Science.gov

Sample records for alternaria stem canker

  1. Phomopsis stem canker: a re-emerging threat to sunflowers (Helianthus annuus) in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phomopsis stem canker frequently causes yield reductions on sunflowers (Helianthus annuus L.) on several continents, including Australia, Russia, Europe and North America. Between 2001 and 2012, the incidence of Phomopsis stem canker has increased 16 fold in the Northern Great Plains of the United...

  2. Phomopsis Stem Canker: A Reemerging Threat to Sunflower (Helianthus annuus) in the United States.

    PubMed

    Mathew, Febina M; Alananbeh, Kholoud M; Jordahl, James G; Meyer, Scott M; Castlebury, Lisa A; Gulya, Thomas J; Markell, Samuel G

    2015-07-01

    Phomopsis stem canker causes yield reductions on sunflower (Helianthus annuus L.) on several continents, including Australia, Europe, and North America. In the United States, Phomopsis stem canker incidence has increased 16-fold in the Northern Great Plains between 2001 and 2012. Although Diaporthe helianthi was assumed to be the sole causal agent in the United States, a newly described species, D. gulyae, was found to be the primary cause of Phomopsis stem canker in Australia. To determine the identity of Diaporthe spp. causing Phomopsis stem canker in the Northern Great Plains, 275 infected stems were collected between 2010 and 2012. Phylogenetic analyses of sequences of the ribosomal DNA internal transcribed spacer region, elongation factor subunit 1-α, and actin gene regions of representative isolates, in comparison with those of type specimens, confirmed two species (D. helianthi and D. gulyae) in the United States. Differences in aggressiveness between the two species were determined using the stem-wound method in the greenhouse; overall, D. helianthi and D. gulyae did not vary significantly (P≤0.05) in their aggressiveness at 10 and 14 days after inoculation. These findings indicate that both Diaporthe spp. have emerged as sunflower pathogens in the United States, and have implications on the management of this disease. PMID:26121367

  3. Leaf Petiole and Stem Blight Disease of Sweet Potato Caused by Alternaria Bataticola in Uganda

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria leaf petiole and stem blight is an important disease of sweet potato (Ipomoea batatus (L.) Lam.) in tropical and sub-tropical regions. In surveys conducted in Uganda from 2001 to 2003, disease incidence ranged from 0-49%. Symptoms of Alternaria leaf and stem blight disease consisted of sm...

  4. Rhizoctonia damping-off stem canker and root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani has been reported to cause damping-off and root rot of rhododendrons and azaleas. Damping-off often includes groups of dying and dead seedlings. Decline of rooted plants in containers results from both root rot and stem necrosis below or above the soil line. Root rot is usually no...

  5. Stability of Sweet Potato Cultivars to Alternaria Leaf and Stem Blight Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria leaf petiole and stem blight is an economically important disease of sweet potato (Ipomoea batatus L) in tropical and sub-tropical environments. Published research on cultivar resistance to the sweet potato disease is limited. To evaluate cultivar reaction and stability to the disease, mu...

  6. Draft genome sequence of diaporthe aspalathi isolate ms-ssc91 a fungus causing stem canker in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diaporthe aspalathi (formerly D. phaseolorum var. meridionalis) is the causal agent of the southern stem canker disease in soybean. This disease can kill plants from the middle to the end of the growing season resulting in severe yield loss. The mechanisms of disease development and pathogen invasi...

  7. Assessing Quantitative Resistance against Leptosphaeria maculans (Phoma Stem Canker) in Brassica napus (Oilseed Rape) in Young Plants

    PubMed Central

    Huang, Yong-Ju; Qi, Aiming; King, Graham J.; Fitt, Bruce D. L.

    2014-01-01

    Quantitative resistance against Leptosphaeria maculans in Brassica napus is difficult to assess in young plants due to the long period of symptomless growth of the pathogen from the appearance of leaf lesions to the appearance of canker symptoms on the stem. By using doubled haploid (DH) lines A30 (susceptible) and C119 (with quantitative resistance), quantitative resistance against L. maculans was assessed in young plants in controlled environments at two stages: stage 1, growth of the pathogen along leaf veins/petioles towards the stem by leaf lamina inoculation; stage 2, growth in stem tissues to produce stem canker symptoms by leaf petiole inoculation. Two types of inoculum (ascospores; conidia) and three assessment methods (extent of visible necrosis; symptomless pathogen growth visualised using the GFP reporter gene; amount of pathogen DNA quantified by PCR) were used. In stage 1 assessments, significant differences were observed between lines A30 and C119 in area of leaf lesions, distance grown along veins/petioles assessed by visible necrosis or by viewing GFP and amount of L. maculans DNA in leaf petioles. In stage 2 assessments, significant differences were observed between lines A30 and C119 in severity of stem canker and amount of L. maculans DNA in stem tissues. GFP-labelled L. maculans spread more quickly from the stem cortex to the stem pith in A30 than in C119. Stem canker symptoms were produced more rapidly by using ascospore inoculum than by using conidial inoculum. These results suggest that quantitative resistance against L. maculans in B. napus can be assessed in young plants in controlled conditions. Development of methods to phenotype quantitative resistance against plant pathogens in young plants in controlled environments will help identification of stable quantitative resistance for control of crop diseases. PMID:24454767

  8. Canker Sores

    MedlinePlus

    ... causes canker sores. Mouth injuries, stress, poor nutrition, food allergies and menstrual periods are some of the things that may increase your chances of getting a canker sore. Treatment How are canker sores treated? There is no cure for canker sores, but they usually go away ...

  9. Comparative genomic analysis of duplicated homoeologous regions involved in the resistance of Brassica napus to stem canker.

    PubMed

    Fopa Fomeju, Berline; Falentin, Cyril; Lassalle, Gilles; Manzanares-Dauleux, Maria J; Delourme, Régine

    2015-01-01

    All crop species are current or ancient polyploids. Following whole genome duplication, structural and functional modifications result in differential gene content or regulation in the duplicated regions, which can play a fundamental role in the diversification of genes underlying complex traits. We have investigated this issue in Brassica napus, a species with a highly duplicated genome, with the aim of studying the structural and functional organization of duplicated regions involved in quantitative resistance to stem canker, a disease caused by the fungal pathogen Leptosphaeria maculans. Genome-wide association analysis on two oilseed rape panels confirmed that duplicated regions of ancestral blocks E, J, R, U, and W were involved in resistance to stem canker. The structural analysis of the duplicated genomic regions showed a higher gene density on the A genome than on the C genome and a better collinearity between homoeologous regions than paralogous regions, as overall in the whole B. napus genome. The three ancestral sub-genomes were involved in the resistance to stem canker and the fractionation profile of the duplicated regions corresponded to what was expected from results on the B. napus progenitors. About 60% of the genes identified in these duplicated regions were single-copy genes while less than 5% were retained in all the duplicated copies of a given ancestral block. Genes retained in several copies were mainly involved in response to stress, signaling, or transcription regulation. Genes with resistance-associated markers were mainly retained in more than two copies. These results suggested that some genes underlying quantitative resistance to stem canker might be duplicated genes. Genes with a hydrolase activity that were retained in one copy or R-like genes might also account for resistance in some regions. Further analyses need to be conducted to indicate to what extent duplicated genes contribute to the expression of the resistance phenotype

  10. Comparative genomic analysis of duplicated homoeologous regions involved in the resistance of Brassica napus to stem canker

    PubMed Central

    Fopa Fomeju, Berline; Falentin, Cyril; Lassalle, Gilles; Manzanares-Dauleux, Maria J.; Delourme, Régine

    2015-01-01

    All crop species are current or ancient polyploids. Following whole genome duplication, structural and functional modifications result in differential gene content or regulation in the duplicated regions, which can play a fundamental role in the diversification of genes underlying complex traits. We have investigated this issue in Brassica napus, a species with a highly duplicated genome, with the aim of studying the structural and functional organization of duplicated regions involved in quantitative resistance to stem canker, a disease caused by the fungal pathogen Leptosphaeria maculans. Genome-wide association analysis on two oilseed rape panels confirmed that duplicated regions of ancestral blocks E, J, R, U, and W were involved in resistance to stem canker. The structural analysis of the duplicated genomic regions showed a higher gene density on the A genome than on the C genome and a better collinearity between homoeologous regions than paralogous regions, as overall in the whole B. napus genome. The three ancestral sub-genomes were involved in the resistance to stem canker and the fractionation profile of the duplicated regions corresponded to what was expected from results on the B. napus progenitors. About 60% of the genes identified in these duplicated regions were single-copy genes while less than 5% were retained in all the duplicated copies of a given ancestral block. Genes retained in several copies were mainly involved in response to stress, signaling, or transcription regulation. Genes with resistance-associated markers were mainly retained in more than two copies. These results suggested that some genes underlying quantitative resistance to stem canker might be duplicated genes. Genes with a hydrolase activity that were retained in one copy or R-like genes might also account for resistance in some regions. Further analyses need to be conducted to indicate to what extent duplicated genes contribute to the expression of the resistance phenotype

  11. Canker Sores

    MedlinePlus

    ... cycle . Some research suggests that using products containing sodium lauryl sulfate (SLS) can be associated with canker sores. SLS ... with toothpastes and mouthwashes that don't contain sodium lauryl sulfate. And avoid brushing the sore itself with a ...

  12. Alternaria redefined

    PubMed Central

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

    2013-01-01

    Alternaria is a ubiquitous fungal genus that includes saprobic, endophytic and pathogenic species associated with a wide variety of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that do not always correlate to species-groups based on morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera based on nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and six monotypic lineages, the assemblage of which we recognise as Alternaria. This puts the genera Allewia, Brachycladium, Chalastospora, Chmelia, Crivellia, Embellisia, Lewia, Nimbya, Sinomyces, Teretispora, Ulocladium, Undifilum and Ybotromyces in synonymy with Alternaria. In this study, we treat the 24 internal clades in the Alternaria complex as sections, which is a continuation of a recent proposal for the taxonomic treatment of lineages in Alternaria. Embellisia annulata is synonymised with Dendryphiella salina, and together with Dendryphiella arenariae, are placed in the new genus Paradendryphiella. The sexual genera Clathrospora and Comoclathris, which were previously associated with Alternaria, cluster within the Pleosporaceae, outside Alternaria s. str., whereas Alternariaster, a genus formerly seen as part of Alternaria, clusters within the Leptosphaeriaceae. Paradendryphiella is newly described, the generic circumscription of Alternaria is emended, and 32 new combinations and 10 new names are proposed. A further 10 names are resurrected, while descriptions are provided for 16 new Alternaria sections. Taxonomic novelties: New

  13. Canker sore

    MedlinePlus

    ... most cases, the canker sores go away without treatment. Try not to eat hot or spicy foods, which can cause pain. Use over-the-counter medicines that ease pain in the area. Rinse your mouth with salt water or mild, over-the-counter mouthwashes. (DO NOT ...

  14. Three genetic groups of the Eucalyptus stem canker pathogen Teratosphaeria zuluensis introduced into Africa from an unknown source.

    PubMed

    Jimu, Luke; Chen, ShuaiFei; Wingfield, Michael J; Mwenje, Eddie; Roux, Jolanda

    2016-01-01

    The Eucalyptus stem canker pathogen Teratosphaeria zuluensis was discovered in South Africa in 1988 and it has subsequently been found in several other African countries as well as globally. In this study, the population structure, genetic diversity and evolutionary history of T. z uluensis were analysed using microsatellite markers to gain an enhanced understanding of its movement in Africa. Isolates were collected from several sites in Malawi, Mozambique, Uganda and Zambia. Data obtained were compared with those previously published for a South African population. The data obtained from 334 isolates, amplified across eight microsatellite loci, were used for assignment, differentiation and genetic diversity tests. STRUCTURE analyses, θ st and genetic distances revealed the existence of two clusters, one dominated by isolates from South Africa and the other by isolates from the Zambezi basin including Malawi, Mozambique and Zambia. High levels of admixture were found within and among populations, dominated by the Mulanje population in Malawi. Moderate to low genetic diversity of the populations supports the previously held view that the pathogen was introduced into Africa. The clonal nature of the Ugandan population suggests a very recent introduction, most likely from southern Africa. PMID:26499489

  15. Alternaria blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria blight of chickpea is caused by the fungal pathogen Alternaria alternata. The pathogen has wide host range, and affects all above ground parts of the plant. The disease occurs sporadically and occasionally could be economically important and causes significant damage. The pathogen can ...

  16. Botryosphaeria Cane Canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the more serious cane canker diseases of thornless blackberry plants in the eastern U.S. is caused by Botryosphaeria dothidea. Cane canker disease is highly destructive, often killing canes and reducing fruit yields to uneconomic levels. Cankers generally develop around one or more buds on th...

  17. Ethanol attracts scolytid beetles to Phytophthora ramorum cankers on coast live oak

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical abstract: Ethanol in sapwood was analyzed along vertical transects, through small spot cankers and larger basal cankers, of Phytophthora ramorum-infected stems of Quercus agrifolia at three sites in California. Trees with large basal cankers, known to attract scolytid beetles, had a 4.3 ti...

  18. Myrothecium roridum leaf spot and stem canker on watermelon in the southern Great Plains: Possible factors for its outbreak

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases are generally the greatest yield-limiting factor for watermelon across the U.S. In 2010, a foliar and stem-lesion disease was observed for the first time in Oklahoma causing moderate to severe defoliation. Using microscopic examination, the physical features of the fungus were consistent ...

  19. Visualization of wound periderm and hyphal profiles in pine stems inoculated with the pitch canker fungus Fusarium circinatum.

    PubMed

    Kim, Ki Woo; Lee, In Jung; Thoungchaleun, Vilakon; Kim, Chang Soo; Lee, Don Koo; Park, Eun Woo

    2009-12-01

    Postpenetration behavior of Fusarium circinatum in stems of pine species was investigated with light and transmission electron microscopy. Two-year-old stems of Pinus rigida and P. densiflora were wound-inoculated with the fungal conidial suspension and subjected to 25 degrees C for up to 30 days. It was common to observe the formation of wound periderm on each pine species, recovering wounded sites with newly formed tissues. The outermost thick layer of wound periderm was pink to red colored with the phloroglucinol-EtOH staining, indicating heavy deposition of lignin in wound periderm. The cork layers in the wound periderm of the two pine species consisted of cells that were mostly devoid of cellular contents in cytoplasm. The cork cells showed convoluted cell walls with different electron density (lamellations), which was seemingly more prevalent in P. densiflora than P. rigida. Hyphae of F. circinatum appeared normal with typical eucaryotic cytoplasm in P. rigida on ultrathin sections. Meanwhile, hyphae in P. densiflora were found to possess highly vacuolated cytoplasm, implying hyphal weakening and disintegration. Hyphal cytoplasm appeared to be a thin layer between the vacuole and the plasma membrane surrounded by cell wall. In addition, intrahyphal hyphae and concentric bodies were observed in hyphal cytoplasm. These results suggest that the architecture of wound periderm may be responsible for different responses of pine species to the invasion of F. circinatum. PMID:19484779

  20. Canker Sores (For Parents)

    MedlinePlus

    ... if the sores appear more than two or three times a year. Diagnosis Tests are usually not done to diagnose canker sores, as a doctor can identify them based on medical history and physical exam alone. If your child has very frequent or severe bouts of recurrent ...

  1. Direct detection and quantification of Alternaria alternata lycopersici toxins using high-performance liquid chromatography-evaporative light-scattering detection.

    PubMed

    Xu, Li; Du, Liangcheng

    2006-03-01

    Alternaria alternata lycopersici toxins are produced by the tomato pathogenic fungus A. alternata f. sp. lycopersici. They are primary determinants for stem canker disease of tomato and induce apoptosis in animals and plants. Due to the lack of a UV chromophore, their detection has relied on derivatizations or immunoassays, which require tedious pre-assay processes. Here, we describe a method for direct and quantitative detection of the toxins. The method employs an evaporative light-scattering detector (ELSD) coupled to HPLC. It gives a linear response in the range of 400-4000 ng toxin, with a detection limit of about 6 ng/mul. The detection of all major toxin congeners by HPLC-ESLD was confirmed by liquid chromatography-mass spectrometry. Thus, the method provides a simple and sensitive tool for the studies of this group of host-specific mycotoxins. PMID:16014317

  2. Detection of fluorescent compounds in citrus leaf cankers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker caused by the pathogenic bacterium, Xanthomonas citri subsp. citri (Xcc), poses a serious threat to citrus production in Florida, especially for the fresh fruit market. Xcc causes severe damage to fruit, stem, and leaf tissues, and although much has been learned about the complex inter...

  3. Integrated Management of Citrus Canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2012, crop losses in Hamlin f...

  4. Alternaria section Alternaria: Species, formae speciales or pathotypes?

    PubMed Central

    Woudenberg, J.H.C.; Seidl, M.F.; Groenewald, J.Z.; de Vries, M.; Stielow, J.B.; Thomma, B.P.H.J.; Crous, P.W.

    2015-01-01

    The cosmopolitan fungal genus Alternaria consists of multiple saprophytic and pathogenic species. Based on phylogenetic and morphological studies, the genus is currently divided into 26 sections. Alternaria sect. Alternaria contains most of the small-spored Alternaria species with concatenated conidia, including important plant, human and postharvest pathogens. Species within sect. Alternaria have been mostly described based on morphology and / or host-specificity, yet molecular variation between them is minimal. To investigate whether the described morphospecies within sect. Alternaria are supported by molecular data, whole-genome sequencing of nine Alternaria morphospecies supplemented with transcriptome sequencing of 12 Alternaria morphospecies as well as multi-gene sequencing of 168 Alternaria isolates was performed. The assembled genomes ranged in size from 33.3–35.2 Mb within sect. Alternaria and from 32.0–39.1 Mb for all Alternaria genomes. The number of repetitive sequences differed significantly between the different Alternaria genomes; ranging from 1.4–16.5 %. The repeat content within sect. Alternaria was relatively low with only 1.4–2.7 % of repeats. Whole-genome alignments revealed 96.7–98.2 % genome identity between sect. Alternaria isolates, compared to 85.1–89.3 % genome identity for isolates from other sections to the A. alternata reference genome. Similarly, 1.4–2.8 % and 0.8–1.8 % single nucleotide polymorphisms (SNPs) were observed in genomic and transcriptomic sequences, respectively, between isolates from sect. Alternaria, while the percentage of SNPs found in isolates from different sections compared to the A. alternata reference genome was considerably higher; 8.0–10.3 % and 6.1–8.5 %. The topology of a phylogenetic tree based on the whole-genome and transcriptome reads was congruent with multi-gene phylogenies based on commonly used gene regions. Based on the genome and transcriptome data, a set of core

  5. Effect of drought and defoliation on the susceptibility of eucalypts to cankers caused by Endothia gyrosa and Botryosphaeria ribis

    SciTech Connect

    Old, K.M.; Gibbs, R.; Craig, I.; Myers, B.J. ); Yuan, Z.Q. )

    1990-01-01

    Seedlings, saplings and mature eucalypts were susceptible to infection by Endothia gyrosa and Botryosphaeria ribis. Eucalyptus regnans and E. delegatensis were more susceptible than E. grandis and E. saligna. In trees not subjected to stress, cankers were limited in extent and often healed. When trees were defoliated, either manually or by severe insect attack, stem concentrations of both starch and soluble carbohydrates were reduced and canker development in some pathogen/host combinations was increased. Seedlings subjected to water stress were not predisposed to canker formation. The association of E. gyrosa with branch dieback of rural eucalypts suffering from chronic defoliation suggests that canker fungi contribute to the crown dieback syndrome in south-eastern Australia.

  6. Clinical Characteristics of Alternaria Keratitis

    PubMed Central

    Lin, Hsin-Chiung; Chen, Phil Y. F.; Ma, David H. K.; Tan, Hsin-Yuan

    2014-01-01

    Purpose. Alternaria spp. are an uncommon cause of mycotic keratitis. Previous studies on Alternaria keratitis have generally been limited to case reports. We examined the clinical characteristics of Alternaria keratitis in this study. Methods. The characteristics and outcomes of 7 patients with culture-proven Alternaria keratitis treated in our hospital were compared with 25 previously reported cases. Results. The risk factors for Alternaria keratitis were trauma in 5 patients and soft contact lenses in 1 patient. Six patients with early diagnosis (<2 weeks) were cured with medical antimicrobial treatment; a patch graft was required in 1 patient with perforation. When incorporated with previous reports on Alternaria keratitis (n = 32), 14 (44%) infections followed trauma, 10 (31%) were associated with preexisting corneal disease or previous ocular surgery, and 5 (16%) occurred in soft contact lens wearers. Successful medical treatment was achieved in 23 (72%) patients, including 10 out of 21 eyes (48%) treated with natamycin and/or amphotericin B. Therapeutic penetrating keratoplasty was performed in 9 (28%) cases. Conclusions. Alternaria keratitis is generally associated with specific risk factors and responds to medical treatment when early diagnosis is performed and prompt antifungal treatment is initiated. PMID:24778867

  7. CITRUS CANKER: PLANT PATHOLOGY VERSUS PUBLIC POLICY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing international travel and trade has resulted in an unprecedented number of plant pathogen introductions, including Xanthomonas axonopodis pv citri, (Xac), the bacterium that causes citrus canker. The disease affects commercial and dooryard citrus, and has far-reaching politi...

  8. 76 FR 52543 - European Larch Canker; Expansion of Regulated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 European Larch Canker; Expansion of Regulated... European larch canker to include additional areas in Maine. We are also correcting some misidentifications... of European larch canker from infested areas to noninfested areas. DATES: This interim rule...

  9. The HPLC-Fluorescence Detection of Coumarins in ‘Hamlin’ Sweet Orange and ‘Marsh’ Grapefruit Leaf Cankers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canker is a devastating disease for the citrus fresh fruit market and is caused by the pathogenic bacterium Xanthomonas citri var. citri (Xcc). Infection occurs by bacterial penetration through physical damage of leaves, peel and stems, and also by bacterial entry through the stomates of these photo...

  10. Research progress for integrated canker management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2013, crop losses in Hamlin f...

  11. Reasons for inconsistent citrus canker control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop losses from citrus canker in 2014 for Hamlin due to premature fruit drop, or for grapefruit from unacceptable severity of fruit lesions, were highly variable due to periodic rains that in certain locations were coincident with grapefruit flushes in February-March or with early Hamlin fruit deve...

  12. Hyperspectral reflectance imaging for detecting citrus canker based on dual-band ratio image classification method

    NASA Astrophysics Data System (ADS)

    Li, Jiangbo; Rao, Xiuqin; Guo, Junxian; Ying, Yibin

    2010-10-01

    Citrus are one of the major fruit produced in China. Most of this production is exported to Europe for fresh consumption, where consumers increasingly demand best quality. Citrus canker is one of the most devastating diseases that threaten peel of most commercial citrus varieties. The aim of this research was to investigate the potential of using hyperspectral imaging technique for detecting canker lesions on citrus fruit. Navel oranges with cankerous, normal and various common diseased skin conditions including wind scar, thrips scarring, scale insect, dehiscent fruit, phytotoxicity, heterochromatic stripe, and insect damage were studied. The imaging system (400-1000 nm) was established to acquire reflectance images from samples. Region of interest (ROI) spectral feature of various diseased peel areas was analyzed and characteristic wavebands (630, 685, and 720 nm) were extracted. The dual-band reflectance ratio (such as Q720/685) algorithm was performed on the hyperspectral images of navel oranges for differentiating canker from normal fruit skin and other surface diseases. The overall classification success rate was 96.84% regardless of the presence of other confounding diseases. The presented processing approach overcame the presence of stem/navel on navel oranges that typically has been a problematic source for false positives in the detection of defects. Because of the limited sample size, delineation of an optimal detection scheme is beyond the scope of the current study. However, the results showed that two-band ratio (Q685/630) along with the use of a simple threshold value segmentation method for discriminating canker on navel oranges from other peel diseases may be feasible.

  13. First Report and Characterization of Pestalotiopsis ellipsospora Causing Canker on Acanthopanax divaricatus

    PubMed Central

    Yun, Yeo Hong; Ahn, Geum Ran

    2015-01-01

    Acanthopanax divaricatus, a member of the Araliaceae family, has been used as an invigorant in traditional Korean medicine. During disease monitoring, a stem with small, irregular, brown lesions was sampled at a farm in Cheonan in 2011. The symptoms seen were sunken cankers and reddish-brown needles on the infected twig. The isolated fungal colonies were whitish, having crenated edges and aerial mycelium on the surface, and with black gregarious fruiting bodies. The reverse plate was creamy white. Conidia were 17~22 × 3.5~4.2 µm, fusiform, 4-septate, and straight to slightly curved. The nucleotide sequence of the partial translation elongation factor 1 alpha gene of the fungal isolate, shares 99% sequence identity with that of known Pestalotiopsis ellipsospora. Based on the results of the morphological and molecular analyses, the fungal isolate was identified as P. ellipsospora. In Korea, this is the first report of canker on A. divaricatus. PMID:26539058

  14. Research promises earlier warning for grapevine canker diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When it comes to detecting and treating vineyards for grapevine canker diseases (also called trunk diseases), like Botryosphaeria dieback (Bot canker), Esca, Eutypa dieback and Phomopsis dieback, the earlier the better, says plant pathologist Kendra Baumgartner, with the USDA’s Agricultural Research...

  15. Managing citrus canker for the fresh fruit industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The establishment of citrus canker in Florida changed the way the $400 million dollar industry grows, packs ships and stores fruit. Canker regulations have become less strict, but there is still a requirement for compliance for growers and packers to move fruit from Florida to other areas. The comp...

  16. Characteristics of Multi-rater Estimates of Citrus Canker Severity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (CC, caused by Xanthomonas citri) was under eradication for 10 y in Florida. A total of 28 CC surveyors and plant pathologists rated severity of CC symptoms on 200 images to investigate the range of abilities and some factors that influence canker severity estimation. Actual dis...

  17. A new compound from an endophytic fungus Alternaria tenuissima.

    PubMed

    Wu, Wen-Bin; Yue, Gao-Chao; Huang, Qi-Lin; Sun, Ling-Ling; Zhang, Wen

    2014-01-01

    A new secondary metabolite, named altertoxin IV (1), together with altertoxin II (2), was isolated from the fermentation broth of Alternaria tenuissima, an endophytic fungal strain residing in the stem of Tribulus terrestris L. The structure of new compound 1 was established by HR-ESI-MS, multinuclear NMR spectroscopy, and single crystal X-ray diffraction method. In their in vitro bioassay, compound 2 exhibited moderate cytotoxic activity against PC-3 cell lines with an IC50 value of 14.28 μM. PMID:24660902

  18. A comparison of culture and bioassay for detecting citrus canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) causes serious crop losses in tropical and subtropical citrus production regions. Detecting Xcc is important for quarantine purposes, research and disease management. Although PCR methods are available for detecting and quantifying viable bacteria,...

  19. Ungual and cutaneous phaeohyphomycosis caused by Alternaria alternata and Alternaria chlamydospora.

    PubMed

    Singh, S M; Naidu, J; Pouranik, M

    1990-01-01

    Two cases of ungual and cutaneous phaeohyphomycosis caused by Alternaria alternata and Alternaria chlamydospora are described. Oxiconazole and amorolfine were most effective in vitro against A. alternata and A. chlamydospora respectively. This is the first report of A. chlamydospora as an opportunistic pathogen of skin. PMID:2148601

  20. Alternaria keratitis after deep anterior lamellar keratoplasty.

    PubMed

    Naik, Mekhla; Mohd Shahbaaz; Sheth, Jay; Sunderamoorthy, S K

    2014-01-01

    To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

  1. Copper Sprays and Windbreaks for Control of Citrus Canker on Young Orange Trees in Southern Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The benefit of windbreaks and copper sprays for control of citrus canker caused by Xanthomonas axonopodis pv. citri was investigated in a commercial citrus orchard located in a citrus canker endemic area in southern Brazil. Control of canker was evaluated as incidence and severity of lesions on foli...

  2. Horsfall-Barratt recalibration and replicated severity estimates of citrus canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker is a serious disease of citrus in tropical and subtropical citrus growing regions. Accurate and precise assessment of citrus canker and other plant pathogens is needed to obtain good quality data. Citrus canker assessment data were used to ascertain some of the mechanics of the Horsfal...

  3. 78 FR 58992 - Notice of Request for Extension of Approval of an Information Collection; Citrus Canker...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... Collection; Citrus Canker; Interstate Movement of Regulated Nursery Stock and Fruit From Quarantined Areas... nursery stock and fruit from quarantined areas to prevent the spread of citrus canker. DATES: We will... from citrus canker quarantined areas, contact Ms. Lynn Evans-Goldner, National Policy Manager, PHP,...

  4. Genome sequence of a novel mitovirus identified in the phytopathogenic fungus Alternaria arborescens.

    PubMed

    Komatsu, Ken; Katayama, Yukie; Omatsu, Tsutomu; Mizutani, Tetsuya; Fukuhara, Toshiyuki; Kodama, Motoichiro; Arie, Tsutomu; Teraoka, Tohru; Moriyama, Hiromitsu

    2016-09-01

    The phytopathogenic fungus Alternaria spp. contains a variety of double-stranded RNA (dsRNA) elements of different sizes. Detailed analysis of next-generation sequencing data obtained using dsRNA purified from Alternaria arborescens, from which we had previously found Alternaria arborescens victorivirus 1, revealed the presence of another mycoviral-like dsRNA of approximately 2.5 kbp in length. When using the fungal mitochondrial genetic code, this dsRNA has a single open reading frame that potentially encodes an RNA-dependent RNA polymerase (RdRp) with significant to sequence similarity to those of viruses of the genus Mitovirus. Moreover, both the 5'- and 3'-untranslated regions have the potential to fold into stable stem-loop structures, which is characteristic of mitoviruses. Pairwise comparisons and phylogenetic analysis of the deduced amino acid sequences of RdRp indicated that the virus we identified in A. arborescens is a distinct member of the genus Mitovirus in the family Narnaviridae, designated as "Alternaria arborescens mitovirus 1" (AaMV1). PMID:27368994

  5. Experiments with Biocontrol of Alternaria alternata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A biocontrol yeast (WRL-76) developed by USDA-ARS at the Western Regional Research lab was evaluated for control of Alternaria alternata on pistachio. The experiment was conducted over a four year period in a Madera Co., CA orchard. Counts of damaged vs. intact fruit clusters were taken on 100 contr...

  6. Distribution of canker lesions on grapefruit in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker, caused by the plant pathogenic bacterium Xanthomonas citri subsp. citri (Xcc) is an important disease of grapefruit in Florida. To establish disease distribution on fruit, six samples of 24 diseased grapefruit were collected from two groves in east Florida. A plane was sliced through ...

  7. Developing Transgenic Citrus for Resistance to Huanglongbing and Citrus Canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB) and Citrus Bacterial Canker (CBC) are serious threats to citrus production, and resistant transgenic citrus is desirable. Genes for antimicrobial peptides (AMPs) with diverse promoters have been used to generate thousands of rootstock and scion transformants. D35S::D4E1 transfor...

  8. Automating the assessment of citrus canker symptoms with image analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (CC, caused by Xanthomonas citri) is a serious disease of citrus in Florida and other citrus-growing regions. Severity of symptoms can be estimated by visual rating, but there is inter- and intra-rater variation. Automated image analysis (IA) may offer a way of reducing some of ...

  9. Infection and decontamination of citrus-canker-inoculated leaf surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Personnel and equipment decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf su...

  10. Citrus diseases with global ramifications including citrus canker and huanglongbing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although there are a number of diseases that plague citrus production worldwide, two bacterial diseases are particularly problematic. Both are of Asian origin and currently cause severe economic damage: Asiatic citrus canker (ACC) and citrus huanglongbing (HLB). Although ACC has been found in the ...

  11. Pruning for prevention and management of canker diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trunk diseases (wood-canker diseases) threaten all California vineyards due to widespread distribution of the fungal pathogens. The infections are chronic and occur each year. Trunk diseases in mature vineyards reduce yields and increase management costs to the point where the vineyard is no longer ...

  12. Packingline sanitizers for use against canker and decay pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in general sanitation in citrus packinghouses has turned to specific reduction of the canker organism from post harvest fruit and packinglines. Existing methods are not efficient and reduction of the bacterial colonies is not sufficient to allow transport and sale of fruit outside the quara...

  13. PROSPECTS FOR CONTROL OF CITRUS CANKER WITH NOVEL CHEMICAL COMPOUNDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field trials conducted in Brazil demonstrate that copper formulations (copper hydroxide, CH; copper oxychloride, COC) even at reduced rates are consistently effective for control of canker on moderately susceptible orange varieties. Contact activity to replace and/or reduce copper could minimize po...

  14. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata

    PubMed Central

    Wan, Wenting; Long, Ni; Zhang, Jing; Tan, Yuntao; Duan, Shengchang; Zeng, Yan; Dong, Yang

    2016-01-01

    The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS) genes and 13 polyketide synthase (PKS) genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs), such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction. PMID:27159564

  15. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata.

    PubMed

    Hou, Yujie; Ma, Xiao; Wan, Wenting; Long, Ni; Zhang, Jing; Tan, Yuntao; Duan, Shengchang; Zeng, Yan; Dong, Yang

    2016-01-01

    The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS) genes and 13 polyketide synthase (PKS) genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs), such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction. PMID:27159564

  16. Adhesive tablet effective for treating canker sores in humans.

    PubMed

    Mizrahi, Boaz; Golenser, Jacob; Wolnerman, Joseph S; Domb, Abraham J

    2004-12-01

    A new mucoadhesive tablet, which releases natural active agents for pain reduction and rapid healing of canker sores, has been prepared and characterized. Adhesive tablets were prepared by compression molding of mixed powders of crosslinked polyacrylic acid and hydroxypropyl cellulose, absorbed with citrus oil and magnesium salt. The rate of tablet erosion and the rates of citrus oil and magnesium release were determined as well as the adhesiveness of the tablet using bovine gingival tissue and an Instron tensiometer. A clinical trial was conducted on 248 volunteers who had canker sores. Tablets adhere well to the mucosal tissue and gradually erode for 8 h releasing the citrus oil in a zero-order pattern whereas the magnesium is released during a period of 2 h. Both experimental and plain tablets were effective in reducing pain and decreasing healing time (p < 0.05) without adverse side effects. However, the tablets loaded with active agents were more effective. PMID:15459950

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

    PubMed

    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. PMID:26190916

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

    PubMed Central

    Patriarca, Andrea; Magan, Naresh

    2015-01-01

    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. PMID:26190916

  19. Presence of adhesive vesicles in the mycoherbicide Alternaria helianthi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Fungicidal activity of silver nanoparticles against Alternaria brassicicola

    NASA Astrophysics Data System (ADS)

    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.

  1. Immunotherapy with Alternaria alternata: present and future.

    PubMed

    Martínez-Cañavate Burgos, A; Valenzuela-Soria, A; Rojo-Hernández, A

    2007-01-01

    The prevalence of fungal allergies is greater than previously believed; consequently, such processes have been underestimated as potential causes of respiratory tract disease. Most patients sensitized to fungi exhibit perennial symptoms, though their intensity increases in the summer and autumn months. Skin reactions to the antigens of Alternaria alternata are associated with a high risk of allergic respiratory conditions in the presence of spores of this fungus -fundamentally in children and young adults- with a special form of presentation as life-threatening asthma. Very few controlled studies have examined the efficacy and safety of fungal extract immunotherapy -the main problem being the lack of standardized extracts for the diagnosis and treatment of such patients. In the year 2005 a tolerance study was made in children in relation to a depot extract containing the predominant antigen of Alternaria, with two different regimens (short and cluster). Tolerance was found to be good, with a 0.95 % incidence of local reactions and a 0.95 % incidence of grade 2 systemic reactions. Few studies involving sublingual immunotherapy have been conducted to date. PMID:18047818

  2. Characterization of species of Diaporthe from wood cankers of grape in eastern North American vineyards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In eastern North American vineyards, Phomopsis cane and leaf spot (causal fungus Phomopsis viticola) is a destructive foliar disease, but is also associated with wood cankers, along with other fungi. To determine the association between foliar and wood-canker symptoms, we recovered Phomopsis isolate...

  3. Automated image analysis of the severity of foliar citrus canker symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (caused by Xanthomonas citri subsp. citri) is a destructive disease, reducing yield, and rendering fruit unfit for fresh sale. Accurate assessment of citrus canker severity and other diseases is needed for several purposes, including monitoring epidemics and evaluation of germplasm. ...

  4. A novel Fusarium species causes a canker disease of the critically endangered conifer, Torreya taxifolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A canker disease of Florida torreya (Torreya taxifolia), here designated CDFT, has been implicated in the decline of this critically endangered species in its native range of northern Florida and southeastern Georgia. In our current surveys of eight Florida torreya sites, cankers were present on all...

  5. BARK CANKER OF UNKNOWN ETIOLOGY DEVELOPING ON PECAN CARYA ILLINOENSIS TREES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pecan trees in a five-year-old orchard of 17 cultivars had symptoms of an unusual bark canker first noticed in October, 2002. Symptoms appeared from ground line up to 3 meters on the central leader and most likely were initiated during the summer of 2002. Cankers developed around buds of the trunk...

  6. ENHANCED DETECTION AND ISOLATION OF THE WALNUT PATHOGEN BRENNARIA RUBRIFACIENS: CAUSAL AGENT OF DEEP BARK CANKER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deep bark canker (DBC) of walnut is caused by the bacterium Brenneria rubrifaciens which produces the red pigment rubrifacine. This disease of English walnut trees, is characterized by deep vertical cankers which exude sap laden with B. rubrifaciens. Although DBC is not observed on younger trees, ...

  7. Detecting citrus canker by hyperspectral reflectance imaging and PCA-based image classification method

    NASA Astrophysics Data System (ADS)

    Qin, Jianwei; Burks, Thomas F.; Kim, Moon S.; Chao, Kuanglin; Ritenour, Mark A.

    2008-04-01

    Citrus canker is one of the most devastating diseases that threaten citrus crops. Technologies that can efficiently identify citrus canker would assure fruit quality and safety and enhance the competitiveness and profitability of the citrus industry. This research was aimed to investigate the potential of using hyperspectral imaging technique for detecting canker lesions on citrus fruit. A portable hyperspectral imaging system consisting of an automatic sample handling unit, a light source, and a hyperspectral imaging unit was developed for citrus canker detection. The imaging system was used to acquire reflectance images from citrus samples in the wavelength range between 400 nm and 900 nm. Ruby Red grapefruits with normal and various diseased skin conditions including canker, copper burn, greasy spot, wind scar, cake melanose, and specular melanose were tested. Hyperspectral reflectance images were analyzed using principal component analysis (PCA) to compress the 3-D hyperspectral image data and extract useful image features that could be used to discriminate cankerous samples from normal and other diseased samples. Image processing and classification algorithms were developed based upon the transformed images of PCA. The overall accuracy for canker detection was 92.7%. This research demonstrated that hyperspectral imaging technique could be used for discriminating citrus canker from other confounding diseases.

  8. First report of citrus canker caused by Xanthomonas citri in Somalia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xanthomonas citri, causal agent of citrus canker, has been reported in several countries in Africa, but not Somalia. During 2006 and 2007, hyperplasia-type lesions, often surrounded by a water-soaked margin and yellow halo, typical of citrus canker caused by X. citri, were found on 8-10 year-old gr...

  9. Transcriptomic profile of tobacco in response to Alternaria longipes and Alternaria alternata infections.

    PubMed

    Duan, Shengchang; Ma, Xiao; Chen, Wei; Wan, Wenting; He, Yuqi; Ma, Xiaoqin; Ma, Yujin; Long, Ni; Tan, Yuntao; Wang, Yangzi; Hou, Yujie; Dong, Yang

    2016-01-01

    Tobacco brown spot caused by Alternaria fungal species is one of the most damaging diseases, and results in significant yield losses. However, little is known about the systematic response of tobacco to this fungal infection. To fill this knowledge gap, de novo assemblies of tobacco leaf transcriptomes were obtained in cultivars V2 and NC89 after the inoculation of either Alternaria longipes (AL) or Alternaria alternata (AA) at three different time points. We studied the gene expression profile of each cultivar-pathogen combination, and identified eight differentially expressed genes shared among all combinations. Gene ontology enrichment analysis of the differentially expressed genes revealed key components during the fungal infection, which included regulation of gene expression (GO:0010468), regulation of RNA metabolic process (GO:0051252), tetrapyrrole binding (GO:0046906), and external encapsulating structure (GO:0030312). Further analyses of the continuously upregulated/downregulated genes and the resistance genes demonstrated that the gene expression profile upon fungal infection was contingent on the specific cultivar and pathogen. In conclusion, this study provides a solid foundation for the investigation of plant-pathogen interaction, and is of great importance for disease prevention and molecular breeding. PMID:27157477

  10. Transcriptomic profile of tobacco in response to Alternaria longipes and Alternaria alternata infections

    PubMed Central

    Duan, Shengchang; Ma, Xiao; Chen, Wei; Wan, Wenting; He, Yuqi; Ma, Xiaoqin; Ma, Yujin; Long, Ni; Tan, Yuntao; Wang, Yangzi; Hou, Yujie; Dong, Yang

    2016-01-01

    Tobacco brown spot caused by Alternaria fungal species is one of the most damaging diseases, and results in significant yield losses. However, little is known about the systematic response of tobacco to this fungal infection. To fill this knowledge gap, de novo assemblies of tobacco leaf transcriptomes were obtained in cultivars V2 and NC89 after the inoculation of either Alternaria longipes (AL) or Alternaria alternata (AA) at three different time points. We studied the gene expression profile of each cultivar-pathogen combination, and identified eight differentially expressed genes shared among all combinations. Gene ontology enrichment analysis of the differentially expressed genes revealed key components during the fungal infection, which included regulation of gene expression (GO:0010468), regulation of RNA metabolic process (GO:0051252), tetrapyrrole binding (GO:0046906), and external encapsulating structure (GO:0030312). Further analyses of the continuously upregulated/downregulated genes and the resistance genes demonstrated that the gene expression profile upon fungal infection was contingent on the specific cultivar and pathogen. In conclusion, this study provides a solid foundation for the investigation of plant-pathogen interaction, and is of great importance for disease prevention and molecular breeding. PMID:27157477

  11. Large-spored Alternaria pathogens in section Porri disentangled

    PubMed Central

    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.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. PMID:25492985

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

    PubMed

    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. PMID:25492985

  13. Development of a qPCR technique to screen for resistance to Asiatic citrus canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asiatic citrus canker (Acc) (causal organism Xanthomonas citri subspc. citri (Xcc) is threatening sustainability of the Florida citrus industry. Resistant cultivars, whether developed through conventional breeding or genetic transformation, will be he best solution for dealint with Acc. In Florida...

  14. Widespread Distribution of Fungivorus Aphelenchoides spp. in Blight Cankers on American Chestnut Trees.

    PubMed

    Griffin, G J; Eisenback, J D; Oldham, K

    2012-12-01

    Previously we showed in laboratory studies that the fungivorus nematode, Aphelenchoides hylurgi, was attracted to and fed upon the chestnut blight fungus, Cryphonectria parasitica, from American chestnut bark cankers and was a carrier of biocontrol, white hypovirulent C. parasitica strains. In the present field study, we recovered Aphelenchoides spp. in almost all (97.0 %) of 133 blight canker tissue assays (three 5-g samples each) from four eastern states. High mean population densities (227 to 474 nematodes per 5 g tissue) of Aphelenchoides spp. were recovered from cankers in Virginia, West Virginia, and Tennessee but not from New Hampshire (mean = 75 nematodes per 5 g tissue). Overall, most canker assays yielded population densities less than 200 nematodes per 5 g tissue. All of 12 very small or young cankers yielded a few to many Aphelenchoides spp. Regression analysis indicated greatest recovery of Aphelenchoides spp. occurred in the month of May (r = 0.94). The results indicate that Aphelenchoides spp. appear to be widespread in blight cankers on American chestnut trees and could play a role in biocontrol of chestnut blight. PMID:23482428

  15. STEM?!?!

    ERIC Educational Resources Information Center

    Merrill, Jen

    2012-01-01

    The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

  16. Allergic bronchopulmonary mycosis due to Alternaria: Case report and review.

    PubMed

    Singh, Bhagteshwar; Denning, David W

    2012-01-01

    While allergic bronchopulmonary aspergillosis and mycosis are well recognised, no cases have been described related to Alternaria spp. Alternaria is a common sensitising fungus in asthmatics and related to thunderstorm asthma. We report a case of an asthmatic who presented with worsening asthma control, mild eosinophilia on high dose inhaled corticosteroids (800 μg/day), a total IgE of 3800 KIU/L, an Alternaria-specific IgE of 21.3 KUa/L and positive skin prick test, negative specific IgE and skin prick test to Aspergillus fumigatus, Penicillium spp., Cladosporium spp., Trichophyton spp. and a normal CT scan of the thorax. He responded well to a short course of oral prednisolone and then oral itraconazole, given over 17 months but relapsed 1 month after stopping it. PMID:24371728

  17. Cutaneous Alternariosis Caused by Alternaria infectoria: Three Cases in Kidney Transplant Patients.

    PubMed

    Lopes, Leonor; Borges-Costa, João; Soares-Almeida, Luís; Filipe, Paulo; Neves, Fernanda; Santana, Alice; Guerra, José; Kutzner, Heinz

    2013-01-01

    The genus Alternaria has more than 80 species. Alternaria alternata and Alternaria infectoria are the most frequent species associated with infections in humans. Their clinical importance lies in the growing number of cases reported in immunocompromised patients. Herein, we report three cases of kidney-transplanted patients with different clinical presentations of cutaneous alternariosis and we discuss the treatment options. PMID:27429134

  18. Cutaneous Alternariosis Caused by Alternaria infectoria: Three Cases in Kidney Transplant Patients

    PubMed Central

    Lopes, Leonor; Borges-Costa, João; Soares-Almeida, Luís; Filipe, Paulo; Neves, Fernanda; Santana, Alice; Guerra, José; Kutzner, Heinz

    2013-01-01

    The genus Alternaria has more than 80 species. Alternaria alternata and Alternaria infectoria are the most frequent species associated with infections in humans. Their clinical importance lies in the growing number of cases reported in immunocompromised patients. Herein, we report three cases of kidney-transplanted patients with different clinical presentations of cutaneous alternariosis and we discuss the treatment options. PMID:27429134

  19. 40 CFR 180.1256 - Alternaria destruens strain 059; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Alternaria destruens strain 059... RESIDUES IN FOOD Exemptions From Tolerances § 180.1256 Alternaria destruens strain 059; exemption from the... the microbial pesticide Alternaria destruens Strain 059 when used in or on all raw...

  20. Pulmonary hypersensitivity to Alternaria and Aspergillus in baker's asthma.

    PubMed

    Klaustermeyer, W B; Bardana, E J; Hale, F C

    1977-05-01

    In two cases of baker's asthma pulmonary hypersensitivity was found to the fungi Alternaria and Aspergillus. Provocative bronchial challenge revealed a dual response; an immediate and an Arthus type hypersensitivity to Aspergillus in the first case. A primary binding assay revealed high titres of anti-Aspergillus antibody in the serum. In the second case intradermal and bronchial challenge suggested an immediate type I hypersensitivity response to Alternaria. The suspected organisms were present in the room air of the bakeries. It is suggested that an immunological response to these airborne fungi may have contributed to the pathogenesis of baker's asthma. PMID:561668

  1. TWO NEW SPECIES OF ALTERNARIA FROM PEAR FRUIT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During studies conducted over the past 15 years of various diseases of deciduous tree fruit from around the world, hundreds of Alternaria isolates have been made and characterized using morphological and molecular methods. Two such fungi are newly described here as A. calycipyricola sp. nov. from th...

  2. Draft Genome Sequence of Alternaria alternata ATCC 34957.

    PubMed

    Nguyen, Hai D T; Lewis, Christopher T; Lévesque, C André; Gräfenhan, Tom

    2016-01-01

    We report the draft genome sequence of Alternaria alternata ATCC 34957. This strain was previously reported to produce alternariol and alternariol monomethyl ether on weathered grain sorghum. The genome was sequenced with PacBio technology and assembled into 27 scaffolds with a total genome size of 33.5 Mb. PMID:26769939

  3. CHARACTERIZATION OF SPORULATION OF ALTERNARIA ALTERNATA F. SP. SPHENOCLEAE.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted on agar media to characterize the factors for the optimization of sporulation of Alternaria alternata f. sp. sphenocleae, a fungal pathogen being evaluated as a biological control agent for Sphenoclea zeylanica (gooseweed). A. alternata f. sp. sphenocleae conidiation was affec...

  4. Genetic variability in the pistachio late blight fungus, Alternaria alternata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variation in the pistachio late blight fungus, Alternaria alternata, was investigated by restriction fragment length polymorphism (RFLP) in the rDNA region. Southern hybridization of EcoRI, HindIII, and Xbal digested fungal DNA with a RNA probe derived from Alt1, an rDNA clone isolated from ...

  5. Airborne fungal spores of Alternaria, meteorological parameters and predicting variables

    NASA Astrophysics Data System (ADS)

    Filali Ben Sidel, Farah; Bouziane, Hassan; del Mar Trigo, Maria; El Haskouri, Fatima; Bardei, Fadoua; Redouane, Abdelbari; Kadiri, Mohamed; Riadi, Hassane; Kazzaz, Mohamed

    2015-03-01

    Alternaria is frequently found as airborne fungal spores and is recognized as an important cause of respiratory allergies. The aerobiological monitoring of fungal spores was performed using a Burkard volumetric spore traps. To establish predicting variables for daily and weakly spore counts, a stepwise multiple regression between spore concentrations and independent variables (meteorological parameters and lagged values from the series of spore concentrations: previous day or week concentration (Alt t - 1) and mean concentration of the same day or week in other years ( C mean)) was made with data obtained during 2009-2011. Alternaria conidia are present throughout the year in the atmosphere of Tetouan, although they show important seasonal fluctuations. The highest levels of Alternaria spores were recorded during the spring and summer or autumn. Alternaria showed maximum daily values in April, May or October depending on year. When the spore variables of Alternaria, namely C mean and Alt t - 1, and meteorological parameters were included in the equation, the resulting R 2 satisfactorily predict future concentrations for 55.5 to 81.6 % during the main spore season and the pre-peak 2. In the predictive model using weekly values, the adjusted R 2 varied from 0.655 to 0.676. The Wilcoxon test was used to compare the results from the expected values and the pre-peak spore data or weekly values for 2012, indicating that there were no significant differences between series compared. This test showed the C mean, Alt t - 1, frequency of the wind third quadrant, maximum wind speed and minimum relative humidity as the most efficient independent variables to forecast the overall trend of this spore in the air.

  6. Oak tree canker disease supports arthropod diversity in a natural ecosystem.

    PubMed

    Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

    2014-03-01

    Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

  7. Oak Tree Canker Disease Supports Arthropod Diversity in a Natural Ecosystem

    PubMed Central

    Lee, Yong-Bok; An, Su Jung; Park, Chung Gyoo; Kim, Jinwoo; Han, Sangjo; Kwak, Youn-Sig

    2014-01-01

    Microorganisms have many roles in nature. They may act as decomposers that obtain nutrients from dead materials, while some are pathogens that cause diseases in animals, insects, and plants. Some are symbionts that enhance plant growth, such as arbuscular mycorrhizae and nitrogen fixation bacteria. However, roles of plant pathogens and diseases in natural ecosystems are still poorly understood. Thus, the current study addressed this deficiency by investigating possible roles of plant diseases in natural ecosystems, particularly, their positive effects on arthropod diversity. In this study, the model system was the oak tree (Quercus spp.) and the canker disease caused by Annulohypoxylon truncatum, and its effects on arthropod diversity. The oak tree site contained 44 oak trees; 31 had canker disease symptoms while 13 were disease-free. A total of 370 individual arthropods were detected at the site during the survey period. The arthropods belonged to 25 species, 17 families, and seven orders. Interestingly, the cankered trees had significantly higher biodiversity and richness compared with the canker-free trees. This study clearly demonstrated that arthropod diversity was supported by the oak tree canker disease. PMID:25288984

  8. Development and validation of standard area diagrams as assessment aids for estimating the severity of citrus canker on unripe oranges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canker (caused by Xanthomonas citri subsp. citri) is an important disease of citrus in Brazil and elsewhere in the world, and can cause severe disease on the fruit. The severity of citrus canker of fruit must often be estimated visually. The objective of this research was to construct and validate s...

  9. REAL-TIME PCR DETECTION AND DEVELOPMENT OF A BIOASSAY FOR THE DEEP BARK CANKER PATHOGEN, BRENNARIA RUBRIFACIENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deep Bark Canker (DBC), caused by the bacterium Brennaria rubrifaciens afflicts English walnut cultivars and is characterized by late onset of symptoms in trees greater than 15 years old. These symptoms include deep bleeding vertical cankers along the trunk and larger branches that exude a bacteria...

  10. [Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng].

    PubMed

    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. PMID:25282882

  11. Detection of citrus canker and Huanglongbing using fluorescence imaging spectroscopy and support vector machine technique.

    PubMed

    Wetterich, Caio Bruno; Felipe de Oliveira Neves, Ruan; Belasque, José; Marcassa, Luis Gustavo

    2016-01-10

    Citrus canker and Huanglongbing (HLB) are citrus diseases that represent a serious threat to the citrus production worldwide and may cause large economic losses. In this work, we combined fluorescence imaging spectroscopy (FIS) and a machine learning technique to discriminate between these diseases and other ordinary citrus conditions that may be present at citrus orchards, such as citrus scab and zinc deficiency. Our classification results are highly accurate when discriminating citrus canker from citrus scab (97.8%), and HLB from zinc deficiency (95%). These results show that it is possible to accurately identify citrus diseases that present similar symptoms. PMID:26835778

  12. Comparison of enzyme immunoassay–based assays for environmental Alternaria alternata

    PubMed Central

    Barnes, Charles; Portnoy, Jay; Sever, Michelle; Arbes, Samuel; Vaughn, Ben; Zeldin, Darryl C.

    2007-01-01

    Background Alternaria alternata–derived allergenic materials are causes of human disease. Several immunoassays exist to quantify these materials. Objective To compare methods for evaluating Alternaria content. Methods Four methods, including 1 monoclonal antibody (MAb)–based assay specific for recombinant Alt a 1, 1 MAb-based assay for chromatographically purified Alt a 1, 1 polyclonal antibody (PAb)–based assay for chromatographically purified Alt a 1, and 1 PAb-based assay for whole Alternaria extract, were evaluated. Environmental samples collected as part of the National Survey of Lead and Allergens in Housing were examined. Alternaria spore counts were determined in dust by observation. Results The MAb-based assay for recombinant Alt a 1 detected Alternaria in few samples (25%); the PAb-based assay for whole Alternaria proteins detected antigen in 97% of the samples. The PAb- and MAb-based assays for purified Alt a 1 detected antigen in 100% of the samples. There was a significant positive correlation between the 2 assays directed against purified Alt a 1. There was a positive correlation between the PAb-based assay for whole Alternaria and the PAb-based assay for Alt a 1. Nearly all the dust samples contained Alternaria spores, and there was a strong positive correlation between counts and all assays. Conclusion Because of the multifaceted nature of Alternaria, the disparities between methods for quantifying Alternaria, the cross-reactivity between fungal allergens, and the documented genetic promiscuity of this fungus, enzyme immunoassays using PAbs against a range of Alternaria proteins will probably produce the most reliable estimation of overall Alternaria exposure in house dust. PMID:17042141

  13. Different Transcriptional Response to Xanthomonas citri subsp. citri between Kumquat and Sweet Orange with Contrasting Canker Tolerance

    PubMed Central

    Fu, Xing-Zheng; Gong, Xiao-Qing; Zhang, Yue-Xin; Wang, Yin; Liu, Ji-Hong

    2012-01-01

    Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating biotic stresses affecting the citrus industry. Meiwa kumquat (Fortunella crassifolia) is canker-resistant, while Newhall navel orange (Citrus sinensis Osbeck) is canker-sensitive. To understand the molecular mechanisms underlying the differences in responses to Xcc, transcriptomic profiles of these two genotypes following Xcc attack were compared by using the Affymetrix citrus genome GeneChip. A total of 794 and 1324 differentially expressed genes (DEGs) were identified as canker-responsive genes in Meiwa and Newhall, respectively. Of these, 230 genes were expressed in common between both genotypes, while 564 and 1094 genes were only significantly expressed in either Meiwa or Newhall. Gene ontology (GO) annotation and Singular Enrichment Analysis (SEA) of the DEGs showed that genes related to the cell wall and polysaccharide metabolism were induced for basic defense in both Meiwa and Newhall, such as chitinase, glucanase and thaumatin-like protein. Moreover, apart from inducing basic defense, Meiwa showed specially upregulated expression of several genes involved in the response to biotic stimulus, defense response, and cation binding as comparing with Newhall. And in Newhall, abundant photosynthesis-related genes were significantly down-regulated, which may be in order to ensure the basic defense. This study revealed different molecular responses to canker disease in Meiwa and Newhall, affording insight into the response to canker and providing valuable information for the identification of potential genes for engineering canker tolerance in the future. PMID:22848606

  14. Potential sources of airborne Alternaria spp. spores in South-west Spain.

    PubMed

    Fernández-Rodríguez, Santiago; Sadyś, Magdalena; Smith, Matt; Tormo-Molina, Rafael; Skjøth, Carsten Ambelas; Maya-Manzano, José María; Silva-Palacios, Inmaculada; Gonzalo-Garijo, Ángela

    2015-11-15

    Fungi belonging to the genus of Alternaria are recognised as being significant plant pathogens, and Alternaria allergens are one of the most important causes of respiratory allergic diseases in Europe. This study aims to provide a detailed and original analysis of Alternaria transport dynamics in Badajoz, SW Spain. This was achieved by examining daily mean and hourly observations of airborne Alternaria spores recorded during days with high airborne concentrations of Alternaria spores (>100 s m(-3)) from 2009 to 2011, as well as four inventory maps of major Alternaria habitats, the overall synoptic weather situation and analysis of air mass transport using Hybrid Single Particle Lagrangian Integrated Trajectory model and geographic information systems. Land use calculated within a radius of 100 km from Badajoz shows that crops and grasslands are potentially the most important local sources of airborne Alternaria spores recorded at the site. The results of back trajectory analysis show that, during the examined four episodes, the two main directions where Alternaria source areas were located were: (1) SW-W; and (2) NW-NE. Regional scale and long distance transport could therefore supplement the airborne catch recorded at Badajoz with Alternaria conidia originating from sources such as crops and orchards situated in other parts of the Iberian Peninsula. PMID:26156135

  15. Daily variations of Alternaria spores in the city of Murcia (semi-arid southeastern Spain)

    NASA Astrophysics Data System (ADS)

    Munuera Giner, M.; Carrión García, J. S.

    1995-12-01

    Annual variations in the abundance of Alternaria spores were related to the length of the spore period for data from Murcia (southeastern Spain). To understand the relationship between the number of spores and climatic factors, Alternaria spore counts for March 1993 to February 1994 were examined by means of correlation and regression analyses with fourteen different weather parameters. The results indicated that there was a tendency for Alternaria spore concentrations to increase with increases in temperature, wind speed and hours of sunshine. Negative correlations were observed with air pressure, wind direction and humidity. Theoretical curves for Alternaria spore counts are given in relation to temperatures during the period studied.

  16. ANNUAL AND POLYETIC PROGRESSION OF CITRUS CANKER ON TREES PROTECTED WITH COPPER SPRAYS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Mathematical models are important tools for comparative analysis of epidemics. In this paper, parameters obtained from the mathematical model that best fitted to the annual progress curves of citrus canker incidence were used to evaluate the effect of copper sprays and windbreaks on the annual and...

  17. Prevalence, distribution and identification of Phytophthora species from bleeding canker on European beech

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While bleeding canker of European beech (Fagus sylvatica) has long been recognized as a problem, the cause in the northeastern United States has not been clear. To resolve this, we surveyed for disease prevalence, identified the pathogens involved, proved their pathogenicity, compared protocols for ...

  18. Rapid screening for citrus canker resistance employing pattern-triggered immunity (PTI) responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker, caused by the bacterial pathogen Xanthomonas citri ssp. citri (Xcc), has been attributed to millions of dollars in loss or damage to commercial citrus crops in subtropical production areas of the world. Since identification of resistant plants is one of the most effective methods of d...

  19. Efficacy of Cankerguard® Sprays for Effective Decontamination of Citrus Canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is endemic in Florida. We used grapefruit leaf surfaces to explore the efficacy of the personnel decontaminant Cankerguard® to kill inoculum. In three experiments plants in flush (leaves 3/4 expanded) were sprayed with inoculum (2x104-9x105 CFU/ml)...

  20. Canker and twig dieback of blueberry caused by Pestalotiopsis spp. and a Truncatella sp. in Chile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry (Vaccinium spp.) has great economic importance in Chile, currently with about 8,500 ha being cultivated. Recently, the presence of canker and dieback symptoms has been observed along the productive blueberry zone of Chile extending from the V Region (32º49´ South lat.) in the north to the ...

  1. New Phomopsis species identified from wood cankers in eastern North American vineyards.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phomopsis cane and leaf spot, caused by the Ascomycete fungus Phomopsis viticola, is a destructive fruit and foliar disease in eastern North American vineyards. The pathogen typically attacks green tissues, but can also cause wood cankers, presumably due to infection of pruning wounds, as is the cas...

  2. New canker disease of Incense-cedar in Oregon caused by Phaeobotryon cupressi.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incense-cedar (Calocedrus decurrens) is a native tree occurring in Oregon and California. Since the early 2000’s, a new canker disease has been observed with increasing frequency on ornamental and windbreak trees planted in the Willamette Valley of Oregon. Symptoms appear as dead, flagging, small-di...

  3. Characterization of Pear Blister Canker Viroid Isolates from Australian Pome Fruit Orchards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pear blister canker viroid (PBCVd) was detected in pear (Pyrus sp.), nashi (Pyrus serotina) and quince (Cydonia oblonga) trees from various pome fruit growing regions of Australia using dot-blot hybridization and RT-PCR techniques. Characteristic symptoms of PBCVd infection were not observed on the...

  4. Wind speed and wind-associated leaf injury affect severity of citrus canker on Swingle citrumelo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (caused by the bacterial pathogen Xanthomonas citri subsp. citri, Xcc) can cause severe damage to citrus. It is endemic in Florida, and occurs in other citrus growing regions. The bacterium is dispersed predominantly in rain splash. To simulate dispersal in splash, and to investigate t...

  5. Complete DNA Sequence of Pseudomonas syringae pv. actinidiae, the Causal Agent of Kiwifruit Canker Disease.

    PubMed

    Templeton, Matthew D; Warren, Benjamin A; Andersen, Mark T; Rikkerink, Erik H A; Fineran, Peter C

    2015-01-01

    Pseudomonas syringae pv. actinidiae is the causal agent of bacterial canker of kiwifruit, a disease that has rapidly spread worldwide. We have fully sequenced and assembled the chromosomal and plasmid DNA from P. syringae pv. actinidiae ICMP 18884 using the PacBio RS II platform. PMID:26383666

  6. Optimal strategies for the eradication of Asiatic citrus canker in heterogeneous host landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eradication of non-native plant pathogens is a key challenge in plant disease epidemiology. Asiatic citrus canker is an economically significant disease of citrus caused by the bacterial plant pathogen Xanthomonas citri subsp. citri. The pathogen is a major exotic disease problem in many citru...

  7. 78 FR 63369 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... published an interim rule \\1\\ in the Federal Register (76 FR 23449-23459, Docket No. APHIS-2010-0048) that... 7 CFR part 301 that was published at 76 FR 23449-23459 on April 27, 2011, is adopted as a final rule... Animal and Plant Health Inspection Service 7 CFR Part 301 RIN 0579-AD29 Citrus Canker, Citrus...

  8. Exacerbation of citrus canker by citrus leafminer, Phyllocnistis citrella in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (caused by Xanthomonas citri subsp. citri, Xcc) is an important bacterial disease of citrus that is spread naturally by rain and wind. Damage to citrus leaves by the citrus leafminer (CLM) , Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), has been shown to promote infect...

  9. Production of transgenic citrus resistant to citrus canker and Huanglongbing diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the U.S. citrus industry. There are no proven strategies to eliminate HLB disease and no cultivars identified with strong HLB resistance. Citrus canker is also an economically import...

  10. Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) was first documented in India and Java in the mid 19th century. Since that time the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described str...

  11. First report of Phaeobotryon cupressi causing canker of Calocedrus decurrens in Oregon.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since the early 2000’s a canker disease has been noticed with increasing frequency on landscape specimens of native incense cedar (Calocedrus decurrens) planted throughout the Willamette Valley (from Portland south to Eugene) in western Oregon. Symptoms initially appear as dead and flagging small-di...

  12. Update on packing line protocols for citrus canker and their effects on bacterial survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Markets for Florida citrus are severely restricted by regulations in place to minimize the spread of citrus canker to citrus producing areas. Included in these regulations are accepted protocols for sanitation and coating of fruit. However, these measures do not eradicate all the living bacterial ce...

  13. Screening antimicrobial peptides in-vitro for use in developing transgenic citrus resistant to huanglongbing and citrus canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB, associated with Candidatus Liberibacter sp.) and Asiatic citrus canker (ACC, causal organism Xanthomonas citri subsp. citri (XCC)) are bacterial diseases that seriously threaten sustainability of the Florida citrus industry. Sweet orange and grapefruit are highly susceptible to A...

  14. Alternaria roseogrisea, a new species from achenes of Helianthus annuus (sunflower)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria roseogrisea was isolated from the achenes of Helianthus annuus L. during studies conducted in 1983-85 to document the diversity of fungi occurring in sunflower seeds and the possible role these fungi play in degradation of oilseed quality. A. roseogrisea was reported as "Alternaria sp. 2...

  15. Differential gene expression in Alternaria gaisen exposed to dark and light

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Character states observed during sporulation have been the basis for segregation and description of many of the small-spored species of Alternaria. Phylogenetic analyses of ITS and housekeeping genes from small-spored Alternaria spp. do not support most of the currently defined morphological specie...

  16. Phylogenetic, morphological and pathogenic characterization of Alternaria species associated with fruit rots of blueberry in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruits. Alternaria spp. isolates were collected from decayed fruits of blueberry in the Central Valley of California during 2012 and 2013. The aims of this study wer...

  17. Influence of environmental parameters on mycotoxin production by Alternaria arborescens.

    PubMed

    Vaquera, Sandra; Patriarca, Andrea; Fernández Pinto, V

    2016-02-16

    Alternaria arborescens has been reported as a common fungal species invading tomatoes and is capable of producing several mycotoxins in infected plants, fruits and in agricultural commodities. Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants of food. This species can produce these toxic metabolites together with AAL toxins (Alternaria alternata f. sp. lycopersicum toxins), which can act as inhibitors of sphingolipid biosynthesis. The objective of this study was to determine the effect of water activity (aw, 0.995, 0.975, 0.950) and temperature (6, 15, 20, 25 and 30 °C) on mycotoxin production by A. arborescens on a synthetic tomato medium. The optimum production of AOH and AME occurred at 0.975 aw after 40 days of incubation at 30 °C. The maximum TeA accumulation was observed at 0.975 aw and 25 °C and at 0.950 aw and 30 °C. AAL TA was produced in higher quantities at 0.995 aw and 30 °C. At 6 °C no quantifiable levels of AOH or AME were detected, but significant amounts of TeA were produced at 0.975 aw. In general, high aw levels and high temperatures were favorable for mycotoxin production. The greatest accumulation of all four toxins occurred at 0.975 aw and 30 °C. The results obtained here could be extrapolated to evaluate the risk of tomato fruits and tomato products contamination caused by these toxins. PMID:26708802

  18. Modelling and visualizing morphology in the fungus Alternaria.

    PubMed

    Taralova, Ekaterina H; Schlecht, Joseph; Barnard, Kobus; Pryor, Barry M

    2011-11-01

    Alternaria is one of the most cosmopolitan fungal genera encountered and impacts humans and human activities in areas of material degradation, phytopathology, food toxicology, and respiratory disease. Contemporary methods of taxon identification rely on assessments of morphology related to sporulation, which are critical for accurate diagnostics. However, the morphology of Alternaria is quite complex, and precise characterization can be laborious, time-consuming, and often restricted to experts in this field. To make morphology characterization easier and more broadly accessible, a generalized statistical model was developed for the three-dimensional geometric structure of the sporulation apparatus. The model is inspired by the widely used grammar-based models for plants, Lindenmayer-systems, which build structure by repeated application of rules for growth. Adjusting the parameters of the underlying probability distributions yields variations in the morphology, and thus the approach provides an excellent tool for exploring the morphology of Alternaria under different assumptions, as well as understanding how it is largely the consequence of local rules for growth. Further, different choices of parameters lead to different model groups, which can then be visually compared to published descriptions or microscopy images to validate parameters for species-specific models. The approach supports automated analysis, as the models can be fit to image data using statistical inference, and the explicit representation of the geometry allows the accurate computation of any morphological quantity. Furthermore, because the model can encode the statistical variation of geometric parameters for different species, it will allow automated species identification from microscopy images using statistical inference. In summary, the approach supports visualization of morphology, automated quantification of phenotype structure, and identification based on form. PMID:22036294

  19. Mycotoxin production by Alternaria strains isolated from Argentinean wheat.

    PubMed

    Patriarca, A; Azcarate, M P; Terminiello, L; Fernández Pinto, V

    2007-11-01

    The toxigenic potential of Alternaria strains isolated from Argentinean wheat was investigated. A total of 123 strains were assayed for the production of tenuazonic acid (TA), alternariol (AOH) and alternariol monomethyl ether (AME). All but one of the isolates were able to produce at least one of the three mycotoxins. TA was produced by 72% of the strains (1-14782 mg/kg), AOH by 87% (4-622 mg/kg) and AME by 91% (7-2625 mg/kg). The average level of TA detected for all strains (1757 mg/kg) was higher than the average level of both alternariols (162 mg/kg for AOH and 620 mg/kg for AME). TA was the toxin produced at the highest concentration but in lower frequency. Most of the strains were able to synthesize more than one toxin: 74 isolates (60%) were positive for all three toxins, 30 (24%) for both AOH and AME, 5 (4%) for both TA and AME, and 2 (2%) for TA and AOH. The widespread occurrence of Alternaria in wheat and its ability to produce mycotoxins suggests the possible occurrence of its toxins in wheat naturally infected with this fungus. PMID:17804107

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

    PubMed Central

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

    2015-01-01

    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. PMID:26711773

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

    PubMed

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

    2016-03-01

    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. PMID:26711773

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Draft Genome Sequence of Erwinia billingiae OSU19-1, Isolated from a Pear Tree Canker

    PubMed Central

    Klein, Jeannie M.; Bennett, Rhett W.; MacFarland, Logan; Abranches Da Silva, Megan E.; Meza-Turner, Britney M.; Dark, Phillip M.; Frey, Mackenzie E.; Wellappili, Dulani P.; Beugli, Aron D.; Jue, Holman J.; Mellander, Joshua M.; Wei, Wei

    2015-01-01

    Plant-associated Erwinia include pathogenic and nonpathogenic species. We report the 5.6-Mb genome sequence of Erwinia billingiae OSU19-1, isolated from a canker on a pear tree inoculated with Erwinia amylovora. OSU19-1 and a closely related European isolate, E. billingiae Eb661T, share many similarities including 40 kb of plasmid sequence. PMID:26430039

  4. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB)

    PubMed Central

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  5. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).

    PubMed

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  6. Rapid screening for citrus canker resistance employing pathogen-associated molecular pattern-triggered immunity responses

    PubMed Central

    Pitino, Marco; Armstrong, Cheryl M; Duan, Yongping

    2015-01-01

    Citrus canker, caused by the bacterial pathogen Xanthomonas citri ssp. citri (Xcc), has been attributed to millions of dollars in loss or damage to commercial citrus crops in subtropical production areas of the world. Since identification of resistant plants is one of the most effective methods of disease management, the ability to screen for resistant seedlings plays a key role in the production of a long-term solution to canker. Here, an inverse correlation between reactive oxygen species (ROS) production by the plant and the ability of Xcc to grow and form lesions on infected plants is reported. Based on this information, a novel screening method that can rapidly identify citrus seedlings that are less susceptible to early infection by Xcc was devised by measuring ROS accumulation triggered by a 22-amino acid sequence of the conserved N-terminal part of flagellin (flg22) from X. citri ssp. citri (Xcc-flg22). In addition to limiting disease symptoms, ROS production was also correlated with the expression of basal defense-related genes such as the pattern recognition receptors LRR8 and FLS2, the leucine-rich repeat receptor-like protein RLP12, and the defense-related gene PR1, indicating an important role for pathogen-associated molecular pattern-triggered immunity (PTI) in determining resistance to citrus canker. Moreover, the differential expression patterns observed amongst the citrus seedlings demonstrated the existence of genetic variations in the PTI response among citrus species/varieties. PMID:26504581

  7. Biofilm formation, epiphytic fitness, and canker development in Xanthomonas axonopodis pv. citri.

    PubMed

    Rigano, Luciano A; Siciliano, Florencia; Enrique, Ramón; Sendín, Lorena; Filippone, Paula; Torres, Pablo S; Qüesta, Julia; Dow, J Maxwell; Castagnaro, Atilio P; Vojnov, Adrián A; Marano, María Rosa

    2007-10-01

    The phytopathogenic bacterium Xanthomonas axonopodis pv. citri is responsible for the canker disease affecting citrus plants throughout the world. Here, we have evaluated the role of bacterial attachment and biofilm formation in leaf colonization during canker development on lemon leaves. Crystal violet staining and confocal laser scanning microscopy analysis of X. axonopodis pv. citri strains expressing the green fluorescent protein were used to evaluate attachment and biofilm formation on abiotic and biotic (leaf) surfaces. Wild-type X. axonopodis pv. citri attached to and formed a complex, structured biofilm on glass in minimal medium containing glucose. Similar attachment and structured biofilm formation also were seen on lemon leaves. An X. axonopodis pv. citri gumB mutant strain, defective in production of the extracellular polysaccharide xanthan, did not form a structured biofilm on either abiotic or biotic surfaces. In addition, the X. axonopodis pv. citri gumB showed reduced growth and survival on leaf surfaces and reduced disease symptoms. These findings suggest an important role for formation of biofilms in the epiphytic survival of X. axonopodis pv. citri prior to development of canker disease. PMID:17918624

  8. Phylogenetic, Morphological, and Pathogenic Characterization of Alternaria Species Associated with Fruit Rot of Blueberry in California.

    PubMed

    Zhu, X Q; Xiao, C L

    2015-12-01

    Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit. PMID:26267542

  9. First report of stem canker of Salsola tragus caused by Diaporthe eres in Russia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salsola tragus L. (Russian thistle, tumbleweed), family Chenopodiaceae, is a problematic invasive weed in the western United States and a target of biological control efforts. In September of 2007, dying Salsola tragus plants were found along the Azov Sea at Chushka, Russia. About 30 plants in the...

  10. Multiple Ceratocystis smalleyi infections associated with reduced stem water transport in bitternut hickory.

    PubMed

    Park, J-H; Juzwik, J; Cavender-Bares, J

    2013-06-01

    Hundreds of cankers caused by Ceratocystis smalleyi are associated with hickory bark beetle-attacked bitternut hickory exhibiting rapid crown decline in the north-central and northeastern United States. Discolored sapwood colonized by the fungus commonly underlies the cankers. Field studies were conducted to test the hypothesis that C. smalleyi infections cause vascular system dysfunction in infected trees. Fifty C. smalleyi inoculations made at 1.8 to 3.8 m in height on stems of healthy bitternut hickory trees (13 to 28 cm in diameter at 1.4 m in height) resulted in extensive canker formation and sapwood discoloration 12 to 14 months after treatment compared with water-inoculated and noninoculated controls. Sap flow velocity (midday) was significantly lower in the infected trees compared with that in the controls. Sap flow velocity also was inversely correlated with the proportion of bark area with cankered tissues and with tylose abundance in the youngest two growth rings. Tylose formation in current-year vessels associated with C. smalleyi infections is likely responsible for much of the water transport disruption. It is hypothesized that multiple stem infections of C. smalleyi and the resulting xylem dysfunction contribute to crown wilt development in bitternut hickory exhibiting rapid crown decline. PMID:23360533

  11. The effect of wind on dispersal of splash-borne Xanthomonas citri subsp citri at different heights and distances downwind of canker-infected grapefruit trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xanthomonas citri subsp citri (Xcc), which causes citrus canker, is a major pathogen of grapefruit and other canker-susceptible citrus species and cultivars grown in Florida and elsewhere. It is dispersed by rain splash, and wind promotes the dispersal of the pathogen. The aim of this study was to e...

  12. Short distance dispersal of splashed bacteria of Xanthomonas citri subsp. citri from canker-infected grapefruit tree canopies in turbulent wind

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp citri [Xcc]) can result in yield loss and market restrictions. The pathogen is dispersed in rain splash and spread is promoted by wind. The goal of this study was to gain some insight into the behavior of the downwind plume of Xcc from ~1.5 m-tall canker-affect...

  13. Activity of citrus canker lesions on leaves, shoots and fruit of grapefruit in a Florida orchard from June 2010 to January 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lesions of citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), on citrus fruit preclude export to certain markets. Characterizing the population dynamics of bacteria in canker lesions in commercial orchards can help gauge risk associated with diseased fruit entering fresh markets. The aim...

  14. INOCULATION STRATEGIES TO ASSESS BIOLOGICAL INTERACTIONS BETWEEN FUSARIUM AND ALTERNARIA SPECIES INFECTING SORGHUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three bioassays were assessed for experimental utility to either characterize fungal species potentially pathogenic to sorghum [Sorghum bicolor (L.) Moench] or to screen germplasm for advancement in breeding programs. Isolates of species commonly associated with sorghum, Alternaria alternata, Fusari...

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

    PubMed Central

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

    2015-01-01

    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. PMID:25774114

  16. Alternaria-derived serine protease activity drives IL-33–mediated asthma exacerbations

    PubMed Central

    Snelgrove, Robert J.; Gregory, Lisa G.; Peiró, Teresa; Akthar, Samia; Campbell, Gaynor A.; Walker, Simone A.; Lloyd, Clare M.

    2014-01-01

    Background The fungal allergen Alternaria alternata is implicated in severe asthma and rapid onset life-threatening exacerbations of disease. However, the mechanisms that underlie this severe pathogenicity remain unclear. Objective We sought to investigate the mechanism whereby Alternaria was capable of initiating severe, rapid onset allergic inflammation. Methods IL-33 levels were quantified in wild-type and ST2−/− mice that lacked the IL-33 receptor given inhaled house dust mite, cat dander, or Alternaria, and the effect of inhibiting allergen-specific protease activities on IL-33 levels was assessed. An exacerbation model of allergic airway disease was established whereby mice were sensitized with house dust mite before subsequently being challenged with Alternaria (with or without serine protease activity), and inflammation, remodeling, and lung function assessed 24 hours later. Results Alternaria, but not other common aeroallergens, possessed intrinsic serine protease activity that elicited the rapid release of IL-33 into the airways of mice through a mechanism that was dependent upon the activation of protease activated receptor-2 and adenosine triphosphate signaling. The unique capacity of Alternaria to drive this early IL-33 release resulted in a greater pulmonary inflammation by 24 hours after challenge relative to the common aeroallergen house dust mite. Furthermore, this Alternaria serine protease–IL-33 axis triggered a rapid, augmented inflammation, mucus release, and loss of lung function in our exacerbation model. Conclusion Alternaria-specific serine protease activity causes rapid IL-33 release, which underlies the development of a robust TH2 inflammation and exacerbation of allergic airway disease. PMID:24636086

  17. The dynamics of the fungal aerospores Alternaria sp. and Cladosporium sp. in Parisian atmospheric air, in France

    NASA Astrophysics Data System (ADS)

    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

  18. Identification and characterization of microsatellite from Alternaria brassicicola to assess cross-species transferability and utility as a diagnostic marker.

    PubMed

    Singh, Ruchi; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok Kumar; Mishra, Sanjay; Sharma, Arun Kumar

    2014-11-01

    Alternaria blight caused by Alternaria brassicicola (Schwein.) Wiltshire and A. brassicae (Berk.) Sacc., is one of the most important disease of rapeseed-mustard, characterized by the formation of spots on leaves, stem, and siliquae with premature defoliation and stunting of growth. These two species are very difficult to differentiate based on disease symptoms or spore morphology. Therefore, the aim of present investigation was to identify and characterize transferable microsatellite loci from A. brassicicola to A. brassicae for the development of diagnostic marker. A total of 8,457 microsatellites were identified from transcript sequences of A. brassicicola. The average density of microsatellites was one microsatellite per 1.94 kb of transcript sequence screened. The most frequent repeat was tri-nucleotide (74.03 %), whereas penta-nucleotide (1.14 %) was least frequent. Among amino acids, arginine (13.11 %) showed maximum abundance followed by lysine (10.11 %). A total of 32 alleles were obtained across the 31 microsatellite loci for the ten isolates of A. brassicicola. In cross-species amplifications, 5 of the 31 markers amplified the corresponding microsatellite regions in twenty isolates of A. brassicae and showed monomorphic banding pattern. Microsatellite locus ABS28 was highly specific for A. brassicicola, as no amplification was observed from twenty-nine other closely related taxa. Primer set, ABS28F/ABS28R, amplified a specific amplicon of 380 bp from all A. brassicicola isolates. Standard curves were generated for A. brassicicola isolate using SYBR Green I fluorescent dye for detection of amplification in real-time PCR assay. The lowest detection limit of assay was 0.01 ng. Thus, the primer set can be used as diagnostic marker to discriminate and diagnose A. brassicicola from synchronously occurring fungus, A. brassicae associated with rapeseed and mustard. PMID:25048820

  19. Amplification of DNA of Xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.

    PubMed

    Li, Wenbin; Brlansky, Ronald H; Hartung, John S

    2006-05-01

    Herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. The appearance of novel strains of the pathogen in Florida and elsewhere make it increasingly important to understand the relationships among strains of this pathogen. USDA-ARS at Beltsville, Maryland maintains approximately 700 herbarium specimens with citrus canker disease lesions up to 90 years old, originally collected from all over the world, and so is an important resource for phytogeographic studies of this bacterium. Unfortunately, DNA in herbarium specimens is degraded and may contain high levels of inhibitors of PCR. In this study, we compared a total of 23 DNA isolation techniques in combination with 31 novel primer pairs in order to develop an efficient protocol for the analysis of Xac DNA in herbarium specimens. We identified the most reliable extraction method, identified in terms of successful amplification by our panel of 31 primer pairs. We also identified the most robust primer pairs, identified as successful in the largest number of extracts prepared by different methods. We amplified Xac genomic sequences up to 542 bp long from herbarium samples up to 89 years old. Primers varied in effectiveness, with some primer pairs amplifying Xac DNA from a 1/10,000 dilution of extract from a single lesion from a citrus canker herbarium specimen. Our methodology will be useful to identify pathogens and perform molecular analyses of bacterial and possibly fungal genomes from herbarium specimens. PMID:16099061

  20. Effect of Lime on Criconemella xenoplax and Bacterial Canker in Two California Orchards

    PubMed Central

    Underwood, T.; Jaffee, B. A.; Verdegaal, P.; Norton, M. V. K.; Asai, W. K.; Muldoon, A. E.; McKenry, M. V.; Ferris, H.

    1994-01-01

    In a peach orchard with an initial soil pH of 4.9, preplant application of 0, 13.2, 18.2, 27.3, or 54.2 kg lime/tree site altered soil pH (range after 1 year = 4.8-7.3) but did not affect numbers of Criconemella xenoplax or tree circumference. Liming also failed to reduce the incidence of bacterial canker, which affected 17% of the trees by the sixth year after planting. Four years after planting, numbers of C. xenoplax exceeded 400/100 cm³ soil, regardless of treatment. Trees with higher densities of C. xenoplax had a higher incidence of canker. The nematophagous fungus Hirsutella rhossiliensis was not detected until the fourth year. Thereafter, the incidence of H. rhossiliensis and percentage C. xenoplax parasitized by H. rhossiliensis increased, but the increases lagged behind increases in numbers of nematodes. In an almond orchard with an initial soil pH of 4.6, preplant application of 0, 6.4, 12.8, or 25.0 kg lime/tree site altered soil pH (range after 1 year = 4.7-7.1). Numbers of C. xenoplax remained low (<20/100 cm³ soil), whereas numbers of Paratylenchus sp. increased to high levels (>500/100 cm³ soil), regardless of treatment. Low levels (<20/100 cm³ soil) of H. rhossiliensis -parasitized Paratylenchus sp. were detected. No bacterial canker occurred, but tree circumference was greater after 6 years if soil pH was intermediate (6.0-7.0). PMID:19279934

  1. Positive selection is the main driving force for evolution of citrus canker-causing Xanthomonas.

    PubMed

    Zhang, Yunzeng; Jalan, Neha; Zhou, Xiaofeng; Goss, Erica; Jones, Jeffrey B; Setubal, João C; Deng, Xiaoling; Wang, Nian

    2015-10-01

    Understanding the evolutionary history and potential of bacterial pathogens is critical to prevent the emergence of new infectious bacterial diseases. Xanthomonas axonopodis subsp. citri (Xac) (synonym X. citri subsp. citri), which causes citrus canker, is one of the hardest-fought plant bacterial pathogens in US history. Here, we sequenced 21 Xac strains (14 XacA, 3 XacA* and 4 XacA(w)) with different host ranges from North America and Asia and conducted comparative genomic and evolutionary analyses. Our analyses suggest that acquisition of beneficial genes and loss of detrimental genes most likely allowed XacA to infect a broader range of hosts as compared with XacA(w) and XacA*. Recombination was found to have occurred frequently on the relative ancient branches, but rarely on the young branches of the clonal genealogy. The ratio of recombination/mutation ρ/θ was 0.0790±0.0005, implying that the Xac population was clonal in structure. Positive selection has affected 14% (395 out of 2822) of core genes of the citrus canker-causing Xanthomonas. The genes affected are enriched in 'carbohydrate transport and metabolism' and 'DNA replication, recombination and repair' genes (P<0.05). Many genes related to virulence, especially genes involved in the type III secretion system and effectors, are affected by positive selection, further highlighting the contribution of positive selection to the evolution of citrus canker-causing Xanthomonas. Our results suggest that both metabolism and virulence genes provide advantages to endow XacA with higher virulence and a wider host range. Our analysis advances our understanding of the genomic basis of specialization by positive selection in bacterial evolution. PMID:25689023

  2. Dustborne Alternaria alternata antigens in U.S. homes: Results from the National Survey of Lead and Allergens in Housing

    PubMed Central

    Salo, Päivi M.; Yin, Ming; Arbes, Samuel J.; Cohn, Richard D.; Sever, Michelle; Muilenberg, Michael; Burge, Harriet A.; London, Stephanie J.; Zeldin, Darryl C.

    2005-01-01

    Background: Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized. Objective: The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in U.S. homes. Methods: Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the U.S. completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of Alternaria antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay. Results: Alternaria antigens were detected in most (95-99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 μg/g (SE=0.13 μg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of dehumidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes. Conclusion: Exposure to Alternaria alternata antigens in U.S. homes is common. Antigen levels in homes are not only influenced by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors. PMID:16159634

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

    PubMed

    Andersen, Birgitte; Nielsen, Kristian F; Fernández Pinto, Virginia; Patriarca, Andrea

    2015-03-01

    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, few studies on Alternaria mycotoxins and other bioactive secondary metabolites have been carried out on Argentinean cereals, fruit and vegetables. Knowing the full chemical potential and the distribution of Alternaria spp. on crops, it is necessary to establish a toxicological risk assessment for food products for human consumption. In the present study, 87 Alternaria strains from different substrates (tomato, wheat, blueberries and walnuts) were characterized according to morphology and metabolite production. Aggressive dereplication (accurate mass, isotopic patterns and lists of all described compounds from Alternaria) was used for high-throughput evaluation of the chemical potential. Four strains belonged to the Alternaria infectoria sp.-grp., 6 to the Alternaria arborescens sp.-grp., 6 showed a sporulation pattern similar to that of "M" according to Simmons, 1 to that of Alternaria vaccinii, and the remaining 70 constituted a diverse group belonging to morphological groups "G" and "H". The cluster analysis yielded 16 almost identical dendrograms and grouped the Alternaria strains into four clusters and 11 singletons and outlier groups. The chemical analysis showed that AOH and AME were the most common metabolites produced, followed by TEN, ALXs and TeA. The A. infectoria sp.-grp. had no metabolites in common with the rest of the strains. Several secondary metabolites isolated from large-spored Alternaria species or other fungal genera were detected, such as dehydrocurvularin, pyrenochaetic acid and alternarienonic acid. The strains isolated from tomato produced lower amounts of metabolites than strains from blueberries, walnut and wheat, although individual strains from tomato produced the highest amount of some metabolites. The A

  4. Isotope fractionation of selenium during fungal biomethylation by Alternaria alternata.

    PubMed

    Schilling, Kathrin; Johnson, Thomas M; Wilcke, Wolfgang

    2011-04-01

    The natural abundance of stable Se isotopes may reflect sources and formation conditions of methylated Se. We aimed at (1) quantifying the degree of methylation of selenate [Se(VI)] and (hydro)selenite [Se(IV)] by the fungus Alternaria alternata at pH 4 and 7 and (2) determining the effects of these different Se sources and pH values on 82Se/76Se ratios (δ82/76Se) in methylselenides. Alternaria alternata was incubated with Se(VI) and Se(IV) in closed microcosms for 11-15 days and additionally with Se(IV) for 3-5 days at 30 °C. We determined Se concentrations and δ82/76Se values in source Se(VI) and Se(IV), media, fungi, and trapped methylselenides. In Se(VI) incubations, methylselenide volatilization ended before the 11th day, and the amounts of trapped methylselenide were not significantly different among the 11-15 day incubations. In 11-15 days, 2.9-11% of Se(VI) and 21-29% of Se(IV) were methylated, and in 3-5 days, 3-5% of Se(IV) was methylated. The initial δ82/76Se values of Se(VI) and Se(IV) were -0.69±SD 0.07‰, and -0.20±0.05‰, respectively. The δ82/76Se values of methylselenides differed significantly between Se(VI) (-3.97‰ to -3.25‰) and Se(IV) (-1.44‰ to -0.16‰) as sources after 11-15 days of incubation; pH had little influence on δ82/76Se values. Thus, the δ82/76Se values of methylselenide indicate the source species of methylselenides used in this study. The strong isotope fractionation of Se(VI) is probably attributable to the different reduction steps of Se(VI) to Se(-II) which were rate-limiting explaining the low methylation yields, but not to the methylation itself. The shorter incubation of Se(IV) for 3-5 days showed a large Se isotope fractionation of at least -6‰ before the biomethylation reaction reached its end. This initial Se isotope fractionation during methylation of Se(IV) is much larger than previously published. PMID:21366259

  5. Hyperspectral and Thermal Imaging of Oilseed Rape (Brassica napus) Response to Fungal Species of the Genus Alternaria

    PubMed Central

    Baranowski, Piotr; Jedryczka, Malgorzata; Mazurek, Wojciech; Babula-Skowronska, Danuta; Siedliska, Anna; Kaczmarek, Joanna

    2015-01-01

    In this paper, thermal (8-13 µm) and hyperspectral imaging in visible and near infrared (VNIR) and short wavelength infrared (SWIR) ranges were used to elaborate a method of early detection of biotic stresses caused by fungal species belonging to the genus Alternaria that were host (Alternaria alternata, Alternaria brassicae, and Alternaria brassicicola) and non-host (Alternaria dauci) pathogens to oilseed rape (Brassica napus L.). The measurements of disease severity for chosen dates after inoculation were compared to temperature distributions on infected leaves and to averaged reflectance characteristics. Statistical analysis revealed that leaf temperature distributions on particular days after inoculation and respective spectral characteristics, especially in the SWIR range (1000-2500 nm), significantly differed for the leaves inoculated with A. dauci from the other species of Alternaria as well as from leaves of non-treated plants. The significant differences in leaf temperature of the studied Alternaria species were observed in various stages of infection development. The classification experiments were performed on the hyperspectral data of the leaf surfaces to distinguish days after inoculation and Alternaria species. The second-derivative transformation of the spectral data together with back-propagation neural networks (BNNs) appeared to be the best combination for classification of days after inoculation (prediction accuracy 90.5%) and Alternaria species (prediction accuracy 80.5%). PMID:25826369

  6. Identification, characterization and mycotoxigenic ability of Alternaria spp. causing core rot of apple fruit in Greece.

    PubMed

    Ntasiou, Panagiota; Myresiotis, Charalampos; Konstantinou, Sotiris; Papadopoulou-Mourkidou, Euphemia; Karaoglanidis, George S

    2015-03-16

    Alternaria core rot is a major postharvest disease of apple fruit in several countries of the world, including Greece. The study was conducted aiming to identify the disease causal agents at species level, investigate the aggressiveness of Alternaria spp. isolates and the susceptibility of different apple varieties and determine the mycotoxigenic potential of Alternaria spp. isolates from apple fruit. Seventy-five Alternaria spp. isolates obtained from apple fruit showing core rot symptoms were identified as either Alternaria tenuissima or Alternaria arborescens at frequencies of 89.3 and 11.7%, respectively, based on the sequence of endopolygalacturonase (EndoPG) gene. Artificial inoculations of fruit of 4 different varieties (Fuji, Golden Delicious, Granny Smith and Red Delicious) and incubation at two different temperatures (2 and 25°C) showed that fruit of Fuji variety were the most susceptible and fruit of Golden Delicious the most resistant to both pathogens. In addition, the production of 3 mycotoxins, alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) was investigated in 30 isolates of both species. Mycotoxin determination was conducted both in vitro, on artificial nutrient medium and in vivo on artificially inoculated apple fruit, using a high performance liquid chromatography with diode array detector (HPLC-DAD). The results showed that most of the isolates of both species were able to produce all the 3 metabolites both in vivo and in vitro. On apple fruit A. tenuissima isolates produced more AOH than A. arborescens isolates, whereas the latter produced more TEN than the former. Such results indicate that Alternaria core rot represents a major threat of apple fruit production not only due to quantitative yield losses but also for qualitative deterioration of apple by-products. PMID:25560914

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

    PubMed

    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. PMID:27103180

  8. Alternaria infections: laboratory diagnosis and relevant clinical features.

    PubMed

    Pastor, F J; Guarro, J

    2008-08-01

    The genus Alternaria contains several species of melanized hyphomycetes that cause opportunistic human infections. The published literature contains 210 reported cases of human alternarioses between 1933 and the present day. The most frequent clinical manifestations are cutaneous and subcutaneous infections (74.3%), followed by oculomycosis (9.5%), invasive and non-invasive rhinosinusitis (8.1%) and onychomycosis (8.1%). Immunosuppression is frequently associated with cutaneous and subcutaneous infections and rhinosinusitis. The most important risk factors for cutaneous and subcutaneous infections are solid organ transplantation and Cushing's syndrome, and those for rhinosinusitis are bone marrow transplants. Having been exposed to soil and garbage is common in all cases of oculomycosis, with corticotherapy being a risk factor in 50% of these cases. Previous contact with soil and/or trauma to the nails is associated with most cases of onychomycosis. In general, alternariosis shows a good response to conventional antifungal drugs. On some occasions, steroid suppression or reduction is sufficient to resolve an infection. Itraconazole is the antifungal drug used most frequently to successfully treat onychomycosis and cutaneous and subcutaneous infections. Posaconazole and voriconazole are promising therapeutic options, with the latter being especially so for oculomycosis. PMID:18727797

  9. Diversity of Diaporthe species associated with wood cankers of fruit and nut crops in northern California.

    PubMed

    Lawrence, Daniel P; Travadon, Renaud; Baumgartner, Kendra

    2015-01-01

    Diaporthe ampelina, causal agent of Phomopsis cane and leaf spot of grapevine (Vitis vinifera L.) is isolated frequently from grapevine wood cankers, causing Phomopsis dieback. The latter disease is associated with four other Diaporthe species, three of which also are reported from hosts other than grape. To better understand the role of this Diaporthe community in Phomopsis dieback of grapevine and the potential for infection routes among alternate hosts, 76 Diaporthe isolates were recovered from wood cankers of cultivated grape, pear, apricot, almond and the wild host willow in four California counties. Isolates were characterized morphologically and assigned to species based on multigene sequence analyses. This study identified eight Diaporthe species from grapevine and one novel taxon from willow, D. benedicti. We report the first findings of D. australafricana and D. novem in North America. Our findings also expand the host ranges of D. ambigua to apricot and willow, D. australafricana to almond and willow, D. chamaeropis to grapevine and willow, D. foeniculina to willow and D. novem to almond. The generalists D. ambigua and D. eres were the most genetically diverse species, based on high nucleotide and haplotypic diversity, followed by the grapevine specialist D. ampelina. Analyses based on multilocus linkage disequilibrium could not reject the hypothesis of random mating for D. ambigua, which is further supported by relatively high haplotypic diversity, reports of both mating types and reports of successful matings in vitro. Pathogenicity assays revealed that D. ampelina was the most pathogenic species to grapevine wood. PMID:26240309

  10. Gnomoniopsis smithogilvyi causes chestnut canker symptoms in Castanea sativa shoots in Switzerland.

    PubMed

    Pasche, Sabrina; Calmin, Gautier; Auderset, Guy; Crovadore, Julien; Pelleteret, Pegah; Mauch-Mani, Brigitte; Barja, François; Paul, Bernard; Jermini, Mauro; Lefort, François

    2016-02-01

    A screening of Castanea sativa scions for grafting for the presence of endophytes showed that the opportunistic fungal pathogen Gnomoniopsis smithogilvyi was the most abundant member of the endophytic flora. This fungus is known as a pathogen affecting chestnut fruits in Italy and Australia. Here, we present evidence that it causes cankers very similar to the ones due to Cryphonectria parasitica infection on twigs and scions of chestnut trees. We found natural infections of G. smithogilvyi in healthy grafted plants as well as in scions from chestnut trees. The identity of the fungus isolated from asymptomatic tissues was verified by applying Koch's postulates and corroborated by DNA sequencing of four different gene regions. In contrast to C. parasitica that appears on the bark as yellow to orange pycnidia, stromata and slimy twisted tendrils, G. smithogilvyi forms orange to red and black pycnidia, gray stromata and cream-colored to beige slimy twisted tendrils on the bark. These Swiss strains are closely related to G. smithogilvyi strains from Australia and from New Zealand, Gnomoniopsis sp. and Gnomoniopsis castanea from New Zealand, Italy, France and Switzerland. While the strains from Ticino are genetically very close to G. smithogilvyi and G. castanea from Italy, the differences between the strains from Ticino and Geneva suggest two different origins. The present study supports the hypothesis that a single species named G. smithogilvyi, which is known to be the agent of chestnut rot, also causes wood cankers on chestnut. PMID:26768710

  11. Genome sequence of Valsa canker pathogens uncovers a potential adaptation of colonization of woody bark.

    PubMed

    Yin, Zhiyuan; Liu, Huiquan; Li, Zhengpeng; Ke, Xiwang; Dou, Daolong; Gao, Xiaoning; Song, Na; Dai, Qingqing; Wu, Yuxing; Xu, Jin-Rong; Kang, Zhensheng; Huang, Lili

    2015-12-01

    Canker caused by ascomycetous Valsa species are among the most destructive diseases of woody plants worldwide. These pathogens are distinct from other pathogens because they only effectively attack tree bark in the field. To unravel the potential adaptation mechanism of bark colonization, we examined the genomes of Valsa mali and Valsa pyri that preferentially infect apple and pear, respectively. We reported the 44.7 and 35.7 Mb genomes of V. mali and V. pyri, respectively. We also identified the potential genomic determinants of wood colonization by comparing them with related cereal pathogens. Both genomes encode a plethora of pathogenicity-related genes involved in plant cell wall degradation and secondary metabolite biosynthesis. In order to adapt to the nutrient limitation and low pH environment in bark, they seem to employ membrane transporters associated with nitrogen uptake and secrete proteases predominantly with acidic pH optima. Remarkably, both Valsa genomes are especially suited for pectin decomposition, but are limited in lignocellulose and cutin degradation. Besides many similarities, the two genomes show distinct variations in many secondary metabolism gene clusters. Our results show a potential adaptation of Valsa canker pathogens to colonize woody bark. Secondary metabolism gene clusters are probably responsible for this host specificity. PMID:26137988

  12. Reclassification of the butternut canker fungus, Sirococcus clavigignenti-juglandacearum, into the genus Ophiognomonia.

    PubMed

    Broders, K D; Boland, G J

    2011-01-01

    Sirococcus clavigignenti-juglandacearum (Sc-j), which causes a canker disease on butternut, is largely responsible for the decline of this tree in the United States and Canada. The original description of the species was based on anamorphic characters because the teleomorph is unknown. Recent phylogenetic investigations have found that Sc-j is not a member of the genus Sirococcus, and accurate taxonomic classification is required. The objective of this study is to use sequence data to determine the phylogenetic placement of Sc-j within the Gnomoniaceae, Diaporthales. Isolates were recovered from infected Juglans ailantifolia var. cordiformis (heartnut), Juglans cinerea (butternut), and Juglans nigra (black walnut) in Ontario and the eastern United States. The genes coding for β-tubulin, actin, calmodulin, internal transcribed spacers 1 and 2, and the translation elongation factor 1-alpha from 28 isolates of Sc-j and representatives of the major lineages within the Gnomoniaceae were evaluated. There was no difference in the sequences of the five genes among the isolates of Sc-j studied, indicating a recent introduction followed by asexual reproduction and spread via conidia. The phylogenetic analyses demonstrate this fungus does not belong to the genus Sirococcus, and provides strong support (99% MP and 100% NJ bootstrap values, and 100% Bayesian posterior probabilities) for its inclusion in the genus Ophiognomonia, thereby supporting a reclassification of the butternut canker fungus to Ophiognomonia clavigignenti-juglandacearum. PMID:21215957

  13. Isolation and Characterization of Bacteriophages Against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit.

    PubMed

    Yu, Ji-Gang; Lim, Jeong-A; Song, Yu-Rim; Heu, Sunggi; Kim, Gyoung Hee; Koh, Young Jin; Oh, Chang-Sik

    2016-02-01

    Pseudomonas syringae pv. actinidiae causes bacterial canker disease in kiwifruit. Owing to the prohibition of agricultural antibiotic use in major kiwifruit-cultivating countries, alternative methods need to be developed to manage this disease. Bacteriophages are viruses that specifically infect target bacteria and have recently been reconsidered as potential biological control agents for bacterial pathogens owing to their specificity in terms of host range. In this study, we isolated bacteriophages against P. syringae pv. actinidiae from soils collected from kiwifruit orchards in Korea and selected seven bacteriophages for further characterization based on restriction enzyme digestion patterns of genomic DNA. Among the studied bacteriophages, two belong to the Myoviridae family and three belong to the Podoviridae family, based on morphology observed by transmission electron microscopy. The host range of the selected bacteriophages was confirmed using 18 strains of P. syringae pv. actinidiae, including the Psa2 and Psa3 groups, and some were also effective against other P. syringae pathovars. Lytic activity of the selected bacteriophages was sustained in vitro until 80 h, and their activity remained stable up to 50°C, at pH 11, and under UV-B light. These results indicate that the isolated bacteriophages are specific to P. syringae species and are resistant to various environmental factors, implying their potential use in control of bacterial canker disease in kiwifruits. PMID:26628254

  14. Characteristics of the perception of different severity measures of citrus canker and the relations between the various symptom types

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker is a disease of citrus and is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). Ways of managing the disease are being sought, and accurate, precise, reproducible disease assessment is needed for monitoring epidemics. The objective of this study was to investigate...

  15. Visual rating and the use of image analysis for assessing different symptoms of citrus canker on grapefruit leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac) and infects several citrus species in wet tropical and subtropical citrus growing regions. Accurate, precise and reproducible disease assessment is needed for monitoring epidemics and disease response in breeding...

  16. Effect of the duration of inoculum exposure on development of citrus canker symptoms on seedlings of Swingle citrumelo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is one of the most serious diseases citrus in Florida, and elsewhere in the world. The disease causes yield loss and some fresh fruit trade restrictions may apply. Cultural management techniques such as windbreaks may work by not only reducing wind...

  17. Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.

    PubMed

    Li, Jinyun; Wang, Nian

    2014-02-01

    Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides. PMID:23901828

  18. The Efficacy and Underlying Mechanism of Sulfone Derivatives Containing 1,3,4-oxadiazole on Citrus Canker.

    PubMed

    Li, Pei; Ma, Yuhua; Zhou, Junliang; Luo, Hui; Yan, Jiawen; Mao, Yongya; Wang, Zhuang

    2015-01-01

    The objectives of the current study were to isolate and identify the pathogen responsible for citrus canker and investigate the efficacy of sulfone derivatives containing 1,3,4-oxadiazole moiety on controlling citrus canker caused by Xanthomonas citri subsp. citri (Xcc) under in vitro and field conditions. In an in vitro study, we tested eight sulfone derivatives against Xcc and the results demonstrated that compound 3 exhibited the best antibacterial activity against Xcc, with a half-maximal effective concentration (EC50) value of 1.23 μg/mL, which was even better than those of commercial bactericides Kocide 3000 (58.21 μg/mL) and Thiodiazole copper (77.04 μg/mL), respectively. Meanwhile, under field experiments, compound 3 treatments demonstrated the highest ability to reduce the disease of citrus canker in leaves and fruits in two different places relative to an untreated control as well as the commercial bactericides Kocide 3000 and Thiodiazole copper. Meanwhile, compound 3 could stimulate the increase in peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) activities in the navel orange leaves, causing marked enhancement of plant resistance against citrus canker. Moreover, compound 3 could damage the cell membranes, destruct the biofilm formation, inhibit the production of extracellular polysaccharide (EPS), and affect the cell membrane permeability to restrain the growth of the bacteria. PMID:26247929

  19. Overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (HLB, citrus greening)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized e...

  20. Transcriptional Profiling of Canker-Resistant Transgenic Sweet Orange (Citrus sinensis Osbeck) Constitutively Overexpressing a Spermidine Synthase Gene

    PubMed Central

    Fu, Xing-Zheng; Liu, Ji-Hong

    2013-01-01

    Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating diseases affecting the citrus industry worldwide. In our previous study, the canker-resistant transgenic sweet orange (Citrus sinensis Osbeck) plants were produced via constitutively overexpressing a spermidine synthase. To unravel the molecular mechanisms underlying Xcc resistance of the transgenic plants, in the present study global transcriptional profiling was compared between untransformed line (WT) and the transgenic line (TG9) by hybridizing with Affymetrix Citrus GeneChip. In total, 666 differentially expressed genes (DEGs) were identified, 448 upregulated, and 218 downregulated. The DEGs were classified into 33 categories after Gene ontology (GO) annotation, in which 68 genes are in response to stimulus and involved in immune system process, 12 genes are related to cell wall, and 13 genes belong to transcription factors. These genes and those related to starch and sucrose metabolism, glutathione metabolism, biosynthesis of phenylpropanoids, and plant hormones were hypothesized to play major roles in the canker resistance of TG9. Semiquantitative RT-PCR analysis showed that the transcript levels of several candidate genes in TG9 were significantly higher than in WT both before and after Xcc inoculation, indicating their potential association with canker disease. PMID:23509803

  1. Under severe citrus canker and HLB (Huanglongbing) pressure, Triumph and Jackson perform better than Flame and Marsh grapefruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB) and Citrus Canker (CC) threaten the viability of Florida grapefruit production. Triumph (T), reportedly a grapefruit/sweet orange hybrid, is similar to seedy white grapefruit with earlier maturity and lower bitterness. Jackson (J) is a low-seeded budsport of Triumph. Tree health ...

  2. Incidence and severity of Asiatic citrus canker on citrus and citrus–related germplasm in a Florida field planting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xanthomonas citri ssp. citri (Hasse), is the causal agent of Asiatic citrus canker (ACC), a commercially important disease in Florida citrus, as well as in many other regions. In this study we evaluated occurrence of foliar lesions from ACC on progenies of 94 seed-source genotypes (hereafter called ...

  3. Under severe HLB and citrus canker pressure, 'Triumph' and 'Jackson' perform better than 'Flame' and 'Marsh' grapefruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Huanglongbing (HLB) and Citrus Canker (CC) threaten the viability of Florida grapefruit production. ‘Triumph’ (T), reportedly a grapefruit/sweet orange hybrid, is similar to seedy white grapefruit with earlier maturity and lower bitterness. ‘Jackson’ (J) is a low-seeded budsport of ‘Triumph’. Tree h...

  4. Genetic variability of Brazilian isolates of Alternaria alternata detected by AFLP and RAPD techniques

    PubMed Central

    Dini-Andreote, Francisco; Pietrobon, Vivian Cristina; Andreote, Fernando Dini; Romão, Aline Silva; Spósito, Marcel Bellato; Araújo, Welington Luiz

    2009-01-01

    The Alternaria brown spot (ABS) is a disease caused in tangerine plants and its hybrids by the fungus Alternaria alternata f. sp. citri which has been found in Brazil since 2001. Due to the recent occurrence in Brazilian orchards, the epidemiology and genetic variability of this pathogen is still an issue to be addressed. Here it is presented a survey about the genetic variability of this fungus by the characterization of twenty four pathogenic isolates of A. alternata f. sp. citri from citrus plants and four endophytic isolates from mango (one Alternaria tenuissima and three Alternaria arborescens). The application of two molecular markers Random Amplified Polymorphic DNA (RAPD) and Amplified Fragment Length Polymorphism (AFLP) had revealed the isolates clustering in distinct groups when fingerprintings were analyzed by Principal Components Analysis (PCA). Despite the better assessment of the genetic variability through the AFLP, significant modifications in clusters components were not observed, and only slight shifts in the positioning of isolates LRS 39/3 and 25M were observed in PCA plots. Furthermore, in both analyses, only the isolates from lemon plants revealed to be clustered, differently from the absence of clustering for other hosts or plant tissues. Summarizing, both RAPD and AFLP analyses were both efficient to detect the genetic variability within the population of the pathogenic fungus Alternaria spp., supplying information on the genetic variability of this species as a basis for further studies aiming the disease control. PMID:24031413

  5. Isolation and characterization of the grain mold fungi, Cochliobolus and Alternaria spp., from sorghum using semi-selective media and DNA sequence analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mold diseases, caused by fungal complexes including Alternaria, Cochliobolus and Fusarium species, limit sorghum grain production. Media were tested by plating Fusarium thapsinum, Alternaria sp. and Curvularia lunata, individually and competitively. Dichloran chloramphenicol rose bengal (DRBC) and m...

  6. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum

    PubMed Central

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  7. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum.

    PubMed

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  8. Primary subcutaneous Alternaria alternata infection of the hand in an immunocompromised host.

    PubMed

    Kpodzo, Dzifa S; Calderwood, Michael S; Ruchelsman, David E; Abramson, Jeremy S; Piris, Adriano; Winograd, Jonathan M; Kotton, Camille N

    2011-07-01

    We describe a case of a progressive subcutaneous Alternaria alternata infection in the hand of a patient with chronic lymphocytic leukemia (CLL). The diagnosis was based upon the examination of tissue biopsy and isolation of the etiologic agent in culture. The identity of the isolate was determined by phenotypic characteristics and by sequencing the ITS and D1/D2 regions of the rDNA. Despite combination therapy with voriconazole and micafungin, the lesion continued to progress. Posaconazole therapy, along with surgical excision of the infected tissue, resulted in the eradication of infection. The limitations of the clinical management of invasive Alternaria infections are discussed. PMID:21299373

  9. Alternaria toxins in wheat from the Autonomous Province of Vojvodina, Serbia: a preliminary survey.

    PubMed

    Janić Hajnal, Elizabet; Orčić, Dejan; Torbica, Aleksandra; Kos, Jovana; Mastilović, Jasna; Škrinjar, Marija

    2015-01-01

    Although Fusarium species remain a main source of mycotoxin contamination of wheat, in recent years, due to the evident climatic changes, other mycotoxigenic fungi have been recognised as important wheat contaminants. Alternaria species, especially A. alternata, have been found as contaminants of wheat as well as wheat-based products. Under favourable conditions A. alternata very often produce alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA) and others Alternaria toxins. The aim of the present study was to examine the presence of three Alternaria toxins (AOH, AME and TeA) in wheat samples harvested during three years (2011-13). To this end, 92 samples were collected during wheat harvesting from different growing regions of the Autonomous Province of Vojvodina, which represents the most important wheat-growing area in Serbia. The presence of Alternaria toxins was analysed by HPLC with electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-MS/MS). Among all the analysed wheat samples, 63 (68.5%) were contaminated with TeA, 11 (12.0%) with AOH and 6 (6.5%) with AME. Furthermore, the maximum and mean toxin concentrations were 2676 and 92.4 µg kg(-1), 48.9 and 18.6 µg kg(-1), and 70.2 and 39.0 µg kg(-1) for TeA, AOH and AME, respectively. Co-occurrence of three Alternaria toxins in wheat samples was detected in six samples; a combination of two toxins was found in two samples; and 64 samples contained one toxin. The results showed that among 92 analysed wheat samples, only 20 (21.7%) samples were without Alternaria toxins. The presence of Alternaria toxins was also investigated in terms of weather conditions recorded during the period of investigation, as well as with the sampling region. This study represents the first preliminary report of the natural occurrence of Alternaria toxins in wheat (Triticum aestivum) from Serbia. PMID:25585540

  10. Proteome Analysis of Pathogen-Responsive Proteins from Apple Leaves Induced by the Alternaria Blotch Alternaria alternata

    PubMed Central

    Zhang, Cai-xia; Tian, Yi; Cong, Pei-hua

    2015-01-01

    Understanding the defence mechanisms used by apple leaves against Alternaria alternate pathogen infection is important for breeding purposes. To investigate the ultrastructural differences between leaf tissues of susceptible and resistant seedlings, in vitro inoculation assays and transmission electron microscopy (TEM) analysis were conducted with two different inoculation assays. The results indicated that the resistant leaves may have certain antifungal activity against A. alternate that is lacking in susceptible leaves. To elucidate the two different host responses to A. alternate infection in apples, the proteomes of susceptible and resistant apple leaves that had or had not been infected with pathogen were characterised using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS). MS identified 43 differentially expressed proteins in two different inoculation assays. The known proteins were categorised into 5 classes, among these proteins, some pathogenesis-related (PR) proteins, such as beta-1,3-glucanase, ascorbate peroxidase (APX), glutathione peroxidase (GPX) and mal d1, were identified in susceptible and resistant hosts and were associated with disease resistance of the apple host. In addition, the different levels of mal d1 in susceptible and resistant hosts may contribute to the outstanding anti-disease properties of resistant leaves against A. alternate. Taken together, the resistance mechanisms of the apple host against A. alternate may be a result of the PR proteins and other defence-related proteins. Given the complexity of the biology involved in the interaction between apple leaves and the A. alternate pathogen, further investigation will yield more valuable insights into the molecular mechanisms of suppression of the A. alternate pathogen. Overall, we outline several novel insights into the response of apple leaves to pathogen attacks. These findings

  11. Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii

    PubMed Central

    2010-01-01

    Background Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control. PMID:20388224

  12. Transgenic sweet orange plants expressing a dermaseptin coding sequence show reduced symptoms of citrus canker disease.

    PubMed

    Furman, Nicolás; Kobayashi, Ken; Zanek, Maria Cecilia; Calcagno, Javier; Garcia, Maria Laura; Mentaberry, Alejandro

    2013-09-20

    Citrus canker provoked by Xanthomonas axonopodis pv. citri is a bacterial disease causing severe losses in all citrus-producing areas around the world. Xanthomonas infection is considered as an endemic disease in Northeast and Northwest Argentina, affecting as much as 10% of commercial citrus plantations. There is not known natural resistance neither in orange varieties nor in rootstocks used for grafting of commercial cultivars. To introduce resistance to this disease, plants of Pineapple sweet orange were transformed with a genetic construct allowing constitutive accumulation of dermaseptin. In comparison with non-transformed plants, transgenic plants showed symptom reduction levels of up to 50% in in planta assays performed under controlled conditions. PMID:23896218

  13. Adaptive Potential of Maritime Pine (Pinus pinaster) Populations to the Emerging Pitch Canker Pathogen, Fusarium circinatum

    PubMed Central

    Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

    2014-01-01

    There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

  14. Adaptive potential of maritime pine (Pinus pinaster) populations to the emerging pitch canker pathogen, Fusarium circinatum.

    PubMed

    Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

    2014-01-01

    There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

  15. Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi

    PubMed Central

    Bashyal, Bharat P.; Wellensiek, Brian P.; Ramakrishnan, Rajesh; Faeth, Stanley H.; Ahmad, Nafees; Leslie Gunatilaka, A. A.

    2014-01-01

    Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, altertoxins V (1) and VI (2) together with the known compounds, altertoxins I (3), II (4), and III (5). The structures of 1 and 2 were determined by detailed spectroscopic analysis and those of 3–5 were established by comparison with reported data. When tested in our cell-based assay at concentrations insignificantly toxic to T-cells, altertoxins V (1), I (3), II (4), and III (5) completely inhibited replication of the HIV-1 virus at concentrations of 0.50, 2.20, 0.30, and 1.50 μM respectively. Our findings suggest that the epoxyperylene structural scaffold in altertoxins may be manipulated to produce potent anti-HIV therapeutics. 2014 Elsevier Ltd. All rights reserved. PMID:25260957

  16. Altertoxins with potent anti-HIV activity from Alternaria tenuissima QUE1Se, a fungal endophyte of Quercus emoryi.

    PubMed

    Bashyal, Bharat P; Wellensiek, Brian P; Ramakrishnan, Rajesh; Faeth, Stanley H; Ahmad, Nafees; Gunatilaka, A A Leslie

    2014-11-01

    Screening of a small library of natural product extracts derived from endophytic fungi of the Sonoran desert plants in a cell-based anti-HIV assay involving T-cells infected with the HIV-1 virus identified the EtOAc extract of a fermentation broth of Alternaria tenuissima QUE1Se inhabiting the stem tissue of Quercus emoryi as a promising candidate for further investigation. Bioactivity-guided fractionation of this extract led to the isolation and identification of two new metabolites, altertoxins V (1) and VI (2) together with the known compounds, altertoxins I (3), II (4), and III (5). The structures of 1 and 2 were determined by detailed spectroscopic analysis and those of 3-5 were established by comparison with reported data. When tested in our cell-based assay at concentrations insignificantly toxic to T-cells, altertoxins V (1), I (3), II (4), and III (5) completely inhibited replication of the HIV-1 virus at concentrations of 0.50, 2.20, 0.30, and 1.50 μM, respectively. Our findings suggest that the epoxyperylene structural scaffold in altertoxins may be manipulated to produce potent anti-HIV therapeutics. PMID:25260957

  17. Canker sore

    MedlinePlus

    ... with salt water or mild, over-the-counter mouthwashes. (DO NOT use mouthwashes that contain alcohol which can irritate the area ... needed for severe cases. These may include: Chlorhexidine mouthwash Stronger medicines called corticosteroids that are placed on ...

  18. Canker Sores

    MedlinePlus

    ... Executive Committee Board of Trustees Governance Past Presidents Staff/Contact History Awards Our Partners Membership Membership Categories Renew Your Membership Login Fellowship Academic Fellowship Affiliate Fellowship (AFAOM) Application Process Fellowship Study ...

  19. Canker Sores

    MedlinePlus

    ... be triggered by stress, food allergies, lack of vitamins and minerals, hormonal changes or menstrual periods. In some cases the cause is unknown. In most cases, the sores go away by themselves. Some ointments, creams or rinses may help with the pain. Avoiding ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  1. Identification and functional analysis of brassicicene C biosynthetic gene cluster in Alternaria brassicicola.

    PubMed

    Minami, Atsushi; Tajima, Naoto; Higuchi, Yusuke; Toyomasu, Tomonobu; Sassa, Takeshi; Kato, Nobuo; Dairi, Tohru

    2009-02-01

    The biosynthetic gene cluster of brassicicene C was identified in Alternaria brassicicola strain ATCC 96836 from genome database search. In vivo and in vitro study clearly revealed the function of Orf8 and Orf6 as a fusicoccadiene synthase and methyltransferase, respectively. The understanding toward the biosynthetic pathway promises construction of this type of diterpene compounds with genetic engineering. PMID:19097780

  2. Antileukemic alpha-pyrone derivatives from the endophytic fungus Alternaria phragmospora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four new (1–4) and two known (5 and 6)a-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identi'ed to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (2) 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-py...

  3. Resistance to alternaria solani in hybrids between a Solanum tuberosum haploid and S. raphanifolium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early blight of potato (Solanum tuberosum L.), 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 bl...

  4. Biochemical Evaluation of Resistance Responses of Potato to Different Isolates of Alternaria Solani

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Artificial neural network models of relationships between Alternaria spores and meteorological factors in Szczecin (Poland)

    NASA Astrophysics Data System (ADS)

    Grinn-Gofroń, Agnieszka; Strzelczak, Agnieszka

    2008-11-01

    Alternaria is an airborne fungal spore type known to trigger respiratory allergy symptoms in sensitive patients. Aiming to reduce the risk for allergic individuals, we constructed predictive models for the fungal spore circulation in Szczecin, Poland. Monthly forecasting models were developed for the airborne spore concentrations of Alternaria, which is one of the most abundant fungal taxa in the area. Aerobiological sampling was conducted over 2004-2007, using a Lanzoni trap. Simultaneously, the following meteorological parameters were recorded: daily level of precipitation; maximum and average wind speed; relative humidity; and maximum, minimum, average, and dew point temperature. The original factors as well as with lags (up to 3 days) were used as the explaining variables. Due to non-linearity and non-normality of the data set, the modelling technique applied was the artificial neural network (ANN) method. The final model was a split model with classification (spore presence or absence) followed by regression for spore seasons and log(x+1) transformed Alternaria spore concentration. All variables except maximum wind speed and precipitation were important factors in the overall classification model. In the regression model for spore seasons, close relationships were noted between Alternaria spore concentration and average and maximum temperature (on the same day and 3 days previously), humidity (with lag 1) and maximum wind speed 2 days previously. The most important variable was humidity recorded on the same day. Our study illustrates a novel approach to modelling of time series with short spore seasons, and indicates that the ANN method provides the possibility of forecasting Alternaria spore concentration with high accuracy.

  7. Effect of X-irradiation on Citrus Canker Pathogen Xanthomonas citri subsp. citri of Satsuma Mandarin Fruits

    PubMed Central

    Song, Min-A; Park, Jae Sin; Kim, Ki Deok; Jeun, Yong Chull

    2015-01-01

    Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is one of the most important bacterial diseases of citrus. Because citrus canker is not found in many countries including European Union and Australia, Xcc is strictly regulated in order to prevent its spread. In this study, the effects of X-irradiation on Xcc growth either in the suspension or on the surface of citrus fruits were investigated. The suspension containing 1×107 cfu/ml of Xcc was irradiated with different absorbed doses of X-irradiation ranging from 50 to 400 Gy. The results showed that Xcc was fully dead at 400 Gy of X-irradiation. To determine the effect of X-irradiation on quarantine, the Xcc-inoculated citrus fruits were irradiated with different X-ray doses at which Xcc was completely inhibited by an irradiation dose of 250 Gy. The D10 value for Xcc on citrus fruits was found to be 97 Gy, indicating the possibility of direct application on citrus quarantine without any side sterilizer. Beside, presence of Xcc on the surface of asymptomatic citrus fruits obtained from citrus canker-infected orchards was noted. It indicated that the exporting citrus fruits need any treatment so that Xcc on the citrus fruits should be completely eliminated. Based on these results, ionizing radiation can be considered as an alternative method of eradicating Xcc for export of citrus fruits. PMID:26672670

  8. Effects of simulated rainfall on disease development and weed control of the bioherbicidal fungi Alternaria cassiae and Colletotrichum truncatum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria cassiae and Colletotrichum truncatum are virulent pathogens of sicklepod (Senna obtusifolia), and hemp sesbania (Sesbania exaltata), respectively, under favorable environmental conditions. In greenhouse experiments, the effects of simulated rainfall on pathogenesis and mortality of these ...

  9. STEM, STEM Education, STEMmania

    ERIC Educational Resources Information Center

    Sanders, Mark

    2009-01-01

    In this article, the author introduces integrative STEM (science, technology, engineering, and/or mathematics) education and discusses the importance of the program. The notion of integrative STEM education includes approaches that explore teaching and learning between/among any two or more of the STEM subject areas, and/or between a STEM subject…

  10. Quambalaria species, including Q. coyrecup sp. nov., implicated in canker and shoot blight diseases causing decline of Corymbia species in the southwest of Western Australia.

    PubMed

    Paap, Trudy; Burgess, Treena I; McComb, Jennifer A; Shearer, Bryan L; St J Hardy, Giles E

    2008-01-01

    A severe canker disease has been causing decline and death of Corymbia calophylla in the southwest of Western Australia (WA) for some years, but the causal agent has never been investigated. However, there have been historical reports dating back to the 1920s of a canker disease of amenity planted C. ficifolia caused by 'Sporotrichum destructor', though the description and Latin diagnosis were never published. It has been suggested that there may be links between this species and the genus Quambalaria, a group containing leaf and shoot pathogens of species of Eucalyptus and Corymbia. The aim of this study was to investigate the identity of the pathogen historically attributed to canker disease of C. ficifolia, determine whether this pathogen is responsible for the current epidemic of C. calophylla canker, and whether it is synonymous with Quambalaria. Surveys examined the range of Quambalaria spp. on Corymbia spp. endemic to southwest WA. Their phylogenetic relationship to Q. cyanescens, Q. eucalypti, and Q. pitereka was examined using rLSU and ITS sequence data. Morphological characters were also compared. Sequences confirmed that Q. cyanescens and Q. pitereka are present in southwest WA, with the latter associated with leaf and shoot disease. A third group isolated from cankers represent a new species of Quambalaria. Comparisons of disease symptoms and conidiogenesis indicate this species is synonymous with 'S. destructor'. The species is formally described here as Q. coyrecup sp. nov. PMID:18222081

  11. Development of a polymerase chain reaction-based assay for the detection of Alternaria fungal contamination in food products.

    PubMed

    Zur, G; Hallerman, E M; Sharf, R; Kashi, Y

    1999-10-01

    Alternaria sp. are important fungal contaminants of vegetable, fruit, and grain products, including Alternaria alternata, a contaminant of tomato products. To date, the Howard method, based on microscopic observation of fungal filaments, has been the standard examination for inspection of tomato products. We report development of a polymerase chain reaction (PCR)-based method for detection of Alternaria DNA. PCR primers were designed to anneal to the internal transcribed regions ITS1 and ITS2 of the 5.8S rRNA gene of Alternaria but not to other microbial or tomato DNA. We demonstrate use of the PCR assay to detect Alternaria DNA in experimentally infested and commercially obtained tomato sauce and tomato powder. Use of the PCR method offers a rapid and sensitive assay for the presence of Alternaria DNA in tomato products. The apparent breakdown of DNA in tomato sauce may limit the utility of the assay to freshly prepared products. The assay for tomato powder is not affected by storage time. PMID:10528725

  12. Characterization of a novel single-stranded RNA virus, closely related to fusariviruses, infecting the plant pathogenic fungus Alternaria brassicicola.

    PubMed

    Zhong, Jie; Shang, Hong Hong; Zhu, Chuan Xia; Zhu, Jun Zi; Zhu, Hong Jian; Hu, Yan; Gao, Bi Da

    2016-06-01

    The alternaria blackspot of rapeseed is one of the most prominent diseases of rapeseed. It is caused by three species of the genus Alternaria: Alternaria brassicicola, Alternaria brassicae, and Alternaria raphanin. Here we report a novel positive-sense RNA virus from an A. brassicicola strain 817-14. The virus has a 6639 nucleotide (nt) long genome, excluding a poly (A)-tail, and was predicted to contain three putative open reading frames (ORF1, ORF2, and ORF3). The large ORF1 encoded a 174-kDa polyprotein (composed of 1522 amino acid residues) containing a conserved RNA-dependent RNA polymerase (RdRp) domain and a helicase domain. The other two smaller ORFs encoded polypeptides with unknown function. Homology search and phylogenetic analysis, based on the RdRp and helicase domains, suggest that this virus is related to and grouped with Sclerotinia sclerotiorum fusarivirus 1 (SsFV1), Rosellinia necatrix fusarivirus 1 (RnFV1), Fusarium graminearum virus-DK21 (FgV1), and Penicillium roqueforti RNA mycovirus 1 (PrRV1), all of which belong to a newly proposed family Fusariviridae. For this study, we designed the virus as "Alternaria brassicicola fusarivirus 1" (AbFV1). Virus elimination revealed that AbFV1 has no conspicuous impact on the biological properties of its host. PMID:26707921

  13. Summer heat and low soil organic matter influence severity of hazelnut Cytospora canker.

    PubMed

    Lamichhane, Jay Ram; Fabi, Alfredo; Varvaro, Leonardo

    2014-04-01

    Cytospora canker, caused by the fungus Cytospora corylicola, is present in hazelnut production areas worldwide. The disease is widespread throughout the main production areas of Italy. The causal agent is considered to be a secondary invader of damaged tissue that attacks mainly stressed plants. However, little is known of disease severity and stress factors that predispose plants to infection. In particular, the role of pedoclimatic factors was investigated. Direct survey indicated that disease severity varied across several study sites. Geostatistics showed a strong positive correlation between disease severity index and summer heat (r = 0.80 and 0.91 for July and August, respectively) and strong negative correlation between disease severity index and soil organic matter (r = -0.78). A moderate positive correlation between disease severity index and magnesium/potassium ratio (r = 0.58) and moderate negative correlations between disease severity index and total soil nitrogen (r = -0.53), thermal shock (r = -0.46), and rainfall (r = -0.53) were determined. No significant correlation between disease severity index and soil aluminum (r = -0.35), soil pH (r = -0.01), and plant age (r = -0.38) was found. PMID:24168042

  14. Population structure of the butternut canker fungus, Ophiognomonia clavigignenti-juglandacearum, in North American forests.

    PubMed

    Broders, K D; Boraks, A; Sanchez, A M; Boland, G J

    2012-09-01

    The occurrence of multiple introduction events, or sudden emergence from a host jump, of forest pathogens may be an important factor in successful establishment in a novel environment or on a new host; however, few studies have focused on the introduction and emergence of fungal pathogens in forest ecosystems. While Ophiognomonia clavigignenti-juglandacearum (Oc-j), the butternut canker fungus, has caused range-wide mortality of butternut trees in North America since its first observation in 1967, the history of its emergence and spread across the United States and Canada remains unresolved. Using 17 single nucleotide polymorphic loci, we investigated the genetic population structure of 101 isolates of Oc-j from across North America. Clustering analysis revealed that the Oc-j population in North America is made up of three differentiated genetic clusters of isolates, and these genetic clusters were found to have a strong clonal structure. These results, in combination with the geographic distribution of the populations, suggest that Oc-j was introduced or has emerged in North America on more than one occasion, and these clonal lineages have since proliferated across much of the range of butternut. No evidence of genetic recombination was observed in the linkage analysis, and conservation of the distinct genetic clusters in regions where isolates from two or more genetic clusters are present, would indicate a very minimal or non-existent role of sexual recombination in populations of Oc-j in North America. PMID:23139872

  15. The Xanthomonas axonopodis pv. citri flagellum is required for mature biofilm and canker development.

    PubMed

    Malamud, Florencia; Torres, Pablo S; Roeschlin, Roxana; Rigano, Luciano A; Enrique, Ramón; Bonomi, Hernán R; Castagnaro, Atilio P; Marano, María Rosa; Vojnov, Adrián A

    2011-03-01

    Xanthomonas axonopodis pv. citri (Xac) is the causative agent of citrus canker. This bacterium develops a characteristic biofilm on both biotic and abiotic surfaces. To evaluate the participation of the single flagellum of Xac in biofilm formation, mutants in the fliC (flagellin) and the flgE (hook) genes were generated. Swimming motility, assessed on 0.25 % agar plates, was markedly reduced in fliC and flgE mutants. However, the fliC and flgE mutants exhibited a flagellar-independent surface translocation on 0.5 % agar plates. Mutation of either the rpfF or the rpfC gene, which both encode proteins involved in cell-cell signalling mediated by diffusible signal factor (DSF), led to a reduction in both flagellar-dependent and flagellar-independent surface translocation, indicating a regulatory role for DSF in both types of motility. Confocal laser scanning microscopy of biofilms produced in static culture demonstrated that the flagellum is also involved in the formation of mushroom-shaped structures and water channels, and in the dispersion of biofilms. The presence of the flagellum was required for mature biofilm development on lemon leaf surfaces. The absence of flagellin produced a slight reduction in Xac pathogenicity and this reduction was more severe when the complete flagellum structure was absent. PMID:21109564

  16. Genome analysis of the kiwifruit canker pathogen Pseudomonas syringae pv. actinidiae biovar 5.

    PubMed

    Fujikawa, Takashi; Sawada, Hiroyuki

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) is a destructive pathogen of kiwifruit bacterial canker disease, causing severe economic losses to kiwifruit industry worldwide. Biovar 5 is the most recently reported biovar of Psa, and is found in only a local area of Japan at present. There is not much information of genetic characteristics of biovar 5. Thus, the genome of biovar 5 was sequenced and analyzed to clarify its detailed genetic characteristics. Here, the genomes of strain MAFF 212056 and MAFF 212061 of biovar 5 were estimated to be about 6.3 Mbp and 6.5 Mbp, respectively, and their phylogenetic positions were proved to be near that of biovar 2 in the phylogenetic tree. However, it was confirmed that biovar 5 had neither the coronatine biosynthetic genes conserved in biovar 2, its phylogenetic neighbor, nor the phaseolotoxin biosynthetic genes conserved in biovar 1, Japanese native pathogen. In addition, 45 genes of type III secreted effectors were identified in biovar 5 genomes, showing that their composition is different from that in the other biovars. Moreover, some biovar 5-specific regions were identified. Then, biovar 5-specific PCR primers for targeting these regions were designed, and proved to be applicable for detecting biovar 5 specifically. PMID:26891997

  17. Endophytic Cryphonectriaceae on native Myrtales: Possible origin of Chrysoporthe canker on plantation-grown Eucalyptus.

    PubMed

    Mausse-Sitoe, Silvia N D; Rodas, Carlos A; Wingfield, Michael J; Chen, ShuaiFei; Roux, Jolanda

    2016-01-01

    Chrysoporthe austroafricana (Cryphonectriaceae) is a damaging canker pathogen on Eucalyptus species in Southern Africa. Recent studies have shown that the fungus occurs on native Syzygium species and that it has apparently undergone a host range expansion from these native trees to infect non-native Eucalyptus. The aim of this study was to consider whether Chr. austroafricana and other Cryphonectriaceae might exist as endophytes in native Myrtaceae, providing a source of inoculum to infect non-native Myrtales. Healthy branches were collected from Myrtaceae in Mozambique, incubated in florist foam, allowed to dry gradually and monitored for the appearance of fruiting bodies resembling species in the Cryphonectriaceae. Isolates were identified based on DNA sequence data. Two species in the Cryphonectriaceae were obtained, representing the first evidence that species in the Cryphonectriaceae occur as endophytes on native Myrtales, thus providing a source of inoculum to infect non-native and susceptible trees. This has important implications regarding the movement of planting stock used by ornamental tree and forestry enterprises. PMID:27268243

  18. De novo genome assembly of Geosmithia morbida, the causal agent of thousand cankers disease.

    PubMed

    Schuelke, Taruna A; Westbrook, Anthony; Broders, Kirk; Woeste, Keith; MacManes, Matthew D

    2016-01-01

    Geosmithia morbida is a filamentous ascomycete that causes thousand cankers disease in the eastern black walnut tree. This pathogen is commonly found in the western U.S.; however, recently the disease was also detected in several eastern states where the black walnut lumber industry is concentrated. G. morbida is one of two known phytopathogens within the genus Geosmithia, and it is vectored into the host tree via the walnut twig beetle. We present the first de novo draft genome of G. morbida. It is 26.5 Mbp in length and contains less than 1% repetitive elements. The genome possesses an estimated 6,273 genes, 277 of which are predicted to encode proteins with unknown functions. Approximately 31.5% of the proteins in G. morbida are homologous to proteins involved in pathogenicity, and 5.6% of the proteins contain signal peptides that indicate these proteins are secreted. Several studies have investigated the evolution of pathogenicity in pathogens of agricultural crops; forest fungal pathogens are often neglected because research efforts are focused on food crops. G. morbida is one of the few tree phytopathogens to be sequenced, assembled and annotated. The first draft genome of G. morbida serves as a valuable tool for comprehending the underlying molecular and evolutionary mechanisms behind pathogenesis within the Geosmithia genus. PMID:27168971

  19. De novo genome assembly of Geosmithia morbida, the causal agent of thousand cankers disease

    PubMed Central

    Westbrook, Anthony; Woeste, Keith

    2016-01-01

    Geosmithia morbida is a filamentous ascomycete that causes thousand cankers disease in the eastern black walnut tree. This pathogen is commonly found in the western U.S.; however, recently the disease was also detected in several eastern states where the black walnut lumber industry is concentrated. G. morbida is one of two known phytopathogens within the genus Geosmithia, and it is vectored into the host tree via the walnut twig beetle. We present the first de novo draft genome of G. morbida. It is 26.5 Mbp in length and contains less than 1% repetitive elements. The genome possesses an estimated 6,273 genes, 277 of which are predicted to encode proteins with unknown functions. Approximately 31.5% of the proteins in G. morbida are homologous to proteins involved in pathogenicity, and 5.6% of the proteins contain signal peptides that indicate these proteins are secreted. Several studies have investigated the evolution of pathogenicity in pathogens of agricultural crops; forest fungal pathogens are often neglected because research efforts are focused on food crops. G. morbida is one of the few tree phytopathogens to be sequenced, assembled and annotated. The first draft genome of G. morbida serves as a valuable tool for comprehending the underlying molecular and evolutionary mechanisms behind pathogenesis within the Geosmithia genus. PMID:27168971

  20. Population structure of the butternut canker fungus, Ophiognomonia clavigignenti-juglandacearum, in North American forests

    PubMed Central

    Broders, K D; Boraks, A; Sanchez, A M; Boland, G J

    2012-01-01

    The occurrence of multiple introduction events, or sudden emergence from a host jump, of forest pathogens may be an important factor in successful establishment in a novel environment or on a new host; however, few studies have focused on the introduction and emergence of fungal pathogens in forest ecosystems. While Ophiognomonia clavigignenti-juglandacearum (Oc-j), the butternut canker fungus, has caused range-wide mortality of butternut trees in North America since its first observation in 1967, the history of its emergence and spread across the United States and Canada remains unresolved. Using 17 single nucleotide polymorphic loci, we investigated the genetic population structure of 101 isolates of Oc-j from across North America. Clustering analysis revealed that the Oc-j population in North America is made up of three differentiated genetic clusters of isolates, and these genetic clusters were found to have a strong clonal structure. These results, in combination with the geographic distribution of the populations, suggest that Oc-j was introduced or has emerged in North America on more than one occasion, and these clonal lineages have since proliferated across much of the range of butternut. No evidence of genetic recombination was observed in the linkage analysis, and conservation of the distinct genetic clusters in regions where isolates from two or more genetic clusters are present, would indicate a very minimal or non-existent role of sexual recombination in populations of Oc-j in North America. PMID:23139872

  1. Genome analysis of the kiwifruit canker pathogen Pseudomonas syringae pv. actinidiae biovar 5

    PubMed Central

    Fujikawa, Takashi; Sawada, Hiroyuki

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) is a destructive pathogen of kiwifruit bacterial canker disease, causing severe economic losses to kiwifruit industry worldwide. Biovar 5 is the most recently reported biovar of Psa, and is found in only a local area of Japan at present. There is not much information of genetic characteristics of biovar 5. Thus, the genome of biovar 5 was sequenced and analyzed to clarify its detailed genetic characteristics. Here, the genomes of strain MAFF 212056 and MAFF 212061 of biovar 5 were estimated to be about 6.3 Mbp and 6.5 Mbp, respectively, and their phylogenetic positions were proved to be near that of biovar 2 in the phylogenetic tree. However, it was confirmed that biovar 5 had neither the coronatine biosynthetic genes conserved in biovar 2, its phylogenetic neighbor, nor the phaseolotoxin biosynthetic genes conserved in biovar 1, Japanese native pathogen. In addition, 45 genes of type III secreted effectors were identified in biovar 5 genomes, showing that their composition is different from that in the other biovars. Moreover, some biovar 5-specific regions were identified. Then, biovar 5-specific PCR primers for targeting these regions were designed, and proved to be applicable for detecting biovar 5 specifically. PMID:26891997

  2. Four cases of dermatomycosis: superficial cutaneous infection by Alternaria or Bipolaris.

    PubMed

    Robb, Christopher W; Malouf, Peter J; Rapini, Ronald P

    2003-10-01

    Invasive dermal infections in immunosuppressed patients by a wide variety of opportunistic fungi are well described in the literature; however, superficial infections (dermatomycosis) are more rarely described. We report 4 cases of dermatomycosis by Alternaria or Bipolaris species. All but one of the patients had predisposing conditions including topical corticosteroid use, atopic or seborrheic dermatitis, and nail dystrophy. All 4 patients were otherwise immunocompetent. These cases represent some of the very few reports of Bipolaris in a primary stratum corneum infection and the first report of Bipolaris in an otherwise healthy person. We also describe what may be the first report of Bipolaris onychomycosis. All of our patients responded to topical or oral imidazole antifungal therapy. We discuss the significance of Alternaria and Bipolaris as contaminants or irrelevant organisms grown in some cultures of skin scrapings. PMID:14604084

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

    PubMed

    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. PMID:20687560

  4. Chitinase-mediated inhibitory activity of Brassica transgenic on growth of Alternaria brassicae.

    PubMed

    Mondal, Kalyan K; Chatterjee, Subhas Chandra; Viswakarma, Navin; Bhattacharya, Ram Charan; Grover, Anita

    2003-09-01

    Chitinase, capable of degrading the cell walls of invading phytopathogenic fungi, plays an important role in plant defense response, particularly when this enzyme is overexpressed through genetic engineering. In the present study, Brassica plant (Brassica juncea L.) was transformed with chitinase gene tagged with an overexpressing promoter 35 S CaMV. The putative transgenics were assayed for their inhibitory activity against Alternaria brassicae, the inducer of Alternaria leaf spot of Brassica both in vitro and under polyhouse conditions. In in vitro fungal growth inhibition assays, chitinase inhibited the fungal colony size by 12-56% over the non-trangenic control. The bioassay under artificial epiphytotic conditions revealed the delay in the onset of disease as well as reduced lesion number and size in 35S-chitinase Brassica as compared to the untransformed control plants. PMID:14570264

  5. Genome sequence of a novel endornavirus from the phytopathogenic fungus Alternaria brassicicola.

    PubMed

    Shang, Hong-Hong; Zhong, Jie; Zhang, Ru-Jia; Chen, Chuan-Yuan; Gao, Bi-Da; Zhu, Hong-Jian

    2015-07-01

    In an effort to discover new mycoviruses from phytopathogenic fungi, a dsRNA molecule of 10,290 nt, resembling those associated with the viruses belonging to the family Endornaviridae, was isolated from Alternaria brassicicola, one of the causal agents of rapeseed black spot disease. Genome analysis revealed the presence of a single open reading frame coding for a polyprotein of 3400 aa containing conserved viral methyltransferase (MTR), viral RNA helicase 1 (Hel-1), and RNA-dependent RNA polymerase (RdRp) domains. In addition, a cysteine-rich region (CRR) with conserved CXCC motifs, shared among several endornaviruses, was also identified between the MTR and Hel-1 domains. Phylogenetic analysis based on the RdRp sequence strongly suggested that the virus infecting A. brassicicola should be considered a representative of a novel endornavirus species, and this virus was designated as Alternaria brassicicola endornavirus 1 (AbEV1). PMID:25951967

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

    PubMed

    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. PMID:25895272

  7. Stem Cells

    MedlinePlus

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  8. Stem Cells

    MedlinePlus

    Stem cells are cells with the potential to develop into many different types of cells in the body. They serve as a repair ... body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  9. Crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-06-01

    This study tests the hypothesis that Danish agricultural areas are the main source to airborne Alternaria spores in Copenhagen, Denmark. We suggest that the source to the overall load is mainly local, but with intermittent Long Distance Transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  10. Human eosinophil innate response to Alternaria fungus through protease-activated receptor-2.

    PubMed

    Matsuwaki, Yoshinori; Wada, Kota; Moriyama, Hiroshi; Kita, Hirohito

    2011-01-01

    Eosinophils are multifunctional leukocytes implicated in the pathogenesis of allergic diseases. An association between eosinophilic inflammation and infection or colonization by fungi has also been long recognized. However, the mechanisms underlying how eosinophils are activated and how they release proinflammatory and immunomodulatory mediators such as major basic protein (MBP) and eosinophil-derived neurotoxin remain largely unknown. We used a fungus, i.e. Alternaria, as a model microbe relevant to human asthma and chronic rhinosinusitis (CRS) to investigate the molecular mechanisms involved in the immune recognition of ubiquitous environmental allergens. Human eosinophils are activated by live Alternaria alternata organisms, release their granule proteins, and kill the fungi. Eosinophils, but not neutrophils, respond to secreted products from A. alternata. We found that eosinophils are equipped with innate cellular activation machinery that responds to an extracellular aspartate protease secreted by Alternaria. Aspartate protease activation of protease-activated receptor (PAR)-2 probably involves a novel mechanism different from that for serine protease activation of PAR-2. Thus, human eosinophils may recognize certain danger signals or virulence factors produced by fungi and provoke inflammatory responses against these organisms. Dysregulation of such an innate immune mechanism may be involved in the pathophysiology of certain human inflammatory diseases, including asthma and CRS. PMID:21646807

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

    PubMed

    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. PMID:26839497

  12. PCR and real-time PCR assays to detect fungi of Alternaria alternata species.

    PubMed

    Kordalewska, Milena; Brillowska-Dąbrowska, Anna; Jagielski, Tomasz; Dworecka-Kaszak, Bożena

    2015-01-01

    Fungi of the Alternaria genus are mostly associated with allergic diseases. However, with a growing number of immunocompromised patients, these fungi, with A. alternata being the most prevalent one, are increasingly recognized as etiological agents of infections (phaeohyphomycoses) in humans. Nowadays, identification of Alternaria spp. requires their pure culture and is solely based on morphological criteria. Clinically, Alternaria infections may be indistinguishable from other fungal diseases. Therefore, a diagnostic result is often delayed or even not achieved at all. In this paper we present easy to perform and interpret PCR and real-time PCR assays enabling detection of A. alternata species. On the basis of alignment of β-tubulin gene sequences, A. alternata-specific primers were designed. DNA from fungal isolates, extracted in a two-step procedure, were used in PCR and real-time PCR assays followed by electrophoresis or melting temperature analysis, respectively. The assays specificity was confirmed, since positive results were obtained for all A. alternata isolates, and no positive results were obtained neither for other molds, dermatophytes, yeast-like fungi, nor human DNA. The assays developed here enable fast and unambiguous identification of A. alternata pathogens. PMID:26610309

  13. How the Necrotrophic Fungus Alternaria brassicicola Kills Plant Cells Remains an Enigma

    PubMed Central

    2015-01-01

    Alternaria species are mainly saprophytic fungi, but some are plant pathogens. Seven pathotypes of Alternaria alternata use secondary metabolites of host-specific toxins as pathogenicity factors. These toxins kill host cells prior to colonization. Genes associated with toxin synthesis reside on conditionally dispensable chromosomes, supporting the notion that pathogenicity might have been acquired several times by A. alternata. Alternaria brassicicola, however, seems to employ a different mechanism. Evidence on the use of host-specific toxins as pathogenicity factors remains tenuous, even after a diligent search aided by full-genome sequencing and efficient reverse-genetics approaches. Similarly, no individual genes encoding lipases or cell wall-degrading enzymes have been identified as strong virulence factors, although these enzymes have been considered important for fungal pathogenesis. This review describes our current understanding of toxins, lipases, and cell wall-degrading enzymes and their roles in the pathogenesis of A. brassicicola compared to those of other pathogenic fungi. It also describes a set of genes that affect pathogenesis in A. brassicicola. They are involved in various cellular functions that are likely important in most organisms and probably indirectly associated with pathogenesis. Deletion or disruption of these genes results in weakly virulent strains that appear to be sensitive to the defense mechanisms of host plants. Finally, this review discusses the implications of a recent discovery of three important transcription factors associated with pathogenesis and the putative downstream genes that they regulate. PMID:25681268

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

    PubMed Central

    Paul, Narayan Chandra; Deng, Jian Xin

    2015-01-01

    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. PMID:26839497

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

    PubMed

    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. PMID:26887231

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

    PubMed Central

    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 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. PMID:26887231

  17. Comparison of pathogenicity of Alternaria pellucida and Curvularia lunata on weed Echinochloa species.

    PubMed

    Reza, Mohammad; Motlagh, Safari

    2015-07-01

    Echinochloa spp. are the most important weeds in rice fields. In this research Curvularia lunata and Alternaria pellucida were isolated from these weeds and their pathogenicity effects were compared on these weeds and five rice cultivars in a completely random design with three replications in greenhouse conditions. Fungi were inoculated on weeds and rice cultivars, using spore suspension consisting of 10' spore ml(-1) of distilled water. Results indicated significant effect of Curvularia lunata and Alternaria pellucida on Echinochloa oryzicola and E. crus-galli. In the present study, effect of C. lunata on fresh weight, dry weight and height of Echinochloa species based on variance analysis table, a significant reaction was observed for height and fresh weight, but for dry weight reaction was not significant. The effect of A. pellucida on fresh weight, dry weight and height of Echinochloa species based on variance analysis table, a significant reaction was observed for all the three traits. Also, rice cultivars did not show any significant reaction to C. lunata and A. pellucida. The results showed that in comparison between effect of Curvularia lunata and Alternaria pellucida on Echinochloa spp., disease rating caused by A. pellucida on E. oryzicola and E. crusalli was more than disease rating caused by C. lunata and these species of weed were more susceptible to A. pellucida. However, A. alternata can be considered as a better promising bioherbicide to control Echinochloa spp. PMID:26364476

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

    PubMed Central

    Skóra, Justyna; Otlewska, Anna; Gutarowska, Beata; Leszczyńska, Joanna; Majak, Iwona; Stępień, Łukasz

    2015-01-01

    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. PMID:25689994

  19. Production of the allergenic protein Alt a 1 by Alternaria isolates from working environments.

    PubMed

    Skóra, Justyna; Otlewska, Anna; Gutarowska, Beata; Leszczyńska, Joanna; Majak, Iwona; Stępień, Łukasz

    2015-02-01

    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. PMID:25689994

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. DNA polymorphisms and biocontrol of Bacillus antagonistic to citrus bacterial canker with indication of the interference of phyllosphere biofilms.

    PubMed

    Huang, Tzu-Pi; Tzeng, Dean Der-Syh; Wong, Amy C L; Chen, Chun-Han; Lu, Kuan-Min; Lee, Ya-Huei; Huang, Wen-Di; Hwang, Bing-Fang; Tzeng, Kuo-Ching

    2012-01-01

    Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S-23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease. PMID:22848728

  3. A framework to gauge the epidemic potential of plant pathogens in environmental reservoirs: the example of kiwifruit canker.

    PubMed

    Bartoli, Claudia; Lamichhane, Jay Ram; Berge, Odile; Guilbaud, Caroline; Varvaro, Leonardo; Balestra, Giorgio M; Vinatzer, Boris A; Morris, Cindy E

    2015-02-01

    New economically important diseases on crops and forest trees emerge recurrently. An understanding of where new pathogenic lines come from and how they evolve is fundamental for the deployment of accurate surveillance methods. We used kiwifruit bacterial canker as a model to assess the importance of potential reservoirs of new pathogenic lineages. The current kiwifruit canker epidemic is at least the fourth outbreak of the disease on kiwifruit caused by Pseudomonas syringae in the mere 50 years in which this crop has been cultivated worldwide, with each outbreak being caused by different genetic lines of the bacterium. Here, we ask whether strains in natural (non-agricultural) environments could cause future epidemics of canker on kiwifruit. To answer this question, we evaluated the pathogenicity, endophytic colonization capacity and competitiveness on kiwifruit of P. syringae strains genetically similar to epidemic strains and originally isolated from aquatic and subalpine habitats. All environmental strains possessing an operon involved in the degradation of aromatic compounds via the catechol pathway grew endophytically and caused symptoms in kiwifruit vascular tissue. Environmental and epidemic strains showed a wide host range, revealing their potential as future pathogens of a variety of hosts. Environmental strains co-existed endophytically with CFBP 7286, an epidemic strain, and shared about 20 virulence genes, but were missing six virulence genes found in all epidemic strains. By identifying the specific gene content in genetic backgrounds similar to known epidemic strains, we developed criteria to assess the epidemic potential and to survey for such strains as a means of forecasting and managing disease emergence. PMID:24986268

  4. Identification of putative TAL effector targets of the citrus canker pathogens shows functional convergence underlying disease development and defense response

    PubMed Central

    2014-01-01

    Background Transcriptional activator-like (TAL) effectors, formerly known as the AvrBs3/PthA protein family, are DNA-binding effectors broadly found in Xanthomonas spp. that transactivate host genes upon injection via the bacterial type three-secretion system. Biologically relevant targets of TAL effectors, i.e. host genes whose induction is vital to establish a compatible interaction, have been reported for xanthomonads that colonize rice and pepper; however, citrus genes modulated by the TAL effectors PthA“s” and PthC“s” of the citrus canker bacteria Xanthomonas citri (Xc) and Xanthomonas aurantifolii pathotype C (XaC), respectively, are poorly characterized. Of particular interest, XaC causes canker disease in its host lemon (Citrus aurantifolia), but triggers a defense response in sweet orange. Results Based on, 1) the TAL effector-DNA binding code, 2) gene expression data of Xc and XaC-infiltrated sweet orange leaves, and 3) citrus hypocotyls transformed with PthA2, PthA4 or PthC1, we have identified a collection of Citrus sinensis genes potentially targeted by Xc and XaC TAL effectors. Our results suggest that similar with other strains of Xanthomonas TAL effectors, PthA2 and PthA4, and PthC1 to some extent, functionally converge. In particular, towards induction of genes involved in the auxin and gibberellin synthesis and response, cell division, and defense response. We also present evidence indicating that the TAL effectors act as transcriptional repressors and that the best scoring predicted DNA targets of PthA“s” and PthC“s” in citrus promoters predominantly overlap with or localize near to TATA boxes of core promoters, supporting the idea that TAL effectors interact with the host basal transcriptional machinery to recruit the RNA pol II and start transcription. Conclusions The identification of PthA“s” and PthC“s” targets, such as the LOB (LATERAL ORGAN BOUNDARY) and CCNBS genes that we report here, is key for the understanding

  5. Rapid and sensitive detection of Citrus Bacterial Canker by loop-mediated isothermal amplification combined with simple visual evaluation methods

    PubMed Central

    2010-01-01

    Background Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is Xanthomonas citri subsp. citri, while Xanthomonas fuscans subsp. aurantifolii, strain B causes type B CBC and Xanthomonas fuscans subsp. aurantifolii strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment. Results A loop-mediated isothermal amplification assay for the diagnosis of Citrus Bacterial Canker (CBC-LAMP) was developed and evaluated. DNA samples were obtained from infected plants or cultured bacteria. A typical ladder-like pattern on gel electrophoresis was observed in all positive samples in contrast to the negative controls. In addition, amplification products were detected by visual inspection using SYBRGreen and using a lateral flow dipstick, eliminating the need for gel electrophoresis. The sensitivity and specificity of the assay were evaluated in different conditions and using several sample sources which included purified DNA, bacterium culture and infected plant tissue. The sensitivity of the CBC-LAMP was 10 fg of pure Xcc DNA, 5 CFU in culture samples and 18 CFU in samples of infected plant tissue. No cross reaction was observed with DNA of other phytopathogenic

  6. Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease.

    PubMed

    Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B; Yang, Bing; White, Frank F; Wang, Nian; Jones, Jeffrey B

    2014-01-28

    Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccA(w), induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

  7. Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease

    PubMed Central

    Hu, Yang; Zhang, Junli; Jia, Hongge; Sosso, Davide; Li, Ting; Frommer, Wolf B.; Yang, Bing; White, Frank F.; Wang, Nian; Jones, Jeffrey B.

    2014-01-01

    Citrus bacterial canker (CBC) disease occurs worldwide and incurs considerable costs both from control measures and yield losses. Bacteria that cause CBC require one of six known type III transcription activator-like (TAL) effector genes for the characteristic pustule formation at the site of infection. Here, we show that Xanthomonas citri subspecies citri strain Xcc306, with the type III TAL effector gene pthA4 or with the distinct yet biologically equivalent gene pthAw from strain XccAw, induces two host genes, CsLOB1 and CsSWEET1, in a TAL effector-dependent manner. CsLOB1 is a member of the Lateral Organ Boundaries (LOB) gene family of transcription factors, and CsSWEET1 is a homolog of the SWEET sugar transporter and rice disease susceptibility gene. Both TAL effectors drive expression of CsLOB1 and CsSWEET1 promoter reporter gene fusions when coexpressed in citrus or Nicotiana benthamiana. Artificially designed TAL effectors directed to sequences in the CsLOB1 promoter region, but not the CsSWEET1 promoter, promoted pustule formation and higher bacterial leaf populations. Three additional distinct TAL effector genes, pthA*, pthB, and pthC, also direct pustule formation and expression of CsLOB1. Unlike pthA4 and pthAw, pthB and pthC do not promote the expression of CsSWEET1. CsLOB1 expression was associated with the expression of genes associated with cell expansion. The results indicate that CBC-inciting species of Xanthomonas exploit a single host disease susceptibility gene by altering the expression of an otherwise developmentally regulated gene using any one of a diverse set of TAL effector genes in the pathogen populations. PMID:24474801

  8. Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri.

    PubMed

    Moreira, Leandro Marcio; Facincani, Agda Paula; Ferreira, Cristiano Barbalho; Ferreira, Rafael Marine; Ferro, Maria Inês Tiraboshi; Gozzo, Fabio Cesar; de Oliveira, Julio Cezar Franco; Ferro, Jesus Aparecido; Soares, Márcia Regina

    2015-03-01

    The genome of Xanthomonas citri subsp. Citri strain 306 pathotype A (Xac) was completely sequenced more than 10 years; to date, few studies involving functional genomics Xac and its host compatible have been developed, specially related to adaptive events that allow the survival of Xac within the plant. Proteomic analysis of Xac showed that the processes of chemotactic signal transduction and phosphate metabolism are key adaptive strategies during the interaction of a pathogenic bacterium with its plant host. The results also indicate the importance of a group of proteins that may not be directly related to the classical virulence factors, but that are likely fundamental to the success of the initial stages of the infection, such as methyl-accepting chemotaxis protein (Mcp) and phosphate specific transport (Pst). Furthermore, the analysis of the mutant of the gene pstB which codifies to an ABC phosphate transporter subunit revealed a complete absence of citrus canker symptoms when inoculated in compatible hosts. We also conducted an in silico analysis which established the possible network of genes regulated by two-component systems PhoPQ and PhoBR (related to phosphate metabolism), and possible transcriptional factor binding site (TFBS) motifs of regulatory proteins PhoB and PhoP, detaching high degree of conservation of PhoB TFBS in 84 genes of Xac genome. This is the first time that chemotaxis signal transduction and phosphate metabolism were therefore indicated to be fundamental to the process of colonization of plant tissue during the induction of disease associated with Xanthomonas genus bacteria. PMID:25403594

  9. Recovery Plan for Phytophthora kernoviae Causing Bleeding Trunk Cankers, Leaf Blight and Stem Dieback in Trees and Shrubs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora kernoviae, a recently described species of Phytophthora, is an invasive pathogen of forest trees and shrubs such as beech (Fagus sylvatica) and rhododendron (Rhododendron ponticum) that has become established in woodlands and public gardens in Cornwall, United Kingdom. Although the ori...

  10. Effects of Compost and Biocontrol Amendments on Stem Canker, Black Scurf, and Common Scab of Potato, 2006

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two composts and two biological control agents were evaluated alone and in combination for their effects on the development of soilborne diseases of potato. The experiment was conducted on field research plots in Newport, ME. The compost amendments consisted of commercially available compost blends,...

  11. Immunochemical quantitation of airborne short ragweed, Alternaria, antigen E, and Alt-I allergens: a two-year prospective study

    SciTech Connect

    Agarwal, M.K.; Swanson, M.C.; Reed, C.E.; Yunginger, J.W.

    1983-07-01

    We conducted a 2 yr prospective study to measure atmospheric short ragweed and Alternaria allergens by RAST inhibition analysis of eluates from filter sheets exposed in air samplers. In both years ragweed pollen and Alternaria spore counts, obtained with a rotoslide sampler, correlated significantly with immunochemically measured airborne ragweed and Alternaria allergenic activity. Airborne levels of the purified allergens AgE and Alt-I were successfully quantitated; these levels correlated closely with total airborne ragweed and Alternaria allergenic activities, respectively, and also with ragweed pollen and Alternaria spore counts. Eluates from filter sheets exposed during late summer and fall produced positive wheal-and-flare skin tests in patients with fall hay fever. In both years immunochemical measurements of allergenic activity due to airborne short ragweed correlated closely with mean symptom score indices in groups of short ragweed-sensitive individuals. Measurable levels of atmospheric ragweed allergenic activity were noted before and after the ragweed pollination season, and at these times we noted small increases in mean symptom score indices in the short ragweed-sensitive groups. Thus immunochemical analyses provide important information concerning levels of environmental allergens.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Exogenous treatment with salicylic acid attenuates occurrence of citrus canker in susceptible navel orange (Citrus sinensis Osbeck).

    PubMed

    Wang, Yin; Liu, Ji-Hong

    2012-08-15

    Citrus canker caused by Xanthomonas axonopodis pv. citri (Xac) is a devastating bacterial disease threatening the citrus industry. Salicylic acid (SA) plays a key role in plant defense response to biotic stress, but information is scarce concerning the application of SA to enhancing Xac resistance. In the present research attempts were made to investigate how exogenous application of SA influenced canker disease outbreak in navel orange (Citrus sinensis). Exogenously applied SA at 0.25 mM significantly enhanced the endogenous free and bound SA, particularly the latter. Upon exposure to Xac, lower disease incidence rate and smaller lesion sites were observed in the samples pre-treated with SA, accompanied by repression of bacterial growth at the lesion sites. Concurrent with the augmented disease resistance, SA-treated leaves had higher H₂O₂ level and smaller stomata apertures before or after Xac infection when compared with their counterparts pre-treated with water (control). SA treatment elevated the activities of phenylalanine ammonia-lyase and β-1,3-glucanase, but only the latter was higher in the SA-treated samples after Xac infection. In addition, mRNA levels of two pathogenesis-related genes, CsCHI and CsPR4A, were higher in the SA-treated samples relative to the control. Taken together, our results strongly suggest that the exogenously applied SA has evoked a cascade of physiological and molecular events that function singly or in concert to confer resistance to Xac invasion. PMID:22658220

  14. Variables Associated with Severity of Bacterial Canker and Wilt Caused by Clavibacter michiganensis subsp. michiganensis in Tomato Greenhouses.

    PubMed

    Blank, L; Cohen, Y; Borenstein, M; Shulhani, R; Lofthouse, M; Sofer, M; Shtienberg, D

    2016-03-01

    Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker and wilt of tomato, is considered to be one of the most important bacterial pathogens worldwide. In the year 2000 there was an increase in the number of infected greenhouses and in the severity of the disease in Israel. As part of the effort to cope with the disease, a comprehensive survey was conducted. Scouts recorded disease severity monthly in 681 production units. At the end of the season the scouts met with the growers and together recorded relevant details about the crop and cultural practices employed. The results suggested an absence of anisotropy pattern in the study region. Global Moran's I analysis showed that disease severity had significant spatial autocorrelation. The strongest spatial autocorrelation occurred within a 1,500 m neighborhood, which is comparable to the distance between production units maintained by one grower (Farm). Next, we tested three groups of variables including or excluding the Farm as a variable. When the Farm was included the explained variation increased in all the studied models. Overall, results of this study demonstrate that the most influential factor on bacterial canker severity was the Farm. This variable probably encompasses variation in experience, differences in agricultural practices between growers, and the quality of implementation of management practices. PMID:26623996

  15. Genome, Proteome and Structure of a T7-Like Bacteriophage of the Kiwifruit Canker Phytopathogen Pseudomonas syringae pv. actinidiae.

    PubMed

    Frampton, Rebekah A; Acedo, Elena Lopez; Young, Vivienne L; Chen, Danni; Tong, Brian; Taylor, Corinda; Easingwood, Richard A; Pitman, Andrew R; Kleffmann, Torsten; Bostina, Mihnea; Fineran, Peter C

    2015-07-01

    Pseudomonas syringae pv. actinidiae is an economically significant pathogen responsible for severe bacterial canker of kiwifruit (Actinidia sp.). Bacteriophages infecting this phytopathogen have potential as biocontrol agents as part of an integrated approach to the management of bacterial canker, and for use as molecular tools to study this bacterium. A variety of bacteriophages were previously isolated that infect P. syringae pv. actinidiae, and their basic properties were characterized to provide a framework for formulation of these phages as biocontrol agents. Here, we have examined in more detail φPsa17, a phage with the capacity to infect a broad range of P. syringae pv. actinidiae strains and the only member of the Podoviridae in this collection. Particle morphology was visualized using cryo-electron microscopy, the genome was sequenced, and its structural proteins were analysed using shotgun proteomics. These studies demonstrated that φPsa17 has a 40,525 bp genome, is a member of the T7likevirus genus and is closely related to the pseudomonad phages φPSA2 and gh-1. Eleven structural proteins (one scaffolding) were detected by proteomics and φPsa17 has a capsid of approximately 60 nm in diameter. No genes indicative of a lysogenic lifecycle were identified, suggesting the phage is obligately lytic. These features indicate that φPsa17 may be suitable for formulation as a biocontrol agent of P. syringae pv. actinidiae. PMID:26114474

  16. Wind speed effects on the quantity of Xanthomonas citri subsp. citri dispersed downwind from canopies of grapefruit trees infected with citrus canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The epidemic of citrus canker (Xanthomonas citri subsp. citri, Xcc) in Florida continues to expand since termination of the eradication program in 2006. Storms are known to be associated with disease spread, but little information exists on the interaction of fundamental physical and biological proc...

  17. Processes involved in the dispersal of Xanthomonas citri pv. citri from canker-infectd citrus canopies, and in the infection of citrus foliage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida, and epidemics result in yield loss and market penalties both in Florida, and elsewhere where the pathogen occurs, and susceptible citrus is cultivated. The bacterium is dispersed in rain splash, and storms wit...

  18. Two novel Fusarium species that cause canker disease of Sichuan pepper (Zanthoxylum bungeanum Maxim.) in northern China form a novel clade with F. torreyae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canker disease of Sichuan pepper (Zanthoxylum bungeanum) has caused a decline in the production of this economically important spice in northern China over the past twenty-five years. To identify the etiological agent, 38 fungal strains were isolated from symptomatic tissues from trees in five provi...

  19. Development of consumer-friendly transgenic citrus plants with potential broad spectrum resistance to HLB, Citrus canker, Phytopthora and other exotic diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The second year of this CRB funded project has started, which is focused on the development of citrus cultivars that exhibit disease resistance to multiple pathogens such as HLB, Phytophthora and citrus canker diseases. We are using precise genetic engineering to introduce into disease susceptible ...

  20. POST-HURRICANE ANALYSIS OF CITRUS CANKER II: PREDICTIVE MODEL ESTIMATION OF DISEASE SPREAD AND AREA POTENTIALLY IMPACTED BY VARIOUS ERADICATION PROTOCOLS FOLLOWING CATASTROPHIC WEATHER EVENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The affect of 2005 Hurricane Wilma on the dissemination of Xanthomonas axonopodis pv. citri (Xac), the cause of Asiatic citrus canker (ACC), and subsequent disease development was examined and predictions for the areas into which Xac was likely to have spread from known sources of infection was deve...

  1. The epidemiological significance of post-packinghouse survival of Xanthomonas citri ssp. citri for dissemination of Asiatic citrus canker via infected fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The risk of introduction of Xanthomonas citri spp. citri (Xcc) to new, unaffected citrus producing areas is a major concern for those citrus industries attempting to remain free of citrus canker. Citrus fruit, as a potential pathway for Xcc to enter and become established in these areas, is assumed...

  2. A survey of survival and activity of citrus canker lesion populations on foliage, fruit and shoots in a Florida grapefruit orchard in 2009 and 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri (Xcc)) can infect several species of citrus. The disease can develop on the leaves, shoots and fruit, causing erumpent lesions, that on fruit precludes sale to the fresh market. We assessed lesion activity in orchard-grown grapefruit to provide informa...

  3. Effects of Mefenoxam, Phosphonate, and Paclobutrazol on In Vitro Characteristics of Phytophthora cactorum and P. citricola and on Canker Size of European Beech

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora citricola and P. cactorum cause bleeding cankers that lead to the death of mature European beech in the northeastern United States. Because of the economic value placed on these trees, experiments were conducted to investigate the effects of two fungicides and a plant growth regulator ...

  4. Processess involved in the dispersal of Xanthomonas citri pv. citri from canker-infected citrus canopies, and in the infection of citrus foliage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida, and epidemics result in yield loss and market penalties both in Florida and elsewhere, where the pathogen occurs and susceptible citrus is cultivated. The bacterium is dispersed in rain splash, and storms with...

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

    PubMed

    Polizzotto, Rachele; Andersen, Birgitte; Martini, Marta; Grisan, Simone; Assante, Gemma; Musetti, Rita

    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 pooled cluster analysis. Following morphological analyses, all strains were grouped according to their three-dimensional sporulation pattern on PCA and to the colony characteristics on different substrates. After DNA extraction, all strains were analyzed by RAPD-PCR and the resulting profiles were subjected to cluster analysis. The metabolites extracted from the 20 Alternaria endophytes were analyzed by a HPLC and the resulting metabolite profiles were subjected to multivariate statistic analyses. In comparison with reference 'small-spored' Alternaria species, the 20 strains were segregated into two morphological groups: one belonging to the A. arborescens species-group and a second to the A. tenuissima species-group. RAPD analysis also showed that grapevine endophytes belonged to either the A. arborescens or the A. tenuissima species-group and that they were molecularly distinct from strains belonging to A. alternata. Chemotaxonomy gave the same grouping: the grapevine endophytic strains belong to A. arborescens or A. tenuissima species-groups producing known metabolites typical of these species-groups. Interestingly, the 20 grapevine endophytes were able to produce also a number of unknown metabolites, whose characterization could be useful for a more precise segregation of the two species-groups. The results show how complementary morphological, molecular and chemical data can clarify relationships among endophyte species-groups of low morphological divergence. PMID:22123507

  6. Process development for the elucidation of mycotoxin formation in Alternaria alternata

    PubMed Central

    2011-01-01

    The black mould Alternaria alternata produces a wide diversity of mycotoxins which are of particular health concern. Since no maximum allowable limits are set for Alternaria toxins in food and feed, prevention of Alternaria infestations and mycotoxin spoilage is the only way to avoid health risks. Thus, the understanding of mycotoxin biosynthesis is essential. For that purpose, a reliable batch process in a 2 L bioreactor was established which enables the study of several parameters influencing the production of the mycotoxins alternariol (AOH), alternariol monomethylether (AME) and tenuazonic acid (TA) by A. alternata DSM 12633. Modified Czapek-Dox medium was used with glucose as carbon source and ammonium and nitrate as nitrogen sources. Consumption of carbon and nitrogen sources as well as formation of the three mycotoxins were monitored; the average data of five independent fermentations was plotted and fitted using a logistic equation with four parameters. Maximum mycotoxin concentrations of 3.49 ± 0.12 mg/L AOH, 1.62 ± 0.14 mg/L AME and 38.28 ± 0.1 mg/L TA were obtained. In this system the effect of different aeration rates (0.53 vvm-0.013 vvm) was tested which exerted a great influence on mycotoxin production. The use of the semi-synthetic Czapek-Dox medium allowed the exchange of carbon and nitrogen sources for acetate and aspartic acid. The use of acetate instead of glucose resulted in the sole production of alternariol whereas the exchange of ammonium and nitrate for aspartate enhanced the production of both AOH and AME while TA production was not affected. PMID:21970547

  7. Exposure to Alternaria alternata in US homes is associated with asthma symptoms

    PubMed Central

    Salo, Päivi M.; Arbes, Samuel J.; Sever, Michelle; Jaramillo, Renee; Cohn, Richard D.; London, Stephanie J.; Zeldin, Darryl C.

    2007-01-01

    Background Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments. Objective We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes. Methods The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti–A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors. Results Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90−2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18−2.85 for the 3rd tertile). Conclusion Exposure to A alternata in US homes is associated with active asthma symptoms. Clinical implications Measures that reduce indoor exposure to A alternata may help control asthma exacerbations. PMID:17030243

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

    PubMed

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

    2015-03-01

    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

  9. Perylene derivatives produced by Alternaria alternata, an endophytic fungus isolated from Laurencia species.

    PubMed

    Gao, Shu-Shan; Li, Xiao-Ming; Wang, Bin-Gui

    2009-11-01

    Two new perylene derivatives, 7-epi-8-hydroxyaltertoxin I (1) and 6-epi-stemphytriol (2), along with two known compounds stemphyperylenol (3) and altertoxin I (4) were isolated from Alternaria alternata, a marine endophytic fungus derived from an unidentified algal species of the genus Laurencia. Structures of compounds 1-4 were determined on the basis of detailed spectroscopic analysis, as well as by comparison with literature reports. The antimicrobial activities of compounds 1 and 3 against Staphylococcus aureus, Escherichia coli, and Aspergillus niger were evaluated; neither showed obvious activity. PMID:19967977

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

    PubMed

    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. PMID:20036892