternaria solani interaction.

    Science.gov (United States)

    Upadhyay, Priti; Rai, Ashutosh; Kumar, Rajesh; Singh, Major; Sinha, Brajesh

    2015-12-01

    Tomato early blight is an important threat and it has capacity to reduce the production in all major tomato producing areas. Molecular mechanism underlying the resistance against this is not well known. Therefore we studied this system to search the possible mechanism of resistance, which includes pathogenesis related protein, and pathways and transcription factors, which are responsible for resistance against this pathogen using affymetrix gene chip for tomato. Their differential expressions have enhanced the biochemical and other related products, which have, direct or indirect role in stopping the penetration of mycelia in the host plant.

  9. Necrotrophic pathogens use the salicylic acid signaling pathway to promote disease development in tomato.

    Science.gov (United States)

    Rahman, Taha Abd El; Oirdi, Mohamed El; Gonzalez-Lamothe, Rocio; Bouarab, Kamal

    2012-12-01

    Plants use different immune pathways to combat pathogens. The activation of the jasmonic acid (JA)-signaling pathway is required for resistance against necrotrophic pathogens; however, to combat biotrophic pathogens, the plants activate mainly the salicylic acid (SA)-signaling pathway. SA can antagonize JA signaling and vice versa. NPR1 (noninducible pathogenesis-related 1) is considered a master regulator of SA signaling. NPR1 interacts with TGA transcription factors, ultimately leading to the activation of SA-dependent responses. SA has been shown to promote disease development caused by the necrotrophic pathogen Botrytis cinerea through NPR1, by suppressing the expression of two JA-dependent defense genes, proteinase inhibitors I and II. We show here that the transcription factor TGA1.a contributes to disease development caused by B. cinerea in tomato by suppressing the expression of proteinase inhibitors I and II. Finally, we present evidence that the SA-signaling pathway contributes to disease development caused by another necrotrophic pathogen, Alternaria solani, in tomato. Disease development promoted by SA through NPR1 requires the TGA1.a transcription factor. These data highlight how necrotrophs manipulate the SAsignaling pathway to promote their disease in tomato.

  10. 一株昆虫内生真菌 Alternaria sp畅次级代谢产物研究%Secondary metabolites from the insect-derived endophytic Fungus Alternaria sp.

    Institute of Scientific and Technical Information of China (English)

    郭玲芝; 刘呈雄; 徐帮; 陈剑锋; 邹坤; 郭志勇

    2014-01-01

    采用硅胶柱色谱,Sephadex LH-20凝胶柱色谱及HPLC等方法从昆虫共生真菌Alternaria sp.(Be-1)的发酵液分离得到7个代谢产物,经NMR,MS及理化性质等确定为4个环肽和3个聚酮类化合物,4-甲氧基格链孢酚(1),5′-methoxy-6-methyl-biphenyl-3,4,3′-triol(2),altenusin(3),二氢腾毒素(4),腾毒素(5),环(4-羟基-脯-亮)二肽(6)和cyclo(L-Phenylalanine-trans-4-hydroxy-L-proline)(7)。测定了化合物1-7对抗肿瘤治疗靶点-受体酪氨酸激酶的抑制活性,药理实验结果表明,化合物1-6对三种酪氨酸激酶(EGFR,VEGFR-1,c-Met)具有不同程度的抑制活性,化合物1,3,6对EGFR,VEGFR-1,c-Met均具有强的抑制作用,而且化合物6还有选择性抑制EGFR和c-Met的活性。%Seven secondary metabolites were isolated from the endophytic fungus Alternaria sp.(Be-1) by silica gel,Sephadex LH-20 chromatography and HPLC.Their structures were elucidated as alternariol 4-O-methyl ether(1),5′-methoxy-6-methyl-biphenyl-3,4,3′-triol(2),altenusin(3),tentoxin(4),dihydrotentoxin(5),cyclo(4-hydroxyl-Pro-Leu)(6), cyclo(L-Phenylalanine-trans-4-hydroxy-L-proline)(7)by NMR and MS.The activity assay showed that compounds 1-6 displayed inhibitory activities against the three targets of tyrosine kinases (EGFR,VEGFR-1,c-Met),and compounds 1,3 and 6 showed strong inhibiting activities to EGFR, VEGFR-1,c-Met.At last,compound 6 displayed selectively inhibitory activity to EGFR and c-Met.

  11. Determination of Alternaria mycotoxins in wine and juice using ionic liquid modified countercurrent chromatography as a pretreatment method followed by high-performance liquid chromatography.

    Science.gov (United States)

    Fan, Chen; Cao, Xueli; Liu, Man; Wang, Wei

    2016-03-04

    Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples.

  12. Protease-dependent activation of epithelial cells by fungal allergens leads to morphologic changes and cytokine production

    NARCIS (Netherlands)

    Kauffman, HF; Tomee, JFC; van de Riet, MA; Timmerman, AJB; Borger, P

    2000-01-01

    Background: Proteases in extracts of Aspergillus fumigatus cause epithelial cell desquamation and release of proinflammatory cytokines. Objective: We sought to assess protease activity in Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus extracts and study the ability of these e

  13. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Science.gov (United States)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  14. Laboratory research on the efficacy of chlorine dioxide fumigation for the remediation of mold-contaminated buildings--conference paper

    Science.gov (United States)

    The purpose of this project was to determine the efficacy ofCl02 fumigation to inactivate viable mold, mycotoxins, and allergens on building materials. Alternaria alternata, Aspergillus versicolor, Aspergillus Jumigatus, Chaetomium globosum, and Stachybotrys chartarum were indivi...

  15. Fruit-specific overexpression of wound-induced tap1 under E8 promoter in tomato confers resistance to fungal pathogens at ripening stage.

    Science.gov (United States)

    Kesanakurti, Divya; Kolattukudy, Pappachan E; Kirti, Pulugurtha Bhardwaja

    2012-10-01

    Based on high economic importance and nutritious value of tomato fruits and as previous studies employed E8 promoter in fruit ripening-specific gene expression, we have developed transgenic tomato plants overexpressing tomato anionic peroxidase cDNA (tap1) under E8 promoter. Stable transgene integration was confirmed by polymerase chain reaction (PCR) and Southern analysis for nptII. Northern blotting confirmed elevated tap1 levels in the breaker- and red-ripe stages of T(1) transgenic fruits, whereas wild-type (WT) plants did not show tap1 expression in these developmental stages. Further, tap1 expression levels were significantly enhanced in response to wounding in breaker- and red-ripe stages of transgenic fruits, whereas wound-induced expression of tap1 was not detected in WT fruits. Confocal microscopy revealed high accumulation of phenolic compounds at the wound site in transgenic fruits suggesting a role of tap1 in wound-induced phenolic polymerization. Total peroxidase activity has increased remarkably in transgenic pericarp tissues in response to wounding, while very less or minimal levels were recorded in WT pericarp tissues. Transgenic fruits also displayed reduced post-harvest decay and increased resistance toward Alternaria alternata and Fusarium solani infection with noticeable inhibition in lesion formation. Conidiospore germination and mycelial growth of F. solani were severely inhibited when treated with E8-tap1 fruit extracts compared to WT fruits. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay showed reduced spore viability when incubated in E8-tap1 fruit extracts. Thus, fruit-specific expression of tap1 using E8 promoter is associated with enhanced total peroxidase activity and high phenolic accumulation in fruits with minimized post-harvest deterioration caused by wounding and fungal attack in tomato fruits.

  16. Identification of the pathogenic fungus causing brown spot on tangerine( Citrus reticulata CV.Hongjv%红橘褐斑病病原鉴定

    Institute of Scientific and Technical Information of China (English)

    陈昌胜; 黄峰; 程兰; 冯春刚; 黄涛江; 李红叶

    2011-01-01

    自2007年起重庆万州的红橘(Citrus reticulata Blanco,CV.Hongjv)上爆发一种未曾见过的病害,损失严重,因病斑褐色,故被称之为褐斑病.褐斑病贯穿柑橘整个生长季节,主要为害叶片和果实,严重时也为害新梢,引起大量落叶和落果,甚至枝梢枯死.为明确其病原,本研究从病区多个果园采集发病的叶片、果实和枝梢,检查和分离培养发现病组织中广泛存在链格孢菌(Alternaria)和炭疽菌(Colletotrichum).致病性试验证明只有链格孢菌才能引起类似褐斑症状,而炭疽菌和空白对照都不产生任何症状.通过比较研究这些链格孢菌菌株的形态学,培养性状和多聚半乳糖醛酸酶(endoPG)基因的部分序列,可以断定红橘褐斑病的病原为交链格孢菌[A.alternate(Fr.)Keissler].病原性质的确定将为红橘褐斑病发生规律的研究和控制奠定基础.%An unknown disease has been breaking out and causing a great loss on Hongjv (Citrus reticulata Blanco, CV. Hongjv) since 2007 in Wanzhou, Zhongqing, China. The disease was characterized as the brown spot on affected tissues and named "brown spot disease" temporarily. The disease occurs around a growing season and the severe affected leaves and fruits drop quickly. To determine the causing agent, the infected leaves, fruits and shoots were collected from different orchards. Typical conidiospores and cultures of Alternaria and Colletotrichum were always observed and isolated from infected tissues. However, pathogenici-ty test showed that only the isolates of Alternaria were pathogenic to the leaves and fruits of tangerine (Ci. Reticulata CV. Ponkan). Based on the study of morphology, cultural feature and partial sequence of an endopo-lygalacturonase gene (endoPG), the pathogenic Alternaria was identified as A. Alternate (Fr. ) Keissler. The clarification of pathogen would benefit to the study on epidemiology and control of this disease.

  17. Alternaria toxins: Altertoxin II is a much stronger mutagen and DNA strand breaking mycotoxin than alternariol and its methyl ether in cultured mammalian cells.

    Science.gov (United States)

    Fleck, Stefanie C; Burkhardt, Britta; Pfeiffer, Erika; Metzler, Manfred

    2012-10-02

    Altertoxin II (ATX II) is one of the several mycotoxins produced by Alternaria fungi. It has a perylene quinone structure and is highly mutagenic in Ames Salmonella typhimurium, but its mutagenicity in mammalian cells has not been studied before. Here we report that ATX II is a potent mutagen in cultured Chinese hamster V79 cells, inducing a concentration-dependent increase of mutations at the hypoxanthine guanine phosphoribosyltransferase gene locus at concentrations similar to that of the established mutagen 4-quinoline-N-oxide. Thus, ATX II is at least 50-times more potent as a mutagen than the common Alternaria toxins alternariol (AOH) and alternariol methyl ether (AME). In contrast to AOH and AME, ATX II does not affect the cell cycle of V79 cells. ATX II also causes DNA strand breaks in V79 cells, with a potency again exceeding that of AOH and AME. The high mutagenic and DNA strand breaking activity of ATX II raises the question of whether this Alternaria toxin poses a risk for public health, and warrants studies on the occurrence of ATX II and other perylene quinone-type mycotoxins in food and feed.

  18. Comparative study on the effect of chemicals on Alternaria blight in Indian mustard--a multi-location study in India.

    Science.gov (United States)

    Meena, P D; Chattopadhyay, C; Kumar, A; Awasthi, R P; Singh, R; Kaur, S; Thomas, L; Goyal, P; Chand, P

    2011-05-01

    High severity of Altemaria blight disease is a major constraint in production of rapeseed-mustard in India. The aim of this study was to investigate the suppressive potential of chemicals viz., zinc sulphate, borax, sulphur, potash and calcium sulphate, aqueous extracts viz., Eucalyptus globosus (50 g l-1) leaf extract and garlic (Allium sativum) bulb (20 g l-1) extract, cow urine and bio-agents Trichoderma harzianum, Pseudomonas fluorescence in comparison with the recommended chemical fungicide (mancozeb), against foliar disease Alternaria blight of Indian mustard [Brassica juncea (L.) Czern. and Coss] under five different geographical locations of India. Mancozeb recorded the lowest mean severity (leaf: 33.1%; pod: 26.3%) of Alternaria blight with efficacy of garlic bulb extract alone (leaf = 34.4%; pod = 27.3%) or in combination with cow urine (leaf = 34.2%; pod = 28.6%) being statistically at par with the recommended chemical fungicide. Chemicals also proved effective in reducing Alternaria blight severity on leaves and pods of Indian mustard (leaf = 36.3-37.9%; pod = 27.5-30.1%). The effective treatments besides providing significant reduction in disease severity also enabled increase in dry seed yield of the crop (mancozeb = 2052 kg ha-1; garlic = 2006 kg ha-1; control = 1561 kg ha-1).

  19. A 10-year study of Alternaria and Cladosporium in two Polish cities (Szczecin and Cracow) and relationship with the meteorological parameters.

    Science.gov (United States)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka; Stępalska, Danuta; Myszkowska, Dorota

    Alternaria and Cladosporium spores belong to the most frequent and allergenic particles in bioaerosol in the temperate climate. The investigation of Alternaria and Cladosporium spore concentrations was performed in two cities in Poland, Szczecin and Cracow, in 2004-2013. The meteorological parameters taken to assess their impact on fungal spores were average, maximum and minimum temperature, relative humidity and average wind velocity. In order to reveal whether changes in dynamics of spore seasons are driven by meteorological conditions, ordination methods were applied. Canonical correspondence analysis was used to explore redundancy among the predictors (meteorological parameters). Prior to ordination analyses, the data were log(x)-transformed. Concentrations of Alternaria and Cladosporium spores were significantly higher in Szczecin comparing to Cracow, but it was also observed the decreasing trend in the spore concentrations in Szczecin. As regards temperature, it was higher in Cracow and was still increasing in the studied years. Relative humidity and wind velocity were significantly lower in Cracow. In Szczecin meteorological conditions did not explain changes in spore season characteristics (insignificant redundancy analysis models), while in Cracow's redundancy analysis models indicated that spore season parameters were in over 40 % determined by meteorological conditions, mainly air temperature and wind velocity. If they increase, the peak value, total number of spores and their average concentrations in a season will also increase.

  20. Specific PCR-based detection of Alternaria helianthi

    DEFF Research Database (Denmark)

    Udayashankar, A.C.; Nayaka, S. Chandra; Archana, B.

    2012-01-01

    was developed with species-specific primers designed based on the sequence data of a region consisting of the 5.8S RNA gene and internal transcribed spacers-ITS 1 and ITS 2 of nuclear ribosomal RNA gene (rDNA) repeats of A. helianthi. The specificity of the primer pairs AhN1F and AhN1R designed was verified...... tested. The detection limit of the PCR method was of 10 pg from template DNA. The primers could also detect the pathogen in infected sunflower seed. This species-specific PCR method provides a quick, simple, powerful and reliable alternative to conventional methods in the detection and identification...... of A. helianthi. This is the first report of an A. helianthi-specific primer set....

  1. Arabidopsis WRKY33 transcription factor is required for resistance to necrotrophic fungal pathogens.

    Science.gov (United States)

    Zheng, Zuyu; Qamar, Synan Abu; Chen, Zhixiang; Mengiste, Tesfaye

    2006-11-01

    Plant WRKY transcription factors are key regulatory components of plant responses to microbial infection. In addition to regulating the expression of defense-related genes, WRKY transcription factors have also been shown to regulate cross-talk between jasmonate- and salicylate-regulated disease response pathways. The two pathways mediate resistance against different types of microbial pathogens, and there are numerous reports of antagonistic interactions between them. Here we show that mutations of the Arabidopsis WRKY33 gene encoding a WRKY transcription factor cause enhanced susceptibility to the necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola concomitant with reduced expression of the jasmonate-regulated plant defensin PDF1.2 gene. Ectopic over-expression of WRKY33, on the other hand, increases resistance to the two necrotrophic fungal pathogens. The wrky33 mutants do not show altered responses to a virulent strain of the bacterial pathogen Pseudomonas syringae, although the ectopic expression of WRKY33 results in enhanced susceptibility to this pathogen. The susceptibility of WRKY33-over-expressing plants to P. syringae is associated with reduced expression of the salicylate-regulated PR-1 gene. The WRKY33 transcript is induced in response to pathogen infection, or treatment with salicylate or the paraquat herbicide that generates activated oxygen species in exposed cells. WRKY33 is localized to the nucleus of plant cells and recognizes DNA molecules containing the TTGACC W-box sequence. Together, these results indicate that pathogen-induced WRKY33 is an important transcription factor that regulates the antagonistic relationship between defense pathways mediating responses to P. syringae and necrotrophic pathogens.

  2. 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

  3. In vitro antifungal activity of four chemotypes of Lippia alba (Verbenaceae essential oils against Alternaria solani (Pleosporeaceae isolates

    Directory of Open Access Journals (Sweden)

    ELISA Z. TOMAZONI

    2016-06-01

    Full Text Available Several volatile natural compounds produced by plant secondary metabolism have been proven to present antimicrobial action, enabling their use in phytopathogen control. They also present low environmental impact when compared to conventional pesticides. Essential oils contain these compounds and can be found in several plant species, such as Lippia alba (Mill. N.E. Brown (Verbenaceae. Essential oils of four chemotypes of L. alba, characterized by their major compounds, namely camphor, citral, linalool and camphor/1,8-cineole, were tested against the phytopathogen Alternaria solani Sorauer (Pleosporaceae, which causes early blight on tomatoes and is responsible for great economic losses regarding production. Essential oils antifungal action was tested in vitro using potato dextrose agar medium with essential oil concentrations at 0.1, 0.5, 1.0, 1.5 and 2.0 µL mL-1. The chemotype that had the best performance was citral, showing significant inhibition compared to the others, starting at the 0.5 µL mL-1 concentration. The essential oil belonging to the linalool chemotype was efficient starting at the 1.5 µL mL-1 concentration. Conversely, the camphor chemotype did not show any action against the phytopathogen. Moreover, the essential oils had no remarkable effect on tomato germination and growth. In conclusion, these essential oils presented fungicidal action against A. solani.

  4. Content of the Alternaria mycotoxin tenuazonic acid in food commodities determined by a stable isotope dilution assay.

    Science.gov (United States)

    Asam, Stefan; Lichtenegger, Martina; Liu, Yang; Rychlik, Michael

    2012-02-01

    The Alternaria mycotoxin tenuazonic acid (TA) was quantified in fruit juices (n = 50), cereals (n = 12) and spices (n = 38) using a recently developed stable isotope dilution assay (SIDA). [(13) C6,(15) N]-TA was used as the internal standard. Method validation revealed low limits of detection (LODs) of 0.15 μg/kg (fruit juices), 1.0 μg/kg (cereals) and 17 μg/kg (spices). The respective limits of quantitation were about three times higher. Recovery was about 100% for all matrices. The precision (relative standard deviation of replicate analyses of naturally contaminated samples) was 4.2% (grape juice; 1.7 μg/kg), 3.5% (whole wheat flour; 36 μg/kg) and 0.9% (curry powder; 215 μg/kg). The median content of TA in the analyzed samples was 1.8 μg/kg (fruit juices), 16 μg/kg (cereals) and 500 μg/kg (spices). Positive samples amounted to 86% (fruit juices), 92% (cereals) and 87% (spices).

  5. Phosphoproteome profiles of the phytopathogenic fungi Alternaria brassicicola and Botrytis cinerea during exponential growth in axenic cultures.

    Science.gov (United States)

    Davanture, Marlène; Dumur, Jérôme; Bataillé-Simoneau, Nelly; Campion, Claire; Valot, Benoît; Zivy, Michel; Simoneau, Philippe; Fillinger, Sabine

    2014-07-01

    This study describes the gel-free phosphoproteomic analysis of the phytopathogenic fungi Alternaria brassicicola and Botrytis cinerea grown in vitro under nonlimiting conditions. Using a combination of strong cation exchange and IMAC prior to LC-MS, we identified over 1350 phosphopeptides per fungus representing over 800 phosphoproteins. The preferred phosphorylation sites were found on serine (>80%) and threonine (>15%), whereas phosphorylated tyrosine residues were found at less than 1% in A. brassicicola and at a slightly higher ratio in B. cinerea (1.5%). Biological processes represented principally among the phoshoproteins were those involved in response and transduction of stimuli as well as in regulation of cellular and metabolic processes. Most known elements of signal transduction were found in the datasets of both fungi. This study also revealed unexpected phosphorylation sites in histidine kinases, a category overrepresented in filamentous ascomycetes compared to yeast. The data have been deposited to the ProteomeXchange database with identifier PXD000817 (http://proteomecentral.proteomexchange.org/dataset/PXD000817).

  6. Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden.

    Science.gov (United States)

    Odilbekov, Firuz; Edin, Eva; Garkava-Gustavsson, Larisa; Hovmalm, Helena Persson; Liljeroth, Erland

    2016-01-01

    Early blight, caused by the fungus Alternaria solani, occurs on potato mainly in the south-eastern part of Sweden, but also in other parts of the country. The aim of this study was to investigate the genetic diversity of A. solani populations from different potato growing regions in south-eastern Sweden using AFLP marker analysis. In addition, the cultured isolates were examined for substitutions in the gene encoding cytochrome b, associated with loss of sensitivity against QoI fungicides. Nei's gene diversity index for the Swedish populations of A. solani revealed a gene diversity of up to 0.20. Also genetic differentiation was observed among populations of A. solani from different locations in south-eastern Sweden. The mitochondrial genotype of the isolates of A. solani was determined and both known genotypes, GI (genotype 1) and GII (genotype 2), were found among the isolates. The occurrence of the F129L substitution associated with a loss of sensitivity to strobilurins was confirmed among the GII isolates. In vitro conidial germination tests verified that isolates containing the F129L substitution had reduced sensitivity to azoxystrobin and, at a lower extent, to pyraclostrobin. Genetic diversity was relatively high among isolates of A. solani in south-eastern part of Sweden. F129L substitutions, leading to reduced sensitivity to strobilurins, have been established in field populations, which may have implications for the future efficacy of QoI fungicides.

  7. In vitro antifungal activity of four chemotypes of Lippia alba (Verbenaceae) essential oils against Alternaria solani (Pleosporeaceae) isolates.

    Science.gov (United States)

    Tomazoni, Elisa Z; Pansera, Márcia R; Pauletti, Gabriel F; Moura, Sidnei; Ribeiro, Rute T S; Schwambach, Joséli

    2016-05-31

    Several volatile natural compounds produced by plant secondary metabolism have been proven to present antimicrobial action, enabling their use in phytopathogen control. They also present low environmental impact when compared to conventional pesticides. Essential oils contain these compounds and can be found in several plant species, such as Lippia alba (Mill.) N.E. Brown (Verbenaceae). Essential oils of four chemotypes of L. alba, characterized by their major compounds, namely camphor, citral, linalool and camphor/1,8-cineole, were tested against the phytopathogen Alternaria solani Sorauer (Pleosporaceae), which causes early blight on tomatoes and is responsible for great economic losses regarding production. Essential oils antifungal action was tested in vitro using potato dextrose agar medium with essential oil concentrations at 0.1, 0.5, 1.0, 1.5 and 2.0 µL mL-1. The chemotype that had the best performance was citral, showing significant inhibition compared to the others, starting at the 0.5 µL mL-1 concentration. The essential oil belonging to the linalool chemotype was efficient starting at the 1.5 µL mL-1 concentration. Conversely, the camphor chemotype did not show any action against the phytopathogen. Moreover, the essential oils had no remarkable effect on tomato germination and growth. In conclusion, these essential oils presented fungicidal action against A. solani.

  8. Development of a Selective Medium for the Fungal Pathogen Cylindrocarpon destructans Using Radicicol

    Directory of Open Access Journals (Sweden)

    Yunhee Kang

    2014-12-01

    Full Text Available The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus.

  9. Evaluating the Ability of some Medicinal Plants for Controlling Rhizopus (Rhizopu snigricans and Black Spot Rot (Alternaria alternate as Postharvest Diseases in Tomato Produced under Conventional and Organic Cropping Systems

    Directory of Open Access Journals (Sweden)

    S.M Seyyedi

    2016-11-01

    Full Text Available Introduction After crops harvesting, conditions and durations of storage are considered as the most crucial factors formaintaining the nutritional value and quality of agro-horticultural products such as tomato (Lycopersicom esculentum Mill. and its waste reduction. However, the rhizopus rot (Rhizopus stolonifer and black spot rot (Alternaria alternate are the most important postharvest diseases in tomato during storage. In other word, among the factors reducing quality of the postharvest tomato, Rhizopus nigricans Ehrenb. (Rhizopus stolonifer and Alternaria alternate (Fr.:Fr. Keissl. f. sp. lycopersici paly a special role in the contaminated tomato fruits that can affect its taste, firmness and stiffness. In recent years, due to the problems and threats arising from the use of chemical fungicides in agricultural systems, principled management of alternative biological approaches for reducing the postharvest contamination in tomato, especially during storage, is emphasized more than ever. Considering these conditions, the current study was aimed to investigate the effects of some medicinal plants including thyme (Thymus vulgaris L., pennyroyal (Mentha pulegium L., peppermint (Mentha piperita L., eucalyptus (Eucalyptus globules L., caster bean (Ricinus communis L. and tomato in their ability to control the rhizopus (Rhizopus nigricans and black spot rot (Alternaria alternate in tomato production under conventional and organic cropping systems. Materials and methods The experiment was conducted at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during theyear of 2010. A completely randomized design was used based on factorial arrangement with three replications and 14 treatments. Two cropping production systems (conventional and organic and seven medicinal plants (thyme, pennyroyal, peppermint, eucalyptus, caster bean, tomato and control were the first and the second experimental factors, respectively. After collecting plant samples

  10. Market Disease Pathogens Detection of Imported Fruits in Shanghai

    Institute of Scientific and Technical Information of China (English)

    MA Teng-fei; YANG Bo; YU Yue; WANG Yi-wen; LIU Yi; XU Zhen; LIU Yan; ZHU Pin-kuan; ZHANG Wei; ZHANG Zai-bao; Toyoda Hideyoshi; XU Ling

    2009-01-01

    A tremendous amount of imported fresh fruits has been delivered to Shanghai markets,increasing the risk of invasion by harmful plant pathogens.Therefore,it is important to establish an effective detection and supervision system to survey the outbreak of the market diseases of the imported fruits during marketing.The samples were regularly surveyed in different markets to examine varieties,prices,localities,selling conditions,and diseases of the imported fruits from 2004 to 2008.The survey showed that 58 species of 30 different fruits were imported to Shanghai from 16 countries with more expensive price.The larger products were bananas,grapes,apples,and oranges.During the investigation,we found that the imported fruits frequently brought about the relatively serious market diseases.On the basis of morphology and the nuclear internal transcribed spacer (ITS) of ribosomal DNA (rDNA) analysis,151 isolates of 15 fungi genera,which shown to be pathogenic afcer the inoculation assay.were finally identified.Among the identified fungi,Alternaria was the most frequent one with the highest detection rate (47.68%),followed by Penicillium (14.57%) and Fusarium (11.92%),respectively.Additionally,Pestalotiopsis microspora (detected in grapes Red-Globe coming from the USA) and Botrytis sp.(detected in black-plums coming from the USA)were first reported in China market.The present study summarized the selling situation of the imported fruits in Shanghai markets and constructed a library of the pathogens detected in the imported fruits during the selling period.The results obtained are useful to offer technical parameters for Chinese quarantine in order to prevent an invasion of the foreign harmful micro-organisms.

  11. The wild tomato species Solanum chilense shows variation in pathogen resistance between geographically distinct populations

    Science.gov (United States)

    Scheikl, Daniela; Tellier, Aurélien

    2017-01-01

    Wild tomatoes are a valuable source of disease resistance germplasm for tomato (Solanum lycopersicum) breeders. Many species are known to possess a certain degree of resistance against certain pathogens; however, evolution of resistance traits is yet poorly understood. For some species, like Solanum chilense, both differences in habitat and within species genetic diversity are very large. Here we aim to investigate the occurrence of spatially heterogeneous coevolutionary pressures between populations of S. chilense. We investigate the phenotypic differences in disease resistance within S. chilense against three common tomato pathogens (Alternaria solani, Phytophthora infestans and a Fusarium sp.) and confirm high degrees of variability in resistance properties between selected populations. Using generalised linear mixed models, we show that disease resistance does not follow the known demographic patterns of the species. Models with up to five available climatic and geographic variables are required to best describe resistance differences, confirming the complexity of factors involved in local resistance variation. We confirm that within S. chilense, resistance properties against various pathogens show a mosaic pattern and do not follow environmental patterns, indicating the strength of local pathogen pressures. Our study can form the basis for further investigations of the genetic traits involved. PMID:28133579

  12. Screening, Growth Promoting and Control Effect of Antagonistic Strains Against Rhizoctonia solani Kuhn and Alternaria panax Whetz%人参立枯病与黑斑病拮抗细菌的筛选及其促生防病能力∗

    Institute of Scientific and Technical Information of China (English)

    孙卓; 杨利民

    2015-01-01

    采用滤纸片法和牛津杯法从多年生人参根际土壤中筛选出1株对立枯丝核菌( Rhizoctonia solani Ku⁃hn)和人参链格孢菌( Alternaria panax Whetz)均有较强拮抗能力的内生芽孢杆菌( Bacillus endophyticus) SZ-56,并测定了其防病促生效果。结果表明:SZ-56对立枯丝核菌和人参链格孢的抑菌率分别为87�77%和65�40%,其还具备广谱拮抗性;SZ-56具备盆栽防控能力,对人参立枯病、人参黑斑病的保护和治疗作用效果分别为70�25%、73�94%和52�9%、53�41%,防治效果与农药对照组相比持平或略高;SZ-56对人参促生效果显著,经其处理后的人参平均植株高、茎叶鲜质量、茎叶干质量、根长、根鲜质量、根干质量均有不同程度的增加,自然土中人参的茎叶鲜质量、根鲜质量和根干质量均超对照2倍以上,其中根干质量增长率更是高达239�99%,显著优于对照组。%By filter paper method and Oxford cup method,a strain of Bacillus endophyticus SZ-56, which was strongly antagonistic to Rhizoctonia solani Kuhn and Alternaria panax Whetz, was screened from ginseng rhizosphere soil, and control ability and growth⁃promoting effect at the root of the ginseng were determined. The results indicated that the inhibitive rate of the bacterial strain SZ-56 to Rhizoctonia solani Kuhn and Alternaria panax Whetz were 87�77%and 65�40% respectively. The bacterial strain SZ-56 had good control effect on ginseng fungal pathogens. The strain SZ-56 had flat or slightly higher efficacy ( P<0. 05) compared with the pesticides treatments, with no dilu⁃tion in pots trails,the protective and the therapeutic efficacy of the aseptic filtrate of SZ-56 reached 70�25% and 73�94% on Rhizoctonia solani Kuhn, 52�9% and 53�41% on Alternaria panax Whetz, respectively. The study on the growth⁃promoting effect indicated that after drenching the ginseng root with SZ

  13. Study on Prevalence of Mycoflora in Wheat Seeds

    Directory of Open Access Journals (Sweden)

    Pratishtha Adhikari

    2016-01-01

    Full Text Available Forty seed sample of wheat (Triticum aestivum were collected from four locations viz. Chitwan, Kaski, Banke and Lalitpur and tested by blotter method at laboratory during 2013 for determining fungal pathogens associated with wheat seeds in Nepal. Eighteen species representing thirteen genera of fungi were recovered from the seed. Alternaria alternata and Bipolaris sorokiniana were predominant in all the varieties/genotypes from all the locations, where B. sorokiniana was strongly pathogenic in wheat crop. Percentage frequency and type of fungi detected varied with variety and locations. Bipolaris sorokiniana was highest (64.40% in Banke than remaining three locations. Seeds of Chitwan had lowest percentage (5.50% of seed infection as compared to other locations. Relative abundance of Alternaria alternata (55.10% was highest as it was the most prevalent component of seed borne mycoflora, followed by Bipolaris sorokiniana (34.69% and Cladosporium herbarum (7.19%. Differences in quantity of precipitation and relative humidity might be the possible reason for variation in frequency and type of fungi detected in wheat seeds of four locations.

  14. Isolation and characterization of rhizosphere bacteria for the biocontrol of the damping-off disease of tomatoes in Tunisia.

    Science.gov (United States)

    Hammami, Inés; Ben Hsouna, Anis; Hamdi, Naceur; Gdoura, Radhouane; Triki, Mohamed Ali

    2013-01-01

    Fluorescent Pseudomonas spp., isolated from tomato and pepper plants rhizosphere soil, was evaluated in vitro as a potential antagonist of fungal pathogens. Pseudomonas strains were tested against the causal agents of tomatoes damping-off (Sclerotinia sclerotiorum), root rot (Fusarium solani), and causal agents of stem canker and leaf blight (Alternaria alternata). For this purpose, dual culture antagonism assays were carried out on 25% tryptic soy agar, King B medium and potato dextrose agar to determine the effect of the strains on mycelial growth of the pathogens. In addition, strains were screened for their ability to produce exoenzymes and siderophores. All the strains significantly inhibited Alternaria alternata, particularly in 25% TSA medium. Antagonistic effect on Sclerotinia sclerotiorum and Fusarium solani was greater on King B medium. Protease was produced by 30% of the strains, but no strain produced cellulase or chitinase. Finally, the selected Pseudomonas strain, Psf5, was evaluated on tomato seedling development and as a potential candidate for controlling tomato damping-off caused by Sclerotinia sclerotiorum, under growth chamber conditions. In vivo studies resulted in significant increases in plant stand as well as in root dry weight. Psf5 was able to establish and survive in tomato plants rhizosphere after 40days following the planting of bacterized seeds. © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  15. Differential antifungal activity of alfalfa (Medicago santva L. saponins originated from roots and aerial parts for some ornamental plant pathogens

    Directory of Open Access Journals (Sweden)

    Alicja Saniewska

    2013-12-01

    Full Text Available The total saponins isolated from aerial parts and roots of alfalfa (Medicago sativa L. at the concentration of 0,01%, 0,05% and 0,1% showed differential influence on the mycelium growth of Alternaria zinniae, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Phoma poolensis and Rhizoctonia solani. A higher inhibitory effect on in vitro growth of mycelium of all tested pathogens indicated saponins from roots of alfalfa than from aerial parts. Tested saponins from roots at lhe concentration of 0,1% totally inhibited linear growth of Phoma narcissi, and linear growth of Alternaria zinniae was limited about 67%, Botrytis cinerea about 74%, Botrytis tulipae about 68%, Phoma poolensis about 38%, and Rhizoctonia solani about 74% in comparison to the control. The saponins of alfalfa from roots at the concentration of 0,1% and 0,2% applied as preinoculation sprays evidently inhibited the development of Phoma narcissi on Hippeastrum leaves. This dose of aerial saponins of alfalfa did not effect the development of necrotic spots on the leaves.

  16. Zinc hyperaccumulation substitutes for defense failures beyond salicylate and jasmonate signaling pathways of Alternaria brassicicola attack in Noccaea caerulescens.

    Science.gov (United States)

    Gallego, Berta; Martos, Soledad; Cabot, Catalina; Barceló, Juan; Poschenrieder, Charlotte

    2017-04-01

    The hypothesis of metal defense as a substitute for a defective biotic stress signaling system in metal hyperaccumulators was tested using the pathosystem Alternaria brassicicola-Noccaea caerulescens under low (2 µM), medium (12 µM) and high (102 µM) Zn supply. Regardless the Zn supply, N. caerulescens responded to fungal attack with the activation of both HMA4 coding for a Zn transporter, and biotic stress signaling pathways. Salicylate, jasmonate, abscisic acid and indoleacetic acid concentrations, as well as biotic stress marker genes (PDF1.2, CHIB, LOX2, PR1 and BGL2) were activated 24 h upon inoculation. Based on the activation of defense genes 24 h after the inoculation an incompatible fungal-plant interaction could be predicted. Nonetheless, in the longer term (7 days) no effective protection against A. brassicicola was achieved in plants exposed to low and medium Zn supply. After 1 week the biotic stress markers were even further increased in these plants, and this compatible interaction was apparently not caused by a failure in the signaling of the fungal attack, but due to the lack of specificity in the type of the activated defense mechanisms. Only plants receiving high Zn exhibited an incompatible fungal interaction. High Zn accumulation in these plants, possibly in cooperation with high glucosinolate concentrations, substituted for the ineffective defense system and the interaction turned into incompatible. In a threshold-type response, these joint effects efficiently hampered fungal spread and, consequently decreased the biotic stress signaling. © 2016 Scandinavian Plant Physiology Society.

  17. DNA damage and repair kinetics of the Alternaria mycotoxins alternariol, altertoxin II and stemphyltoxin III in cultured cells.

    Science.gov (United States)

    Fleck, Stefanie C; Sauter, Friederike; Pfeiffer, Erika; Metzler, Manfred; Hartwig, Andrea; Köberle, Beate

    2016-03-01

    The Alternaria mycotoxins alternariol (AOH) and altertoxin II (ATX II) have previously been shown to elicit mutagenic and genotoxic effects in bacterial and mammalian cells, although with vastly different activities. For example, ATX II was about 50 times more mutagenic than AOH. We now report that stemphyltoxin III (STTX III) is also highly mutagenic. The more pronounced effects of the perylene quinones ATX II and STTX III at lower concentrations compared to the dibenzo-α-pyrone AOH indicate a marked dependence of the genotoxic potential on the chemical structure and furthermore suggest that the underlying modes of action may be different. We have now further investigated the type of DNA damage induced by AOH, ATX II and STTX III, as well as the repair kinetics and their dependence on the status of nucleotide excision repair (NER). DNA double strand breaks induced by AOH due to poisoning of topoisomerase IIα were completely repaired in less than 2h. Under cell-free conditions, inhibition of topoisomerase IIα could also be measured for ATX II and STTX III at low concentrations, but the perylene quinones were catalytic inhibitors rather than topoisomerase poisons and did not induce DSBs. DNA strand breaks induced by ATX II and STTX III were more persistent and not completely repaired within 24h. A dependence of the repair rate on the NER status could only be demonstrated for STTX III, resulting in an accumulation of DNA damage in NER-deficient cells. Together with the finding that the DNA glycosylase formamidopyrimidine-DNA glycosylase (Fpg), but not T4 endonuclease V, is able to generate additional DNA strand breaks measurable by the alkaline unwinding assay, we conclude that the genotoxicity of the perylene quinones with an epoxide group is probably caused by the formation of DNA adducts which may be converted to Fpg sensitive sites.

  18. Overexpression of a tea flavanone 3-hydroxylase gene confers tolerance to salt stress and Alternaria solani in transgenic tobacco.

    Science.gov (United States)

    Mahajan, Monika; Yadav, Sudesh Kumar

    2014-08-01

    Flavan-3-ols are the major flavonoids present in tea (Camellia sinensis) leaves. These are known to have antioxidant and free radical scavenging properties in vitro. Flavanone 3-hydroxylase is considered to be an important enzyme of flavonoid pathway leading to accumulation of flavan-3-ols in tea. Expression analysis revealed the upregulation in transcript levels of C. sinensis flavanone 3-hydroxylase (CsF3H) encoding gene under salt stress. In this study, the biotechnological potential of CsF3H was evaluated by gene overexpression in tobacco (Nicotiana tabacum cv. Xanthi). Overexpression of CsF3H cDNA increased the content of flavan-3-ols in tobacco and conferred tolerance to salt stress and fungus Alternaria solani infection. Transgenic tobaccos were observed for increase in primary root length, number of lateral roots, chlorophyll content, antioxidant enzyme expression and their activities. Also, they showed lesser malondialdehyde content and electrolyte leakage compared to control tobacco plants. Further, transgenic plants produced higher degree of pectin methyl esterification via decreasing pectin methyl esterase (PME) activity in roots and leaves under unstressed and salt stressed conditions. The effect of flavan-3-ols on pectin methyl esterification under salt stressed conditions was further validated through in vitro experiments in which non-transgenic (wild) tobacco seedlings were exposed to salt stress in presence of flavan-3-ols, epicatechin and epigallocatechin. The in vitro exposed seedlings showed similar trend of increase in pectin methyl esterification through decreasing PME activity as observed in CsF3H transgenic lines. Taken together, overexpression of CsF3H provided tolerance to salt stress and fungus A. solani infection to transgenic tobacco through improved antioxidant system and enhanced pectin methyl esterification.

  19. Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

    Science.gov (United States)

    Atherton, Daniel

    Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p < 0.0001) between disease rating group means. In the majority of the experiments, comparisons of diseased plants with healthy plants using Fisher's LSD revealed more heavily diseased plants were significantly different from healthy plants. PLS analysis demonstrated the feasibility of detecting early blight infected plants, finding four optimal factors for raw spectra with the predictor variation explained ranging from 93.4% to 94.6% and the response variation explained ranging from 42.7% to 64.7%. Cluster analysis successfully distinguished healthy plants from all diseased plants except for the most mildly diseased plants, showing clustering analysis was an effective method for detection of early blight. Analysis of the reflectance spectra using the simple ratio (SR) and the normalized difference vegetative index (NDVI) was effective at differentiating all diseased plants from healthy plants, except for the

  20. Production, partial purification and characterization of protease from a phytopathogenic fungi Alternaria solani (Ell. and Mart.) Sorauer.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Sathiyabama, Muthukrishnan

    2014-08-01

    An alkaline serine protease producing strain Alternaria solani was optimized for its enzyme production under submerged conditions. The maximum production of protease by A. solani was achieved by using sodium nitrate at the optimum concentration of 0.2% w/v. A. solani produced higher quantities (3.75 [unit/mg of protein]) of an inducible extracellular proteases on day 9 after incubation in czapek's dox broth medium amended with 1% casein as an inducer at pH 8.5, temperature 27 °C and 3% sucrose as carbon source. Extracellular proteases were precipitated by ammonium sulphate saturation (80%) method and purified on Sephadex G-100 column chromatography. The molecular mass of SDS-PAGE and Sephadex G-100 Column Gel permeation chromatography purified protease was estimated to 42 kDa. In addition, trypsin digestion of 42 kDa protein band was carried out and analyzed by MALDI-TOF for the identification of protease. The sequence IKELATNGVVTNVK (378-391) segment of the alkaline serine protease was found by using MS/MS spectrum at 1485 m/z from the purified fraction. It showed optimal activity at 50 °C and pH 9-10 and broad pH stability between pH 6-12. The protease activity was inhibited by phenyl methyl sulfonyl fluoride (PMSF), all the results indicated that the presence of a serine residue in the active site and is thus most likely a member of the serine protease family. This may function as a virulence protein during pathogenesis by A. solani. The results suggested that the presence of appreciable extracellular proteolytic activity in filamentous fungi may serve as a marker of their phytopathogenicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Potencial antifúngico de extratos de plantas e de basidiomicetos nativos sobre Colletotrichum acutatum, Alternaria solani e Sclerotium rolfsii

    Directory of Open Access Journals (Sweden)

    Ricardo José Domingues

    2011-09-01

    Full Text Available O emprego de fungicidas na agricultura, principalmente quando utilizados de forma inadequada, tem provocado danos tanto ao homem como ao ambiente. O presente trabalho teve por objetivo o estudo in vitro da eficácia de extratos de três plantas e de dois basidiomicetos nativos do Brasil no controle dos fungos Alternaria solani e Colletotrichum acutatum, causadores de graves prejuízos às culturas de tomate e morango, respectivamente, além de Sclerotium rolfsii, considerado como patógeno polífago. No trabalho foram avaliados: a a inibição de crescimento micelial dos três fitopatógenos, b inibição da germinação de conídios de A. solani e C. acutatum e c inibição da germinação de escleródios de S. rolfsii. Os melhores resultados foram obtidos com o extrato de Oudemansiella canarii, que proporcionou os menores valores de crescimento micelial dos três patógenos, além inibir totalmente a germinação de conídios de A. solani e C. acutatum e de escleródios de S. rolfsii. O extrato de Irpex lacteus inibiu parcialmente o crescimento micelial dos patógenos estudados e o extrato de Avicennia schaueriana promoveu apenas 16 % de inibição do crescimento micelial de S. rolfsii. Nenhum efeito sobre os patógenos foi verificado com os extratos de Senna spectabilis e Senna multijuga nas condições em que foram realizados os experimentos.

  2. Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.

    Science.gov (United States)

    Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

    2010-09-01

    Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants.

  3. IN VITRO BIOACTIVITY OF CREOSOTE BUSH EXTRACTS (LARREA TRIDENTATA ON THE INHIBITION OF POSTHARVEST FUNGI: PENICILLIUM POLONICUM, ASPERGILLUS NIGER, RHIZOPUS ORYZAE Y ALTERNARIA TENUISSIMA

    Directory of Open Access Journals (Sweden)

    O. Peñuelas-Rubio

    2015-11-01

    Full Text Available En el presente estudio se evaluó la eficiencia de extractos vegetales deLarrea tridentataobtenidos con diclorometano, etanol, metanol y agua, sobre el crecimiento radial in vitro de cuatro hongos fitopatógenos, los cuales primeramente fueron identificados en género y especie empleando claves taxonómicas y técnicas moleculares. Para los bioensayosin vitrose aplicaron diseños completamente al azar con cuatro tratamientos y tres repeticiones en cada hongo, utilizando las concentraciones: 0, 250, 500 y 750 ppm paraAlternaria sp.; 0, 2000, 2500 y 3000 paraAspergillus sp.; 0, 1500, 1750 y 2000 paraPenicillium sp. y 0, 150, 200 y 250 ppm paraRhizopus sp. Cada tratamiento tuvo tres repeticiones. El análisis molecular determinó la especie tenuissima paraAlternaria,nigerparaApergillus,polonicumparaPenicilliumyoryzaeparaRhizopus. En cuanto a las pruebasin vitro, se determinaron inhibiciones del 100% para tres de los hongos en estudio:Alternaria tenuissimacon extracto EtOH a 750 ppm;Aspergillus nigercon extracto DCM a 3000 ppm yRhizopus oryzaea partir de 150 ppm y 250 ppm de los extractos DCM y EtOH respectivamente. Se presentó una inhibición del 82% a 2000 ppm paraPenicillium polonicum. Se concluye que a pesar de las diferencias en susceptibilidad entre las especies fúngicas, los extractos deLarrea tridentataobtenidos con etanol y dicloromentano son efectivos para el control de los hongos fitopatógenos bajo estudioin vitro.

  4. Characterization of Alternaria and Penicillium species from similar substrata based on growth at different temperature, pH and water activity

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Frisvad, Jens Christian

    2002-01-01

    Fifty-eight Alternaria isolates representing 10 species or species-groups and 66 Penicillium isolates representing 18 species were examined for their growth response to the combined effects of water activity, temperature and pH in an extended Central Composite Design. Growth responses were recorded...... incubated at two different temperatures were enough to get genus segregation and to some extent species segregation. The results also showed that water activity, temperature and pH interact strongly in their effect on growth rates and that the squared products (optima) of water activity, temperature and p...

  5. Potatoes, pathogens and pests

    NARCIS (Netherlands)

    Lazebnik, Jenny

    2017-01-01

    Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into susceptible

  6. 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.

  7. 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.

  8. Detección de Alternaria spp mediante técnicas genéticas como índice de calidad de materias primas y marcador de bioseguridad en productos hortofrutícolas frescos y procesados

    OpenAIRE

    Pavón Moreno, Miguel Ángel

    2013-01-01

    NOTA 520 8 La contaminación de alimentos con hongos filamentosos productores de toxinas tiene efectos negativos sobre la salud animal y humana, además de causar pérdidas millonarias en la industria agroalimentaria. Entre los mohos toxigénicos más frecuentemente encontrados en los alimentos predominan las especies pertenecientes a los géneros Fusarium, Penicillium, Aspergillus y Alternaria. En el género Alternaria se incluyen numerosas especies patógenas y saprofitas ampliamente distribuidas...

  9. Detección de Alternaria spp mediante técnicas genéticas como índice de calidad de materias primas y marcador de bioseguridad en productos hortofrutícolas frescos y procesados

    OpenAIRE

    Pavón Moreno, Miguel Ángel

    2013-01-01

    NOTA 520 8 La contaminación de alimentos con hongos filamentosos productores de toxinas tiene efectos negativos sobre la salud animal y humana, además de causar pérdidas millonarias en la industria agroalimentaria. Entre los mohos toxigénicos más frecuentemente encontrados en los alimentos predominan las especies pertenecientes a los géneros Fusarium, Penicillium, Aspergillus y Alternaria. En el género Alternaria se incluyen numerosas especies patógenas y saprofitas ampliamente distribuidas...

  10. 河南省小麦黑胚病菌的分离鉴定及致病性测定%Isolation, identification and pathogenicity of the pathogens of wheat black point in Henan Province

    Institute of Scientific and Technical Information of China (English)

    代君丽; 于巧丽; 袁虹霞; 邢小萍; 张猛; 孙炳剑; 李洪连

    2011-01-01

    The pathogens of wheat black point were isolated and identified from 50 wheat varieties (lines) planted in Henan Province. The results showed that there were 4 fungal species, Alternaria alternate, Bipolaris sorokiniana, A. tenuissima and A. triticina, with 63.0%, 18.0%, 12.2% and 6.8% average isolation frequency respectively. And the isolation frequencies of various pathogens were dissimilar in different varieties (lines). Pathogenicity of these isolates was tested in field 10 days after florescence by spore suspension. The results indicated that A. alternate and B. sorokiniana had high pathogenicity. According to the isolation frequency and pathogenicity of the pathogens, A. alternate was considered as the dominant pathogen of wheat black point in Henan Province.%为明确我国小麦主产区河南省小麦黑胚病菌的主要类群,为该病的防治工作提供理论依据,对河南省不同地区种植的50个小麦品种(系)的黑胚籽粒进行了分离鉴定和致病型测定.鉴定结果表明:河南省小麦黑胚籽粒病原分离物包括链格孢(Alternaria alternate)、麦根腐蠕孢(Bipolaris sorokiniana)、细极链格孢(A.tenuissima)和小麦链格孢(A.triticina),平均分离频率分别为63.0%、18.0%、12.2%和6.8%,不同品种小麦黑胚籽粒各种病原菌分离频率有一定差异.扬花后10 d利用孢子悬浮液接种进行分离物的致病性测定,结果表明链格孢(A.alternate)和麦根腐蠕孢(B.sorokiniana)致病力较强.结合分离频率和致病性测定结果,确定链格孢(A.alternate)是河南省小麦黑胚病的优势病原菌.

  11. 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.

  12. Validated UPLC-MS/MS Methods To Quantitate Free and Conjugated Alternaria Toxins in Commercially Available Tomato Products and Fruit and Vegetable Juices in Belgium.

    Science.gov (United States)

    Walravens, Jeroen; Mikula, Hannes; Rychlik, Michael; Asam, Stefan; Devos, Tom; Njumbe Ediage, Emmanuel; Diana Di Mavungu, José; Jacxsens, Liesbeth; Van Landschoot, Anita; Vanhaecke, Lynn; De Saeger, Sarah

    2016-06-22

    Ultraperformance liquid chromatography tandem mass spectrometry and Quick, Easy, Cheap, Effective, Rugged, and Safe based analytical methodologies to quantitate both free (alternariol (1), alternariol monomethyl ether (2), tenuazonic acid (3), tentoxin (4), altenuene (5), altertoxin-I (6)) and conjugated (sulfates and glucosides of 1 and 2) Alternaria toxins in fruit and vegetable juices and tomato products were developed and validated. Acceptable limits of quantitation (0.7-5.7 μg/kg), repeatability (RSDr < 15.7%), reproducibility (RSDR < 17.9%), and apparent recovery (87.0-110.6%) were obtained for all analytes in all matrices investigated. 129 commercial foodstuffs were analyzed, and 3 was detected in 100% of tomato product samples (Alternaria toxins (sulfates of 1 and 2) were repeatedly detected. A deterministic dietary exposure assessment revealed the possible risk for human health related to the presence of 1 and 2 in tomato based foodstuffs, whereas 3 is unlikely to be of human health concern.

  13. Least Wanted Foodborne Pathogens

    Science.gov (United States)

    Least Wanted Foodborne Pathogens The U.S. Public Health Service has identified the following microorganisms as being the biggest culprits of foodborne illness, either because of the severity of the ...

  14. T0 PATHOGENS

    African Journals Online (AJOL)

    African Crop Science Journal, Vol. ... Selection for durable resistance against such pathogens should consist ot' removing the ... major gene resistance has been overcome. .... a simple way. .... which causes either a change in the avirulence.

  15. Bioterrorism: pathogens as weapons.

    Science.gov (United States)

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern.

  16. Solanapyrone synthase, a possible Diels-Alderase and iterative type I polyketide synthase encoded in a biosynthetic gene cluster from Alternaria solani.

    Science.gov (United States)

    Kasahara, Ken; Miyamoto, Takanori; Fujimoto, Takashi; Oguri, Hiroki; Tokiwano, Tetsuo; Oikawa, Hideaki; Ebizuka, Yutaka; Fujii, Isao

    2010-06-14

    The solanapyrone biosynthetic gene cluster was cloned from Alternaria solani. It consists of six genes-sol1-6-coding for a polyketide synthase, an O-methyltransferase, a dehydrogenase, a transcription factor, a flavin-dependent oxidase, and cytochrome P450. The prosolanapyrone synthase (PSS) encoded by sol1 was expressed in Aspergillus oryzae and its product was identified as desmethylprosolanapyrone I (8). Although PSS is closely related to the PKSs/Diels-Alderases LovB and MlcA of lovastatin and compactin biosynthesis, it did not catalyze cycloaddition. Sol5, encoding a flavin-dependent oxidase (solanapyrone synthase, SPS), was expressed in Pichia pastoris and purified. The purified recombinant SPS showed activity for the formation of (-)-solanapyrone A (1) from achiral prosolanapyrone II (2), establishing that this single enzyme catalyzes both the oxidation and the subsequent cycloaddition reaction, possibly as a Diels-Alder enzyme.

  17. 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.

  18. Generation of selectable marker-free transgenic eggplant resistant to Alternaria solani using the R/RS site-specific recombination system.

    Science.gov (United States)

    Darwish, Nader Ahmed; Khan, Raham Sher; Ntui, Valentine Otang; Nakamura, Ikuo; Mii, Masahiro

    2014-03-01

    Marker-free transgenic eggplants, exhibiting enhanced resistance to Alternaria solani , can be generated on plant growth regulators (PGRs)- and antibiotic-free MS medium employing the multi-auto-transformation (MAT) vector, pMAT21 - wasabi defensin , wherein isopentenyl transferase ( ipt ) gene is used as a positive selection marker. Use of the selection marker genes conferring antibiotic or herbicide resistance in transgenic plants has been considered a serious problem for environment and the public. Multi-auto-transformation (MAT) vector system has been one of the tools to excise the selection marker gene and produce marker-free transgenic plants. Ipt gene was used as a selection marker gene. Wasabi defensin gene, isolated from Wasabia japonica (a Japanese horseradish which has been a potential source of antimicrobial proteins), was used as a gene of interest. Wasabi defensin gene was cloned from the binary vector, pEKH-WD, to an ipt-type MAT vector, pMAT21, by gateway cloning technology and transferred to Agrobacterium tumefaciens strain EHA105. Infected cotyledon explants of eggplant were cultured on PGRs- and antibiotic-free MS medium. Extreme shooty phenotype/ipt shoots were produced by the explants infected with the pMAT21-wasabi defensin (WD). The same PGRs- and antibiotic-free MS medium was used in subcultures of the ipt shoots. Subsequently, morphologically normal shoots emerged from the Ipt shoots. Molecular analyses of genomic DNA from transgenic plants confirmed the integration of the WD gene and excision of the selection marker (ipt gene). Expression of the WD gene was confirmed by RT-PCR and Northern blot analyses. In vitro whole plant and detached leaf assay of the marker-free transgenic plants exhibited enhanced resistance against Alternaria solani.

  19. [Salmonella pathogenicity islands].

    Science.gov (United States)

    Sırıken, Belgin

    2013-01-01

    Salmonella species are facultative intracellular pathogenic bacteria. They can invade macrophages, dendritic and epithelial cells. The responsible virulence genes for invasion, survival, and extraintestinal spread are located in Salmonella pathogenicity islands (SPIs). SPIs are thought to be acquired by horizontal gene transfer. Some of the SPIs are conserved throughout the Salmonella genus, and some of them are specific for certain serovars. There are differences between Salmonella serotypes in terms of adaptation to host cell, virulence factors and the resulting infection according to SPA presence and characteristics. The most important Salmonella virulence gene clusters are located in 12 pathogenicity islands. Virulence genes that are involved in the intestinal phase of infection are located in SPI-1 and SPI-2 and the remaining SPIs are required for intracellular survival, fimbrial expression, magnesium and iron uptake, multiple antibiotic resistance and the development of systemic infections. In addition SPIs, Sigma ss (RpoS) factors and adaptive acid tolerance response (ATR) are the other two important virulence factors. RpoS and ATR found in virulent Salmonella strains help the bacteria to survive under inappropriate conditions such as gastric acidity, bile salts, inadequate oxygen concentration, lack of nutrients, antimicrobial peptides, mucus and natural microbiota and also to live in phagosomes or phagolysosomes. This review article summarizes the data related to pathogenicity islands in Salmonella serotypes and some factors which play role in the regulation of virulence genes.

  20. Fungal pathogens of Proteaceae

    NARCIS (Netherlands)

    Crous, P.W.; Summerell, B.A.; Swart, L.; Denman, S.; Taylor, J.E.; Bezuidenhout, C.M.; Palm, M.E.; Marincowitz, S.; Groenewald, J.Z.

    2011-01-01

    Species of Leucadendron, Leucospermum and Protea (Proteaceae) are in high demand for the international floriculture market due to their brightly coloured and textured flowers or bracts. Fungal pathogens, however, create a serious problem in cultivating flawless blooms. The aim of the present study

  1. Fungal pathogens of Proteaceae

    NARCIS (Netherlands)

    Crous, P.W.; Summerell, B.A.; Swart, L.; Denman, S.; Taylor, J.E.; Bezuidenhout, C.M.; Palm, M.E.; Marincowitz, S.; Groenewald, J.Z.

    2012-01-01

    Species of Leucadendron, Leucospermum and Protea (Proteaceae) are in high demand for the international floriculture market due to their brightly coloured and textured flowers or bracts. Fungal pathogens, however, create a serious problem in cultivating flawless blooms. The aim of the present study

  2. Determination and control of the main pathogens of post-harvest fruit and vegetables rot disease in Ningxia%果蔬采后致腐病菌检测及防治

    Institute of Scientific and Technical Information of China (English)

    顾沛雯; 张光弟; 王华荣; 丁波

    2012-01-01

    It was showed that the main pathogens of post-harvest fruit and vegetables rot disease postharvest fruit and vegetables rot disease were Botrytis, Aspergillus, Penicillium, Rhizopus and Alternaria through isolating, purifing, pathogenicity determination, identification and ways of infection in Ningxia. Among these pathogens, Aspergillus sp. and Rhizopus sp. were the chief pathogens during post-harvest transportation and marketing because they cause rot disease during high temperature, yet Botrytis sp. , Alternaria sp. , and Penicillium sp. were the major pathogens during transportation and storage under 10-15℃. Through two preservation tests of post-harvest fruit and vegetables with 2-butanamine fumigating and chlorine dioxide immersing, it is showed that combination of low temperature and antistaling agent can obviously prolong 9-11 days delivery period and shelf life.%引起果蔬采后腐烂的病原菌主要分属于葡萄孢属(Botrytis)、曲霉属(Aspergillus)、青霉属(Penicillium)、根霉属(Rhizopus)和链格孢属(Alternaria).其中A.sp.和R.sp.是果蔬常温运输过程中的主要致腐菌,B.sp.、A.sp.和P.sp.是果蔬低温贮运条件下的主要致腐菌.采用仲丁胺和二氧化氯2种药剂对采后蔬菜进行熏蒸和浸泡保鲜处理.结果表明:低温与保鲜剂处理相结合,可明显提高果蔬采后运输及货架期9~11d.

  3. Antipathogenic effects of structurally-related Schiff base derivatives: Structure–activity relationship

    Directory of Open Access Journals (Sweden)

    Soleiman Hisaindee

    2015-11-01

    Full Text Available Eighteen structurally-related Schiff base derivatives, which belong to salicylidenebenzylamine and 2-hydroxy-1-naphthylidenebenzylamine families were prepared and characterized by spectroscopic techniques. All the synthesized compounds were screened in vitro for their antibacterial and antifungal activities. Human pathogenic gram-negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens, gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus and Bacillus subtilis, and fungi (Alternaria alternata, Aspergillus niger, Penicillium roqueforti, and Saccharomyces cerevisiae were evaluated based on their toxicity to different concentrations of Schiff base compounds. For assessment of toxicity to pathogens, a disc diffusion assay was used to test the antimicrobial properties. The results revealed some antimicrobial activities of some of the synthesized compounds. Among the tested pathogens, the synthesized salicylidinaniline derivatives show highly potent action towards Alternaria alternata. Interestingly, a compound which contains the –Cl group is only effective against gram negative bacteria, but not gram positive bacteria. No remarkable antibacterial or antifungal activities were observed in the presence of –CH3 or –Br group. Furthermore, most of the naphthalene-containing compounds show no growth retardation towards bacterial or fungal pathogens. On the other hand, the presence of –OH or –SH group at para or ortho position, respectively, on the aniline site is correlated with an increased inhibitory drug effect on all pathogens. The importance of our findings to the drug research and developments is discussed in the context of finding a correlation between the structural properties of the new drugs and their biological activities.

  4. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  5. Phyllosphere mycobiota of Eucalyptus camaldulensis Dehnh. and E. globulus Labill.

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica V.

    2015-01-01

    Full Text Available Diversity of phyllosphere microfungi of two Eucalypti species (E. camaldulensis and E. globulus was investigated using moist chamber method. A total of 19 different taxa of phyllosphere microfungal community were identified in leaves and seed bearing capsules. Aspergillus niger was the most frequent isolate in both investigated Eucalyptus species along with Alternaria alternata and Penicillium spp. Saprotrophic species occurred more frequently in Eucalypti phyllosphere compared to plant pathogens. Epiphytes were quantitatively prevalent. Microscopic analyses of E. globulus phylloplane microfungal community revealed potential inhibitory effect of Trichoderma viride against Eucalypti pathogenic species Seimatosporium eucalypti which formed aberrant, collapsed conidia. The study of phyllosphere mycobiota is of significant importance, considering that numerous leaf inhabiting fungi are in complex interactions with each other and their host plant. [Projekat Ministarstva nauke Republike Srbije, br. 173032

  6. Screening of antimicrobial potential of polysaccharide from cuttlebone and methanolic extract from body tissue of Sepia prashadi Winkworth, 1936

    Institute of Scientific and Technical Information of China (English)

    Pasiyappazham Ramasamy; Aruldhason Barwin Vino; Ramachandran Saravanan; Namasivayam Subhapradha; Vairamani Shanmugam; Annaian Shanmugam

    2011-01-01

    Objective: To evaluate the antimicrobial activity of polysaccharide from cuttlebone and methanolic extract from body tissue of Sepia prashadi, against ten human pathogenic bacteria and five fungi. Methods:The activity of polysaccharide and methanolic extract was investigated against Vibrio cholerae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Vibrio alginolyticus, Staphylococcus aureus, Vibrio parahaemolyticus, Streptococcus sp., Streptococcus pneumoniae, Salmonella sp. and Escherichia coli, and five fungal strains such as Alternaria alternata, Candida tropicalis, Penicillium italicum, Fusarium equiseti and Candida albican using disc diffusion method and minimum inhibitory concentration (MIC) were also calculated. Results:Both polysaccharide and methanolic extract was active against gram positive than that of gram negative pathogenic bacteria but inactive against fungi. The MIC of both the extract ranging from 60 to 100 mg/mL. Conclusions: These results suggest that cephalopod polysaccharide and methanolic extract possess relatively good antibacterial activity.

  7. Optimization for rapid synthesis of silver nanoparticles and its effect on phytopathogenic fungi

    Science.gov (United States)

    Krishnaraj, C.; Ramachandran, R.; Mohan, K.; Kalaichelvan, P. T.

    In this present study, silver nanoparticles were synthesized by green chemistry approach using Acalypha indica leaf extract as reducing agents. The reaction medium employed in the synthesis process was optimized to attain better yield, controlled size and stability. Further, the biosynthesized silver nanoparticles were conformed through UV-vis spectrum, XRD and HR-TEM analyses. Different concentration of silver nanoparticles were tested to know the inhibitory effect of fungal plant pathogens namely Alternaria alternata, Sclerotinia sclerotiorum, Macrophomina phaseolina, Rhizoctonia solani, Botrytis cinerea and Curvularia lunata. Interestingly, 15 mg concentration of silver nanoparticles showed excellent inhibitory activity against all the tested pathogens. Thus, the obtained results clearly suggest that silver nanoparticles may have important applications in controlling various plant diseases caused by fungi.

  8. DINÂMICA DE INÓCULOS E DOENÇAS EM VIDEIRA SOB SISTEMA CONVENCIONAL E PROTEGIDO

    Directory of Open Access Journals (Sweden)

    DIÓGENES DA CRUZ BATISTA

    2015-01-01

    Full Text Available The effect of the covered and conventional cultivation of grapevine (cv. Superior Seedless on the aerial dispersion of pathogen inoculum and dynamic of diseases was investigated in two-year (2009 and 2010 and period similar to the year. The experiment was conducted at the experimental station of Embrapa semiarid. The traps were maintained at 0.5 meters above the canopy of the grapevine, and the samples taken every 24 hours with the exchange of slides 9:00 a.m. Greater dispersion of pathogens (Plasmopara viticola, Phakopsora euvitis, Alternaria alternata and intensity of diseases (downy mildew, rust, and bacterial canker were detected in grapevines under conventional cultivation. The aerial dispersal of the fungus Lasiodiplodia theobromae was similar under grapevine covered and uncovered.

  9. 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) ,

  10. 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) ,

  11. In-vitro evaluation of fungicides, bioagents and aqueous leaf extracts against Alternaria leaf blight of cotton

    Directory of Open Access Journals (Sweden)

    U. Dey

    2012-07-01

    Full Text Available All the six fungicides viz.,Mancozeb (75% WP; Carbendazim (50WP, Copper oxychloride (50WP, Captan (50 WP, Thiram (75 % WP, Chlorothalonil (75 WP evaluated in vitro (@500, 1000 and 1500 ppm were found effective against A. macrospora and caused significant inhibition of test pathogen over untreated control. However, Thiram was found most effective and recorded significantly highest mean mycelial inhibition (90.42%. This was followed by the fungicides, Captan (82.04%, Mancozeb (79.88%, Carbendazim(77.5%, Chlorothalonil (74.52% and copper oxychloride (71.75%. All the five fungal and one bacterial bioagents/ antagonists evaluated in vitro against A. macrospora were found antifungal/ antagonistic against the test pathogen. However, T. viride was found most effective and recorded least linear mycelial growth (32.72 mm with corresponding significantly highest mycelial inhibition (63.64% of the test pathogen. The second and third best bioagents found were T. koningii and P. fluorescens, which recorded linear mycelial growth, respectively of 33.90 mm and 33.95 mm with corresponding mycelial inhibition, respectively of 62.33 and 62.27 per cent. All the six botanicals/plant extracts evaluated in vitro (@5, 10 and 15 % each were found fungistatic/ fungicidal against. A.macrospora. However, significantly least mean radial mycelial growth (56.18mm and significantly highest mean mycelial inhibition (37.47% was recorded with Garlic. The second and third best botanicals found were onion and Tulsi which recorded second and third least mean radial mycelial growth, respectively of 58.52 mm and 62.51 mm with corresponding mean mycelial inhibition of 34.97 and 32.86 per cent, respectively.

  12. Effect of crude plant extracts from some Oaxacan flora on two deleterious fungal phytopathogens and extract compatibility with a biofertilizer strain

    Directory of Open Access Journals (Sweden)

    Karla Isabel eLira-De León

    2014-08-01

    Full Text Available The antimicrobial activity of twelve plant extracts was tested against the phytopathogens Alternaria alternata and Fusarium solani. In addition, the compatibility of the extracts towards Bacillus liqueniformis, a biofertilizer and a non-target microorganism, was assessed. Plants tested belong to Euphorbiaceae, Asteraceae, Crassulaceae, Rubiaceae, Convolvulaceae, Verbenaceae, Orchidaceae, Nyctaginaceae, Boraginaceae, and Tiliaecae families and were collected in the State of Oaxaca. The antifungal activity of the plant extracts (50 to 100 mg/mL against A. alternata and F. solani, was determined by measuring the mycelium radial growth and obtaining the minimum inhibitory concentration (MIC of fungal growth. In addition, with the aim of finding plant extracts which are compatible with a B. licheniformis biofertilizer strain and to test the nontoxic nature of the treatments, the toxicity of the extracts towards this strain was evaluated using the agar diffusion method. Azoxystrobin (12 μg and chloramphenicol (30 μg were used as positive controls for the pathogens and for the non-target bacteria, respectively. Plant extracts inhibited fungal growth in the ranges of 0.76 to 56.17 % against F. solani and 2.02 to 69.07 % against A. alternata. The extracts of Acalypha subviscida, Ipomoea murucoides, Tournefortia densiflora and Lantana achyranthifolia showed MIC values between 5.77-12.5 mg/mL for at least one of the fungal species. The best treatment, Adenophyllum aurantium, exhibited a maximum inhibition for both F. solani (56.17%, MIC = 7.78 mg/mL and A. alternata (68.64% MIC = 7.78 mg/mL, and resulted innocuous toward B. licheniformis. Therefore, this plant has an outstanding potential for the agroecological control of fungal phytopathogens in industrial crops.

  13. Effect of crude plant extracts from some Oaxacan flora on two deleterious fungal phytopathogens and extract compatibility with a biofertilizer strain

    Science.gov (United States)

    Lira-De León, Karla I.; Ramírez-Mares, Marco V.; Sánchez-López, Vladimir; Ramírez-Lepe, Mario; Salas-Coronado, Raúl; Santos-Sánchez, Norma F.; Valadez-Blanco, Rogelio; Hernández-Carlos, Beatriz

    2014-01-01

    The antimicrobial activity of 12 plant extracts was tested against the phytopathogens Alternaria alternata and Fusarium solani. In addition, the compatibility of the extracts toward Bacillus liqueniformis, a biofertilizer and a non-target microorganism, was assessed. Plants tested belong to the Euphorbiaceae, Asteraceae, Crassulaceae, Rubiaceae, Convolvulaceae, Verbenaceae, Orchidaceae, Nyctaginaceae, Boraginaceae, and Tiliaceae families and were collected in the State of Oaxaca. The antifungal activity of the plant extracts (50–100 mg/mL) against A. alternata and F. solani, was determined by measuring the mycelium radial growth and obtaining the minimum inhibitory concentration (MIC) of fungal growth. In addition, with the aim of finding plant extracts which are compatible with a B. licheniformis biofertilizer strain and to test the non-toxic nature of the treatments, the toxicity of the extracts toward this strain was evaluated using the agar diffusion method. Azoxystrobin (12 μg) and chloramphenicol (30 μg) were used as positive controls for the pathogens and for the non-target bacteria, respectively. Plant extracts inhibited fungal growth in the ranges of 0.76–56.17% against F. solani and 2.02–69.07% against A. alternata. The extracts of Acalypha subviscida, Ipomoea murucoides, Tournefortia densiflora and Lantana achyranthifolia showed MIC values between 5.77–12.5 mg/mL for at least one of the fungal species. The best treatment, Adenophyllum aurantium, exhibited a maximum inhibition for both F. solani (56.17%, MIC = 7.78 mg/mL) and A. alternata (68.64% MIC = 7.78 mg/mL), and resulted innocuous toward B. licheniformis. Therefore, this plant has an outstanding potential for the agroecological control of fungal phytopathogens in industrial crops. PMID:25147544

  14. Essential Oils as Biocides for the Control of Fungal Infections and Devastating Pest (Tuta absoluta) of Tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Bouayad Alam, Samira; Dib, Mohammed El Amine; Djabou, Nassim; Tabti, Boufeldja; Gaouar Benyelles, Nassira; Costa, Jean; Muselli, Alain

    2017-07-01

    Thymus capitatus and Tetraclinis articulata essential oils as well their major components (carvacrol and α-pinene) were evaluated for their antifungal and insecticidal activities. Both oils showed good in vitro antifungal activity against Fusarium oxysporum, Aspergillus niger, Penicillium sp., Alternaria alternata, and Botrytis cinerea, the fungi causing tomato rot. In vivo results indicate the efficacies of both essential oils and carvacrol of reduce postharvest fungal pathogens, such as B. cinerea and Al. alternata that are responsible of black and gray rot of tomato fruit. Disease incidence of Al. alternata and B. cinerea decreased on average from 55% to 80% with essential oil of Th. capitatus and pure carcvacrol, while Te. articulata essential oil exhibited inhibition of fungal growth of 55% and 25% against Al. alternata and B. cinerea, respectively, with concentration of 0.4 μl/l air. The insecticidal activity of Th. capitatus and Te. articulata essential oils exhibited also a good insecticidal activity. At the concentration of 0.2 μl/ml air, the oils caused mortality over 80% for all larval stages of Tuta absoluta and 100% mortality for the first-instar after 1.5 h only of exposure. α-Pinene presented lower insecticidal and antifungal activities compared to essential oils of Th. capitatus, Te. articulata and pure carvacrol. Thus, these essential oils can be used as a potential source to develop control agents to manage some of the main pests and fungal diseases of tomato crops. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  15. Effect of crude plant extracts from some Oaxacan flora on two deleterious fungal phytopathogens and extract compatibility with a biofertilizer strain.

    Science.gov (United States)

    Lira-De León, Karla I; Ramírez-Mares, Marco V; Sánchez-López, Vladimir; Ramírez-Lepe, Mario; Salas-Coronado, Raúl; Santos-Sánchez, Norma F; Valadez-Blanco, Rogelio; Hernández-Carlos, Beatriz

    2014-01-01

    The antimicrobial activity of 12 plant extracts was tested against the phytopathogens Alternaria alternata and Fusarium solani. In addition, the compatibility of the extracts toward Bacillus liqueniformis, a biofertilizer and a non-target microorganism, was assessed. Plants tested belong to the Euphorbiaceae, Asteraceae, Crassulaceae, Rubiaceae, Convolvulaceae, Verbenaceae, Orchidaceae, Nyctaginaceae, Boraginaceae, and Tiliaceae families and were collected in the State of Oaxaca. The antifungal activity of the plant extracts (50-100 mg/mL) against A. alternata and F. solani, was determined by measuring the mycelium radial growth and obtaining the minimum inhibitory concentration (MIC) of fungal growth. In addition, with the aim of finding plant extracts which are compatible with a B. licheniformis biofertilizer strain and to test the non-toxic nature of the treatments, the toxicity of the extracts toward this strain was evaluated using the agar diffusion method. Azoxystrobin (12 μg) and chloramphenicol (30 μg) were used as positive controls for the pathogens and for the non-target bacteria, respectively. Plant extracts inhibited fungal growth in the ranges of 0.76-56.17% against F. solani and 2.02-69.07% against A. alternata. The extracts of Acalypha subviscida, Ipomoea murucoides, Tournefortia densiflora and Lantana achyranthifolia showed MIC values between 5.77-12.5 mg/mL for at least one of the fungal species. The best treatment, Adenophyllum aurantium, exhibited a maximum inhibition for both F. solani (56.17%, MIC = 7.78 mg/mL) and A. alternata (68.64% MIC = 7.78 mg/mL), and resulted innocuous toward B. licheniformis. Therefore, this plant has an outstanding potential for the agroecological control of fungal phytopathogens in industrial crops.

  16. Influence of temperature, precipitation, and cultivar characteristics on changes in the spectrum of pathogenic fungi in winter wheat

    Science.gov (United States)

    Hýsek, Josef; Vavera, Radek; Růžek, Pavel

    2016-12-01

    In view of the threat posed by climate change, we studied the influence of temperature, precipitation, cultivar characteristics, and technical management measures on the occurrence of phytopathogenic fungi in wheat during 2009-2013. This work involved experiments at two sites differing in average temperatures and precipitation. Temperature and precipitation appear to influence differences in the spectrum of phytopathogenic fungi at the individual sites. In 2009 (the warmest year), Alternaria triticina was dominant. In 2010 (having the smallest deviations from the average for individual years), Septoria tritici dominated. In 2011, Puccinia triticina was most prominent, while in 2012, the genus Drechslera (Pyrenophora) and in 2013, S. tritici and Drechslera tritici-repentis (DTR) dominated. Temperature and precipitation levels in the individual spring months (warmer March to May) played a large role, especially for the leaf rust P. triticina in 2011. A change of only 1 °C with different precipitation during a year played a significant role in changing wheat's fungal spectrum. Cluster analysis showed the differences between single pathogenic fungi on wheat in a single year due to temperature and precipitation. Alternaria abundance was strongly influenced by year (p < 0.001) while locality was significant only in certain years (2012, 2013; p = 0.004 and 0.015, respectively). The same factors were revealed to be significant in the case of Puccinia, but locality played a role (p < 0.001) in different years (2011, 2013). The abundance of S. tritici and Pyrenophora tritici-repentis (Drechslera tritici-repentis) was influenced only by year (p < 0.001).

  17. Antifungal potential of Bacillus vallismortis R2 against different phytopathogenic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, P.K.; Kaur, J.; Saini, H.S.

    2015-07-01

    The cash crops grown in an agro-climatic region are prone to infection by various fungal pathogens. The use of chemical fungicides over the years has resulted in emergence of resistant fungal strains, thereby necessitating the development of effective and environmental friendly alternatives. The natural antagonistic interactions among different microbial populations have been exploited as an eco-friendly approach for controlling fungal pathogens resistant to synthetic chemicals. Morphologically distinct bacterial cultures (150), isolated from rhizospheric soils of wheat, rice, onion and tomato plants were screened for their antifungal potential against seven phytopathogenic fungi prevalent in the State of Punjab (India). The bacterial isolate R2, identified as Bacillus vallismortis, supported more than 50% inhibition of different phytopathogenic fungi (Alternaria alternata, Rhizoctonia oryzae, Fusarium oxysporum, Fusarium moniliforme, Colletotrichum sp, Helminthosporium sp and Magnaporthe grisea) in dual culture plate assay. The thin layer chromatography based bio-autography of acid-precipitated biomolecules (APB) indicated the presence of more than one type of antifungal molecule, as evidenced from zones of inhibition against the respective fungal pathogen. The initial analytical studies indicated the presence of surfactin, iturin A and fengycin-like compounds in APB. The antifungal activity of whole cells and APB of isolate R2 was evaluated by light and scanning electron microscopy. The wheat grains treated with APB and exposed to spores of A. alternata showed resistance to the development of black point disease, thereby indicating the potential application of R2 and its biomolecules at field scale level. (Author)

  18. Antifungal potential of Bacillus vallismortis R2 against different phytopathogenic fungi

    Directory of Open Access Journals (Sweden)

    Preet K. Kaur

    2015-06-01

    Full Text Available The cash crops grown in an agro-climatic region are prone to infection by various fungal pathogens. The use of chemical fungicides over the years has resulted in emergence of resistant fungal strains, thereby necessitating the development of effective and environmental friendly alternatives. The natural antagonistic interactions among different microbial populations have been exploited as an eco-friendly approach for controlling fungal pathogens resistant to synthetic chemicals. Morphologically distinct bacterial cultures (150, isolated from rhizospheric soils of wheat, rice, onion and tomato plants were screened for their antifungal potential against seven phytopathogenic fungi prevalent in the State of Punjab (India. The bacterial isolate R2, identified as Bacillus vallismortis, supported more than 50% inhibition of different phytopathogenic fungi (Alternaria alternata, Rhizoctonia oryzae, Fusarium oxysporum, Fusarium moniliforme, Colletotrichum sp, Helminthosporium sp and Magnaporthe griseain dual culture plate assay. The thin layer chromatography based bio-autography of acid-precipitated biomolecules (APB indicated the presence of more than one type of antifungal molecule, as evidenced from zones of inhibition against the respective fungal pathogen. The initial analytical studies indicated the presence of surfactin, iturin A and fengycin-like compounds in APB. The antifungal activity of whole cells and APB of isolate R2 was evaluated by light and scanning electron microscopy. The wheat grains treated with APB and exposed to spores of A. alternata showed resistance to the development of black point disease, thereby indicating the potential application of R2 and its biomolecules at field scale level.

  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. Introduction to Pathogenic Protozoa

    Science.gov (United States)

    2011-06-01

    1 1 Introduction Mary K. Klassen-Fischer and Ronald C. Neafie Introduction Protozoa Protozoa are single-celled eukaryotic animals first dis...phylogeny of protozoa , see Table 1.1. A recent trend is to replace the term “ protozoa ” with “protista.” For these topics we retain “pro- tozoa” and...JUN 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Introduction to Pathogenic Protozoa 5a. CONTRACT

  1. Antifungal activity of indigenous bacillus sp. isolate Q3 against marshmallow mycobiota

    Directory of Open Access Journals (Sweden)

    Jošić Dragana Lj.

    2011-01-01

    Full Text Available Marshmallow is a host of a number of saprophytic and parasitic fungi in Serbia. The seeds of marshmallow are contaminated with fungi from different genera, especially Alternaria and Fusarium, which significantly reduced seed germination and caused seedling decay. In this study we investigate antagnonism of indigenous Bacillus sp. isolate Q3 against marshmallow mycopopulation. Bacillus sp. Q3 was isolated from maize rhizosphere, characterized by polyphasic approch and tested for plant growth promoting treats. Bacillus sp. Q3 produced antifungal metabolites with growth inhibition activity against numerous fungi in dual culture: 61.8% of Alternaria alternata, 74.8% of Myrothecium verrucaria and 33.6% of Sclerotinia sclerotiorum. That effect could be caused by different antifungal metabolites including siderophores, hydrolytic enzymes, organic acids and indole acetic acid (IAA. Suppression of natural marshmallow seed infection by Q3 isolate was observed. The seeds were immersed in different concentrations of bacterial suspension during 2h and their infections by phytopathogenic fungi were estimated. The results showed significant reduction of seed infection by Alternaria spp. The presented results indicate possible application of this isolate as promising biological agent for control of marshmallow seed pathogenic fungi.

  2. Occurrence, characterization and management of fruit rot of immature cucumber fruits under arid greenhouse conditions

    Directory of Open Access Journals (Sweden)

    ABDULLAH M AL-SADI

    2012-01-01

    Full Text Available A study was undertaken to characterize and manage pathogens associated with fruit rot of immature cucumber fruits in greenhouses in Oman. A survey over 5 growing seasons from 2008 to 2010 in 99 different greenhouses in Oman showed that the disease is prevalent in 91 (92% greenhouses and results in losses of 10 to 60% (avg. 33% of immature fruits per plant. Incidence of the disease was not found to be affected by growing seasons, which could be attributed to the limited fluctuations in ambient temperatures in greenhouses. Isolations from diseased cucumber fruits yielded Alternaria alternata (isolation frequency = 52%, Fusarium equiseti (40%, Cladosporium tenuissium (27%, Botrytis cinerea (6%, Fusarium solani (6%, Corynespora cassiicola (3%, Aspergillus spp. (2%, Curvularia sp. (1% and Bipolaris sp. (1%. With the exception of Curvularia and Bipolaris species, all other fungi were pathogenic on cucumber fruits, with Fusarium equiseti being the most aggressive, followed by Corynespora cassiicola, Botrytis cinerea and Alternaria alternata. Cladosporium and Aspergillus spp. were found to be weakly pathogenic. Comparing the efficacy of foliar and soil applications of carbendazim fungicide on fruit rot of cucumber showed that foliar applications significantly reduced fruit rot and increased cucumber yield when compared to soil application or to control (P < 0.01. This appears to be the first report of the association of Corynespora cassiicola and Fusarium equiseti with fruit rot of immature greenhouse cucumbers. This is also the first report in Oman for the association of Cladosporium tenuissimum with fruit rot of immature cucumbers. Findings are discussed in terms of factors affecting disease control in greenhouses using carbendazim.

  3. Cell wall integrity and high osmolarity glycerol pathways are required for adaptation of Alternaria brassicicola to cell wall stress caused by brassicaceous indolic phytoalexins.

    Science.gov (United States)

    Joubert, Aymeric; Bataille-Simoneau, Nelly; Campion, Claire; Guillemette, Thomas; Hudhomme, Piétrick; Iacomi-Vasilescu, Béatrice; Leroy, Thibault; Pochon, Stéphanie; Poupard, Pascal; Simoneau, Philippe

    2011-01-01

    Camalexin, the characteristic phytoalexin of Arabidopsis thaliana, inhibits growth of the fungal necrotroph Alternaria brassicicola. This plant metabolite probably exerts its antifungal toxicity by causing cell membrane damage. Here we observed that activation of a cellular response to this damage requires cell wall integrity (CWI) and the high osmolarity glycerol (HOG) pathways. Camalexin was found to activate both AbHog1 and AbSlt2 MAP kinases, and activation of the latter was abrogated in a AbHog1 deficient strain. Mutant strains lacking functional MAP kinases showed hypersensitivity to camalexin and brassinin, a structurally related phytoalexin produced by several cultivated Brassica species. Enhanced susceptibility to the membrane permeabilization activity of camalexin was observed for MAP kinase deficient mutants. These results suggest that the two signalling pathways have a pivotal role in regulating a cellular compensatory response to preserve cell integrity during exposure to camalexin. AbHog1 and AbSlt2 deficient mutants had reduced virulence on host plants that may, at least for the latter mutants, partially result from their inability to cope with defence metabolites such as indolic phytoalexins. This constitutes the first evidence that a phytoalexin activates fungal MAP kinases and that outputs of activated cascades contribute to protecting the fungus against antimicrobial plant metabolites. © 2010 Blackwell Publishing Ltd.

  4. ASPECTOS EPIDEMIOLÓGICOS DA QUEIMA DAS FOLHAS DA CENOURA (Daucus carota L CAUSADA POR Alternaria dauci (Kühn Groves & Skolko: Efeito da Concentração de Inóculo e Determinação do Período de Geração de Alternaria dauci (Kühn Groves & Skolko. EPIDEMIOLOGICAL ASPECTS OF LEAF BLIGHT OF CARROT (Daucus carota L. CAUSED BY Alternaria dauci (KÜHN GROVES & SKOLKO: EFFECT OF INOCULUN CONCENTRATION AND DETERMINATION OF THE GENERATION TIME OF Alternaria dauci

    Directory of Open Access Journals (Sweden)

    Yvo de Carvalho

    2007-09-01

    Full Text Available

    O efeito da concentração do inóculo de Alternaria dauci sobre a severidade de ocorrência da queima das folhas e produção de cenoura foi estudado em ensaio conduzido em casa-de-vegetação. O cultivar usado foi Nantes Meio Comprida e as concentrações de inóculo testadas foram 2x10^4, 5x10³, 10³ e 10² esporos/ml, comparadas com uma testemunha não inoculada. O grau de severidade da queima foi avaliado 10 dias após a inoculação e os resultados de produção foram tomados 150 dias após a semeadura. Diferenças estatisticamente significantes entre os tratamentos foram observadas em relação à severidade de ocorrência da queima das folhas, peso total e peso das raízes, mas não em peso das raízes comercializáveis, número total de plantas e número das raízes comercializáveis. O ciclo das infecções secundárias foi bastante reduzido, denotando baixa esporulação do fungo sob as condições reinantes na casa-de-vegetação durante o ensaio. Determinou-se o período de geração de Alternaria dauci em folíolos destacados de cenoura do cultivar Nantes Meio Comprida, sob temperatura ambiente, 16, 20 e 24 °C. Placas de Petri (150 x 20 mm, forradas com papel de filtro embebido em água, funcionaram como câmaras úmidas. Dentro dos limites estudados, a temperatura parece não exercer efeitos consideráveis sobre o ciclo biótico do fungo. Usando-se esporos produzidos em agar-V8, observou-se que a duração média do período de geração foi de 6 a 7, 5, 6 e 6 dias, respectivamente, para 16, 20, 24°C e temperatura ambiente. Notou-se que a procedência de inóculo, ou mais propriamente sua vitalidade, afetou substancialmente a amplitude do período de geração do fungo. Esporos mantidos em tubos de vidro abertos, sob condições ambientes, durante 180 dias, tiveram período de geração aproximadamente duas vezes mais longo do que esporos jovens e vigorosos

  5. Assessment of genetic diversity and distribution of endophytic fungal communities of Alternaria solani isolates associated with the dominant Karanja plants in Sanganer Region of Rajasthan.

    Science.gov (United States)

    Tiwari, Kartikeya; Chittora, Manish

    2013-12-01

    Higher plants are ubiquitously colonized with fungal endophytes that often lack readily detectable structures. Current study examines the distribution of endophytic fungal communities within Karanja plants and diversity of novel fungal endophyte Alternaria solani isolates collected from different locations of Sanganer region of Rajasthan. Results confirmed that A. solani is a major fungal endophyte consortium associated with Karanja plants. PCR Amplified fragments using random amplified polymorphic DNA (RAPD) primers were subjected to unweighted pair group method analysis (UPGMA), which clearly distinguished twelve ecologically diverse A. solani isolates. A total of 58 RAPD loci were amplified, out of which 35 (60.34%) were polymorphic and 23 were monomorphic (39.66%) in nature. These polymorphic loci were identified with an average of 2.92 bands per primer. The efficacy of RAPD markers proved as an efficient marker system with respect to detection of polymorphism and number of loci scored and can be used for the identification of a particular isolates, thereby defining core collections and strengthening their exploitation in acquiring novel products produced by them.

  6. [Streptococcus pyogenes pathogenic factors].

    Science.gov (United States)

    Bidet, Ph; Bonacorsi, S

    2014-11-01

    The pathogenicity of ß-hemolytic group A streptococcus (GAS) is particularly diverse, ranging from mild infections, such as pharyngitis or impetigo, to potentially debilitating poststreptococcal diseases, and up to severe invasive infections such as necrotizing fasciitis or the dreaded streptococcal toxic shock syndrome. This variety of clinical expressions, often radically different in individuals infected with the same strain, results from a complex interaction between the bacterial virulence factors, the mode of infection and the immune system of the host. Advances in comparative genomics have led to a better understanding of how, following this confrontation, GAS adapts to the immune system's pressure, either peacefully by reducing the expression of certain virulence factors to achieve an asymptomatic carriage, or on the contrary, by overexpressing them disproportionately, resulting in the most severe forms of invasive infection.

  7. Rapid Detection of Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  8. Screening of different Trichoderma species against agriculturally important foliar plant pathogens.

    Science.gov (United States)

    Prabhakaran, Narayanasamy; Prameeladevi, Thokala; Sathiyabama, Muthukrishnan; Kamil, Deeba

    2015-01-01

    Different isolates of Trichoderma were isolated from soil samples which were collected from different part of India. These isolates were grouped into four Trichoderma species viz., Trichoderma asperellum (Ta), T. harzianum (Th), T. pseudokoningii (Tp) and T. longibrachiatum (Tl) based on their morphological characters. Identification of the above isolates was also confirmed through ITS region analysis. These Trichoderma isolates were tested for in vitro biological control of Alternaria solani, Bipolaris oryzae, Pyricularia oryzae and Sclerotinia scierotiorum which cause serious diseases like early blight (target spot) of tomato and potato, brown leaf spot disease in rice, rice blast disease, and white mold disease in different plants. Under in vitro conditions, all the four species of Trichoderma (10 isolates) proved 100% potential inhibition against rice blast pathogen Pyracularia oryzae. T. harzianum (Th-01) and T. asperellum (Ta-10) were effective with 86.6% and 97.7%, growth inhibition of B. oryzae, respectively. Among others, T. pseudokoningii (Tp-08) and T. Iongibrachiatum (Tl-09) species were particularly efficient in inhibiting growth of S. sclerotiorum by 97.8% and 93.3%. T. Iongibrachiatum (TI-06 and TI-07) inhibited maximum mycelial growth of A. solani by 87.6% and 84.75. However, all the T. harzianum isolates showed significantly higher inhibition against S. sclerotiorum (CD value 9.430), causing white mold disease. This study led to the selection of potential Trichoderma isolates against rice blast, early blight, brown leaf spot in rice and white mold disease in different crops.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Screening of three novel antimicrobial peptides with antifungal pathogens%三条新颖短肽筛选及抑菌作用的初报

    Institute of Scientific and Technical Information of China (English)

    兰金苹; 李莉云; 汪洋; 王宪云; 刘丽娟; 刘国振; 成雄鹰

    2011-01-01

    [目的]为了发现新的农作物病原菌抗菌肽,人工设计并构建了大容量短肽文库,从中筛选并合成96条短肽用于鉴定其对农作物病原菌的抑菌活性.[方法]采用琼脂扩散法,对靶标菌一棉花枯萎病菌(Fusarium f.sp.vasinfecum)、棉花红腐病菌(Fusarium moniliforme)、小麦根腐病菌(Bipolaris sorokiniana)和马铃薯早疫病菌(Alternaria solani)进行抑菌初筛,并测定了有抗菌作用短肽的最小抑菌浓度和抑菌持久性.[结果]得到了A6、D4和F10对上述四种病原真菌抑菌效果较强,抑菌时间较长的抗菌肽,通过与抗菌肽数据库氨基酸序列对比,未见这3条抗菌肽的同源序列.[结论]研制的3条短肽属于新颖抗菌肽,为防治农作物真菌病害提供了新的基因资源.%[Objective] In order to discover novel antimicrobial peptides against important crop pathogens, we designed and screened a high capacity random peptide library and isolated a number of clones expressing peptides with antifungal activity. We selected 96 peptides from the library and synthesized their sequence, which were used to assay their activity against crop fungal pathogens. [ Methods ] Using agar diffusion assay, these peptides were assayed for their activity against pathogens that cause cotton Fusarium wilt (Fusarium f. Sp. Vasinfecum) , cotton red rot (Fusarium nwniliforme) , wheat spot blotch ( Bipolaris sorokiniana ) and potato early blight ( Alternaria solani). [ Results ] The three random peptides, A6, D4 and F10, showed the strongest activity against the above four crop fungal pathogens. Through Blastp analysis, we did not find they have homologous sequences with known antimicrobial peptides. [ Conclusion ] The novel antimicrobial peptides will provide gene resources for preventing important crop pathogens.

  14. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    Directory of Open Access Journals (Sweden)

    Andong eGong

    2015-10-01

    Full Text Available Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these pests is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production in the field and during storage.

  15. Germin-like protein 2 gene promoter from rice is responsive to fungal pathogens in transgenic potato plants.

    Science.gov (United States)

    Munir, Faiza; Hayashi, Satomi; Batley, Jacqueline; Naqvi, Syed Muhammad Saqlan; Mahmood, Tariq

    2016-01-01

    Controlled transgene expression via a promoter is particularly triggered in response to pathogen infiltration. This is significant for eliciting disease-resistant features in crops through genetic engineering. The germins and germin-like proteins (GLPs) are known to be associated with plant and developmental stages. The 1107-bp Oryza sativa root GLP2 (OsRGLP2) gene promoter fused to a β-glucuronidase (GUS) reporter gene was transformed into potato plants through an Agrobacterium-mediated transformation. The OsRGLP2 promoter was activated in response to Fusarium solani (Mart.) Sacc. and Alternaria solani Sorauer. Quantitative real-time PCR results revealed 4-5-fold increase in promoter activity every 24 h following infection. There was a 15-fold increase in OsRGLP2 promoter activity after 72 h of F. solani (Mart.) Sacc. treatment and a 12-fold increase observed with A. solani Sorauer. Our results confirmed that the OsRGLP2 promoter activity was enhanced under fungal stress. Furthermore, a hyperaccumulation of H2O2 in transgenic plants is a clear signal for the involvement of OsRGLP2 promoter region in the activation of specific genes in the potato genome involved in H2O2-mediated defense response. The OsRGLP2 promoter evidently harbors copies of GT-I and Dof transcription factors (AAAG) that act in response to elicitors generated in the wake of pathogen infection.

  16. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  17. USEPA PATHOGEN EQUIVALENCY COMMITTEE RETREAT

    Science.gov (United States)

    The Pathogen Equivalency Committee held its retreat from September 20-21, 2005 at Hueston Woods State Park in College Corner, Ohio. This presentation will update the PEC’s membership on emerging pathogens, analytical methods, disinfection techniques, risk analysis, preparat...

  18. Proteomics of Foodborne Bacterial Pathogens

    Science.gov (United States)

    Fagerquist, Clifton K.

    This chapter is intended to be a relatively brief overview of proteomic techniques currently in use for the identification and analysis of microorganisms with a special emphasis on foodborne pathogens. The chapter is organized as follows. First, proteomic techniques are introduced and discussed. Second, proteomic applications are presented specifically as they relate to the identification and qualitative/quantitative analysis of foodborne pathogens.

  19. Inhibition Effect of Extract Liquids from Chinese Herbal Medicines on Three Pathogens of Citrus Disease%中草药提取液对3种柑橘病原菌的抑制作用

    Institute of Scientific and Technical Information of China (English)

    刘畅; 任艳芳; 何俊瑜; 张兰兰; 尹国胜

    2011-01-01

    为了对中草药提取物应用于水果保鲜领域和开发新型植物源农药提供理论基础和依据,在中药质量浓度为0.05g/mL条件下,测定19种中草药水提物对3种来自柑橘采后病害的病原菌意大利青霉(Penicillium italicum Wehmer)、指状青霉(Penicillium digitatum Sacc.)和柑橘链格孢(Alternaria citri Ellis et Pierce)的抑菌效果.结果表明:同一种中药对不同病原菌及不同中药对同一病原菌的抑制作用存在差异.19种中草药水提物中,黄连对3种病原菌的综合抑菌率最高,为98.37%,且黄连提取物对意大利青霉,指状青霉,柑橘链格孢的最小抑菌浓度(MIC)分别为:0.2,0.025,0.05g/mL.而白芥子对意大利青霉以及桃仁、茯苓和玄参对指状青霉的生长则具有不同程度的促进作用.%The inhibition effect of 19 extract liquids with 0. 05 g/mL concentration from Chineae herbal medicines on Penicillium italicum. Penicillium digitatum and Alternaria citri of citrua diseasea was determined to provide the theoretical basis for application of Chineae herbal medicine extract in fruit preaervation and development of new batanical pesticiden. The results showed that there was difference in inhibition effect of the same extract liquid against different pathogens and inhibition effect of different extract liquids against the same pathogen , the comprehenaive inhibition rate of Coptis chinensis extract liquid against three pathogens reached 98. 37 % , the minimal inhibitony concentra tion of Coptis chinensis extract liquid against Penicillium italicum , Penicillium digitatum and Alternaria citri was 0 . 2 , 0. 025 and 0. 05 g/mL respectively , Sinapis alba extract liquid could promote growth of Peniciltium italicum , and liquida extracted from Prunus persica , Poria cocos and Scrophularia ningpoensis could promote growth of Penicillium digitatum to varying degrees.

  20. Isolation, identification and antimicrobial activity of propolis-associated fungi.

    Science.gov (United States)

    de Souza, Giovanni Gontijo; Pfenning, Ludwig Heinrich; de Moura, Fabiana; Salgado, Mírian; Takahashi, Jacqueline Aparecida

    2013-01-01

    Propolis is a natural product widely known for its medicinal properties. In this work, fungi present on propolis samples were isolated, identified and tested for the production of antimicrobial metabolites. Twenty-two fungal isolates were obtained, some of which were identified as Alternaria alternata, Aspergillus flavus, Bipolaris hawaiiensis, Fusarium merismoides, Lasiodiplodia theobromae, Penicillium citrinum, Penicillium crustosum, Penicillium janthinellum, Penicillium purpurogenum, Pestalotiopsis palustris, Tetracoccosporium paxianum and Trichoderma koningii. These fungi were grown in liquid media to obtain crude extracts that were evaluated for their antibiotic activity against pathogenic bacteria, yeast and Cladosporium cladosporioides and A. flavus. The most active extract was obtained from L. theobromae (minimum inhibitory concentration = 64 μg/mL against Listeria monocitogenes). Some extracts showed to be more active than the positive control in the inhibition of Staphylococcus aureus and L. monocitogenes. Therefore, propolis is a promising source of fungi, which produces active agents against relevant food poisoning bacteria and crop-associated fungi.

  1. Molecular pathogenicity of Streptococcus anginosus.

    Science.gov (United States)

    Asam, D; Spellerberg, B

    2014-08-01

    Streptococcus anginosus and the closely related species Streptococcus constellatus and Streptococcus intermedius, are primarily commensals of the mucosa. The true pathogenic potential of this group has been under-recognized for a long time because of difficulties in correct species identification as well as the commensal nature of these species. In recent years, streptococci of the S. anginosus group have been increasingly found as relevant microbial pathogens in abscesses and blood cultures and they play a pathogenic role in cystic fibrosis. Several international studies have shown a surprisingly high frequency of infections caused by the S. anginosus group. Recent studies and a genome-wide comparative analysis suggested the presence of multiple putative virulence factors that are well-known from other streptococcal species. However, very little is known about the molecular basis of pathogenicity in these bacteria. This review summarizes our current knowledge of pathogenicity factors and their regulation in S. anginosus.

  2. Genomics of clostridial pathogens: implication of extrachromosomal elements in pathogenicity.

    Science.gov (United States)

    Brüggemann, Holger

    2005-10-01

    The recently decoded genomes of the major clostridial toxin-producing pathogens Clostridium perfringens, Clostridium tetani, Clostridium botulinum and Clostridium difficile have provided a huge amount of new sequence data. Recent studies have focused on the identification and investigation of pathogenic determinants and the regulatory events governing their expression. The sequence data revealed also the genomic background of virulence genes, as well as the contribution of extrachromosomal elements to a pathogenic phenotype. This has generated new insights in clostridial pathogenesis - and will continue to do so in the future - and has deepened our understanding of the anaerobic lifestyle of clostridial species.

  3. Effects of fungal endophytes from perennial ryegrass on the growth of plant pathogens%黑麦草内生真菌对植物病原真菌生长的影响

    Institute of Scientific and Technical Information of China (English)

    马敏芝; 南志标

    2011-01-01

    为确定黑麦草内生真菌及其发酵产物对病原真菌生长的影响,从不同品种的多年生黑麦草(Lolium perenne)(爱神特、美迭丽、顶峰和球道)中分离出N-A1、N-M2、N-P2和N-F1共4株Neotyphodium属的内生真菌菌株,分别采用平板对峙培养、菌落生长及孢子萌发等方法对细交链孢(Alternaria alternata)、小麦根腐离蠕孢(Bipolaris sorokiniana)、新月弯孢霉(Curvularia lunata)和德氏霉(Drechslera sp.)等病原真菌进行室内生物测定.结果表明,在平板对峙培养中,不同内生真菌对同一种病原菌的抑制作用不同,不同病原菌对同一内生真菌的敏感程度表现出差异,4株内生真菌对各病原菌的抑制率范围依次为42.51%~46.25%、31.45%~43.97%、34.51%~46.55%和40.19%~46.62%.在对病原菌的生物测定中,4株内生真菌的发酵产物均可抑制病原菌的生长,N-F1菌株的抑菌效果显著高于其他3株内生真菌(P<0.05),对小麦根腐离蠕孢的菌落生长和孢子萌发表现出较强的抑制作用,抑制率分别达到57.20%和86.60%.

  4. Microwave Influence in Fungi a Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Manoliu, A. I.; Tufescu, F. M.; Oprica, L.; Olteanu, Z.; Creanga, D. E.

    2004-07-01

    The behavior of two cellulolytic fungus species under the influence of low intensity microwaves was studied: Chaetomium globosum and Alternaria alternata. Enzyme activity of dehydrogenase complex was investigated by spectrophotometric method in order to real the effect of relatively short daily exposure times. Inhibitory effect was noticed for malate dehydrogenase and succinate dehydrogenase in both fungi while differentiated influence was revealed in alpha ceto glutarate dehydrogenase (inhibitory in Chaetomium globosum but stimulatory in Alternaria alternata). Isocitrate dehydrogenase activity was significantly stimulated in both fungi for 3 hours exposure time. (Author) 15 refs.

  5. Precise determination of the Alternaria mycotoxins alternariol and alternariol monomethyl ether in cereal, fruit and vegetable products using stable isotope dilution assays.

    Science.gov (United States)

    Asam, Stefan; Konitzer, Katharina; Rychlik, Michael

    2011-02-01

    Cereal, fruit and vegetable products were analyzed for contamination with the Alternaria mycotoxins alternariol (AOH) and alternariol monomethyl ether (AME) using stable isotope dilution assays (SIDAs). Both toxins were practically not detected in cereals and cereal products: AOH-one out of 13 samples at a content of 4.1 μg/kg; AME-two out of 13 samples at contents ranging between 0.2 and 0.6 μg/kg. However, if cereals for animal nutrition were analyzed, much higher values were found: AOH-five out of six samples (13-250 μg/kg); AME-six out of six samples (3-100 μg/kg). This finding may pose a potential problem concerning animal health. AOH and AME were frequently detected in vegetable products: AOH-5 out of 10 samples (2.6-25 μg/kg); AME-6 out of 10 samples (0.1-5 μg/kg). Tomato products were affected, especially. The highest content of AOH (25 μg/kg) and AME (5 μg/kg) were found in triple concentrated tomato paste. Special wines like "Trockenbeerenauslese" or "Spätlese" (affected by noble rot in the vineyard) contained AOH (4/6 samples; 1.2-4.9 μg/kg) and AME (4/6 samples; 0.1-0.3 μg/kg), but the values did not exceed the values of both toxins that were found generally in wines.

  6. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  7. 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.

  8. 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. 

  9. Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Catherine G. Harwood

    2014-06-01

    Full Text Available Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  10. Host pathogen relations: exploring animal models for fungal pathogens.

    Science.gov (United States)

    Harwood, Catherine G; Rao, Reeta P

    2014-06-30

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  11. Efeito de meios de cultura e fatores físicos no crescimento e esporulação de Alternaria dauci e A. solani Effect of culture media and physical factors on growth and sporulation of Alternaria dauci and A. solani

    Directory of Open Access Journals (Sweden)

    Pablo Pulz

    2009-06-01

    Full Text Available Alternaria dauci e Alternaria solani são espécies / 24 h. O método desenvolvido neste trabalho foi comparado ao reconhecidamente difíceis de esporular em meios de cultura. Este tradicionalmente utilizado (BDA, 25 ºC, 12 h luz branca / 12 h trabalho teve o objetivo de verificar a influência de alguns meios escuro e raspagem da colônia. O meio V8-ágar, temperatura de 25 de cultura e fatores fisicos sobre o crescimento micelial e a ºC, luz NUV e raspagem das colônias exerceram influência mais esporulação dessas espécies. Testaram-se os meios de cultura BDA, marcante no crescimento e esporulação. O fotoperíodo 12 h luz NUV Aveia e V8; temperaturas (15ºC, 20ºC, 25ºC, 30ºC e 35ºC / 12 h escuro foi o que mais estimulou a esporulação. Observou-se que, comprimentos de onda da luz durante a incubação (amarelo, azul, de modo geral, períodos de escuro maiores que os períodos de luz, branco, NUV, verde e vermelho; tipos de injúria aplicados à aplicados após injúria da colônia, favoreceram a esporulação. O colônia (raspagem, UV, irradiação de microondas, e temperatura método desenvolvido mostrou-se nitidamente superior ao de 100 ºC e fotoperíodos (luz / escuro, respectivamente, de 24 h tradicionalmente utilizado, para crescimento e esporulação de ambas / 0 h, 22 h / 2 h, 17 h / 7 h, 12 h / 12 h, 7 h / 17 h, 2 h / 22 e 0 h as espécies.Alternaria dauci and A. solani are fungal species known for h and 0 h / 24 h were tested. The method developed in this study was difficult sporulation in culture media. This study had the objective of compared to the traditional procedure (BDA, 25 ºC, 12 h white / 12 verifying the influence of some physical factors on mycelia growth h dark light and scratching of the colony. V8-agar medium, and sporulation of these two species. Culture media (BDA, oat and temperature of 25 ºC, NUV light and scratching of the colonies had a V8, temperature (15ºC, 20ºC, 25ºC, 30ºC and 35ºC, light

  12. 广西桂花叶枯病病原菌鉴定及其生物学特性研究%Identification and Characterization of Causal Agent of Sweet Osmanthus Leaf Blight in Guangxi

    Institute of Scientific and Technical Information of China (English)

    谢玲; 唐晨光; 岑贞陆; 黄思良; 秦碧霞; 覃丽萍; 胡春锦

    2009-01-01

    A sweet osmanthus leaf blight severely occurred in Nanning city, Guangxi, China. The pathogen was isolated and its pathogenicity to sweet osmanthus plants confirmed by inoculation tests. The pathogenic isolate CHS was identified as Alternaria alternata (Fr.)Keissler based on its morphological characteristics and ITS sequence. The optimum temperature and pH value for growth and conidial germination were 28 ℃ and 6-7, respectively. Different conditions of light showed no obvious effect on the mycelial growth. Black light was favorable for conidial production. Tests on fungicidal sensitivity in vitro showed that the pathogen was highly sensitive to difenoconazole, prochloraz and propiconazole. This is the first record of sweet osmanthus leaf blight caused by A. alternata in Guangxi.%在广西南宁桂花树上严重发生一种叶枯病,从病叶上分离到桂花叶枯病菌(编号CHS),在致病性测定的基础上,根据病原菌株CHS的形态及ITS序列,将其鉴定为Alternaria alternata(Fr.)Keissler.对该菌的生物学特性研究结果表明:菌丝生长、孢子形成和孢子萌发的最适温度均为28 ℃;生长发育最适pH值为6~7;不同光环境对该菌菌丝生长发育影响不大,黑光环境最利于孢子萌发;在供试的培养基中PDA最适合菌丝生长和产孢;苯醚甲环唑、咪鲜胺和丙环唑对该菌的抑制作用最强.由A. alternata引起的桂花叶枯病在广西的发生属首次报道.

  13. Future research needs involving pathogens in groundwater

    Science.gov (United States)

    Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important barriers to preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to ...

  14. Pathogen detection using engineered bacteriophages.

    Science.gov (United States)

    Smartt, Abby E; Xu, Tingting; Jegier, Patricia; Carswell, Jessica J; Blount, Samuel A; Sayler, Gary S; Ripp, Steven

    2012-04-01

    Bacteriophages, or phages, are bacterial viruses that can infect a broad or narrow range of host organisms. Knowing the host range of a phage allows it to be exploited in targeting various pathogens. Applying phages for the identification of microorganisms related to food and waterborne pathogens and pathogens of clinical significance to humans and animals has a long history, and there has to some extent been a recent revival in these applications as phages have become more extensively integrated into novel detection, identification, and monitoring technologies. Biotechnological and genetic engineering strategies applied to phages are responsible for some of these new methods, but even natural unmodified phages are widely applicable when paired with appropriate innovative detector platforms. This review highlights the use of phages as pathogen detector interfaces to provide the reader with an up-to-date inventory of phage-based biodetection strategies.

  15. Mucin dynamics and enteric pathogens.

    Science.gov (United States)

    McGuckin, Michael A; Lindén, Sara K; Sutton, Philip; Florin, Timothy H

    2011-04-01

    The extracellular secreted mucus and the cell surface glycocalyx prevent infection by the vast numbers of microorganisms that live in the healthy gut. Mucin glycoproteins are the major component of these barriers. In this Review, we describe the components of the secreted and cell surface mucosal barriers and the evidence that they form an effective barricade against potential pathogens. However, successful enteric pathogens have evolved strategies to circumvent these barriers. We discuss the interactions between enteric pathogens and mucins, and the mechanisms that these pathogens use to disrupt and avoid mucosal barriers. In addition, we describe dynamic alterations in the mucin barrier that are driven by host innate and adaptive immune responses to infection.

  16. Field study on changes in viability of airborne fungal propagules exposed to UV radiation.

    Science.gov (United States)

    Ulevicius, V; Peciulyte, D; Lugauskas, A; Andriejauskiene, J

    2004-08-01

    The responses of airborne fungi to UV-B under natural conditions were investigated at the coastal station in Preila, Lithuania. Results of this investigation demonstrated that solar radiation has a marked lethal effect on outdoor airborne fungi. Sensitivity to solar radiation was the highest for the fungal propagules collected late in the evening (relative recovery 6.2%) and early morning (25.3%). The lowest sensitivity to solar radiation was observed for fungal propagules collected at midday (50.0%) and in the afternoon (53.0%). The reason for the lethal effect is thought to be elimination of the sensitive fraction of the night-time fungal populations as solar radiation gradually increases beginning at dawn. Among 356 fungus strains isolated during the investigations, 128 can be characterized as potential pathogens, and 21 strains among those most common in fungal populations belonging to plant, animal, and human pathogen groups. The collected fungal populations were exposed to solar UV-B irradiation for 2 h (from 12 p.m. to 2 p.m.). Fungal communities in the air samples were composed of saprotrophs, some of which are regarded as potential phytopathogens (Alternaria, Cladosporium, and Fusarium) or as entomopathogens (Beauveria, Paecilomyces, and Metarhizium). The airborne fungal species identified after exposure to solar radiation were predominantly: Aspergillus niger, Alternaria alternata, Cladosporium cladosporioides, Arthrinium phaerosporum, and dematiaceous sterile mycelium.

  17. 核桃内生菌与病原真菌的体外互作研究%A Study on the in vitro Interaction of Endophyte with Pathogenic Fungi in Walnut

    Institute of Scientific and Technical Information of China (English)

    傅本重; 周攀; 王立华; 李国元; 邹礼平; 吴瑶

    2013-01-01

    为挖掘核桃内生菌的生物防治潜能。对核桃的内生菌和病原菌进行了分离,并通过平板对峙和发酵液抑菌试验,对其体外互作进行了研究。结果发现3株核桃内生细菌XHE7、XHE8和XHE12对2种病原真菌HK2( Colletotrichium sp.)和HD1( Alternaria sp.)有拮抗作用,抑制率高达82%。其发酵液对HK2的抑制作用高达100%。对其中2株拮抗作用明显的细菌进行了生理生化和16S rDNA分子鉴定,初步确定XHE8和XHE12皆为芽孢杆菌( Bacillus sp.)。%In order to exploring the biocontrol talent of walnut endophytic bacteria ,several endophytes and two pathogens in walnut were isolated , and the in vitro interactions between endophyte and pathogens were studied by using plate-confrontation and zymotic fluid inhibition assay .The results showed that three endophyt-ic strains XHE7,XHE8 and XHE12 represented significant antagonism to both HK2(Colletotrichium sp.) and HD1 (Alternaria sp.),and the highest inhibition rate reached 82.01%.Their zymotic fluid could suppress HK2 growth rate as high as 100%.Combined physiological and biochemical characters with 16S rDNA sequencing results,both strains XHE8 and XHE12 were identified as Bacillus sp..

  18. Analysis of Meteorological Condition for Infection of the pathogen of Tobacco Brown Spot (Alternaria alternate)%烟草赤星病病原菌侵染的气象条件分析

    Institute of Scientific and Technical Information of China (English)

    莫建国; 陈庆园; 于飞

    2012-01-01

    [目的]明确赤星病侵染与流行的适宜气象指标及其关键气象因子.[方法]对贵州省5个典型山地气候区烟草赤星病进行调查,在室内分析不同菌株间生物学特性差异;在人工气候箱内采用均匀设计法模拟不同气象条件(光照、温度和湿度),在离体叶片上采用悬滴法分析不同气候区赤星病病原菌的侵染能力差异.[结果]贵州省不同气候带的赤星病病原菌侵染率表现出一定的差异性,在湿度50%~60%、温度10~20℃即低温中等湿度条件下即可侵染烟叶,各菌株间有一定差异,但差异不大.[结论]为赤星病的流行预测和防治提供了理论依据.%[Objective]The aim was to study the change law of agronomic characters of winter wheat under different conditions of soil water.[Method]With the winter wheat variety Jimai 20 as experimental material, the variation of plant height, panel length and dry weight of organs were studied, and the relationship between agronomic characters and moisture content in soil was studied.[Result]Under the conditions of slight drought stress, the stem height was 63.4% -73.2% of that under appropriate moisture, while the internode length under ear increased by 9. 2%. Under severe drought, the length of internode under ear got shorter, while the length of penultimate and the third internode from top decreased firstly and then increased. The dry matter accumulation of stem, leaves and spikelet decreased while that of root increased. The length of the internode under ear, penultimate and the third intemodes from top increased firstly and then declined during the soil moisture pro cessing from appropriate to waterlogged, and also the variation of dry matter of organs.[Conclusion]The research provides theoretical basis for study on the water-saving and high yield of wheat.

  19. Characterization of Pathogenicity, Virulence and Host-Pathogen Interractions

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, A; Folta, P

    2006-07-27

    The threats of bio-terrorism and newly emerging infectious diseases pose serious challenges to the national security infrastructure. Rapid detection and diagnosis of infectious disease in human populations, as well as characterizing pathogen biology, are critical for reducing the morbidity and mortality associated with such threats. One of the key challenges in managing an infectious disease outbreak, whether through natural causes or acts of overt terrorism, is detection early enough to initiate effective countermeasures. Much recent attention has been directed towards the utility of biomarkers or molecular signatures that result from the interaction of the pathogen with the host for improving our ability to diagnose and mitigate the impact of a developing infection during the time window when effective countermeasures can be instituted. Host responses may provide early signals in blood even from localized infections. Multiple innate and adaptive immune molecules, in combination with other biochemical markers, may provide disease-specific information and new targets for countermeasures. The presence of pathogen specific markers and an understanding of the molecular capabilities and adaptations of the pathogen when it interacts with its host may likewise assist in early detection and provide opportunities for targeting countermeasures. An important question that needs to be addressed is whether these molecular-based approaches will prove useful for early diagnosis, complement current methods of direct agent detection, and aid development and use of countermeasures. Lawrence Livermore National Laboratory (LLNL) will host a workshop to explore the utility of host- and pathogen-based molecular diagnostics, prioritize key research issues, and determine the critical steps needed to transition host-pathogen research to tools that can be applied towards a more effective national bio-defense strategy. The workshop will bring together leading researchers/scientists in the

  20. Efeito da adubação sobre a incidência de traça-do-tomateiro e alternaria em plantas de tomate Effect of fertilization on the incidence of leafminer and early blight on tomato plants

    Directory of Open Access Journals (Sweden)

    Germano L.D. Leite

    2003-09-01

    Full Text Available Avaliou-se o efeito de quatro níveis de adubação nitrogenada e potássica (NK na resposta do tomateiro Lycopersicon esculentum, c.v Santa Clara, ao ataque de mancha de alternaria (Alternaria solani, e da traça-do-tomateiro (Tuta absoluta, em casa de vegetação, em três diferentes idades da planta. O delineamento experimental foi blocos casualizados com sete repetições, no esquema fatorial 3 x 4. Foram avaliados a altura da planta (cm, área foliar (cm² e o número de cachos por planta, flores por cacho, flores abortadas por cacho, frutos por cacho, frutos com mancha de alternaria por cacho, frutos atacados por traça-do-tomateiro por cacho, peso dos frutos por planta e minas de traça-de-tomateiro. A maior percentagem de frutos atacados pela traça foi observado em plantas de tomate cultivadas com altas doses de N. Com o aumento do número de flores ocorreu menor número de frutos atacados por alternaria. Tanto o ataque de A. solani como o de traça-do-tomateiro foi concentrado em frutos de menor peso, sendo que quanto maior o número de flores atacadas por A. solani, menor foi o ataque da traça aos frutos. O ataque da traça aos frutos foi maior em plantas de dois meses do que em plantas de quatro meses de idade, sendo o mesmo observado para o número de minas da traça-do-tomateiro.The effect of NK fertilization on tomato plants (Lycopersicon esculentum, cv. "Santa Clara", over early blight (Alternaria solani and the leafminer (Tuta absoluta attack in greenhouse, in the different plant ages, was evaluated. The 3 x 4 factorial experiment was established in a randomized blocks design with seven replicates. Plant height (cm, leaf area (cm² and number of raceme per plant, number of flowers per raceme, flower drop per raceme, number of fruits per raceme, damaged fruits per raceme by early blight and leafminer, fruit weight per plant and number of mines of leafminer were evaluated. Greater percentage of fruits damaged by leafminer was

  1. 紫斑病菌粗毒素对大蒜幼苗防御酶活性和叶片解剖结构的影响%Effects of Alternaria porri (Elliott) Cif. Crude Toxin on Protective Enzyme Activities and Leaf Anatomical Structure of Garlic Seedlings

    Institute of Scientific and Technical Information of China (English)

    李晓敏; 程智慧; 董殷鑫

    2012-01-01

    以抗病品种G087和感病品种G025为试材,研究了大蒜紫斑病菌粗毒素对大蒜幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性和丙二醛(MDA)含量及叶片解剖结构的影响.结果表明:在大蒜紫斑病菌粗毒素处理后120 h内,抗病品种和感病品种叶片SOD活性呈现一致的变化趋势,均在96 h达到峰值,但抗病品种SOD活性始终高于感病品种.随着大蒜紫斑病菌粗毒素处理时间的延长,感病品种叶片POD和PAL活性均呈先持续升高后稍下降的趋势,均有1个峰值;而抗病品种叶片POD和PAL活性均出现2个峰值,POD活性的2个峰值分别出现在48 h和96 h,PAL活性的2个峰值分别出现48 h和120 h;抗病品种酶活性的最大峰值高于感病品种.在大蒜紫斑病菌粗毒素处理后的大部分时间内,抗病品种叶片MDA含量低于感病品种.抗病品种叶肉组织结构比感病品种紧密;经大蒜紫斑病菌粗毒素处理后,两个品种叶片栅栏组织及海绵组织的密度都比处理前增加,抗病品种叶肉组织结构比感病品种更加紧密.%The effects of Alternaria porri (Elliott) Cif. crude toxin on the activities of SOD, POD, PAL and contents of MDA and leaf anatomical structure were studied, taking the resistant cultivar G087 and susceptible cultivar G025 of garlic ( Allium sativum L.) as experiment materials. The results showed that the SOD activities of both cultivars appeared the same dynamic changing trend in 120 hours after the pathogen crude toxin treatment and reached the peak at 96 hours. But the SOD activities in resistant cultivar were higher than that in susceptible cultivar. The POD and PAL activities in the leaves of susceptible cultivar showed a trend of sustaining increase first then a slight decrease and had a peak value. However, the activities of POD and PAL in the leaves of resistant cultivar had 2 peak values, which presented at 48 hours and 96 hours for POD

  2. Radiation-induced mutagenesis of antifungal metabolite producing bacillus sp. HKA-17

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Keun; Senthilkumar, M. [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2009-09-15

    Bacillus sp. Strain HKA-17, isolated from the surface sterilized root nodule of Glycine max, inhibited several fungal plant pathogens. It produced a diffusible extracellular antifungal metabolite that was extracted with n-butanol. The crude extract was purified through Superdex{sup TM} 75 10/300 GL FPLC column. FT-IR spectrum of the FPLC purified-antifungal metabolite confirmed the presence of peptide and glycosidic bonds in its structure. Gamma induced mutagenesis of HKA-17 was carried out at an LD{sub 99} dose (8.46 kGy) to generate a mutant library. By screening the mutant library through a duel plate assay with Alternaria alternata, we selected one mutant with enhanced biocontrol activity (HKA-17e1) and two defective mutants (HKA-17d1 and HKA-17d2). Overproducing mutant recorded the largest inhibition zone (16.25 {+-} 0.86 mm) compared to any other mutant clone as well as wild type, and could be used as a potential biocontrol agent for plant disease suppression. The effect of HKA-17 antifungal metabolite on hyphal morphology was clearly demonstrated through scanning electron microscopy. The crude extract of defective mutant HKA-17 d1 did not induce any changes in hyphal morphology of A. alternata. However, antifungal metabolites of HKA-17 induced abnormal hyphal structures such as hyphal shrivelling, the bulging and swelling of intercalary cells, fragmentation, and cell lysis.

  3. Increased Soil Heavy Metal Concentrations Aff ect the Structure of Soil Fungus Community

    Directory of Open Access Journals (Sweden)

    Vaidilutė Dirginčiutė-volodkienė

    2011-03-01

    Elevated Cu, Zn and Pb concentrations in the soil influenced fungus community structure. Some species (Absidia glauca, Acremonium kiliense, Aspergillus fumigatus, and Alternaria alternata detected in the control soil community were eliminated, while the abundance of the other species increased. Paecillomyces genus dominated in the soil amended with either of Cu or Zn. P. farinosus, P. fumosoroseum and fungal species from the Clonostachys, Penicillium and Lecanicillium genera were Znresistant. P. lilacinus and plant pathogenic fungi, A. alternata, Fusarium oxysporum, F. solani and Phoma lingam were very abundant in soil amended with Cu salts, followed by some saprotrophic fungi such as Cunninghamella echinulata and Mucor hiemalis f. hiemalis. An overall change in the plant (cress, Lepidum sativum; wheat, Ticicum aestivum; lupine, Lupinus polyphyllus, and sunflower, Heliannthus annus seed viability was observed in comparison with control. Most deleterious effects on the seed germination were observed in case of zinc, medium – in case of copper, and the least – in case of lead. Zinc salts at used concentrations were unfavorable to both fungus populations and consequently to the seed viability.

  4. Compositions and methods for pathogen transport

    Energy Technology Data Exchange (ETDEWEB)

    El-Etr, Sahar; Farquar, George R.

    2016-01-26

    This disclosure provides a method for transporting a pathogen under ambient conditions, by culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite, starving the amoeba until it encysts, then culturing under conditions that favor conversion of the amoeba back to a trophozoite. In one aspect, the conditions that favor incorporation of the pathogen into the cyst of the amoeba comprises contacting the pathogen with the amoeba in an iron rich environment. Virus and/or bacteria are pathogens that can be transported by the disclosed method. Amoeba that are useful in the disclosed methods include, without limitation Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi. The disclosed methods have utility in: transporting pathogens from military field hospitals and clinics to the laboratory; transporting pathogens from global satellite laboratories to clinical laboratories; long term storage of pathogens; enriching contaminated patient samples for pathogens of interest; biosurveillance and detection efforts.

  5. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  6. Metabolic traits of pathogenic streptococci.

    Science.gov (United States)

    Willenborg, Jörg; Goethe, Ralph

    2016-11-01

    Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction. © 2016 Federation of European Biochemical Societies.

  7. Antigenic Variation in Bacterial Pathogens.

    Science.gov (United States)

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.

  8. Acinetobacter: an underrated foodborne pathogen?

    Science.gov (United States)

    Amorim, Angelo Maximo Batista de; Nascimento, Janaína Dos Santos

    2017-02-28

    The increasing prevalence of foodborne diseases observed in developing countries has been linked to a rise in the consumption of raw foods. However, unlike the classical pathogens that are commonly implicated in foodborne illnesses, members of the genus Acinetobacter are rarely associated with diarrheal disease, probably because of the difficulty in isolating these Gram-negative bacteria from food sources. Nevertheless, several species of Acinetobacter, especially A. baumannii, possess many of the characteristics associated with successful pathogens and exhibit a prodigious ability to acquire the multiple-drug resistance (MDR) phenotype. In this mini-review, we summarize the epidemiological data relating to MDR Acinetobacter and consider evidence suggesting that contaminated dairy products, along with raw fruit and vegetables, constitute extra-hospital reservoirs of this underrated pathogen, and may represent an increased risk to immunocompromised individuals and young children in healthcare settings.

  9. Infectious pathogens and bronchiolitis outcomes.

    Science.gov (United States)

    Hasegawa, Kohei; Mansbach, Jonathan M; Camargo, Carlos A

    2014-07-01

    Bronchiolitis is a common early childhood illness and an important cause of morbidity, it is the number one cause of hospitalization among US infants. Bronchiolitis is also an active area of research, and recent studies have advanced our understanding of this illness. Although it has long been the conventional wisdom that the infectious etiology of bronchiolitis does not affect outcomes, a growing number of studies have linked specific pathogens of bronchiolitis (e.g., rhinovirus) to short- and long-term outcomes, such as future risk of developing asthma. The authors review the advent of molecular diagnostic techniques that have demonstrated diverse pathogens in bronchiolitis, and they review recent studies on the complex link between infectious pathogens of bronchiolitis and the development of childhood asthma.

  10. Pathogenicity of highly pathogenic avian influenza virus in mammals

    NARCIS (Netherlands)

    E. de Wit (Emmie); Y. Kawaoka (Yoshihiro); M.D. de Jong (Menno); R.A.M. Fouchier (Ron)

    2008-01-01

    textabstractIn recent years, there has been an increase in outbreaks of highly pathogenic avian influenza (HPAI) in poultry. Occasionally, these outbreaks have resulted in transmission of influenza viruses to humans and other mammals, with symptoms ranging from conjunctivitis to pneumonia and death.

  11. New trends in emerging pathogens.

    Science.gov (United States)

    Skovgaard, Niels

    2007-12-15

    The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne

  12. Priming by Hexanoic acid induce activation of mevalonic and linolenic pathways and promotes the emission of plant volatiles.

    Directory of Open Access Journals (Sweden)

    Eugenio eLlorens

    2016-04-01

    Full Text Available Hexanoic acid is a short natural monocarboxylic acid present in some fruits and plants. Previous studies reported that soil drench application of this acid induces effective resistance in tomato plants against Botrytis cinerea and Pseudomonas syringae and in citrus against Alternaria alternata and Xanthomonas citri. In this work, we performed an in deep study of the metabolic changes produced in citrus by the application of hexanoic acid in response to the challenge pathogen Alternaria alternata, focusing on the response of the plant. Moreover, we used 13C labeled hexanoic to analyze its behavior inside the plants. Finally, we studied the volatile emission of the treated plants after the challenge inoculation. Drench application of 13C labeled hexanoic demonstrated that this molecule stays in the roots and is not mobilized to the leaves, suggesting long distance induction of resistance. Moreover, the study of the metabolic profile showed an alteration of more than two hundred molecules differentially induced by the application of the compound and the inoculation with the fungus. Bioinformatics analysis of data showed that most of these altered molecules could be related with the mevalonic and linolenic pathways suggesting the implication of these pathways in the induced resistance mediated by hexanoic acid. Finally, the application of this compound showed an enhancement of the emission of 17 volatile metabolites. Taken together, this study indicates that after the application of hexanoic acid this compound remains in the roots, provoking molecular changes that may trigger the defensive response in the rest of the plant mediated by changes in the mevalonic and linolenic pathways and enhancing the emission of volatile compounds, suggesting for the first time the implication of mevalonic pathway in response to hexanoic application.

  13. Combining real-time PCR and next-generation DNA sequencing to provide quantitative comparisons of fungal aerosol populations

    Science.gov (United States)

    Dannemiller, Karen C.; Lang-Yona, Naama; Yamamoto, Naomichi; Rudich, Yinon; Peccia, Jordan

    2014-02-01

    We examined fungal communities associated with the PM10 mass of Rehovot, Israel outdoor air samples collected in the spring and fall seasons. Fungal communities were described by 454 pyrosequencing of the internal transcribed spacer (ITS) region of the fungal ribosomal RNA encoding gene. To allow for a more quantitative comparison of fungal exposure in humans, the relative abundance values of specific taxa were transformed to absolute concentrations through multiplying these values by the sample's total fungal spore concentration (derived from universal fungal qPCR). Next, the sequencing-based absolute concentrations for Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, and Penicillium/Aspergillus spp. were compared to taxon-specific qPCR concentrations for A. alternata, C. cladosporioides, E. nigrum, and Penicillium/Aspergillus spp. derived from the same spring and fall aerosol samples. Results of these comparisons showed that the absolute concentration values generated from pyrosequencing were strongly associated with the concentration values derived from taxon-specific qPCR (for all four species, p 0.70). The correlation coefficients were greater for species present in higher concentrations. Our microbial aerosol population analyses demonstrated that fungal diversity (number of fungal operational taxonomic units) was higher in the spring compared to the fall (p = 0.02), and principal coordinate analysis showed distinct seasonal differences in taxa distribution (ANOSIM p = 0.004). Among genera containing allergenic and/or pathogenic species, the absolute concentrations of Alternaria, Aspergillus, Fusarium, and Cladosporium were greater in the fall, while Cryptococcus, Penicillium, and Ulocladium concentrations were greater in the spring. The transformation of pyrosequencing fungal population relative abundance data to absolute concentrations can improve next-generation DNA sequencing-based quantitative aerosol exposure assessment.

  14. Retransformation of marker-free potato for enhanced resistance against fungal pathogens by pyramiding chitinase and wasabi defensin genes.

    Science.gov (United States)

    Khan, Raham Sher; Darwish, Nader Ahmed; Khattak, Bushra; Ntui, Valentine Otang; Kong, Kynet; Shimomae, Kazuki; Nakamura, Ikuo; Mii, Masahiro

    2014-09-01

    Multi-auto-transformation vector system has been one of the strategies to produce marker-free transgenic plants without using selective chemicals and plant growth regulators and thus facilitating transgene stacking. In the study reported here, retransformation was carried out in marker-free transgenic potato CV. May Queen containing ChiC gene (isolated from Streptomyces griseus strain HUT 6037) with wasabi defensin (WD) gene (isolated from Wasabia japonica) to pyramid the two disease resistant genes. Molecular analyses of the developed shoots confirmed the existence of both the genes of interest (ChiC and WD) in transgenic plants. Co-expression of the genes was confirmed by RT-PCR, northern blot, and western blot analyses. Disease resistance assay of in vitro plants showed that the transgenic lines co-expressing both the ChiC and WD genes had higher resistance against the fungal pathogens, Fusarium oxysporum (Fusarium wilt) and Alternaria solani (early blight) compared to the non-transformed control and the transgenic lines expressing either of the ChiC or WD genes. The disease resistance potential of the transgenic plants could be increased by transgene stacking or multiple transformations.

  15. Evaluation of antimicrobial activity of extracts of in vivo and in vitro grown Vinca rosea L. (Catharanthus roseus) against pathogens.

    Science.gov (United States)

    Naz, Shagufta; Haq, Rukhama; Aslam, Farah; Ilyas, Saiqa

    2015-05-01

    The antimicrobial activity of Vinca rosea was evaluated against pathogenic bacterial strains (Bacillus subtilis, B. licheniformis and Azotobacter sp.) and fungal strains (Asprgillus niger, Alternaria solani and Rhizopus oryzae) using agar well diffusion method. Methanolic extracts of in vivo leaf, in vitro leaf, in vitro calluses of leaf, nodal and fruit explants were used and exhibited antimicrobial activity as indicated by minimum inhibitory concentration (MIC). In vitro extracts showed better results as compared to the in vivo extracts for both the antibacterial as well as the antifungal activity. Among all the extracts, maximum zone of inhibition (30.3 mm ± 0.58(a)) was formed by in vitro leaf callus extract concentration of 2.0mg/ml against B. licheniformis. Similarly in case of antifungal activity, maximum zone of inhibition (34.6mm ± 0.57(a)) was formed by in vitro leaf callus extract and MIC value is 6.0mg/ml against A. niger. Hence these results clearly depicts that V. rosea possess a great strength to fight against the microbial activity and can be used against various infections.

  16. Agrobacterium-mediated transformation of tomato with rolB gene results in enhancement of fruit quality and foliar resistance against fungal pathogens.

    Science.gov (United States)

    Arshad, Waheed; Haq, Ihsan-ul-; Waheed, Mohammad Tahir; Mysore, Kirankumar S; Mirza, Bushra

    2014-01-01

    Tomato (Solanum lycopersicum L.) is the second most important cultivated crop next to potato, worldwide. Tomato serves as an important source of antioxidants in human diet. Alternaria solani and Fusarium oxysporum cause early blight and vascular wilt of tomato, respectively, resulting in severe crop losses. The foremost objective of the present study was to generate transgenic tomato plants with rolB gene and evaluate its effect on plant morphology, nutritional contents, yield and resistance against fungal infection. Tomato cv. Rio Grande was transformed via Agrobacterium tumefaciens harbouring rolB gene of Agrobacterium rhizogenes. rolB. Biochemical analyses showed considerable improvement in nutritional quality of transgenic tomato fruits as indicated by 62% increase in lycopene content, 225% in ascorbic acid content, 58% in total phenolics and 26% in free radical scavenging activity. Furthermore, rolB gene significantly improved the defence response of leaves of transgenic plants against two pathogenic fungal strains A. solani and F. oxysporum. Contrarily, transformed plants exhibited altered morphology and reduced fruit yield. In conclusion, rolB gene from A. rhizogenes can be used to generate transgenic tomato with increased nutritional contents of fruits as well as improved foliar tolerance against fungal pathogens.

  17. Pathogen pollution and the emergence of a deadly amphibian pathogen.

    Science.gov (United States)

    McKenzie