Science.gov

Sample records for dieback fungus eutypa

  1. Species identification of the causal agent of Eutypa dieback of grapevine in northeastern American and southeastern Canadian vineyards

    USDA-ARS?s Scientific Manuscript database

    Eutypa dieback of Vitis (grape) is caused by the Ascomycete fungus Eutypa lata. The pathogen infects grapevine through wounds, and cause wood canker and dieback symptoms. E. lata has been identified in all major grape production areas in the world. The first report of Eutypa dieback from northeaster...

  2. Eutypa dieback in northern California vineyards

    USDA-ARS?s Scientific Manuscript database

    In 1959, Eutypa dieback was recognized as a serious problem in apricot orchards in Santa Clara County, California. Symptomatic trees showed extensive ‘gumming’ near rotted sections of the bark around branch scars. A more severe symptom was the sudden death of branches and sometimes of entire trees. ...

  3. Identification of Eutypa spp. causing Eutypa dieback of grapevine in Eastern North America

    USDA-ARS?s Scientific Manuscript database

    Eutypa dieback of grapevine is caused by Eutypa lata in production areas with Mediterranean climates in California, Australasia, Europe, and South Africa. Eutypa dieback has also been described in the colder, eastern North American vineyards where cultivars adapted from native Vitis spp. (e.g., Viti...

  4. Genetic structure of the fungal grapevine pathogen Eutypa lata from four continents

    USDA-ARS?s Scientific Manuscript database

    The generalist ascomycete fungus Eutypa lata causes Eutypa dieback of grapevine (Vitis vinifera) worldwide. To decipher the cosmopolitan distribution of this fungus, the population genetic structure of 17 geographic samples was investigated from four continental regions (Australia, California, Europ...

  5. Genetic structure of the fungal grapevine pathogen Eutypa lata from four continents

    USDA-ARS?s Scientific Manuscript database

    Deciphering the geographic origins of pathogens and elucidating the population biology of these microscopic organisms are necessary steps to establish effective disease-control strategies. The generalist ascomycete fungus Eutypa lata causes Eutypa dieback of grapevine (Vitis vinifera) worldwide. To ...

  6. Wood-decay abilities of grapevine trunk pathogens Diaporthe ampelina, Diplodia seriata, Eutypa lata, and Neofusicoccum parvum

    USDA-ARS?s Scientific Manuscript database

    Trunk pathogens are fungi that infect grapevine wood through pruning wounds and destroy fruiting positions, thereby impacting grape production. Neofusicoccum parvum (causal fungus of Botryosphaeria dieback) and Eutypa lata (causal fungus of Eutypa dieback) cause chronic infections (cankers) of the t...

  7. Intercontinental genetic structure of the fungal grapevine pathogen Eutypa lata

    USDA-ARS?s Scientific Manuscript database

    The ascomycete fungus Eutypa lata, causal agent of Eutypa dieback of grapevine (Vitis vinifera), impacts all vineyard production systems worldwide. Our objectives were to characterize the population structure of E. lata at different geographical scales to identify migration patterns through ascospor...

  8. A transcriptomic study of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) interaction with the vascular ascomycete fungus Eutypa lata

    PubMed Central

    Camps, Céline; Kappel, Christian; Lecomte, Pascal; Léon, Céline; Gomès, Eric; Coutos-Thévenot, Pierre; Delrot, Serge

    2010-01-01

    Eutypa dieback is a vascular disease that may severely affect vineyards throughout the world. In the present work, microarrays were made in order (i) to improve our knowledge of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) responses to Eutypa lata, the causal agent of Eutypa dieback; and (ii) to identify genes that may prevent symptom development. Qiagen/Operon grapevine microarrays comprising 14 500 probes were used to compare, under three experimental conditions (in vitro, in the greenhouse, and in the vineyard), foliar material of infected symptomatic plants (S+R+), infected asymptomatic plants (S–R+), and healthy plants (S–R–). These plants were characterized by symptom notation after natural (vineyard) or experimental (in vitro and greenhouse) infection, re-isolation of the fungus located in the lignified parts, and the formal identification of E. lata mycelium by PCR. Semi-quantitative real-time PCR experiments were run to confirm the expression of some genes of interest in response to E. lata. Their expression profiles were also studied in response to other grapevine pathogens (Erysiphe necator, Plasmopara viticola, and Botrytis cinerea). (i) Five functional categories of genes, that is those involved in metabolism, defence reactions, interaction with the environment, transport, and transcription, were up-regulated in S+R+ plants compared with S–R– plants. These genes, which cannot prevent infection and symptom development, are not specific since they were also up-regulated after infection by powdery mildew, downy mildew, and black rot. (ii) Most of the genes that may prevent symptom development are associated with the light phase of photosynthesis. This finding is discussed in the context of previous data on the mode of action of eutypin and the polypeptide fraction secreted by Eutypa. PMID:20190040

  9. Molecular polymorphism and phenotypic diversity in the generalist, wood-decay fungus Eutypa lata

    USDA-ARS?s Scientific Manuscript database

    Pathogen adaptation to different ecological niches can lead to host specialization and, when coupled with reproductive isolation, ecological speciation. We tested the hypothesis of host specialization in northern California populations of the fungus Eutypa lata, which causes a soft-rot wood decay in...

  10. Pathogenesis of Eutypa lata in grapevine: Identification of virulence factors and biochemical characterization of cordon dieback

    USDA-ARS?s Scientific Manuscript database

    Eutypa lata is a vascular pathogen of woody plants. In the present study we (i) determined which component(s) of the cell wall polymers were degraded in naturally infected grapevines and in artificially inoculated grape wood blocks; (ii) compared the pattern of wood decay in the tolerant grape culti...

  11. Transformation of Eutypa dieback and esca disease pathogen toxins by antagonistic fungal strains reveals a second detoxification pathway not present in Vitis vinifera.

    PubMed

    Christen, Danilo; Tharin, Manuel; Perrin-Cherioux, Sandrine; Abou-Mansour, Eliane; Tabacchi, Raphaël; Défago, Geneviève

    2005-09-07

    Eutypine, 4-hydroxybenzaldehyde, and 3-phenyllactic acid are some of the phytotoxins produced by the pathogens causing Eutypa dieback and esca disease, two trunk diseases of grapevine (Vitis vinifera). Known biocontrol agents such as Fusarium lateritium and Trichoderma sp. were screened for their ability to consume these toxins. Transformation time courses were performed, and an high-performance liquid chromatography-based method was developed to analyze toxin metabolism and to identify and quantify the converted products. The results show that the aldehyde function of eutypine was reduced to eutypinol, as by V. vinifera cv. Merlot, the cultivar tolerant to Eutypa dieback. We revealed a supplementary detoxification pathway, not known in Merlot, where the aldehyde function was oxidized to eutypinic acid. Moreover, some strains tested could further metabolize the transformation products. Every strain tested could transform 4-hydroxybenzaldehyde to the corresponding alcohol and acid, and these intermediates disappeared totally at the end of the time courses. When biological assays on cells of V. vinifera cv. Chasselas were carried out, the transformation products exhibited a lower toxicity than the toxins. The possibility of selecting new biocontrol agents against trunk diseases of grapevine based on microbial detoxification is discussed.

  12. Population genetics of Eutypa lata in the major grape-growing regions of the world and historical patterns of viticulture.

    USDA-ARS?s Scientific Manuscript database

    The causal agent of Eutypa dieback of grape, Eutypa lata (Ascomycota), is a destructive disease worldwide. The pathogen has a broad host range, but causes severe symptoms on only a few cultivated hosts (e.g., apricot & grape). To decipher its cosmopolitan distribution, we examined the population gen...

  13. A method to detect and quantify Eutypa lata and Diplodia seriata/intermedia complex DNA in grapevine pruning wounds

    USDA-ARS?s Scientific Manuscript database

    Trunk diseases are factors that limit sustainability of vineyards worldwide. Bot canker and Eutypa dieback are caused by several fungi belonging to the Botryosphaericeae and Diatrypaceae, respectively with Diplodia seriata and Eutypa lata being two of the most common species. Previous information in...

  14. Draft Genome Sequence of the Phytopathogenic Fungus Fusarium euwallaceae, the Causal Agent of Fusarium Dieback

    PubMed Central

    Sánchez-Rangel, Diana; Hernández-Domínguez, Eric; Pérez-Torres, Claudia-Anahí; Ortiz-Castro, Randy; Villafán, Emanuel; Alonso-Sánchez, Alexandro; Rodríguez-Haas, Benjamín; López-Buenfil, Abel; García-Avila, Clemente; Ramírez-Pool, José-Abrahán

    2017-01-01

    ABSTRACT Here, we report the genome of Fusarium euwallaceae strain HFEW-16-IV-019, an isolate obtained from Kuroshio shot hole borer (a Euwallacea sp.). These beetles were collected in Tijuana, Mexico, from elm trees showing typical symptoms of Fusarium dieback. The final assembly consists of 287 scaffolds spanning 48,274,071 bp and 13,777 genes. PMID:28860245

  15. Potential impact of global warming on deciduous oak dieback caused by ambrosia fungus Raffaelea sp. carried by ambrosia beetle Platypus quercivorus (Coleoptera: Platypodidae) in Japan.

    PubMed

    Kamata, N; Kamata, N; Esaki, K; Kato, K; Igeta, Y; Wada, K

    2002-04-01

    Deciduous oak dieback in Japan has been known since the 1930s, but in the last ten years epidemics have intensified and spread to the island's western coastal areas. The symbiotic ambrosia fungus Raffaelea sp. is the causal agent of oak dieback, and is vectored by Platypus quercivorus (Murayama). This is the first example of an ambrosia beetle fungus that kills vigorous trees. Mortality of Quercus crispula was approximately 40% but much lower for associated species of Fagaceae, even though each species had a similar number of beetle attacks. It is likely that other oaks resistant to the fungus evolved under a stable relationship between the tree, fungus and beetle during a long evolutionary process. Quercus crispula was probably not part of this coevolution. This hypothesis was supported by the fact that P. quercivorus showed the least preference for Q. crispula yet exhibited highest reproductive success in this species. Therefore, P. quercivorus could spread more rapidly in stands with a high composition of Q. crispula. The present oak dieback epidemic in Japan probably resulted from the warmer climate that occurred from the late 1980s which made possible the fateful encounter of P. quercivorus with Q. cripsula by allowing the beetle to extend its distribution to more northerly latitudes and higher altitudes. Future global warming will possibly accelerate the overlapping of the distributions of P. quercivorus and Q. crispula with the result that oak dieback in Q. crispula will become more prevalent in Japan.

  16. Global genetic structure of the fungal grapevine pathogen Eutypa lata

    USDA-ARS?s Scientific Manuscript database

    The ascomycete fungus Eutypa lata is a trunk pathogen of cultivated grapevine (Vitis vinifera) in all major grape-growing regions of the world. Throughout its geographic range, it is considered a generalist pathogen that can complete its life cycle on a broad range of hosts. To decipher the cosmopol...

  17. A role for the asexual spores in infection of Fraxinus excelsior by the ash-dieback fungus Hymenoscyphus fraxineus

    PubMed Central

    Fones, Helen Nicola; Mardon, Charlotte; Gurr, Sarah Jane

    2016-01-01

    The invasive pathogen, ash dieback fungus Hymenoscyphus fraxineus, is spreading rapidly across Europe. It shows high levels of outcrossing and limited population structure, even at the epidemic front. The anamorphic (asexual) form produces prolific conidia, thought to function solely as spermatia (male gametes), facilitating gene flow between sympatric strains. Here, we show that conidia are capable of germination on ash leaves and in vitro, and can infect seedlings via leaves or soil. In leaves, germlings form structures resembling fruiting bodies. Additionally, H. fraxineus colonises ash debris and grows in soil in the absence of ash tissues. We propose an amended life-cycle in which wind-dispersed, insect-vectored or water-spread conidia infect ash and may sporulate in planta, as well as in forest debris. This amplifies inoculum levels of different strains in ash stands. In combination with their function as spermatia, conidia thus act to maximise gene flow between sympatric strains, including those originally present at low inoculum. Such mixing increases evolutionary potential, as well as enhancing the likelihood of gene introgression from closely-related strains or assimilation of further genetic diversity from parental Asian populations. This scenario increases the adaptability of H. fraxineus to new climates and, indeed, onto new host species. PMID:27694963

  18. Toxicity of extracellular proteins from Diplodia seriata and Neofusicoccum parvum involved in grapevine Botryosphaeria dieback.

    PubMed

    Bénard-Gellon, M; Farine, S; Goddard, M L; Schmitt, M; Stempien, E; Pensec, F; Laloue, H; Mazet-Kieffer, F; Fontaine, F; Larignon, P; Chong, J; Tarnus, C; Bertsch, C

    2015-03-01

    Botryosphaeria dieback, esca and Eutypa dieback are three economic major grapevine trunk diseases that cause severe yield reduction in vineyards worldwide. The frequency of disease symptoms has increased considerably over the past decade, and no efficient treatment is currently available to control these diseases. The different fungi associated with grapevine trunk diseases mainly induce necrotic wood and characteristic foliar symptoms. In this context, fungi virulence factors and host invasion are not well understood. We hypothesise that extracellular proteins produced by Diplodia seriata and Neofusicoccum parvum, two causal agents associated with Botryosphaeria dieback, are virulence factors responsible for the pathogenicity. In our previous work, we demonstrated that the total extracellular compounds produced by N. parvum induced more necrosis on Chardonnay calli and triggered a different defence gene expression pattern than those produced by D. seriata. Furthermore, this aggressiveness was not clearly correlated with the production of mellein, a characteristic phytotoxin of Botryosphaeriaceae, in our in vitro calli model. To characterise other potential virulence factors and to understand the mechanisms of host invasion by the fungus, we evaluated the profile, quantity and the impact of extracellular proteins produced by these fungi on Vitis vinifera calli necrosis and defence gene expression. Our results reveal that, under the same conditions, N. parvum produces more extracellular proteins and in higher concentrations than D. seriata. With Vitis vinifera cv. Chardonnay cells, we showed that equivalent concentrations of proteins secreted by N. parvum were more aggressive than those of D. seriata in producing necrosis and that they clearly induced more grapevine defence genes.

  19. Phenolic and heterocyclic metabolite profiles of the grapevine pathogen Eutypa lata.

    PubMed

    Mahoney, Noreen; Lardner, Richard; Molyneux, Russell J; Scott, Eileen S; Smith, Leverett R; Schoch, Thomas K

    2003-09-01

    The ascomycete Eutypa lata is the causative agent of eutypa dieback in grapevines, a serious economic problem in major wine grape producing areas. In order to develop a predictive, non-destructive assay for early detection of fungal infection, the phenolic metabolite profiles of 11 strains of E. lata grown on four different artificial growth media were analyzed by HPLC and their variability compared with growth on Cabernet Sauvignon grapevine wood and wood extracts. Six compounds were generally produced in significant amounts, namely eutypinol, eulatachromene, and eutypine and its benzofuran cyclization product, together with siccayne and eulatinol. The two most widely distributed and abundant metabolites were eutypinol and eulatachromene, which were present in 8 of the strains grown on grapewood aqueous extract fortified with sucrose. Metabolite production on grapevine extract was greatly enhanced relative to the artificial media, indicating that this native substrate provides optimal conditions and a more representative profile of the metabolites produced in the natural disease state. The primary metabolites were tested in a grapeleaf disc bioassay to establish their relative toxicity. Neither eutypinol nor siccayne were phytotoxic; eulatachromene, eulatinol, eutypine, and the benzofuran exhibited necrotic effects in the bioassay. The results indicate that eutypa dieback may be caused by several E. lata metabolites rather than a single compound.

  20. Water stress exacerbates the severity of Botryosphaeria dieback in grapevines infected by Neofusicoccum parvum

    USDA-ARS?s Scientific Manuscript database

    Botryosphaeria dieback (causal fungus Neofusicoccum parvum) is a detrimental grapevine trunk disease, causing internal wood degradation, killing shoots, and reducing yields. We examined the interactive effects of drought and N. parvum infection, common vineyard stresses, on wood-lesion development. ...

  1. Shoot dieback in pecan

    USDA-ARS?s Scientific Manuscript database

    Two shoot dieback maladies (SDM) of pecan [Carya illinoinensis (Wangenh.) C. Koch] are of unknown cause and can adversely affect canopy health. They occur during either early spring (SpSDM) or early summer (SuSDM). Field evaluation found that both maladies predominately occur on shoots retaining p...

  2. First report of Albizia lebbeck dieback caused by Scytalidium dimidiatum in Oman.

    PubMed

    Elshafie, Abdulkadir E; Ba-Omar, Taher

    2002-01-01

    Over 200 Albizia lebbeck trees at Sultan Qaboos University campus wilted and died. The symptoms were dieback of large branches due to infection by Scytalidium dimidiatum. The fungus has also infected Ficus benghalensis, F. carica, F. retusa, Thespesia populnea, Delonix regia and Peltophorum petrocarpum. This is the first report of the fungus in Oman and on A. lebbeck, T. populnea, D. regia and P. petrocarpum. The strain of this fungus has not been found to cause human disease in Oman.

  3. Climate change and the ash dieback crisis

    PubMed Central

    Goberville, Eric; Hautekèete, Nina-Coralie; Kirby, Richard R.; Piquot, Yves; Luczak, Christophe; Beaugrand, Grégory

    2016-01-01

    Beyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time. PMID:27739483

  4. Climate change and the ash dieback crisis.

    PubMed

    Goberville, Eric; Hautekèete, Nina-Coralie; Kirby, Richard R; Piquot, Yves; Luczak, Christophe; Beaugrand, Grégory

    2016-10-14

    Beyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time.

  5. Nuclear technology and forest dieback

    SciTech Connect

    Koenig, L. A.; Penzhorn, R. D.; Schuettelkopf, H.

    1985-01-01

    The possibility that forest dieback in the vicinity of nuclear power plants is due to the emission of radioactive materials was investigated. Damage was assumed to be caused by direct radiation by tritium as well as the production of O/sub 3/ and NO/sub x/ by radiochemical reactions and radioactive byproducts. 41 references.

  6. First Report of Dieback Caused by Lasiodiplodia theobromae in Strawberry Plants in Korea

    PubMed Central

    Park, Myung Soo; Kim, Hyun Sook; Kim, Tae il; Lee, Eun Mo; Park, Jong Dae; Kim, Hong Gi

    2016-01-01

    Dieback in strawberry (Seolhyang cultivar) was first observed during the nursery season (June to September) in the Nonsan area of Korea in the years 2012 and 2013. Initial disease symptoms included dieback on runners, as well as black rot on roots, followed by wilting and eventually blackened, necrotic discoloration in the crowns of daughter plants. A fungus isolated from the diseased roots, runners, and crowns is close to Lasiodiplodia theobromae based on morphological characteristics. Analysis of a combined dataset assembled from sequences of the internal transcribed spacer and translation elongation factor 1-alpha genes grouped nine fungal isolates with the type strain of L. theobromae. The isolates showed strong pathogenicity on strawberry cultivars Kumhyang, Seolhyang, and Akihimae, fulfilling Koch's postulates. Based on these results, the pathogen responsible for dieback on strawberry plants in Korea was identified as L. theobromae. PMID:28154491

  7. Dieback of Acacia koa in Hawaii: Ecological and pathological characteristics of affected stands

    USGS Publications Warehouse

    Anderson, R.C.; Gardner, D.E.; Daehler, C.C.; Meinzer, F.C.

    2002-01-01

    Koa (Acacia koa) is an endemic Hawaiian tree that serves as a keystone species in the upper elevation forests of all the main islands. In the Mauna Loa Strip area of Hawaii Volcanoes National Park, mature koa stands are suffering from an unexplained dieback that has increased in severity since it was first noticed approximately 25 years ago. The dieback is often evident in patches, and generally spreads within stands in a radial fashion from a localized infection center. Entire crowns of affected trees become wilted, with foliage gradually progressing from an apparent healthy to a completely chlorotic condition. Although most trees die soon after the onset of symptoms, some trees are able to survive crown death by producing epicormic shoots on the lower portions of the trunk. Previously published studies reported that a vascular wilt fungus (Fusarium oxysporum f. sp. koae) was associated with koa seeds and the rhizosphere of healthy and dieback-affected koa stands. The purpose of this study was to characterize the stand structure, soil conditions, and physiological condition of dieback-affected trees, and to assess the possible role of F. oxysporum f. sp. koae in the current dieback stands. This fungus was isolated from branches of symptomatic koa in dieback-affected stands and roots from healthy and dieback-affected stands. Possible differences in the pathogenicity and virulence of F. oxysporum f. sp. koae isolates obtained from the roots of healthy koa in unaffected stands and those from branches of dieback-affected koa were determined by greenhouse inoculations of koa seedlings. Healthy koa saplings in stands unaffected by dieback were also inoculated to determine if disease symptoms could be induced by inoculation of injured roots in the field. Both branch and root isolates were pathogenic; with the percent mortality of inoculated seedlings ranging from 30 to 60% for all isolates. Disease severity between branch and root isolates was not significantly different

  8. Dieback of Black Walnut Saplings (Pest Alert)

    Treesearch

    USDA Forest Service

    1977-01-01

    Top dieback of black walnut has been observed in 3-7 year old plantations in Illinois, Indiana, and North Carolina. In infected plantations, mortality has averaged 30% of the trees in one growing season. The most common symptom is basal sprouting of the affected trees. Other symptoms include wilted leaves, top dieback, and cankers on the main stem. Bark separation and...

  9. Tip-Dieback in Young Loblolly Pine Plantations

    Treesearch

    David B. South; Patrick Brown; Phillip M. Dougherty; Sonya Olykan; Brett Runion; Adya Singh; Malcolm Skinner

    2002-01-01

    Dieback of loblolly pine (Pinus taeda L.) has been observed in certain intensively managed plantations throughout the South. There are two distinct types of dieback; winter dieback usually appears in February and March while summer dieback appears in July (or later) and increases during the fall. Both types have very high levels of K in terminal...

  10. Wood-rotting basidiomycetes associated with grapevine trunk diseases in Texas

    USDA-ARS?s Scientific Manuscript database

    Grapevine trunk diseases Esca, Botryosphaeria dieback, Eutypa dieback, and Phomopsis dieback impact vineyards in all major grape-growing regions of the world. The causal pathogens (Phaeomoniella chlamydospora and Phaeoacremonium minimum, Neofusicoccum parvum, Eutypa lata, and Diaporthe ampelina, res...

  11. Vascular Streak Dieback of cacao in Southeast Asia detection and Melanesia: in planta detection of the pathogen and a new taxonomy

    USDA-ARS?s Scientific Manuscript database

    Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus described in a monotypic genus as Oncobasidium theobromae (syn. =Thanatephorus theobromae). The symptoms of the disease include green-spotted chloro...

  12. Response and resilience of Spartina alterniflora to sudden dieback

    USGS Publications Warehouse

    Marsh, Amanda; Blum, Linda K.; Christian, Robert R.; Ramsey III, Elijah W.; Rangoonwala, Amina

    2016-01-01

    We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however.

  13. Mangrove dieback during fluctuating sea levels.

    PubMed

    Lovelock, Catherine E; Feller, Ilka C; Reef, Ruth; Hickey, Sharyn; Ball, Marilyn C

    2017-05-10

    Recent evidence indicates that climate change and intensification of the El Niño Southern Oscillation (ENSO) has increased variation in sea level. Although widespread impacts on intertidal ecosystems are anticipated to arise from the sea level seesaw associated with climate change, none have yet been demonstrated. Intertidal ecosystems, including mangrove forests are among those ecosystems that are highly vulnerable to sea level rise, but they may also be vulnerable to sea level variability and extreme low sea level events. During 16 years of monitoring of a mangrove forest in Mangrove Bay in north Western Australia, we documented two forest dieback events, the most recent one being coincident with the large-scale dieback of mangroves in the Gulf of Carpentaria in northern Australia. Diebacks in Mangrove Bay were coincident with periods of very low sea level, which were associated with increased soil salinization of 20-30% above pre-event levels, leading to canopy loss, reduced Normalized Difference Vegetation Index (NDVI) and reduced recruitment. Our study indicates that an intensification of ENSO will have negative effects on some mangrove forests in parts of the Indo-Pacific that will exacerbate other pressures.

  14. Tree regeneration in black ash (Fraxinus nigra) stands exhibiting crown dieback in Minnesota

    Treesearch

    Brian J. Palik; Michael E. Ostry; Robert C. Venette; Ebrahim. Abdela

    2012-01-01

    Crown dieback and mortality of black ash (Fraxinus nigra) has been noted across the range of the species in North America for several decades. Causes of dieback and mortality are not definitive, but may be related to spring drought or excessive moisture. Where black ash is the dominant tree species in the forest, continued dieback and mortality may...

  15. Phytotoxic metabolites from Neofusicoccum parvum, a pathogen of Botryosphaeria dieback of grapevine.

    PubMed

    Abou-Mansour, Eliane; Débieux, Jean-Luc; Ramírez-Suero, Montserrat; Bénard-Gellon, Mélanie; Magnin-Robert, Maryline; Spagnolo, Alessandro; Chong, Julie; Farine, Sibylle; Bertsch, Christohpe; L'Haridon, Floriane; Serrano, Mario; Fontaine, Florence; Rego, Cecilia; Larignon, Philippe

    2015-07-01

    Liquid chromatography-diode array screening of the organic extract of the cultures of 13 isolates of the fungus Neofusicoccum parvum, the main causal agent of botryosphaeria dieback of grapevine, showed similar metabolites. One strain was selected for further chemical studies and led to the isolation and characterisation of 13 metabolites. Structures were elucidated through spectroscopic analyses, including one- and two-dimensional NMR and mass spectrometry, and through comparison to literature data. The isolated compounds belong to four different chemical families: five metabolites, namely, (-)-terremutin (1), (+)-terremutin hydrate (2), (+)-epi-sphaeropsidone (3) (-)-4-chloro-terremutin hydrate (4) and(+)-4-hydroxysuccinate-terremutin hydrate (5), belong to the family of dihydrotoluquinones; two metabolites, namely, (6S,7R) asperlin (6) and (6R,7S)-dia-asperlin (7), belong to the family of epoxylactones; four metabolites, namely, (R)-(-)-mellein (8), (3R,4R)-4-hydroxymellein (9), (3R,4S)-4-hydroxymellein (10) (R)(-)-3-hydroxymellein (11), belong to the family of dihydroisocoumarins; and two of the metabolites, namely, 6-methyl-salicylic acid (12) and 2-hydroxypropyl salicylic acid (13), belong to the family of hydroxybenzoic acids. We determined the phytotoxic activity of the isolated metabolites through a leaf disc assay and the expression of defence-related genes in Vitis vinifera cells cv. Chardonnay cultured with (-)-terremutin (1), the most abundant metabolite. Finally, analysis of the brown stripes of grapevine wood from plants showing botryosphaeria dieback symptoms revealed the presence of two of the isolated phytotoxins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Stress triggered tree diseases, The diebacks and declines

    Treesearch

    David R. Houston

    1981-01-01

    Traditionally, dieback and decline diseases of trees have been described in generalities, attributed to unknown or mysterious causes, and thought to be beyond the scope of human intervention. This publication provides a basis for understanding and coping with these diseases. Discussed are concepts relating to: (1) diagnosing the factors that initiate the disease; (2)...

  17. Survey of Sycamore Plantations for Canker, Leaf Scorch, and Dieback

    Treesearch

    T. H. Filer; D. T. Cooper; R. J. Collins; R. Wolfe

    1975-01-01

    Twenty-six sycamore plantations surveyed in Louisiana, Mississippi, Arkansas, and Tennessee in 1973 had leaf scorch symptoms; cankers caused mor tality in six lower Mississippi Delta s tands. Symptoms of the disease are leaf scorch, top diebac k, and trunk canker. No trees under 4 years old had dieback, and none unde r 6 years old had lethal trunk canker.

  18. Japanese oak wilt as a newly emerged forest pest in Japan: why does a symbiotic ambrosia fungus kill host trees?

    Treesearch

    Naoto Kamata; Koujiro Esaki; Kenryu Kato; Hisahito Oana; Yutaka Igeta; Ryotaro Komura

    2007-01-01

    Japanese oak wilt (JOW) has been known since the 1930s, but in the last 15 years epidemics have intensified and spread to the island's western coastal areas. The symbiotic ambrosia fungus Raffaelea quercivora is the causal agent of oak dieback, and is vectored by Platypus quercivorus (Murayama). This is the first example of an...

  19. An economic case for early adoption of preventative practices for management of grapevine trunk diseases

    USDA-ARS?s Scientific Manuscript database

    The trunk diseases Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback, significantly decrease yields and vineyard longevity in California. Despite high disease prevalence and substantial yield impacts, most growers routinely wait to adopt preventative practices until vineyards are ...

  20. Preventative disease management and grower decision making: A case study of California wine-grape growers

    USDA-ARS?s Scientific Manuscript database

    We examined the adoption and timing of preventative grapevine trunk disease-management practices among agricultural decision-makers (growers) in California. These diseases (Botryosphaeria dieback, Esca, Eutypa dieback, Phomopsis dieback) significantly diminish vineyard productivity and longevity. Gi...

  1. Differential responses of three grapevine cultivars to Botryosphaeria dieback.

    PubMed

    Spagnolo, Alessandro; Magnin-Robert, Maryline; Alayi, Tchilabalo Dilezitoko; Cilindre, Clara; Schaeffer-Reiss, Christine; Van Dorsselaer, Alain; Clément, Christophe; Larignon, Philippe; Ramirez-Suero, Montserrat; Chong, Julie; Bertsch, Christophe; Abou-Mansour, Eliane; Fontaine, Florence

    2014-10-01

    Botryosphaeria dieback is a fungal grapevine trunk disease that represents a threat for viticulture worldwide due to the decreased production of affected plants and their premature death. This dieback is characterized by a typical wood discoloration called brown stripe. Herein, a proteome comparison of the brown striped wood from Botryosphaeria dieback-affected standing vines cultivars Chardonnay, Gewurztraminer, and Mourvèdre was performed. The transcript analysis for 15 targeted genes and the quantification of both total phenolics and specific stilbenes were also performed. Several pathogenesis-related proteins and members of the antioxidant system were more abundant in the brown striped wood of the three cultivars, whereas other defense-related proteins were less abundant. Additionally, total phenolics and some specific stilbenes were more accumulated in the brown striped wood. Strongest differences among the cultivars concerned proteins of the primary metabolism, which looked to be particularly impaired in the brown striped wood of 'Chardonnay'. Low abundance of some proteins involved in defense response probably contributes to make global response insufficient to avoid the symptom development. The differential susceptibility of the three grapevine cultivars could be linked to the diverse expression of various proteins involved in defense response, stress tolerance, and metabolism.

  2. Forest dieback in Russia: Causes, distribution and implications for the future

    SciTech Connect

    Krankina, O.N. . Dept. of Forest Science); Dixon, R.K. . Environmental Research Lab.); Shvidenko, A.Z. ); Selikhovkin, A.V. )

    1994-12-01

    The Russian Federation with its great expanse of forest land plays a prominent role in the global environment. Over 20% of the world's forest resources and about one-half of boreal forest are located on Russian territory. Forest dieback following natural or anthropogenic disturbance is a significant factor in boreal forest dynamics. The leading causes of dieback are forest fires and adverse weather conditions. Although natural disturbance accounts for the greater part of dieback, anthropogenic factors are significant in increasing susceptibility of forests to stress natural agents. In industrially developed regions air pollution, harvesting, major constructions, and mining are directly responsible for forest dieback. Since factors of forest dieback are closely interrelated a single cause of dieback is often impossible to establish. In 1991 the largest proportion of forest dieback occurred in the southern part of Europe-Urals and West Siberia as well as in the Far East. Data on forest dieback is available only for monitored forest, which constitutes 60% of the total forest land in Russia, so, these values should be regarded as fairly conservative. Decline of forests is estimated to affect additionally about 2 [times] 10[sup 6] ha per year. Projected global climate change is likely to dramatically increase forest decline and dieback.

  3. Double pruning to prevent trunk diseases in Washington vineyards

    USDA-ARS?s Scientific Manuscript database

    Trunk diseases (aka wood-canker diseases) present a serious challenge to vineyard productivity and longevity. There are four main trunk diseases: Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback. The causal fungi (e.g., Eutypa lata, Neofusicoccum parvum) establish chronic infectio...

  4. Association mapping and marker-assisted selection of the lettuce dieback resistance gene Tvr1.

    USDA-ARS?s Scientific Manuscript database

    Lettuce (Lactuca saliva L.) is susceptible to dieback, a soilborne disease caused by two viruses from the family Tombusviridae. Susceptibility to dieback is widespread in romaine and leaf-type lettuce, while modern iceberg cultivars are resistant to this disease. Resistance in iceberg cultivars is c...

  5. Sweetgum blight and dieback of associated hardwoods on the Beltsville Experimental Forest in Maryland

    Treesearch

    R. H. Fenton; J. D. Diller

    1960-01-01

    In 1948, a dieback of sweetgum (Liquidambar styraciflua L.) was first observed and reported at College Park, Md. Since then, surveys made from Maryland southward have shown that the dieback, now termed sweetgum blight, has increased in both distribution and severity and now occurs throughout much of the species range. No pathogenic organism has been found to be...

  6. Fraxinus nigra (black ash) dieback in Minnesota: Regional variation and potential contributing factors

    Treesearch

    Brian J. Palik; Michael E. Ostry; Robert C. Venette; Ebrahim Abdela

    2011-01-01

    Extensive tree dieback is a recurrent issue in many regions. Crown dieback of Fraxinus nigra Marsh. (black ash; brown ash) in the northeastern and north central United States is an example. F. nigra is a widely distributed hardwood that is often the dominant species in wetland forests from Manitoba to Newfoundland and West...

  7. Climate-induced forest dieback: An escalating global phenomenon?

    USGS Publications Warehouse

    Allen, C.D.

    2009-01-01

    The impacts of growing human populations and economies are both rapidly and directly transforming forests in many areas. However, little known are the pervasive effects of the ongoing climatic changes on the condition and status of forests around the world. Global patterns are now evident with the global tree mortality that is now above its usual mortality levels as it is affected by drought and heat-related forest stress and dieback. Thus, the possibility of an increased risk of climate-induced dieback is now being considered within many of the forests and woodlands of today. A focus will be given on the climatic water stress that is driven by both drought and warm temperatures. However, studying the trends in forest mortality and predictions has its limitations with such a number of information gaps and scientific uncertainties. First is the absence of an adequate global data on forest health status, followed by the fact that only a few tree species have the researchers an adequate quantitative knowledge with regards to its physiological thresholds of individual tree mortality from chronic or acute water stress. Lastly, the adequate knowledge of the feedback and non-linear interactions between climate-induced forest stress and other climate-related disturbance processes are lacking among the current scientists.

  8. Fungus Amongus

    ERIC Educational Resources Information Center

    Wakeley, Deidra

    2005-01-01

    This role-playing simulation is designed to help teach middle level students about the typical lifecycle of a fungus. In this interactive simulation, students assume the roles of fungi, spores, living and dead organisms, bacteria, and rain. As they move around a playing field collecting food and water chips, they discover how the organisms…

  9. Fungus Amongus

    ERIC Educational Resources Information Center

    Wakeley, Deidra

    2005-01-01

    This role-playing simulation is designed to help teach middle level students about the typical lifecycle of a fungus. In this interactive simulation, students assume the roles of fungi, spores, living and dead organisms, bacteria, and rain. As they move around a playing field collecting food and water chips, they discover how the organisms…

  10. Abstracts from "Coastal Marsh Dieback in the Northern Gulf of Mexico: Extent, Causes, Consequences, and Remedies

    USGS Publications Warehouse

    Stewart, Robert E.; Proffitt, C. Edward; Charron, Tammy Michelle

    2001-01-01

    In the spring of 2000, scientists discovered a new and unprecedented loss of salt marsh vegetation in coastal Louisiana and other areas along the northern coast of the Gulf of Mexico. This dieback of salt marsh vegetation, sometimes called the brown marsh phenomenon', primarily involved the rapid browning and dieback of smooth cordgrass (Spanina alterniflora). Coastal Louisiana has already undergone huge, historical losses of coastal marsh due to both human-induced and natural factors, and the current overall rate of wetland loss (25-35 sq mi 65-91 SQ KM each year) stands to threaten Louisiana's coastal ecosystem, infrastructure, and economy. On January 11-12, 2001, individuals from Federal and State agencies, universities, and the private sector met at the conference 'Coastal Marsh Dieback in the Northern Gulf of Mexico: Extent, Causes, Consequences, and Remedies' to discuss and share information shout the marsh dieback. Presentations discussed trends in the progress of dieback during the summer of 2000 and in environmental conditions occurring at field study sites, possible causes including drought and Mississippi low flow' conditions, changes in soil conditions (salinity, the bioavailability of metals, pathogens, etc.), the potential for wetland loss that could occur if above and below normality occurs and is sustained over an extended period, advanced techniques for tracking the dieback via aerial photography and remote sensing, linkages of marsh hydrology to the dieback, and mechanisms of modeling dieback and recovery. In addition, presentations were made regarding development of a web site to facilitate information sharing and progress in preparation for requests for proposals based on an emergency appropriation by the U.S. Congress. All findings tended to support the idea that the dieback constituted a continuing environmental emergency and research and natural resource management efforts should be expended accordingly.

  11. Forest die-back modified plankton recovery from acidic stress.

    PubMed

    Vrba, Jaroslav; Kopáček, Jiří; Fott, Jan; Nedbalová, Linda

    2014-03-01

    We examined long-term data on water chemistry of Lake Rachelsee (Germany) following the changes in acidic depositions in central Europe since 1980s. Despite gradual chemical recovery of Rachelsee, its biological recovery was delayed. In 1999, lake recovery was abruptly reversed by a coincident forest die-back, which resulted in elevated terrestrial export of nitrate and ionic aluminum lasting ~5 years. This re-acidification episode provided unique opportunity to study plankton recovery in the rapidly recovering lake water after the abrupt decline in nitrate leaching from the catchment. There were sudden changes both in lake water chemistry and in plankton biomass structure, such as decreased bacterial filaments, increased phytoplankton biomass, and rotifer abundance. The shift from dominance of heterotrophic to autotrophic organisms suggested their substantial release from severe phosphorus stress. Such a rapid change in plankton structure in a lake recovering from acidity has, to the best of our knowledge, not been previously documented.

  12. Marsh dieback, loss, and recovery mapped with satellite optical, airborne polarimetric radar, and field data

    USGS Publications Warehouse

    Ramsey, Elijah W.; Rangoonwala, Amina; Chi, Zhaohui; Jones, Cathleen E.; Bannister, Terri

    2014-01-01

    Landsat Thematic Mapper and Satellite Pour l'Observation de la Terre (SPOT) satellite based optical sensors, NASA Uninhabited Aerial Vehicle synthetic aperture radar (UAVSAR) polarimetric SAR (PolSAR), and field data captured the occurrence and the recovery of an undetected dieback that occurred between the summers of 2010, 2011, and 2012 in the Spartina alterniflora marshes of coastal Louisiana. Field measurements recorded the dramatic biomass decrease from 2010 to 2011 and a biomass recovery in 2012 dominated by a decrease of live biomass, and the loss of marsh as part of the dieback event. Based on an established relationship, the near-infrared/red vegetation index (VI) and site-specific measurements delineated a contiguous expanse of marsh dieback encompassing 6649.9 ha of 18,292.3 ha of S. alterniflora marshes within the study region. PolSAR data were transformed to variables used in biophysical mapping, and of this variable suite, the cross-polarization HV (horizontal send and vertical receive) backscatter was the best single indicator of marsh dieback and recovery. HV backscatter exhibited substantial and significant changes over the dieback and recovery period, tracked measured biomass changes, and significantly correlated with the live/dead biomass ratio. Within the context of regional trends, both HV and VI indicators started higher in pre-dieback marshes and exhibited substantially and statistically higher variability from year to year than that exhibited in the non-dieback marshes. That distinct difference allowed the capturing of the S. alterniflora marsh dieback and recovery; however, these changes were incorporated in a regional trend exhibiting similar but more subtle biomass composition changes.

  13. Friend or foe? Biological and ecological traits of the European ash dieback pathogen Hymenoscyphus fraxineus in its native environment

    PubMed Central

    Cleary, Michelle; Nguyen, Diem; Marčiulynienė, Diana; Berlin, Anna; Vasaitis, Rimvys; Stenlid, Jan

    2016-01-01

    Hymenoscyphus fraxineus, an introduced ascomycete fungus and primary causal agent of European ash dieback, was investigated on Fraxinus mandshurica trees in its native range in Primorye region of Far East Russia. This evidence is the first report of H. fraxineus on healthy, asymptomatic F. mandshurica trees. High-throughput sequencing revealed 49 distinct fungal taxa associated with leaves of F. mandshurica, 12 of which were identified to species level. Phyllosphere fungal assemblages were similar among sites despite being largely geographically distant. Many organisms comprising the foliar fungal community on F. mandshurica in Far East Russia have similarity to those reported inhabiting F. excelsior in Europe based on previous studies. However, Mycosphaerella sp., the most dominant species in this study and detected in nearly all samples, was associated only with F. mandshurica. Genetic diversity of H. fraxineus was significantly higher in the Far East Russian population than in Europe. In contrast to its aggressive behaviour on Fraxinus excelsior in Europe, H. fraxineus appears to be a benign associate of indigenous F. mandshurica that initially induces quiescent and asymptomatic infections in healthy trees prior to active host colonization normally associated with modification of host tissue during senescence. PMID:26900083

  14. Friend or foe? Biological and ecological traits of the European ash dieback pathogen Hymenoscyphus fraxineus in its native environment

    NASA Astrophysics Data System (ADS)

    Cleary, Michelle; Nguyen, Diem; Marčiulynienė, Diana; Berlin, Anna; Vasaitis, Rimvys; Stenlid, Jan

    2016-02-01

    Hymenoscyphus fraxineus, an introduced ascomycete fungus and primary causal agent of European ash dieback, was investigated on Fraxinus mandshurica trees in its native range in Primorye region of Far East Russia. This evidence is the first report of H. fraxineus on healthy, asymptomatic F. mandshurica trees. High-throughput sequencing revealed 49 distinct fungal taxa associated with leaves of F. mandshurica, 12 of which were identified to species level. Phyllosphere fungal assemblages were similar among sites despite being largely geographically distant. Many organisms comprising the foliar fungal community on F. mandshurica in Far East Russia have similarity to those reported inhabiting F. excelsior in Europe based on previous studies. However, Mycosphaerella sp., the most dominant species in this study and detected in nearly all samples, was associated only with F. mandshurica. Genetic diversity of H. fraxineus was significantly higher in the Far East Russian population than in Europe. In contrast to its aggressive behaviour on Fraxinus excelsior in Europe, H. fraxineus appears to be a benign associate of indigenous F. mandshurica that initially induces quiescent and asymptomatic infections in healthy trees prior to active host colonization normally associated with modification of host tissue during senescence.

  15. Salt Marsh Dieback: An overview of recent events in the US

    NASA Astrophysics Data System (ADS)

    Alber, Merryl; Swenson, Erick M.; Adamowicz, Susan C.; Mendelssohn, Irving A.

    2008-10-01

    This paper provides an overview of the marsh dieback events that have been observed along the east and gulf coasts of the U.S. over the past decade. It is likely that some of the recently reported changes in marsh vegetation were affected by physical or biotic disturbances that are known to generate bare areas, such as overgrazing or wrack smothering. Other areas may be experiencing a state change such as that caused by long-term changes in sea level. However, sites in many areas are not readily explained by these causes and are considered to have experienced "sudden dieback." In such cases, there are observations that the above-ground plant material thinned or browned or, in some cases, failed to re-emerge in the spring; the dieback occurred over a period of months and usually affected multiple sites within the area; and there is evidence that these events are transient (through successful transplants or natural regrowth/recovery), although some areas take years to recover. We explored the potential linkage of dieback with drought (as characterized by the Palmer Severity Drought Index), and found that there is evidence for an association in the southeast (GA and SC) and the Gulf (LA), but not in the mid-Atlantic (DE, VA) or northeast (ME, RI, CT). We also review the evidence for potential causes of sudden dieback, including changes in soil chemistry, fungal pathogens, top-down consumer controls, and multiple stressors. There is currently no single explanation that can be applied to recent dieback. We highlight the need for the development of improved diagnostics that will allow us to better classify dieback areas and provide evidence for (or against) potential causes.

  16. Acute salt marsh dieback in the Mississippi River deltaic plain: A drought-induced phenomenon?

    USGS Publications Warehouse

    McKee, K.L.; Mendelssohn, I.A.; Materne, M.D.

    2004-01-01

    Aims Extensive dieback of salt marsh dominated by the perennial grass Spartina alterniflora occurred throughout the Mississippi River deltaic plain during 2000. More than 100,000 ha were affected, with 43,000 ha severely damaged. The aim of this work was to determine if sudden dieback could have been caused by a coincident drought and to assess the significance of this event with respect to long-term changes in coastal vegetation. Location Multiple dieback sites and reference sites were established along 150 km of shoreline in coastal Louisiana, USA. Methods Aerial and ground surveys were conducted from June 2000 to September 2001 to assess soil conditions and plant mortality and recovery. Results Dieback areas ranged in size from???300 m2-5 km2 in area with 50-100% mortality of plant shoots and rhizomes in affected zones. Co-occurring species such as Avicennia germinans (black mangrove) and Juncus roemerianus (needlegrass rush) were unaffected. Historical records indicate that precipitation, river discharge, and mean sea level were unusually low during the previous year. Although the cause of dieback is currently unknown, plant and soil characteristics were consistent with temporary soil desiccation that may have reduced water availability, increased soil salinity, and/or caused soil acidification (via pyrite oxidation) and increased uptake of toxic metals such as Fe or Al. Plant recovery 15 months after dieback was variable (0-58% live cover), but recovering plants were vigorous and indicated no longlasting effects of the dieback agent. Main conclusions These findings have relevance for global change models of coastal ecosystems that predict vegetation responses based primarily on long-term increases in sea level and submergence of marshes. Our results suggest that large-scale changes in coastal vegetation may occur over a relatively short time span through climatic extremes acting in concert with sea-level fluctuations and pre-existing soil conditions. ?? 2004

  17. Canopy reflectance related to marsh dieback onset and progression in Coastal Louisiana

    USGS Publications Warehouse

    Ramsey, Elijah W.; Rangoonwala, A.

    2006-01-01

    In this study, we extended previous work linking leaf spectral changes, dieback onset, and progression of Spartina alterniflora marshes to changes in site-specific canopy reflectance spectra. First, we obtained canopy reflectance spectra (approximately 20 m ground resolution) from the marsh sites occupied during the leaf spectral analyses and from additional sites exhibiting visual signs of dieback. Subsequently, the canopy spectra were analyzed at two spectral scales: the first scale corresponded to whole-spectra sensors, such as the NASA Earth Observing-1 (EO-1) Hyperion, and the second scale corresponded to broadband spectral sensors, such as the EO-1 Advanced Land Imager and the Landsat Enhanced Thematic Mapper. In the whole-spectra analysis, spectral indicators were generated from the whole canopy spectra (about 400 nm to 1,000 nm) by extracting typical dead and healthy marsh spectra, and subsequently using them to determine the percent composition of all canopy reflectance spectra. Percent compositions were then used to classify canopy spectra at each field site into groups exhibiting similar levels of dieback progression ranging from relatively healthy to completely dead. In the broadband reflectance analysis, blue, green, red, red-edge, and near infrared (NIR) spectral bands and NIR/green and NIR/red transforms were extracted from the canopy spectra. Spectral band and band transform indicators of marsh dieback and progression were generated by relating them to marsh status indicators derived from classifications of the 35 mm slides collected at the same time as the canopy reflectance recordings. The whole spectra and broadband spectral indicators were both able to distinguish (a) healthy marsh, (b) live marsh impacted by dieback, and (c) dead marsh, and they both provided some discrimination of dieback progression. Whole-spectra resolution sensors like the EO-1 Hyperion, however, offered an enhanced ability to categorize dieback progression. ?? 2006

  18. Effects of endophytic fungi on the ash dieback pathogen.

    PubMed

    Schlegel, Markus; Dubach, Vivanne; von Buol, Larissa; Sieber, Thomas N

    2016-09-01

    While Hymenoscyphus fraxineus causes dieback of the European ash (Fraxinus excelsior), flowering ash (F. ornus) appears resistant to the pathogen. To date, contributions of endophytic fungi to host resistance are unknown. The following hypotheses were tested: (i) endophytic fungi enhance the resistance of F. excelsior to the pathogen; (ii) resistance of F. ornus relies on its community of endophytic fungi. Two experiments were performed. (i) The effect of exudates of ash endophytes on the germination rate of H. fraxineus ascospores was studied in vitro Isolates of abundant Fraxinus leaf endophytes, such as Venturia fraxini, Paraconiothyrium sp., Boeremia exigua, Kretzschmaria deusta and Neofabraea alba inhibited ascospore germination. (ii) Ash seedlings inoculated in a climate chamber, with fungi sporulating on the previous year's leaf litter, were exposed to natural infections by the pathogen present in the forest. Non-inoculated seedlings were used as controls. Venturia spp. dominated the inoculated endophyte 'communities'. Subsequent exposure to H. fraxineus led to infection of F. excelsior leaves by the pathogen, but no differences in health status between pre-inoculated and non-inoculated seedlings were detected. Fraxinus ornus leaves experienced a low infection rate, independent of their colonization by endophytic fungi. These results did not support either hypothesis. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Plant dieback under exceptional drought driven by elevation, not by plant traits, in Big Bend National Park, Texas, USA

    PubMed Central

    Waring, Elizabeth F.

    2014-01-01

    In 2011, Big Bend National Park, Texas, USA, experienced the most severe single year drought in its recorded history, resulting in significant plant mortality. We used this event to test how perennial plant response to drought varied across elevation, plant growth form and leaf traits. In October 2010 and October 2011, we measured plant cover by species at six evenly-spaced elevations ranging from Chihuahuan desert (666 m) to oak forest in the Chisos mountains (1,920 m). We asked the following questions: what was the relationship between elevation and stem dieback and did susceptibility to drought differ among functional groups or by leaf traits? In 2010, pre-drought, we measured leaf mass per area (LMA) on each species. In 2011, the percent of canopy dieback for each individual was visually estimated. Living canopy cover decreased significantly after the drought of 2011 and dieback decreased with elevation. There was no relationship between LMA and dieback within elevations. The negative relationship between proportional dieback and elevation was consistent in shrub and succulent species, which were the most common growth forms across elevations, indicating that dieback was largely driven by elevation and not by species traits. Growth form turnover did not influence canopy dieback; differences in canopy cover and proportional dieback among elevations were driven primarily by differences in drought severity. These results indicate that the 2011 drought in Big Bend National Park had a large effect on communities at all elevations with average dieback for all woody plants ranging from 8% dieback at the highest elevation to 83% dieback at lowest elevations. PMID:25083346

  20. Evaluation of Sugar Maple Dieback in the Upper Great Lakes Region and Development of a Forest Health Youth Education Program

    ERIC Educational Resources Information Center

    Bal, Tara L.

    2013-01-01

    Sugar Maple, "Acer saccharum" Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as…

  1. Evaluation of Sugar Maple Dieback in the Upper Great Lakes Region and Development of a Forest Health Youth Education Program

    ERIC Educational Resources Information Center

    Bal, Tara L.

    2013-01-01

    Sugar Maple, "Acer saccharum" Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as…

  2. Towards quantifying uncertainty in predictions of Amazon 'dieback'.

    PubMed

    Huntingford, Chris; Fisher, Rosie A; Mercado, Lina; Booth, Ben B B; Sitch, Stephen; Harris, Phil P; Cox, Peter M; Jones, Chris D; Betts, Richard A; Malhi, Yadvinder; Harris, Glen R; Collins, Mat; Moorcroft, Paul

    2008-05-27

    Simulations with the Hadley Centre general circulation model (HadCM3), including carbon cycle model and forced by a 'business-as-usual' emissions scenario, predict a rapid loss of Amazonian rainforest from the middle of this century onwards. The robustness of this projection to both uncertainty in physical climate drivers and the formulation of the land surface scheme is investigated. We analyse how the modelled vegetation cover in Amazonia responds to (i) uncertainty in the parameters specified in the atmosphere component of HadCM3 and their associated influence on predicted surface climate. We then enhance the land surface description and (ii) implement a multilayer canopy light interception model and compare with the simple 'big-leaf' approach used in the original simulations. Finally, (iii) we investigate the effect of changing the method of simulating vegetation dynamics from an area-based model (TRIFFID) to a more complex size- and age-structured approximation of an individual-based model (ecosystem demography). We find that the loss of Amazonian rainforest is robust across the climate uncertainty explored by perturbed physics simulations covering a wide range of global climate sensitivity. The introduction of the refined light interception model leads to an increase in simulated gross plant carbon uptake for the present day, but, with altered respiration, the net effect is a decrease in net primary productivity. However, this does not significantly affect the carbon loss from vegetation and soil as a consequence of future simulated depletion in soil moisture; the Amazon forest is still lost. The introduction of the more sophisticated dynamic vegetation model reduces but does not halt the rate of forest dieback. The potential for human-induced climate change to trigger the loss of Amazon rainforest appears robust within the context of the uncertainties explored in this paper. Some further uncertainties should be explored, particularly with respect to the

  3. Relationship between crown dieback and drought in the southeastern United States

    Treesearch

    Michael K. Crosby; Zhaofei Fan; Martin A. Spetich; Theodor D. Leininger; Xingang. Fan

    2012-01-01

    Forest Health and Monitoring (FHM) and Palmer's Drought Severity Index (PDSI) data were obtained for 11 states in the southeastern United States to assess the relationship between drought and crown dieback. Correlation analyses were performed at the species group and ecoregion levels within the study area. The results indicate a negative correlation between...

  4. Predicting forest dieback in Maine, USA: a simple model based on soil frost and drought

    Treesearch

    Allan N.D. Auclair; Warren E. Heilman; Blondel. Brinkman

    2010-01-01

    Tree roots of northern hardwoods are shallow rooted, winter active, and minimally frost hardened; dieback is a winter freezing injury to roots incited by frost penetration in the absence of adequate snow cover and exacerbated by drought in summer. High soil water content greatly increases conductivity of frost. We develop a model based on the sum of z-scores of soil...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  6. Dieback and episodic mortality of Cercidium microphyllum (foothill paloverde), a dominant Sonoran Desert tree

    USGS Publications Warehouse

    Bowers, Janice E.; Turner, R.M.

    2001-01-01

    Past and current dieback of Cercidium microphyllum, a dominant, drought-deciduous tree in the Sonoran Desert, was investigated at Tumamoc Hill, Tucson, Arizona, USA. Logistic regression predicted that the odds of a Cercidium plant being alive should decrease with increasing circumference, association with the columnar cactus Carnegiea gigantea, and occurrence on steep slopes. Slope azimuth, parasitization by Phoradendron californicum, and distance to nearest Cercidium within 5 m did not significantly affect the odds of survival. Carnegiea was a source of background mortality rather than a primary cause of dieback. Of the >1,000 living and dead plants sampled, 7.7% had died within the past 5 to 7 years. An additional 12.8% died in the more distant past. Diebacks tended to occur during severe deficits in annual, especially summer, rain. More than half of the dead plants in the sample were ???50 cm in girth. In current and past diebacks on Tumamoc Hill, it seems likely that severe drought interacted with natural senescence of an aging population, weakening large, old trees and hastening their deaths.

  7. Relationship of shoot dieback in pecan to fungi and fruiting stress

    USDA-ARS?s Scientific Manuscript database

    Two shoot dieback maladies (SDM) of pecan [Carya illinoinensis (Wangenh.) C. Koch] are of unknown cause and can adversely affect tree canopy health. They occur during either early spring (SpSDM) or early summer (SuSDM). Field studies found that both maladies predominately occur on shoots retaining...

  8. Interactive Effects of Water Stress and Neofusicoccum Parvum on Botryosphaeria Dieback of Grapevines

    USDA-ARS?s Scientific Manuscript database

    The relationship between vascular pathogens and water stress is an important topic in California agriculture, given successive years of drought and restrictions on water use. We examined the interactive effects of water stress and Neofusicoccum parvum on severity of Botryosphaeria dieback of grapevi...

  9. Searching for early-warning signals of impending dieback and death in Mediterranean oaks

    NASA Astrophysics Data System (ADS)

    Colangelo, Michele; Ripullone, Francesco; Julio Camarero, Jesus; De Micco, Veronica; Gazol, Antonio; Gentilesca, Tiziana; Borghetti, Marco

    2017-04-01

    In recent decades, forest dieback episodes have been recorded worldwide affecting different tree species. In particular, several cases of widespread dieback and increased mortality rates have been described for Mediterranean oak (Quercus spp.) species. These dieback cases are revealing the high vulnerability of Mediterranean oaks, manifested as a loss in tree vigour (leaf shedding, canopy and shoot dieback), growth decline and sometimes tree death, as a consequence of temperatures rising at unprecedented rates and drying trends. However, in the wake of the so-called 'oak decline phenomenon', the attention on these species has generally been limited, perhaps because they are often regarded as well-adapted to the dry conditions typical of Mediterranean areas. Indeed, according to recent studies, the reduced size, the ability to sprout and the anisohydric behavior of Mediterranean oak species (reduced control of water loss and high stomatal conductance rates) would make them better adapted to withstand heat and drought stress then taller and non-sprouting isohydric species (e.g. conifer, with strict control of water loss by closing stomata). Here, we investigated the vulnerability of Mediterranean oaks by comparing neighboring living and recently dead trees in species with low (Q. pubescens), intermediate (Q. cerris, Q. frainetto) and high (Q. robur) sensitivity to water shortage. We analysed changes in tree vigour using tree-ring width and functional wood anatomical traits as proxies to search for early-warning signals of dieback, in connection with the main proposed dieback mechanisms (hydraulic failure and/or carbon starvation). We also modeled the probability of tree death as a function of tree size (diameter, height) by quantifying recent changes in growth and wood anatomy along tree-ring series. Contrary to the general concept that trees tend to experience increasing cavitation risk with increasing height, our studies show that smaller oaks are more prone to die

  10. A multi-proxy assessment of dieback causes in a Mediterranean oak species.

    PubMed

    Colangelo, Michele; Camarero, J Julio; Battipaglia, Giovanna; Borghetti, Marco; De Micco, Veronica; Gentilesca, Tiziana; Ripullone, Francesco

    2017-05-01

    Drought stress causes forest dieback that is often explained by two interrelated mechanisms, namely hydraulic failure and carbon starvation. However, it is still unclear which functional and structural alterations, related to these mechanisms, predispose to dieback. Here we apply a multi-proxy approach for the characterization of tree structure (radial growth, wood anatomy) and functioning (δ13C, δ18O and non-structural carbohydrates (NSCs)) in tree rings before and after drought-induced dieback. We aim to discriminate which is the main mechanism and to assess which variables can act as early-warning proxies of drought-triggered damage. The study was tailored in southern Italy in two forests (i.e., San Paolo (SP) and Oriolo (OR)) where declining and non-declining trees of a ring-porous tree species (Quercus frainetto Ten.) showing anisohydric behavior coexist. Both stands showed growth decline in response to warm and dry spring conditions, although the onset of dieback was shifted between them (2002 in SP and 2009 in OR). Declining trees displayed a sharp growth drop after this onset with reductions of 49% and 44% at SP and OR sites, respectively. Further, contrary to what we expected, declining trees showed a lower intrinsic water-use efficiency compared with non-declining trees after the dieback onset (with reductions of 9.7% and 5.6% at sites SP and OR, respectively), due to enhanced water loss through transpiration, as indicated by the lower δ18O values. This was more noticeable at the most drought-affected SP stand. Sapwood NSCs did not differ between declining and non-declining trees, indicating no carbon starvation in affected trees. Thus, the characterized structural and functional alterations partially support the hydraulic failure mechanism of dieback. Finally, we show that growth data are reliable early-warning proxies of drought-triggered dieback. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please

  11. Vascular Streak Dieback of cacao in Southeast Asia and Melanesia: in planta detection of the pathogen and a new taxonomy.

    PubMed

    Samuels, Gary J; Ismaiel, Adnan; Rosmana, Ade; Junaid, Muhammad; Guest, David; McMahon, Peter; Keane, Philip; Purwantara, Agus; Lambert, Smilja; Rodriguez-Carres, Marianela; Cubeta, Marc A

    2012-01-01

    Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus Oncobasidium theobromae (syn. =Thanatephorus theobromae). The most characteristic symptoms of the disease are green-spotted leaf chlorosis or, commonly since about 2004, necrotic blotches, followed by senescence of leaves beginning on the second or third flush behind the shoot apex, and blackening of infected xylem in the vascular traces at the leaf scars resulting from the abscission of infected leaves. Eventually the shoot apex is killed and infected branches die. In susceptible cacao the fungus may grow through the xylem down into the main stem and kill a mature cacao tree. Infections in the stem of young plants prior to the formation of the first 3-4 lateral branches usually kill the plant. Basidiospores released from corticioid basidiomata developed on leaf scars or along cracks in the main vein of infected leaves infect young leaves. The pathogen commonly infects cacao but there are rare reports from avocado. As both crops are introduced to the region, the pathogen is suspected to occur asymptomatically in native vegetation. The pathogen is readily isolated but cultures cannot be maintained. In this study, DNA was extracted from pure cultures of O. theobromae obtained from infected cacao plants sampled from Indonesia. The internal transcribed spacer region (ITS), consisting of ITS1, 5.8S ribosomal RNA and ITS2, and a portion of nuclear large subunit (LSU) were sequenced. Phylogenetic analysis of ITS sequences placed O. theobromae sister to Ceratobasidium anastomosis groups AG-A, AG-Bo, and AG-K with high posterior probability. Therefore the new combination Ceratobasidium theobromae is proposed. A PCR-based protocol was developed to detect and identify C. theobromae in plant tissue of cacao enabling early detection of the pathogen in plants. A second species of Ceratobasidium, Ceratobasidium ramicola

  12. Shoot dieback during prolonged drought in Ceanothus (Rhamnaceae) chaparral of California: a possible case of hydraulic failure.

    PubMed

    Davis, Stephen D; Ewers, Frank W; Sperry, John S; Portwood, Kimberly A; Crocker, Michelle C; Adams, Gerard C

    2002-05-01

    Progressive diebacks of outer canopy branchlets of Ceanothus crassifolius were repeatedly observed after rainless periods up to 9 mo in duration in the Santa Monica Mountains of southern California. Mean xylem pressures of branchlets near the end of drought were as low as -11.2 MPa (N = 22) with a mean of about 60 dead branchlets per shrub. Inoculation (N = 15) with three species of fungi previously isolated from the same population of C. crassifolius did not promote dieback, suggesting that the observed decline was not fungal induced, as had been proposed. Further, at least 50% of healthy-appearing twigs, without symptoms of dieback, contained isolatible endophytic fungi. We used a centrifugal force method to determine the range of xylem pressure causing cavitation (vulnerability curves) for branchlets (N = 12) and roots (N = 16). We combined vulnerability curves with soil texture data (N = 6) into a water transport model that estimated the critical values (P(Lcrit)) of leaf xylem pressure associated with the loss of water from soil to foliage. Maximum P(Lcrit) was between -10 and -11 MPa and within the range of minimum measured xylem pressures of branchlets during drought and dieback. Branchlet dieback correlated with seasonal declines in xylem pressure in concert with declining safety margins from hydraulic failure. Symptoms of dieback were duplicated in the field by partially severing stem xylem that normally supplied branchlets with water. Taken together, these results indicate that loss of hydraulic conductance to foliage was the probable cause of the observed dieback in C. crassifolius. Partial dieback of peripheral branchlets, and its attendant reduction in evaporative surface area, may be a last-resort mechanism for whole-plant water conservation and drought survival in this species.

  13. Response of Vitis vinifera cell cultures to Eutypa lata and Trichoderma atroviride culture filtrates: expression of defence-related genes and phenotypes.

    PubMed

    Mutawila, C; Stander, C; Halleen, F; Vivier, M A; Mostert, L

    2017-03-01

    Cell suspension cultures of Vitis vinifera cv. Dauphine berries were used to study the response to the vascular pathogen, Eutypa lata, in comparison with a biological control agent, Trichoderma atroviride, that was previously shown to be effective in pruning wound protection. The expression of genes coding for enzymes of the phenylpropanoid pathway and pathogenesis-related (PR) proteins was profiled over a 48-h period using quantitative reverse transcriptase PCR. The cell cultures responded to elicitors of both fungi with a hypersensitive-like response that lead to a decrease in cell viability. Similar genes were triggered by both the pathogen and biocontrol agent, but the timing patterns and magnitude of expression was dependent on the specific fungal elicitor. Culture filtrates of both fungi caused upregulation of phenylalanine ammonia-lyase (PAL), 4-coumaroyl Co-A ligase (CCo-A) and stilbene synthase (STS), and a downregulation of chalcone synthase (CHS) genes. The pathogen filtrate caused a biphasic pattern in the upregulation of PAL and STS genes which was not observed in cells treated with filtrates of the biocontrol agent. Analytical assays showed significantly higher total phenolic content and chitinolytic enzyme activity in the cell cultures treated with the T. atroviride filtrate compared to the pathogen filtrate. These results corresponded well to the higher expression of PAL and chitinase class IV genes. The response of the cell cultures to T. atroviride filtrate provides support for the notion that the wound protection by the biocontrol agent at least partially relies on the induction of grapevine resistance mechanisms.

  14. Characterizing the marsh dieback spectral response at the plant and canopy level with hyperspectral and temporal remote sensing data

    USGS Publications Warehouse

    Ramsey, E.; Rangoonwala, A.

    2008-01-01

    We describe newly developed remote sensing tools to map the localized occurrences and regional distribution of the marsh dieback in coastal Louisiana (Fig. 1). As a final goal of our research and development, we identified what spectral features accompanied the onset of dieback and could be directly linked to the optical signal measured at the satellite. In order to accomplish our research goal, we carried out two interlinked objectives. First, we determined the spectral features within the hyperspectral spectra of the impacted plant that could be linked to the spectral return. This was accomplished by measuring the differences in leaf optical properties of impacted and non impacted marsh plants in such a way that the measured differences could be linked to the dieback onset and progression. The spectral analyses were constrained to selected wavelengths (bands of reflectance data) historically associated with changes in leaf composition and structure caused by changes in the plant biophysical environment. Second, we determined what changes in the canopy reflectance (canopy signal sensed at the satellite) could be linked to dieback onset and progression. Third, we transformed a suite of six Landsat Thematic Mapper images collected before, during, and in the final stages of dieback to maps of dieback occurrences. ??2008 IEEE.

  15. Molecular markers for tolerance of European ash (Fraxinus excelsior) to dieback disease identified using Associative Transcriptomics

    PubMed Central

    Harper, Andrea L.; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Havlickova, Lenka; Li, Yi; Trick, Martin; Fraser, Fiona; Wang, Lihong; Fellgett, Alison; Sollars, Elizabeth S. A.; Janacek, Sophie H.; Downie, J. Allan; Buggs, Richard. J. A.; Kjær, Erik Dahl; Bancroft, Ian

    2016-01-01

    Tree disease epidemics are a global problem, impacting food security, biodiversity and national economies. The potential for conservation and breeding in trees is hampered by complex genomes and long lifecycles, with most species lacking genomic resources. The European Ash tree Fraxinus excelsior is being devastated by the fungal pathogen Hymenoscyphus fraxineus, which causes ash dieback disease. Taking this system as an example and utilizing Associative Transcriptomics for the first time in a plant pathology study, we discovered gene sequence and gene expression variants across a genetic diversity panel scored for disease symptoms and identified markers strongly associated with canopy damage in infected trees. Using these markers we predicted phenotypes in a test panel of unrelated trees, successfully identifying individuals with a low level of susceptibility to the disease. Co-expression analysis suggested that pre-priming of defence responses may underlie reduced susceptibility to ash dieback. PMID:26757823

  16. Detection and classification of ash dieback on large-scale color aerial photographs

    Treesearch

    Ralph J. Croxton

    1966-01-01

    Aerial color photographs were taken at two scales over ash stands in New York State that were infected with ash dieback. Three photo interpreters then attempted to distinguish ash trees from other hardwoods and classify their disease condition. The scale of 1:7,920 was too small to permit accurate identification, but accuracy at the scale 1:1,584 was fair (60 to 70...

  17. Changes in surface water chemistry caused by natural forest dieback in an unmanaged mountain catchment.

    PubMed

    Kopáček, J; Fluksová, H; Hejzlar, J; Kaňa, J; Porcal, P; Turek, J

    2017-04-15

    Ionic and nutrient compositions of throughfall, tributaries and lake outlet were analysed in the Plešné catchment-lake system (an unmanaged mountain forest in Central Europe) from 1997 to 2016. The aim was to evaluate changes in surface water chemistry after natural forest dieback. In the 2004-2008, 93% of the Norway spruce trees were killed by bark beetle outbreak, and all dead biomass remained in the catchment. Forest dieback changed the chemistry of all water fluxes, and the magnitude, timing, and duration of these changes differed for individual water constituents. The most pronounced decreases in throughfall concentrations occurred for K(+), dissolved organic carbon (DOC), Ca(2+) and Mg(2+), i.e. elements mostly originating from canopy leaching, while concentrations of NH4(+) and soluble reactive phosphorus (SRP) remained almost unaffected. In tributaries, the most rapid changes were increases in NO3(-), K(+), H(+) and ionic aluminium (Ali) concentrations, while terrestrial export of DOC and P forms started more slowly. Immediately after the forest dieback, increase in NO3(-) concentrations was delayed by elevated DOC availability in soils. NO3(-) became the dominant anion, with maximum concentrations up to 346μeqL(-1) within 5-7years after the bark beetle outbreak, and then started to decrease. Terrestrial exports of Ali, K(+), H(+), Mg(2+), and Ca(2+) accompanied NO3(-) leaching, but their trends differed due to their different sources. Elevated losses of SRP, DOC, and dissolved organic nitrogen continued until the end of the study. In the lake, microbial processes significantly decreased concentrations of NO3(-), organic acid anions, H(+) and Ali, and confounded the chemical trends observed in tributaries. Our results suggest that terrestrial losses of elements and the deterioration of waters after forest dieback are less pronounced in unmanaged than managed (clear-cut) catchments. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Interactions across spatial scales among forest dieback, fire, and erosion in northern New Mexico landscapes

    USGS Publications Warehouse

    Allen, Craig D.

    2007-01-01

    Ecosystem patterns and disturbance processes at one spatial scale often interact with processes at another scale, and the result of such cross-scale interactions can be nonlinear dynamics with thresholds. Examples of cross-scale pattern-process relationships and interactions among forest dieback, fire, and erosion are illustrated from northern New Mexico (USA) landscapes, where long-term studies have recently documented all of these disturbance processes. For example, environmental stress, operating on individual trees, can cause tree death that is amplified by insect mortality agents to propagate to patch and then landscape or even regional-scale forest dieback. Severe drought and unusual warmth in the southwestern USA since the late 1990s apparently exceeded species-specific physiological thresholds for multiple tree species, resulting in substantial vegetation mortality across millions of hectares of woodlands and forests in recent years. Predictions of forest dieback across spatial scales are constrained by uncertainties associated with: limited knowledge of species-specific physiological thresholds; individual and site-specific variation in these mortality thresholds; and positive feedback loops between rapidly-responding insect herbivore populations and their stressed plant hosts, sometimes resulting in nonlinear “pest” outbreak dynamics. Fire behavior also exhibits nonlinearities across spatial scales, illustrated by changes in historic fire regimes where patch-scale grazing disturbance led to regional-scale collapse of surface fire activity and subsequent recent increases in the scale of extreme fire events in New Mexico. Vegetation dieback interacts with fire activity by modifying fuel amounts and configurations at multiple spatial scales. Runoff and erosion processes are also subject to scale-dependent threshold behaviors, exemplified by ecohydrological work in semiarid New Mexico watersheds showing how declines in ground surface cover lead to non

  19. Mapping past salt marsh dieback in South Carolina's North Inlet-Winyah Bay National Estuarine Research Reserve using remote sensing

    NASA Astrophysics Data System (ADS)

    Miller, G. J.; Morris, J. T.; Wang, C.

    2016-12-01

    : Brown marsh, or marsh dieback, occurs when portions of salt marsh either thin in vegetation, or completely die. The exact extent and locations of marsh dieback are often unknown due to the difficulty accessing salt marshes for in-field observations. Remote sensing provides a synoptic view of Earth surfaces and can help highlight vegetation thinning or loss in large spatial extents. In 2002-2003 there was a marsh dieback event that affected South Carolina. While most research centered on causes of the event, its extent has not been mapped yet. Using satellite data to extract the Normalized Difference Vegetation Index (NDVI) for years 1999 and 2003, this study calculated the change in vegetation greenness within a salt marsh in North Inlet, Georgetown, South Carolina. Results showed where the marsh increased in vegetation and where vegetation was lost/thinned. The northern section of the marsh experienced the most dieback, with the southern end of the mash experienced a gain in vegetation. Though the causes of this dieback event are unknown, there are a few potential causes. The regions of greatest lost often occur with lower marsh elevations and, South Carolina experienced a prolonged extreme drought during 2001. The regions of vegetation loss may be due to the marsh not keeping up with sea level rise, stress from the drought, or a combination of the two.

  20. Fungus Infections: Tinea

    MedlinePlus

    ... cat, or from exposure to fungus in the soil. Itchy red scaly patches come up anywhere the ... Truth 12/19/2013 Osteopathic Training Statement Online Surveys About AOCD The AOCD was recognized in 1958 ...

  1. A Climate Change Threshold for Forest Dieback in the African Sahel

    NASA Astrophysics Data System (ADS)

    Gonzalez, P.; Tucker, C. J.; Sy, H.

    2007-12-01

    Increases in human greenhouse gas emissions to the atmosphere have increased global sea surface temperatures. Reinforced by a reduction in vegetation cover in the African Sahel, warmer sea surface temperatures have reduced rainfall in the Sahel by up to 30% in the 20th Century. In Senegal, annual precipitation fell to below one standard deviation of the 148 year mean for 5 years in the period 1968-1973. Although the region had experienced high historic variability in precipitation, the 1968-1973 drought crossed a climate threshold for agriculture that caused famine and human death. Sahel, Sudan, and Guinean ecosystems also crossed a climate threshold of aridity in an abrupt, nonlinear manner. The long-term decrease in precipitation caused extensive forest dieback and a latitudinal shift of the Sahel, Sudan, and Guinean ecological zones. The range of xeric forest species has expanded and mesic species have retracted southward towards areas of higher precipitation. Field inventories of tree species richness show declines in local biodiversity across the Sahel. Analyses of 1954 and 1989 aerial photographs and 2002 1-meter resolution IKONOS satellite images of three 200 km2 areas in Senegal and Mauritania also show declines in the density of trees of height > 3 m. Forest dieback fuels three positive feedback mechanisms: reduction of the evapotranspiration inputs necessary for the northward advance of the summer monsoon rains that sustain vegetation and forestall desertification, increases in the greenhouse gas emissions that cause the reduction in rainfall, and reduction of the forest biodiversity that strengthens ecosystem resilience to long-term drought. The interaction of climate change, desertification, and loss of biodiversity, as well as the complex social, economic, and political factors that lead to forest dieback and other ecological changes in the Sahel present difficulties in monitoring and foreseeing future threshold behavior. Nevertheless, any reduction in

  2. Outbreaks of Yuzu Dieback in Goheung Area: Possible Causes Deduced from Weather Extremes.

    PubMed

    Kim, Kwang-Hyung; Kim, Gyoung Hee; Son, Kyeong In; Koh, Young Jin

    2015-09-01

    Starting in 2012, severe diebacks usually accompanied by abundant gum exudation have occurred on yuzu trees in Goheung-gun, Jeonnam Province, where severely affected trees were occasionally killed. On-farm surveys were conducted at 30 randomly-selected orchards located at Pungyang-myeon, Goheung-gun, and the resulting disease incidences were 18.5% and 39.6% for dieback and gumming symptoms, respectively. Black spots on branches and leaves also appeared on infected trees showing a typical dieback symptom. Morphological and molecular identifications of the isolated fungal organisms from lesions on the symptomatic leaves and branches revealed that they are identical to Phomopsis citri, known to cause gummosis. In order to find the reason for this sudden epidemic, we investigated the weather conditions that are exclusively distinct from previous years, hypothesizing that certain weather extremes might have caused the severe induction of pre-existing disease for yuzu. There were two extreme temperature drops beyond the yuzu's cold hardiness limit right after an abnormally-warm-temperature-rise during the winter of 2011-12, which could cause severe frost damage resulting in mechanical injuries and physiological weakness to the affected trees. Furthermore, there was an increased frequency of strong wind events, seven times in 2012 compared to only a few times in the previous years, that could also lead to extensive injuries on branches. In conclusion, we estimated that the possible damages by severe frost and frequent strong wind events during 2012 could cause the yuzu trees to be vulnerable to subsequent fungal infection by providing physical entries and increasing plant susceptibility to infections.

  3. Outbreaks of Yuzu Dieback in Goheung Area: Possible Causes Deduced from Weather Extremes

    PubMed Central

    Kim, Kwang-Hyung; Kim, Gyoung Hee; Son, Kyeong In; Koh, Young Jin

    2015-01-01

    Starting in 2012, severe diebacks usually accompanied by abundant gum exudation have occurred on yuzu trees in Goheung-gun, Jeonnam Province, where severely affected trees were occasionally killed. On-farm surveys were conducted at 30 randomly-selected orchards located at Pungyang-myeon, Goheung-gun, and the resulting disease incidences were 18.5% and 39.6% for dieback and gumming symptoms, respectively. Black spots on branches and leaves also appeared on infected trees showing a typical dieback symptom. Morphological and molecular identifications of the isolated fungal organisms from lesions on the symptomatic leaves and branches revealed that they are identical to Phomopsis citri, known to cause gummosis. In order to find the reason for this sudden epidemic, we investigated the weather conditions that are exclusively distinct from previous years, hypothesizing that certain weather extremes might have caused the severe induction of pre-existing disease for yuzu. There were two extreme temperature drops beyond the yuzu’s cold hardiness limit right after an abnormally-warm-temperature-rise during the winter of 2011–12, which could cause severe frost damage resulting in mechanical injuries and physiological weakness to the affected trees. Furthermore, there was an increased frequency of strong wind events, seven times in 2012 compared to only a few times in the previous years, that could also lead to extensive injuries on branches. In conclusion, we estimated that the possible damages by severe frost and frequent strong wind events during 2012 could cause the yuzu trees to be vulnerable to subsequent fungal infection by providing physical entries and increasing plant susceptibility to infections. PMID:26361477

  4. Research promises earlier warning for grapevine canker diseases

    USDA-ARS?s Scientific Manuscript database

    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...

  5. The role of pest control advisors in managing grapevine trunk diseases: a survey of perceptions of practice efficacy and trends in recommendations

    USDA-ARS?s Scientific Manuscript database

    Trunk diseases (Botryosphaeria dieback, Esca, Eutypa dieback, Phomopsis dieback) significantly limit vineyard productivity. The causal fungi establish chronic wood infections, which accumulate over time. Symptoms do not become obvious until the vineyard is 6-8 years old. Post-infection practices (vi...

  6. Making the economic case for early adoption of practices to prevent trunk diseases

    USDA-ARS?s Scientific Manuscript database

    All California vineyards become infected at some point by one or more of the following trunk diseases: Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback. The symptoms do not become obvious until the vineyard is approximately 6-8 years old. Trunk diseases limit the productive life o...

  7. Identifying economic hurdles of early adoption of preventative practices: The case of trunk diseases in California winegrape vineyards

    USDA-ARS?s Scientific Manuscript database

    Trunk diseases including Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback, present a serious challenge to grape growers around the world. In California, where approximately 90% of US winegrape production occurs, most vineyards over age 10 are likely infected and yield losses in su...

  8. Estimating Amazonian rainforest stability and the likelihood for large-scale forest dieback

    NASA Astrophysics Data System (ADS)

    Rammig, Anja; Thonicke, Kirsten; Jupp, Tim; Ostberg, Sebastian; Heinke, Jens; Lucht, Wolfgang; Cramer, Wolfgang; Cox, Peter

    2010-05-01

    Annually, tropical forests process approximately 18 Pg of carbon through respiration and photosynthesis - more than twice the rate of anthropogenic fossil fuel emissions. Current climate change may be transforming this carbon sink into a carbon source by changing forest structure and dynamics. Increasing temperatures and potentially decreasing precipitation and thus prolonged drought stress may lead to increasing physiological stress and reduced productivity for trees. Resulting decreases in evapotranspiration and therefore convective precipitation could further accelerate drought conditions and destabilize the tropical ecosystem as a whole and lead to an 'Amazon forest dieback'. The projected direction and intensity of climate change vary widely within the region and between different scenarios from climate models (GCMs). In the scope of a World Bank-funded study, we assessed the 24 General Circulation Models (GCMs) evaluated in the 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4) with respect to their capability to reproduce present-day climate in the Amazon basin using a Bayesian approach. With this approach, greater weight is assigned to the models that simulate well the annual cycle of rainfall. We then use the resulting weightings to create probability density functions (PDFs) for future forest biomass changes as simulated by the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJmL) to estimate the risk of potential Amazon rainforest dieback. Our results show contrasting changes in forest biomass throughout five regions of northern South America: If photosynthetic capacity and water use efficiency is enhanced by CO2, biomass increases across all five regions. However, if CO2-fertilisation is assumed to be absent or less important, then substantial dieback occurs in some scenarios and thus, the risk of forest dieback is considerably higher. Particularly affected are regions in the central Amazon basin. The range of

  9. Widespread dieback of riparian trees on a dammed ephemeral river and evidence of local mitigation by tributary flows

    PubMed Central

    Mulligan, Mark; Harrison, Xavier A.; Henschel, Joh R.; Pettorelli, Nathalie; Cowlishaw, Guy

    2016-01-01

    Ephemeral rivers act as linear oases in drylands providing key resources to people and wildlife. However, not much is known about these rivers’ sensitivities to human activities. We investigated the landscape-level determinants of riparian tree dieback along the Swakop River, a dammed ephemeral river in Namibia, focusing on the native ana tree (Faidherbia albida) and the invasive mesquite (Prosopis spp.). We surveyed over 1,900 individual trees distributed across 24 sites along a 250 km stretch of the river. General linear mixed models were used to test five hypotheses relating to three anthropogenic threats: river flow disruption from damming, human settlement and invasive species. We found widespread dieback in both tree populations: 51% mortality in ana tree, with surviving trees exhibiting 18% canopy death (median); and 26% mortality in mesquite, with surviving trees exhibiting 10% canopy death. Dieback in the ana tree was most severe where trees grew on drier stretches of the river, where tributary flow was absent and where mesquite grew more abundantly. Dieback in the mesquite, a more drought-tolerant taxon, did not show any such patterns. Our findings suggest that dieback in the ana tree is primarily driven by changes in river flow resulting from upstream dam creation and that tributary flows provide a local buffer against this loss of main channel flow. The hypothesis that the invasive mesquite may contribute to ana tree dieback was also supported. Our findings suggest that large dams along the main channels of ephemeral rivers have the ability to cause widespread mortality in downstream riparian trees. To mitigate such impacts, management might focus on the maintenance of natural tributary flows to buffer local tree populations from the disruption to main channel flow. PMID:27812420

  10. Widespread dieback of riparian trees on a dammed ephemeral river and evidence of local mitigation by tributary flows.

    PubMed

    Douglas, Caitlin M S; Mulligan, Mark; Harrison, Xavier A; Henschel, Joh R; Pettorelli, Nathalie; Cowlishaw, Guy

    2016-01-01

    Ephemeral rivers act as linear oases in drylands providing key resources to people and wildlife. However, not much is known about these rivers' sensitivities to human activities. We investigated the landscape-level determinants of riparian tree dieback along the Swakop River, a dammed ephemeral river in Namibia, focusing on the native ana tree (Faidherbia albida) and the invasive mesquite (Prosopis spp.). We surveyed over 1,900 individual trees distributed across 24 sites along a 250 km stretch of the river. General linear mixed models were used to test five hypotheses relating to three anthropogenic threats: river flow disruption from damming, human settlement and invasive species. We found widespread dieback in both tree populations: 51% mortality in ana tree, with surviving trees exhibiting 18% canopy death (median); and 26% mortality in mesquite, with surviving trees exhibiting 10% canopy death. Dieback in the ana tree was most severe where trees grew on drier stretches of the river, where tributary flow was absent and where mesquite grew more abundantly. Dieback in the mesquite, a more drought-tolerant taxon, did not show any such patterns. Our findings suggest that dieback in the ana tree is primarily driven by changes in river flow resulting from upstream dam creation and that tributary flows provide a local buffer against this loss of main channel flow. The hypothesis that the invasive mesquite may contribute to ana tree dieback was also supported. Our findings suggest that large dams along the main channels of ephemeral rivers have the ability to cause widespread mortality in downstream riparian trees. To mitigate such impacts, management might focus on the maintenance of natural tributary flows to buffer local tree populations from the disruption to main channel flow.

  11. Characterisation of Phomopsis spp. associated with die-back of rooibos (Aspalathus linearis) in South Africa.

    PubMed

    van Rensburg, Johan C Janse; Lamprecht, Sandra C; Groenewald, Johannes Z; Castlebury, Lisa A; Crous, Pedro W

    2006-01-01

    Die-back of rooibos (Aspalathus linearis) causes substantial losses in commercial Aspalathus plantations in South Africa. In the past, the disease has been attributed to Phomopsis phaseoli (teleomorph: Diaporthe phaseolorum). Isolates obtained from diseased plants, however, were highly variable with regard to morphology and pathogenicity. The aim of the present study was thus to identify the Phomopsis species associated with die-back of rooibos. Isolates were subjected to DNA sequence comparisons of the internal transcribed spacer region (ITS1, 5.8S, ITS2) and partial sequences of the translation elongation factor-1 alpha gene. Furthermore, isolates were also compared in glasshouse inoculation trials on 8-mo-old potted plants to evaluate their pathogenicity. Five species were identified, of which D. aspalathi (formerly identified as D. phaseolorum or D. phaseolorum var. meridionalis) proved to be the most virulent, followed by D. ambigua, Phomopsis theicola, one species of Libertella and Phomopsis, respectively, and a newly described species, P. cuppatea. A description is also provided for D. ambigua based on a newly designated epitype specimen.

  12. Phylogeny and pathogenicity of Lasiodiplodia species associated with dieback of mango in Peru.

    PubMed

    Rodríguez-Gálvez, Edgar; Guerrero, Pakita; Barradas, Carla; Crous, Pedro W; Alves, Artur

    2017-04-01

    Mango, which is an important tropical fruit crop in the region of Piura (Peru), is known to be prone to a range of diseases caused by Lasiodiplodia spp. The aim of this study was to evaluate the incidence and prevalence of mango dieback in the region of Piura, and to identify the species of Lasiodiplodia associated with the disease and evaluate their pathogenicity towards mango. Mango dieback was present in all orchards surveyed but incidence varied with location. Identification of fungal isolates was based on morphological and cultural characteristics as well as sequence data of the rDNA internal transcribed spacer region (ITS) and translation elongation factor 1-alpha gene (tef1-α). The following Lasiodiplodia species were identified: Lasiodiplodia brasiliense, Lasiodiplodia egyptiacae (for which the new combination Lasiodiplodia laeliocattleyae is introduced), Lasiodiplodia iraniensis, Lasiodiplodia pseudotheobromae, Lasiodiplodia theobromae, and a Lasiodiplodia sp. Individual and combined gene genealogies suggest that this Lasiodiplodia sp. is possibly a hybrid of Lasiodiplodia citricola and Lasiodiplodia parva. Apart from Lasiodiplodia theobromae, which was the most prevalent species, all other species are newly reported from Peru. Moreover, L. iraniensis is reported for the first time on mango. Inoculation trials of mango plants confirmed Koch's postulates, and revealed differences in aggressiveness among species and isolates. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Association mapping and marker-assisted selection of the lettuce dieback resistance gene Tvr1

    PubMed Central

    2009-01-01

    Background Lettuce (Lactuca saliva L.) is susceptible to dieback, a soilborne disease caused by two viruses from the family Tombusviridae. Susceptibility to dieback is widespread in romaine and leaf-type lettuce, while modern iceberg cultivars are resistant to this disease. Resistance in iceberg cultivars is conferred by Tvr1 - a single, dominant gene that provides durable resistance. This study describes fine mapping of the resistance gene, analysis of nucleotide polymorphism and linkage disequilibrium in the Tvr1 region, and development of molecular markers for marker-assisted selection. Results A combination of classical linkage mapping and association mapping allowed us to pinpoint the location of the Tvr1 resistance gene on chromosomal linkage group 2. Nine molecular markers, based on expressed sequence tags (EST), were closely linked to Tvr1 in the mapping population, developed from crosses between resistant (Salinas and Salinas 88) and susceptible (Valmaine) cultivars. Sequencing of these markers from a set of 68 cultivars revealed a relatively high level of nucleotide polymorphism (θ = 6.7 × 10-3) and extensive linkage disequilibrium (r2 = 0.124 at 8 cM) in this region. However, the extent of linkage disequilibrium was affected by population structure and the values were substantially larger when the analysis was performed only for romaine (r2 = 0.247) and crisphead (r2 = 0.345) accessions. The association mapping approach revealed that one of the nine markers (Cntg10192) in the Tvr1 region matched exactly with resistant and susceptible phenotypes when tested on a set of 200 L. sativa accessions from all horticultural types of lettuce. The marker-trait association was also confirmed on two accessions of Lactuca serriola - a wild relative of cultivated lettuce. The combination of three single-nucleotide polymorphisms (SNPs) at the Cntg10192 marker identified four haplotypes. Three of the haplotypes were associated with resistance and one of them was always

  14. Crowdsourcing genomic analyses of ash and ash dieback – power to the people

    PubMed Central

    2013-01-01

    Ash dieback is a devastating fungal disease of ash trees that has swept across Europe and recently reached the UK. This emergent pathogen has received little study in the past and its effect threatens to overwhelm the ash population. In response to this we have produced some initial genomics datasets and taken the unusual step of releasing them to the scientific community for analysis without first performing our own. In this manner we hope to ‘crowdsource’ analyses and bring the expertise of the community to bear on this problem as quickly as possible. Our data has been released through our website at oadb.tsl.ac.uk and a public GitHub repository. PMID:23587306

  15. Can forest dieback and tree death be predicted by prior changes in wood anatomy?

    NASA Astrophysics Data System (ADS)

    Colangelo, Michele; Julio Camarero, Jesus; De Micco, Veronica; Borghetti, Marco; Gentilesca, Tiziana; Sanchez-Salguero, Raul; Ripullone, Francesco

    2017-04-01

    Climate warming is expected to amplify drought stress resulting in more intense and widespread dieback episodes and increasing mortality rates. Studies on quantitative wood anatomy and dendrochronology have demonstrated their potential to supply useful information on the causes of tree decline, although this approach is basically observational and retrospective. Moreover, the long-term reconstruction of wood anatomical features, strictly linked to the evolution of xylem anatomy plasticity through time, allow investigating hydraulic adjustments of trees. In this study, we analyzed wood-anatomical variables in two Italian oak forests where recent episodes of dieback and mortality have been reported. We analyzed in coexisting now-dead and living trees the following wood-anatomical variables: annual tree-ring area, earlywood (EW) and latewood (LW) areas, absolute and relative (%) areas occupied by vessels in the EW and LW, EW and LW vessel areas, EW and LW vessel density and vessel diameter classification. We also calculated the hydraulic diameter (Dh) for all vessels measured within each ring by weighting individual conduit diameters to correspond to the average Hagen-Poiseuille lumen theoretical hydraulic conductivity for a vessel size. Wood-anatomical analyses showed that declining and dead trees were more sensitive to drought stress compared to non declining trees, indicating different susceptibility to water shortage between trees. Dead trees did not form earlywood vessels with smaller lumen diameter than surviving trees but tended to form wider latewood vessels with a higher percentage of vessel area. We discuss the results and implications focusing on those proved more sensitive to the phenomena of decline and mortality.

  16. New species of Fusarium associated with dieback of Spartina alterniflora in Atlantic salt marshes.

    PubMed

    Elmer, Wade H; Marra, Robert E

    2011-01-01

    Sudden vegetation dieback (SVD) is the loss of smooth cordgrass (Spartina alterniflora) along intertidal creeks in salt marshes of the Atlantic and Gulf states. The underlying cause of SVD remains unclear, but earlier work suggested a contributing role for Fusarium spp. in Louisiana. This report investigated whether these or other Fusarium species were associated with S. alterniflora dieback in mid- to north-Atlantic states. Isolations from seven SVD sites yielded 192 isolates of Fusarium spp., with more than 75% isolated from aboveground tissue. Most isolates (88%) fell into two undescribed morphospecies (MS) distinguished from each other by macroconidial shape, phialide ontogeny and growth rates. Pathogenicity tests on wound-inoculated S. alterniflora stems and seedling roots revealed that isolates in MS1 were more virulent than those in MS2 but no single isolate caused plant mortality. No matches to known species of Fusarium were revealed by DNA sequence queries of translation elongation factor 1-α (tef1) sequences. A phylogenetic analysis of partial sequences of three genes, β-tubulin (β-tub), calmodulin (cal) and tef1, was conducted on representative isolates from MS1 (n = 20) and MS2 (n = 18); it provided strong evidence that the MS1 isolates form a clade that represents a heretofore undescribed species, which we designate Fusarium palustre sp. nov. Isolates from the more variable MS2 clustered with the F. incarnatum-equiseti species complex as F. cf. incarnatum. Although a strong association exists between both species and declining S. alterniflora in SVD sites, neither appears to play a primary causal role in SVD. However, our findings suggest that F. palustre might play an important secondary role in the ecological disruption of the salt marshes.

  17. Salt marsh dieback in coastal Louisiana: survey of plant and soil conditions in Barataria and Terrebonne basins, June 2000-September 2001

    USGS Publications Warehouse

    McKee, Karen L.; Mendelssohn, Irving A.; Materne, Michael D.

    2006-01-01

    Sudden and extensive dieback of the perennial marsh grass, Spartina alterniflora Loisel (smooth cordgrass), which dominates regularly flooded salt marshes along the Gulf of Mexico and Atlantic coastlines, occurred in the coastal zone of Louisiana. The objectives of this study were to assess soil and plant conditions in dieback areas of the Barataria-Terrebonne estuarine system as well as vegetative recovery during and after this dieback event. Multiple dieback sites were examined along 100 km of shoreline from the Atchafalaya River to the Mississippi River during the period from June 2000 through September 2001. The species primarily affected was S. alterniflora; sympatric species such as Avicennia germinans (L.) Stearn (black mangrove) and Juncus roemerianus Scheele (needlegrass rush) showed no visible signs of stress. The pattern of marsh dieback was distinctive with greatest mortality in the marsh interior, suggesting a correlation with local patterns of soil chemistry and/or hydrology. Little or no expansion of dieback occurred subsequent to the initial event, and areas with 50 percent or less mortality in the fall of 2000 had completely recovered by April 2001. Recovery was slower in interior marshes with 90 percent or greater mortality initially. However, regenerating plants in dieback areas showing some recovery were robust, and reproductive output was high, indicating that the causative agent was no longer present and that post-dieback soil conditions were actually promoting plant growth. Stands of other species within or near some dieback sites remained largely unchanged or expanded (A. germinans) into the dead salt marsh. The cause of the dieback is currently unknown. Biotic agents and excessive soil waterlogging/high sulfide were ruled out as primary causes of this acute event, although they could have contributed to overall plant stress and/or interacted with the primary agent to cause plant mortality. Our observations over the 15 month study

  18. SM09A and SM09B: Romaine Lettuce Breeding Lines Resistant to Dieback and with Improved Shelf-life.

    USDA-ARS?s Scientific Manuscript database

    SM09A and SM09B are F8 romaine breeding lines of lettuce (Lactuca sativa L.) resistant to dieback and with good shelf-life. SM09B was selected from a cross between ‘Darkland’ and PI491224, while SM09A was developed from ‘Green Towers’ × (‘Darkland’ × PI491224). Resistance to the disease in both bree...

  19. Genetic effects of a large-scale Spartina alterniflora (smooth cordgrass) dieback and recovery in the northern Gulf of Mexico

    USGS Publications Warehouse

    Edwards, K.R.; Travis, S.E.; Proffitt, C.E.

    2005-01-01

    A large-scale dieback event struck marshes along the northwestern Gulf of Mexico coast during summer 2000, in apparent response to a prolonged and severe drought. Along the Louisiana coast, large areas of the dominant marsh species, Spartina alterniflora, turned brown, followed by death of at least the aboveground structures or entire plant mortality. Key ecological and genetic measures were studied in a dieback-affected marsh in southwest Louisiana (C83 marsh, Sabine National Wildlife Refuge), for which existed predieback ecologic and genetic datasets. Effects on genetic diversity only were studied in a second set of sites in southeastern Louisiana (near Bay Junop), where the dieback was more widespread. We hypothesized that stem density, live aboveground biomass, and genetic diversity would be significantly reduced compared to predieback conditions and to nearby unaffected marshes. Stem densities and biomass levels approached predieback conditions 14 months after first observance of the dieback in the Sabine marsh and were similar to or exceeded the same measures for a nearby unaffected marsh. DNA extracted from leaf samples in the Sabine and Bay Junop sites was used to construct genotype profiles using AFLPs and analyzed using the complement of Simpson's Index (1-D), the richness measure G/N, average heterozygosity ???H???, and the estimated proportion of polymorphic genes ???P???. Genetic diversity was relatively unaffected by the dieback at either the Sabine or Bay Junop sites. Evidence from field observations and the results of the genetic analyses suggest that seedling recruitment is an important factor in the recovery of both the Bay Junop and C83 sites, although re-growth from surviving below-ground rhizomes appeared to dominate recovery at the latter site. Survival of below-ground structures, leading to the rapid recovery observed, indicates a high level of resilience of the Sabine marsh to drought-induced stress. Still, the genetic diversity of S

  20. Fungus Resistant XM205 Nonmetallic Cartridge Case,

    DTIC Science & Technology

    CARTRIDGE CASES, *FUNGICIDES, FUNGUS PROOFING, FUNGUS DETERIORATION, RESISTANCE, NITROCELLULOSE, POLYMERS, FIBERS, SYNTHETIC FIBERS, MATERIALS, ZINC COMPOUNDS, ORGANIC COMPOUNDS, ORGANIC SULFUR COMPOUNDS.

  1. Variation in woody plant mortality and dieback from severe drought among soils, plant groups, and species within a northern Arizona ecotone.

    PubMed

    Koepke, Dan F; Kolb, Thomas E; Adams, Henry D

    2010-08-01

    Vegetation change from drought-induced mortality can alter ecosystem community structure, biodiversity, and services. Although drought-induced mortality of woody plants has increased globally with recent warming, influences of soil type, tree and shrub groups, and species are poorly understood. Following the severe 2002 drought in northern Arizona, we surveyed woody plant mortality and canopy dieback of live trees and shrubs at the forest-woodland ecotone on soils derived from three soil parent materials (cinder, flow basalt, sedimentary) that differed in texture and rockiness. Our first of three major findings was that soil parent material had little effect on mortality of both trees and shrubs, yet canopy dieback of trees was influenced by parent material; dieback was highest on the cinder for pinyon pine (Pinus edulis) and one-seed juniper (Juniperus monosperma). Ponderosa pine (Pinus ponderosa) dieback was not sensitive to parent material. Second, shrubs had similar mortality, but greater canopy dieback, than trees. Third, pinyon and ponderosa pines had greater mortality than juniper, yet juniper had greater dieback, reflecting different hydraulic characteristics among these tree species. Our results show that impacts of severe drought on woody plants differed among tree species and tree and shrub groups, and such impacts were widespread over different soils in the southwestern U.S. Increasing frequency of severe drought with climate warming will likely cause similar mortality to trees and shrubs over major soil types at the forest-woodland ecotone in this region, but due to greater mortality of other tree species, tree cover will shift from a mixture of species to dominance by junipers and shrubs. Surviving junipers and shrubs will also likely have diminished leaf area due to canopy dieback.

  2. Modelling drought-induced dieback of Aleppo pine at the arid timberline

    NASA Astrophysics Data System (ADS)

    Wingate, Lisa; Preisler, Yakir; Bert, Didier; Rotenberg, Eyal; Yakir, Dan; Maseyk, Kadmiel; Ogee, Jerome

    2016-04-01

    During the mid 1960's an ambitious afforestation programme was initiated in the Negev desert of Israel. After five decades enduring harsh growing conditions, the Aleppo pine forest of Yatir is now exhibiting signs of 'drought-induced' dieback. Since 2010, 5-10% of the entire Yatir population have died, however the pattern of mortality is extremely patchy with some areas exhibiting >80% mortality whilst others display none. In this presentation, we reflect on historic climatic and edaphic conditions that have triggered this landscape mosaic of survival and mortality and how physiological and hydraulic traits vary within this patchwork. In addition, we explore how these pine trees have responded physiologically over recent years (1996-2010) to a series of severe drought events using a combined approach that brings together micrometeorological, dendro-isotopic and dendro-climatological datasets alongside process-based modelling. In particular the dataset trends were investigated with the isotope-enabled ecosystem model MuSICA to explore the consequences of subsequent droughts and embolism on modelled carbohydrate and water pool dynamics and their impact on carbon allocation and ecosystem function.

  3. Isolation of Enterobacter cowanii from Eucalyptus showing symptoms of bacterial blight and dieback in Uruguay.

    PubMed

    Brady, C L; Venter, S N; Cleenwerck, I; Engelbeen, K; de Vos, P; Wingfield, M J; Telechea, N; Coutinho, T A

    2009-10-01

    This study was performed to identify bacterial strains isolated simultaneously with Pantoea species from Eucalyptus trees showing symptoms of bacterial blight and dieback in Uruguay. Several molecular techniques including 16S rRNA and rpoB gene sequencing and DNA-DNA hybridization were used to characterize the gram-negative, facultatively anaerobic, slime-producing bacterial strains isolated along with Pantoea species from Eucalyptus. Hypersensitivity reactions (HR) and pathogenicity tests were performed on tobacco and Eucalyptus seedlings, respectively. The isolates clustered closely with the type strain of Enterobacter cowanii in both phylogenetic trees constructed. The DNA-DNA similarity between the isolates and the type strain of Ent. cowanii ranged from 88% to 92%. A positive HR was observed on the tobacco seedlings, but no disease symptoms were visible on the inoculated Eucalyptus seedlings. Enterobacter cowanii was isolated from trees with symptoms of bacterial blight although strains of this bacterial species do not appear to be the causal agent of the disease. This study provides the first report of Ent. cowanii isolated from Eucalyptus. Its presence in Eucalyptus tissue suggests that it is an endophyte in trees showing symptoms of blight.

  4. Genome characterization of a novel Burkholderia cepacia complex genomovar isolated from dieback affected mango orchards.

    PubMed

    Khan, Asifullah; Asif, Huma; Studholme, David J; Khan, Ishtiaq A; Azim, M Kamran

    2013-11-01

    We characterized the genome of the antibiotic resistant, caseinolytic and non-hemolytic Burkholderia sp. strain TJI49, isolated from mango trees (Mangifera indica L.) with dieback disease. This isolate produced severe disease symptoms on the indicator plants. Next generation DNA sequencing and short-read assembly generated the 60X deep 7,631,934 nucleotide draft genome of Burkholderia sp. TJI49 which comprised three chromosomes and at least one mega plasmid. Genome annotation studies revealed a total 8,992 genes, out of which 8,940 were protein coding genes. Comparative genomics and phylogenetics identified Burkholderia sp. TJI49 as a distinct species of Burkholderia cepacia complex (BCC), closely related to B. multivorans ATCC17616. Genome-wide sequence alignment of this isolate with replicons of BCC members showed conservation of core function genes but considerable variations in accessory genes. Subsystem-based gene annotation identified the active presence of wide spread colonization island and type VI secretion system in Burkholderia sp. TJI49. Sequence comparisons revealed (a) 28 novel ORFs that have no database matches and (b) 23 ORFs with orthologues in species other than Burkholderia, indicating horizontal gene transfer events. Fold recognition of novel ORFs identified genes encoding pertactin autotransporter-like proteins (a constituent of type V secretion system) and Hap adhesion-like proteins (involved in cell-cell adhesion) in the genome of Burkholderia sp. TJI49. The genomic characterization of this isolate provided additional information related to the 'pan-genome' of Burkholderia species.

  5. Botryosphaeriaceae associated with the die-back of ornamental trees in the Western Balkans.

    PubMed

    Zlatković, Milica; Keča, Nenad; Wingfield, Michael J; Jami, Fahimeh; Slippers, Bernard

    2016-04-01

    Extensive die-back and mortality of various ornamental trees and shrubs has been observed in parts of the Western Balkans region during the past decade. The disease symptoms have been typical of those caused by pathogens residing in the Botryosphaeriaceae. The aims of this study were to isolate and characterize Botryosphaeriaceae species associated with diseased ornamental trees in Serbia, Montenegro, Bosnia and Herzegovina. Isolates were initially characterized based on the DNA sequence data for the internal transcribed spacer rDNA and six major clades were identified. Representative isolates from each clade were further characterized using DNA sequence data for the translation elongation factor 1-alpha, β-tubulin-2 and large subunit rRNA gene regions, as well as the morphology of the asexual morphs. Ten species of the Botryosphaeriaceae were identified of which eight, i.e., Dothiorella sarmentorum, Neofusicoccum parvum, Botryosphaeria dothidea, Phaeobotryon cupressi, Sphaeropsis visci, Diplodia seriata, D. sapinea and D. mutila were known taxa. The remaining two species could be identified only as Dothiorella spp. Dichomera syn-asexual morphs of D. sapinea, Dothiorella sp. 2 and B. dothidea, as well as unique morphological characters for a number of the known species are described. Based on host plants and geographic distribution, the majority of Botryosphaeriaceae species found represent new records. The results of this study contribute to our knowledge of the distribution, host associations and impacts of these fungi on trees in urban environments.

  6. European Ash (Fraxinus excelsior L.) dieback: Disintegrating forest in the mountain protected areas, Czech Republic

    Treesearch

    Stanislav Vacek; Zdenek Vacek; Daniel Bulusek; Tereza Putalova; Murat Sarginci; Otakar Schwarz; Petr Srutka; Vilem Podrazsky; W. Keith Moser

    2015-01-01

    European ash (Fraxinus excelsior) is an important tree species in most temperate forests in Europe. Its future is threatened however, especially by an invasive fungus, Hymenoscyphus fraxineus (Hymenoscyphus pseudoalbidus, Chalara fraxinea). The current study is focused on the health of ash in the Krkonoše Mountains National Park, Czech Republic. On permanent...

  7. A retrospective, dual-isotope approach reveals individual predispositions to winter-drought induced tree dieback in the southernmost distribution limit of Scots pine.

    PubMed

    Voltas, Jordi; Camarero, Jesús Julio; Carulla, David; Aguilera, Mònica; Ortiz, Araceli; Ferrio, Juan Pedro

    2013-08-01

    Winter-drought induced forest diebacks in the low-latitude margins of species' distribution ranges can provide new insights into the mechanisms (carbon starvation, hydraulic failure) underlying contrasting tree reactions. We analysed a winter-drought induced dieback at the Scots pine's southern edge through a dual-isotope approach (Δ(13) C and δ(18) O in tree-ring cellulose). We hypothesized that a differential long-term performance, mediated by the interaction between CO(2) and climate, determined the fates of individuals during dieback. Declining trees showed a stronger coupling between climate, growth and intrinsic water-use efficiency (WUEi) than non-declining individuals that was noticeable for 25 years prior to dieback. The rising stomatal control of water losses with time in declining trees, indicated by negative Δ(13) C-δ(18) O relationships, was likely associated with their native aptitude to grow more and take up more water (suggested by larger tracheid lumen widths) than non-declining trees and, therefore, to exhibit a greater cavitation risk. Freeze-thaw episodes occurring in winter 2001 unveiled such physiological differences by triggering dieback in those trees more vulnerable to hydraulic failure. Thus, WUEi tightly modulated growth responses to long-term warming in declining trees, indicating that co-occurring individuals were differentially predisposed to winter-drought mortality. These different performances were unconnected to the depletion of stored carbohydrates.

  8. Wood anatomy and carbon-isotope discrimination support long-term hydraulic deterioration as a major cause of drought-induced dieback.

    PubMed

    Pellizzari, Elena; Camarero, J Julio; Gazol, Antonio; Sangüesa-Barreda, Gabriel; Carrer, Marco

    2016-06-01

    Hydraulic impairment due to xylem embolism and carbon starvation are the two proposed mechanisms explaining drought-induced forest dieback and tree death. Here, we evaluate the relative role played by these two mechanisms in the long-term by quantifying wood-anatomical traits (tracheid size and area of parenchyma rays) and estimating the intrinsic water-use efficiency (iWUE) from carbon isotopic discrimination. We selected silver fir and Scots pine stands in NE Spain with ongoing dieback processes and compared trees showing contrasting vigour (declining vs nondeclining trees). In both species earlywood tracheids in declining trees showed smaller lumen area with thicker cell wall, inducing a lower theoretical hydraulic conductivity. Parenchyma ray area was similar between the two vigour classes. Wet spring and summer conditions promoted the formation of larger lumen areas, particularly in the case of nondeclining trees. Declining silver firs presented a lower iWUE than conspecific nondeclining trees, but the reverse pattern was observed in Scots pine. The described patterns in wood anatomical traits and iWUE are coherent with a long-lasting deterioration of the hydraulic system in declining trees prior to their dieback. Retrospective quantifications of lumen area permit to forecast dieback in declining trees 2-5 decades before growth decline started. Wood anatomical traits provide a robust tool to reconstruct the long-term capacity of trees to withstand drought-induced dieback. © 2016 John Wiley & Sons Ltd.

  9. An Endophytic Fungus, Talaromyces radicus, Isolated from Catharanthus roseus, Produces Vincristine and Vinblastine, Which Induce Apoptotic Cell Death.

    PubMed

    Palem, Padmini P C; Kuriakose, Gini C; Jayabaskaran, Chelliah

    2015-01-01

    Endophytic fungi isolated from Catharanthus roseus were screened for the production of vincristine and vinblastine. Twenty-two endophytic fungi isolated from various tissues of C. roseus were characterized taxonomically by sequence analysis of the internal transcribed spacer (ITS) region of rDNA and grouped into 10 genera: Alternaria, Aspergillus, Chaetomium, Colletotrichum, Dothideomycetes, Eutypella, Eutypa, Flavodon, Fusarium and Talaromyces. The antiproliferative activity of these fungi was assayed in HeLa cells using the MTT assay. The fungal isolates Eutypella sp--CrP14, obtained from stem tissues, and Talaromyces radicus--CrP20, obtained from leaf tissues, showed the strongest antiproliferative activity, with IC50 values of 13.5 μg/ml and 20 μg/ml, respectively. All 22 endophytic fungi were screened for the presence of the gene encoding tryptophan decarboxylase (TDC), the key enzyme in the terpenoid indole alkaloid biosynthetic pathway, though this gene could only be amplified from T. radicus--CrP20 (NCBI GenBank accession number KC920846). The production of vincristine and vinblastine by T. radicus--CrP20 was confirmed and optimized in nine different liquid media. Good yields of vincristine (670 μg/l) in modified M2 medium and of vinblastine (70 μg/l) in potato dextrose broth medium were obtained. The cytotoxic activity of partially purified fungal vincristine was evaluated in different human cancer cell lines, with HeLa cells showing maximum susceptibility. The apoptosis-inducing activity of vincristine derived from this fungus was established through cell cycle analysis, loss of mitochondrial membrane potential and DNA fragmentation patterns.

  10. An Endophytic Fungus, Talaromyces radicus, Isolated from Catharanthus roseus, Produces Vincristine and Vinblastine, Which Induce Apoptotic Cell Death

    PubMed Central

    Jayabaskaran, Chelliah

    2015-01-01

    Endophytic fungi isolated from Catharanthus roseus were screened for the production of vincristine and vinblastine. Twenty-two endophytic fungi isolated from various tissues of C. roseus were characterized taxonomically by sequence analysis of the internal transcribed spacer (ITS) region of rDNA and grouped into 10 genera: Alternaria, Aspergillus, Chaetomium, Colletotrichum, Dothideomycetes, Eutypella, Eutypa, Flavodon, Fusarium and Talaromyces. The antiproliferative activity of these fungi was assayed in HeLa cells using the MTT assay. The fungal isolates Eutypella sp—CrP14, obtained from stem tissues, and Talaromyces radicus—CrP20, obtained from leaf tissues, showed the strongest antiproliferative activity, with IC50 values of 13.5 μg/ml and 20 μg/ml, respectively. All 22 endophytic fungi were screened for the presence of the gene encoding tryptophan decarboxylase (TDC), the key enzyme in the terpenoid indole alkaloid biosynthetic pathway, though this gene could only be amplified from T. radicus—CrP20 (NCBI GenBank accession number KC920846). The production of vincristine and vinblastine by T. radicus—CrP20 was confirmed and optimized in nine different liquid media. Good yields of vincristine (670 μg/l) in modified M2 medium and of vinblastine (70 μg/l) in potato dextrose broth medium were obtained. The cytotoxic activity of partially purified fungal vincristine was evaluated in different human cancer cell lines, with HeLa cells showing maximum susceptibility. The apoptosis-inducing activity of vincristine derived from this fungus was established through cell cycle analysis, loss of mitochondrial membrane potential and DNA fragmentation patterns. PMID:26697875

  11. Exploring the likelihood and mechanism of a climate-change-induced dieback of the Amazon rainforest.

    PubMed

    Malhi, Yadvinder; Aragão, Luiz E O C; Galbraith, David; Huntingford, Chris; Fisher, Rosie; Zelazowski, Przemyslaw; Sitch, Stephen; McSweeney, Carol; Meir, Patrick

    2009-12-08

    We examine the evidence for the possibility that 21st-century climate change may cause a large-scale "dieback" or degradation of Amazonian rainforest. We employ a new framework for evaluating the rainfall regime of tropical forests and from this deduce precipitation-based boundaries for current forest viability. We then examine climate simulations by 19 global climate models (GCMs) in this context and find that most tend to underestimate current rainfall. GCMs also vary greatly in their projections of future climate change in Amazonia. We attempt to take into account the differences between GCM-simulated and observed rainfall regimes in the 20th century. Our analysis suggests that dry-season water stress is likely to increase in E. Amazonia over the 21st century, but the region tends toward a climate more appropriate to seasonal forest than to savanna. These seasonal forests may be resilient to seasonal drought but are likely to face intensified water stress caused by higher temperatures and to be vulnerable to fires, which are at present naturally rare in much of Amazonia. The spread of fire ignition associated with advancing deforestation, logging, and fragmentation may act as nucleation points that trigger the transition of these seasonal forests into fire-dominated, low biomass forests. Conversely, deliberate limitation of deforestation and fire may be an effective intervention to maintain Amazonian forest resilience in the face of imposed 21st-century climate change. Such intervention may be enough to navigate E. Amazonia away from a possible "tipping point," beyond which extensive rainforest would become unsustainable.

  12. Flowering, die-back and recovery of a semelparous woody bamboo in the Atlantic Forest

    NASA Astrophysics Data System (ADS)

    Montti, Lía; Campanello, Paula I.; Goldstein, Guillermo

    2011-07-01

    Chusquea ramosissima is a semelparous woody bamboo growing in the understory of the semideciduous Atlantic Forest that increases in abundance after disturbance and consequently has profound effects on vegetation dynamics. Flowering and death of C. ramosissima may open a window of opportunity leaving space vacant for the recruitment of tree seedlings. We describe the flowering pattern and seedling demography of this species at different spatio-temporal scales between the years 2001 and 2009, and evaluate if tree seedling abundance of canopy species increased after the flowering event. At a landscape scale, flowering sites were interspersed with sites that did not flower. At a local scale, the flowering extended over 5 years, with flowering and non-flowering culms intermingled, also in small patches (i.e., 4 m 2). Seeds germinated soon after flowering and die-back. Four successive seedling cohorts were studied. Mortality rate was high during the first 4 months after seedling emergence but several fast-growing seedlings were able to become established successfully. At the end of the study, 10%-20% of the initial number of bamboo seedlings in each cohort survived. Seedling abundance of tree canopy species was similar in flowering and non-flowering sites. C. ramosissima was able to re-colonize and perpetuate in sites it previously occupied. The coexistence of flowering and non-flowering culms at different spatio-temporal scales and clonal growth by rhizomes, together with the successful bamboo seedlings establishment, enhanced bamboo persistence in gaps and disturbed sites. Flowering and death of C. ramosissima did not facilitate seedling growth of canopy tree species.

  13. Exploring uncertainty of Amazon dieback in a perturbed parameter Earth system ensemble.

    PubMed

    Boulton, Chris A; Booth, Ben B B; Good, Peter

    2017-04-27

    The future of the Amazon rainforest is unknown due to uncertainties in projected climate change and the response of the forest to this change (forest resiliency). Here, we explore the effect of some uncertainties in climate and land surface processes on the future of the forest, using a perturbed physics ensemble of HadCM3C. This is the first time Amazon forest changes are presented using an ensemble exploring both land vegetation processes and physical climate feedbacks in a fully coupled modelling framework. Under three different emissions scenarios, we measure the change in the forest coverage by the end of the 21st century (the transient response) and make a novel adaptation to a previously used method known as "dry-season resilience" to predict the long-term committed response of the forest, should the state of the climate remain constant past 2100. Our analysis of this ensemble suggests that there will be a high chance of greater forest loss on longer timescales than is realized by 2100, especially for mid-range and low emissions scenarios. In both the transient and predicted committed responses, there is an increasing uncertainty in the outcome of the forest as the strength of the emissions scenarios increases. It is important to note however, that very few of the simulations produce future forest loss of the magnitude previously shown under the standard model configuration. We find that low optimum temperatures for photosynthesis and a high minimum leaf area index needed for the forest to compete for space appear to be precursors for dieback. We then decompose the uncertainty into that associated with future climate change and that associated with forest resiliency, finding that it is important to reduce the uncertainty in both of these if we are to better determine the Amazon's outcome. © 2017 John Wiley & Sons Ltd.

  14. Making the case for early adoption of preventative practices for management of grapevine trunk diseases

    USDA-ARS?s Scientific Manuscript database

    Experimental trials on prevention of trunk diseases Botryosphaeria dieback, Esca, and Eutypa dieback have shown that delayed pruning, double pruning, and applications of the pruning-wound protectant thiophanate-methyl (Topsin) can reduce pruning-wound infections by 25-75%. Despite this biological e...

  15. When Is It Nail Fungus?

    MedlinePlus

    ... medlineplus.gov/news/fullstory_167455.html When Is It Nail Fungus? Dermatologist says only an expert can ... but you shouldn't be embarrassed to discuss it with a board-certified dermatologist, who can help ...

  16. Compensatory axon sprouting for very slow axonal die-back in a transgenic model of spinal muscular atrophy type III.

    PubMed

    Udina, Esther; Putman, Charles T; Harris, Luke R; Tyreman, Neil; Cook, Victoria E; Gordon, Tessa

    2017-03-01

    Smn(+/-) transgenic mouse is a model of the mildest form of spinal muscular atrophy. Although there is a loss of spinal motoneurons in 11-month-old animals, muscular force is maintained. This maintained muscular force is mediated by reinnervation of the denervated fibres by surviving motoneurons. The spinal motoneurons in these animals do not show an increased susceptibility to death after nerve injury and they retain their regenerative capacity. We conclude that the hypothesized immaturity of the neuromuscular system in this model cannot explain the loss of motoneurons by systematic die-back. Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans and is the leading genetic cause of infantile death. Patients lack the SMN1 gene with the severity of the disease depending on the number of copies of the highly homologous SMN2 gene. Although motoneuron death in the Smn(+/-) transgenic mouse model of the mildest form of SMA, SMA type III, has been reported, we have used retrograde tracing of sciatic and femoral motoneurons in the hindlimb with recording of muscle and motor unit isometric forces to count the number of motoneurons with intact neuromuscular connections. Thereby, we investigated whether incomplete maturation of the neuromuscular system induced by survival motoneuron protein (SMN) defects is responsible for die-back of axons relative to survival of motoneurons. First, a reduction of ∼30% of backlabelled motoneurons began relatively late, at 11 months of age, with a significant loss of 19% at 7 months. Motor axon die-back was affirmed by motor unit number estimation. Loss of functional motor units was fully compensated by axonal sprouting to retain normal contractile force in four hindlimb muscles (three fast-twitch and one slow-twitch) innervated by branches of the sciatic nerve. Second, our evaluation of whether axotomy of motoneurons in the adult Smn(+/-) transgenic mouse increases their susceptibility to cell death

  17. Shifts in functional traits elevate risk of fire-driven tree dieback in tropical savanna and forest biomes.

    PubMed

    Pellegrini, Adam F A; Franco, Augusto C; Hoffmann, William A

    2016-03-01

    Numerous predictions indicate rising CO2 will accelerate the expansion of forests into savannas. Although encroaching forests can sequester carbon over the short term, increased fires and drought-fire interactions could offset carbon gains, which may be amplified by the shift toward forest plant communities more susceptible to fire-driven dieback. We quantify how bark thickness determines the ability of individual tree species to tolerate fire and subsequently determine the fire sensitivity of ecosystem carbon across 180 plots in savannas and forests throughout the 2.2-million km(2) Cerrado region in Brazil. We find that not accounting for variation in bark thickness across tree species underestimated carbon losses in forests by ~50%, totaling 0.22 PgC across the Cerrado region. The lower bark thicknesses of plant species in forests decreased fire tolerance to such an extent that a third of carbon gains during forest encroachment may be at risk of dieback if burned. These results illustrate that consideration of trait-based differences in fire tolerance is critical for determining the climate-carbon-fire feedback in tropical savanna and forest biomes. © 2015 John Wiley & Sons Ltd.

  18. Shifts in Functional Traits Elevate Risk of Fire-driven Tree Dieback in Tropical Savanna-forest Biomes

    NASA Astrophysics Data System (ADS)

    Pellegrini, A.; Franco, A. C.; Hoffmann, W. A.

    2015-12-01

    Rising CO2 is predicted to accelerate the expansion of forests into savannas. Although encroaching forests can sequester carbon over the short-term, the carbon pools may become increasingly sensitive to fire due to a shift towards plant communities more susceptible to fire-driven dieback. We quantify how functional traits determine the ability of individual tree species to tolerate fire and subsequently determine the fire-sensitivity of ecosystem carbon across 180 plots throughout the 2.2-million km2 Cerrado region in Brazil. We find that accounting for variation in functional traits fundamentally changes fire-driven dieback predictions: savannas and forests switched from having similar amounts of potential carbon losses to forests containing substantially greater potential carbon losses when differences in functional traits were considered. In fact, we find that not accounting for variation in functional traits underestimated carbon losses in forests by ~50%, summing to an underestimation of 0.22PgC across the Cerrado region. In total, shifts in the fire sensitivity of forests due to changes in community composition and functional traits may offset a third of carbon gains during forest encroachment. These results illustrate that functional traits are critical for determining the climate-carbon-fire feedback in tropical savanna-forest biomes.

  19. Patterns of tree dieback in Queensland, Australia: the importance of drought stress and the role of resistance to cavitation.

    PubMed

    Rice, Kevin J; Matzner, Steven L; Byer, William; Brown, Joel R

    2004-04-01

    During the extreme 1992-1997 El Niño drought event, widespread stem mortality, or tree "dieback", of both mature and juvenile eucalypts occurred within the tropical savannas of northeast Australia. Most of the dieback occurred in individuals of the ironbark species complex ( Eucalyptus crebra- E. xanthoclada) while individuals of the bloodwood species Corymbia erythrophloia, exhibited significantly less stem mortality. Indicative of greater water stress, predawn and midday xylem water potentials of ironbark adults and saplings were significantly more negative than predawn values of bloodwoods. The very negative xylem water potentials in ironbarks suggest that stem mortality in both adult and juvenile ironbarks results from drought-induced embolism and that ironbarks perhaps have a shallower and less extensive root system than bloodwoods. Although predawn and midday water potentials for ironbark adults and saplings were similar, a census of mature and juvenile ironbark trees indicated that mortality was higher in adult trees. Cavitation vulnerability curves indicated that ironbark saplings may be better buffered against cavitation than adult trees. If they possess smaller root systems, saplings are more likely than adults to experience low xylem water potentials, even in non-drought years. Xylem conduits produced in adult trees during periods of normal rainfall, although perhaps more efficient in water conduction, may be more vulnerable to cavitation during infrequent severe droughts.

  20. Hydrologic variability in a salt marsh: Assessing the links between drought and acute marsh dieback

    NASA Astrophysics Data System (ADS)

    Hughes, Andrea L. H.; Wilson, Alicia M.; Morris, James T.

    2012-10-01

    It has been hypothesized that acute marsh dieback (AMD) observed along the Gulf Coast and South Atlantic Bight in the early 2000s was the result of drought-induced changes to porewater and sediment chemistry through hypersalinity or through mobilization of metals and acidification associated with redox changes. The impact of drought on coastal wetlands remains unclear because the hydrology of these wetlands is strongly influenced by regular tidal inundation. In order to test the links between hydrologic variability and changes to marsh groundwater conditions that may be stressful to the salt marsh grass Spartina alterniflora, we installed piezometers and passive diffusion samplers in a salt marsh island at North Inlet, South Carolina, where AMD was observed in fall 2001. Significant variations in tidal inundation, rainfall, evapotranspiration, groundwater dynamics, and porewater chemistry were observed. The island was typically inundated twice daily, but there were occasional 19-21 h periods in winter and spring when the marsh was not inundated and a singular event when the marsh was not inundated for three days (March 2008). Enhanced exposure resulted in seasonal redox chemistry changes, as indicated by changes in the ratio of ferrous iron [Fe(II)] to total iron [Fe(II) + Fe(III)], but our observations do not support redox and pH changes as the cause of AMD at this site. Porewater salinity varied from 14 to 40 in the upper 1 m of the marsh. Salinity was most variable near the surface and increased with depth, reflecting root zone transpiration and downward movement of porewater through the marsh mud into the underlying confined sand aquifer. Pearson Correlation tests among porewater constituents and hydrologic parameters indicated significant associations between porewater salinity, tidal inundation, rainfall, and ET, and additional associations between porewater iron concentration, speciation, and tidal inundation. Linear regression model estimates of porewater

  1. In vivo two-photon imaging reveals a role of progesterone in reducing axonal dieback after spinal cord injury in mice.

    PubMed

    Yang, Zhijie; Xie, Wenguang; Ju, Furong; Khan, Akbar; Zhang, Shengxiang

    2017-04-01

    Progesterone (PG) as a neuroprotective reagent has been used for the treatment of spinal cord injury (SCI) in experimental animal models. However, its effect and mechanism on axonal dieback at the early stage of SCI remain unclear. Here, we investigate the dynamics of injured axons and the effect of PG on the axonal dieback, glial response, and behavioral recovery in a mouse model of SCI. Two-photon intravital imaging combined with a simplified imaging window chamber were used to image axons in hemisected spinal cords over a period of 3 days. Repeated imaging showed that axonal dieback distance in mice treated with PG after SCI was significantly reduced than that in mice treated with vehicle after SCI (P < 0.05) at the time point of 24 h, 48 h, and 72 h after SCI. The densities of astrocytes and microglia in the SCI-vehicle treated group were significantly higher than those in mice treated with PG after SCI (P < 0.05). Real time polymerase chain reaction assay indicated that administration of PG after SCI down-regulated the expression of pro-inflammatory cytokines MCP-1, NOS2, and IL-1β (P < 0.05). PG treatment also improved the behavioral performance post injury. These findings suggested that PG exerted a neuroprotective effect by attenuating axonal dieback, reducing the accumulation of astrocytes and microglia and inhibiting the release of pro-inflammatory cytokines.

  2. Evaluating elevated levels of crown dieback among northern white-cedar (Thuja occidentalis L.) trees in Maine and Michigan: a summary of evaluation monitoring

    Treesearch

    KaDonna Randolph; William A. Bechtold; Randall S. Morin; Stanley J. Zarnoch

    2012-01-01

    Analysis of crown condition data for the 2006 national technical report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, exposed clusters of phase 3 plots (by the Forest Inventory and Analysis [FIA] Program of the Forest Service) with northern white-cedar (Thuja occidentalis L.) crown dieback...

  3. [Book review] Epiphytic Lichen Diversity and its Dependence on Chemical Site Factors in Differently Elevated Dieback-affected Spruce Stands of the Harz Mountains, by Volker Hesse

    USGS Publications Warehouse

    Bennett, J.P.

    2002-01-01

    Review of: Epiphytic lichen diversity and its dependence on chemical site factors in differently elevated dieback-affected spruce stands of the Harz Mountains. (Dissertationes Botanicae, Band 354). Volker Hesse. 2002. 191 pages, 66 figures, 49 tables, 23x14cm, 390 g. ISBN 978-3-443-64266-2.

  4. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species.

    PubMed

    Guada, Guillermo; Camarero, J Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die.

  5. Effects of simulated thaw on xylem cavitation, residual embolism, spring dieback and shoot growth in yellow birch.

    PubMed

    Cox, R M; Zhu, X B

    2003-06-01

    Yellow birch seedlings (Betula alleghaniensis Britt.) that had lost more than 90% of their stem hydraulic conductivity during ambient winter temperatures were exposed to 0 and 20 days of a simulated winter thaw followed by a 48-h freezing treatment at 0, -5, -10, -20 and -30 degrees C. After measuring freezing injury to shoots and roots, the seedlings were placed in a greenhouse where recovery of xylem conductivity and new growth were measured. Shoot xylem cavitation was measured as percent loss of hydraulic conductivity. Shoot freezing injury was assessed by electrolyte leakage (EL) and root freezing injury was assessed by EL and triphenyl tetrazolium chloride reduction. Seedlings pretreated with thaw had higher stem water contents and suffered more freezing damage to roots and shoots (at -20 and -30 degrees C, respectively) than unthawed seedlings. After 3 weeks in a greenhouse, seedlings from the 0, -5 and -10 degrees C freezing treatments showed complete recovery of xylem conductivity, with substantially increased stem water contents. Poor recovery of hydraulic conductivity was observed only in seedlings that were subjected to freezing treatments at -20 and -30 degrees C, regardless of thaw treatment. Of these embolized seedlings, however, only those not previously thawed showed recovery of hydraulic conductivity or regained stem water content after 9 weeks in the greenhouse. Shoot dieback, bud burst and length of new shoots were significantly related to the extent of stem xylem cavitation and freezing injury. We conclude that (1) the simulated winter thaw predisposed yellow birch seedlings to freezing damage in shoots and roots by dehardening tissues and increasing their water content; (2) root freezing damage in turn affected the seedlings' ability to refill embolized stem xylem, resulting in considerable residual xylem embolism after spring refilling; (3) further recovery of stem xylem conductivity was attributable to growth of new vessels; (4) and the

  6. Geochemical factors promoting die-back gap formation in colonizing patches of Spartina densiflora in an irregularly flooded marsh

    NASA Astrophysics Data System (ADS)

    Mirlean, Nicolai; Costa, Cesar S. B.

    2017-04-01

    Circular (RP) and ring-shape (RP) patches of vegetation in intertidal flats have been associated with the radial expansion of tussock growth forms and die-back gap in older central stands, respectively. RP formation has not yet been sufficiently explained. We accomplished a comparative geochemical study of CP and RP structures of Spartina densiflora within a single saltmarsh in a microtidal estuary (<0.5 m). The pore water under these structures demonstrated distinctive physical-chemical properties by marked seasonal changing in water level and salinity. During high-water period dissolved H2S was frequently low in pore waters of S. densiflora structures due to reactive-Fe, which scavenge the sulfide from solution and form solid sulfides. During less flooded-brackish water period, pore water pH goes down below 4 inside the vegetated bordering areas of RP. In these locations the concentration of soluble sulfides dramatically increases up to 140 μM L-1. The high concentration of protons in pore water is the result of solid sulfides atmospheric oxidation to sulfuric acid. High dissolution of H2S, along with the low pH, creates a toxic environment for S. densiflora and die-back central gap formation in RP. CP structure was 5 cm higher in the intertidal than RP but shows frequent presence of a water layer, less severe oxidation of sulfides and limited building-up of toxic condition to plants. Development of S. densiflora RP probably indicates the uplift of sediment by this bioengineer grass and/or periodic lowering of the water surface below a certain critical level.

  7. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species

    PubMed Central

    Guada, Guillermo; Camarero, J. Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M. Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die. PMID:27066053

  8. Cavitation, stomatal conductance, and leaf dieback in seedlings of two co-occurring Mediterranean shrubs during an intense drought.

    PubMed

    Vilagrosa, A; Bellot, J; Vallejo, V R; Gil-Pelegrin, E

    2003-09-01

    Seedling shrubs in the Mediterranean semi-arid climate are subjected to intense droughts during summer. Thus, seedlings often surpass their limits of tolerance to water stress, resulting in the loss of hydraulic conductivity due to xylem cavitation. The response in terms of stomatal conductance, vulnerability to cavitation, leaf dieback, and survival were analysed in two co-occurring seedlings of mastic tree (Pistacia lentiscus L.) and kermes oak (Quercus coccifera L.) during an intense drought period. Both species reacted to drought with steep decreases in stomatal conductance before the critical water potential brought about the onset of cavitation events. Q. coccifera showed wider safety margins for avoiding runaway embolism than P. lentiscus and these differences could be related to the particular drought strategy displayed by each species: water saver or water spender. The limits for survival, resprout capacity and leaf dieback were also analysed in terms of loss of conductivity. By contrast with previous studies, the species showing higher seedling survival in the presence of drought also showed higher susceptibility to cavitation and operated with a lower safety margin for cavitation. Both species showed a leaf specific conductivity (LSC) threshold below which leaf biomass had to be regulated to avoid runaway embolism. However, each species displayed a different type of response: P. lentiscus conserved total leaf area up to 100% loss of LSC, whereas Q. coccifera continuously adjusted leaf biomass throughout the drought period in order to maintain the LSC very close to the maximum values recorded without loss of conductivity. Both species maintained the capacity for survival until the loss of conductivity was very nearly 100%.

  9. Isotope signals and anatomical features in tree rings suggest a role for hydraulic strategies in diffuse drought-induced die-back of Pinus nigra.

    PubMed

    Petrucco, Laura; Nardini, Andrea; von Arx, Georg; Saurer, Matthias; Cherubini, Paolo

    2017-04-01

    The 2003 and 2012 summer seasons were among the warmest and driest of the last 200 years over southeastern Europe, and in particular in the Karst region (northeastern Italy). Starting from winter-spring 2013, several black pines (Pinus nigra J.F. Arnold) suffered crown die-back. Declining trees occurred nearby individuals with no signs of die-back, raising hypotheses about the occurrence of individual-specific hydraulic strategies underlying different responses to extreme drought. We investigated possible processes driving black pine decline by dendrochronological and wood anatomical measurements, coupled with analysis of tree-ring carbon (δ13C) and oxygen (δ18O) isotopic composition in healthy trees (H) and trees suffering die-back (D). Die-back trees showed higher growth rates than H trees at the beginning of the last century, but suffered important growth reduction following the dry summers in 2003 and 2012. After the 2012 drought, D trees produced tracheids with larger diameter and greater vulnerability to implosion than H ones. Healthy trees had significantly higher wood δ13C than D trees, reflecting higher water-use efficiency for the surviving trees, i.e., less water transpired per unit carbon gain, which could be related to lower stomatal conductance and a more conservative use of water. Relatively high δ18O for D trees indicates that they were strongly dependent on shallow water sources, or that they sustained higher transpiration rates than H trees. Our results suggest that H trees adopted a more conservative water-use strategy under drought stress compared with D trees. We speculate that this diversity might have a genotypic basis, but other possible explanations, like different rooting depth, cannot be ruled out. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Draft genome sequence of Pseudomonas syringae pathovar syringae strain FF5, causal agent of stem tip dieback disease on ornamental pear.

    PubMed

    Sohn, Kee Hoon; Jones, Jonathan D G; Studholme, David J

    2012-07-01

    Pseudomonas syringae FF5 causes stem tip dieback disease on ornamental pear (Pyrus calleryana). Its genome encodes a complete type III secretion system (T3SS) and HopAC1, HopM1, AvrE1, HopI1, HopAA1, HopJ1, HopAH2, HopAH1, HopAG1, and HopAZ1. Lacking detectable homologues of other T3SS effectors, it may encode novel, undiscovered effectors.

  11. Herbicides implicated as the cause of severe mangrove dieback in the Mackay region, NE Australia: consequences for marine plant habitats of the GBR World Heritage Area.

    PubMed

    Duke, Norman C; Bell, Alicia M; Pederson, Dan K; Roelfsema, Chris M; Bengtson Nash, Susan

    2005-01-01

    Herbicides, particularly diuron, were correlated with severe and widespread dieback of the dominant mangrove, Avicennia marina (Forsk.) Vierh. var. eucalyptifolia (Val.) N.C. Duke (Avicenniaceae), its reduced canopy condition, and declines in seedling health within three neighbouring estuaries in the Mackay region of NE Australia. This unusual species-specific dieback, first observed in the early 1990s, had gotten notably worse by 2002 to affect >30 km(2) of mangroves in at least five adjacent estuaries in the region. Over the past century, agricultural production has responded well to the demands of increasing population with improvements in farm efficiency assisted by significant increases in the use of agricultural chemicals. However, with regular and episodic river flow events, these chemicals have sometimes found their way into estuarine and nearshore water and sediments where their effects on marine habitats have been largely unquantified. Investigations over the last three years in the Mackay region provide compelling evidence of diuron, and possibly other agricultural herbicides, as the most likely cause of the severe and widespread mangrove dieback. The likely consequences of such dieback included declines in coastal water quality with increased turbidity, nutrients and sediment deposition, as well as further dispersal of the toxic chemicals. The implications of such findings are immense since they describe not only the serious deterioration of protected and beneficial mangrove habitat but also the potential for significant direct and indirect effects on other highly-valued estuarine and marine habitats in the region, including seagrass beds and coral reefs of the Great Barrier Reef lagoon. This article reviews all key findings and observations to date and describes the essential correlative and causative evidence.

  12. Quercivorol as a lure for the polyphagous and Kuroshio shot hole borers, Euwallacea spp. nr. fornicatus (Coleoptera: Scolytinae), vectors of Fusarium dieback.

    PubMed

    Dodge, Christine; Coolidge, Jessica; Cooperband, Miriam; Cossé, Allard; Carrillo, Daniel; Stouthamer, Richard

    2017-01-01

    The polyphagous shot hole borer and Kuroshio shot hole borer, two members of the Euwallacea fornicatus species complex (Coleoptera: Curculionidae: Scolytinae), are invasive ambrosia beetles that harbor distinct species of Fusarium fungal symbionts. Together with the damage caused by gallery construction, these two phytopathogenic Fusarium species are responsible for the emerging tree disease Fusarium dieback, which affects over 50 common tree species in Southern California. Host trees suffer branch dieback as the xylem is blocked by invading beetles and fungi, forcing the costly removal of dead and dying trees in urban areas. The beetles are also threatening natural riparian habitats, and avocado is susceptible to Fusarium dieback as well, resulting in damage to the avocado industries in California and Israel. Currently there are no adequate control mechanisms for shot hole borers. This paper summarizes efforts to find a suitable lure to monitor shot hole borer invasions and dispersal. Field trials were conducted in two counties in Southern California over a span of two years. We find that the chemical quercivorol is highly attractive to these beetles, and perform subsequent field experiments attempting to optimize this lure. We also explore other methods of increasing trap catch and effects of other potential attractants, as well as the deterrents verbenone and piperitone.

  13. Effects of xylem cavitation and freezing injury on dieback of yellow birch (Betula alleghaniensis) in relation to a simulated winter thaw.

    PubMed

    Zhu, X. B.; Cox, R. M.; Arp, P. A.

    2000-04-01

    Shoot dieback, shoot growth, stem xylem cavitation, stem and root freezing injury, and root pressure were measured in 2-year-old, cold-hardened, potted yellow birch (Betula alleghaniensis Britt.) seedlings that had been subjected to a simulated winter thaw for 0, 5, 10, 19 or 27 days followed by 10 weeks at -10 degrees C. Stem xylem cavitation was determined as percent loss of hydraulic conductivity. Stem freezing injury was measured as electrolyte leakage (EL). Root freezing injury was determined by EL and by triphenyl tetrazolium chloride (TTC) reduction. Thaw duration was significantly correlated with dieback, new shoot growth, stem xylem cavitation, stem and root freezing damage, and root pressure (P < 0.05). In particular, shoot dieback was positively correlated with stem xylem cavitation (P < 0.001), residual stem xylem cavitation (P < 0.01) and root freezing injury (P < 0.010), but only weakly correlated with stem freezing damage (P < 0.05). In roots, freezing damage was negatively correlated with root pressure (P < 0.05), which, in turn, was negatively correlated with residual stem xylem cavitation after root pressure development. In stems, there was no correlation between freezing damage and xylem cavitation. We conclude that long periods of winter thaw followed by freezing resulted in freezing injury to roots concomitant with a reduction in root pressures, leading to poor recovery from freezing-induced xylem embolism.

  14. Passive immunization with myelin basic protein activated T cells suppresses axonal dieback but does not promote axonal regeneration following spinal cord hemisection in adult rats.

    PubMed

    Wang, Hong-Ju; Hu, Jian-Guo; Shen, Lin; Wang, Rui; Wang, Qi-Yi; Zhang, Chen; Xi, Jin; Zhou, Jian-Sheng; Lü, He-Zuo

    2012-08-01

    The previous studies suggested that some subpopulations of T lymphocytes against central nervous system (CNS) antigens, such as myelin basic protein (MBP), are neuroprotective. But there were few reports about the effect of these T cells on axon regeneration. In this study, the neonatally thymectomied (Tx) adult rats which contain few T lymphocytes were subjected to spinal cord hemisection and then passively immunized with MBP-activated T cells (MBP-T). The regeneration and dieback of transected axons of cortico-spinal tract (CST) were detected by biotin dextran amine (BDA) tracing. The behavioral assessments were performed using the Basso, Beattie, and Bresnahan locomotor rating scale. We found that passive transferring of MBP-T could attenuate axonal dieback. However, no significant axon regeneration and behavioral differences were observed among the normal, Tx and sham-Tx (sTx) rats with or without MBP-T passive immunization. These results indicate that passive transferring of MBP-T cells can attenuate axonal dieback and promote neuroprotection following spinal cord injury (SCI), but may not promote axon regeneration.

  15. Botryosphaeriaceae species associated with dieback and canker disease of bay laurel in northern California with the description of Dothiorella californica sp. nov.

    PubMed

    Lawrence, Daniel P; Peduto Hand, Francesca; Gubler, W Douglas; Trouillas, Florent P

    2017-04-01

    Members of the Botryosphaeriaceae are cosmopolitan fungi that may exist as seemingly innocuous endophytes or as destructive pathogens of numerous woody hosts, including fruit and nut crops, urban ornamental trees and shrubs, and forest trees. Surveys of bay laurel in northern California have revealed symptoms of dieback and branch canker of unknown aetiology. The goals of this study were to identify and clarify the species of Botryosphaeriaceae associated with these symptoms and to confirm their pathogenicity. To understand the role of members of the Botryosphaeriaceae in the dieback and canker disease of bay laurel, 23 isolates were isolated from symptomatic wood. Phylogenetic analyses of ITS, translation elongation factor 1-α, and beta-tubulin revealed three species: Botryosphaeria dothidea, Neofusicoccum nonquaesitum, and the newly described and typified species Dothiorella californica sp. nov. When select isolates were inoculated to 2- to 3-year-old branches of Umbellularia californica in a natural forest, both B. dothidea and N. nonquaesitum were pathogenic with N. nonquaesitum producing the largest lesions at 12- and 18-months post inoculation, respectively, while Do. californica did not cause wood lesions significantly greater than the mock-inoculated controls. This study represents the first attempt to identify and test the pathogenicity of Botryosphaeriaceae species associated with dieback and canker disease of bay laurel in a northern California forest.

  16. Carry over effects of nutrient addition on the recovery of an invasive seaweed from the winter die-back.

    PubMed

    Uyà, Marc; Maggi, Elena; Mori, Giovanna; Nuccio, Caterina; Gribben, Paul E; Bulleri, Fabio

    2017-05-01

    Nutrient enrichment of coastal waters can enhance the invasibility and regrowth of non-native species. The invasive alga Caulerpa cylindracea has two distinct phases: a well-studied fast-growing summer phase, and a winter latent phase. To investigate the effects of nutrient enrichment on the regrowth of the seaweed after the winter resting-phase, a manipulative experiment was carried out in intertidal rockpools in the North-western Mediterranean. Nutrients were supplied under different temporal regimes: press (constant release from January to May), winter pulse (January to March) and spring pulse (March to May). Independently from the temporal characteristics of their addition, nutrients accelerated the re-growth of C. cylindracea after the winter die-back, resulting in increased percentage covers at the peak of the growing season. Nutrient addition did not influence the number and length of fronds and the biomass. Native components of the algal community did not respond to nutrient additions. Our results show that nutrient supply can favour the spread of C. cylindracea even when occurring at a time of the year at which the seaweed is not actively growing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Afritoxinones A and B, dihydrofuropyran-2-ones produced by Diplodia africana the causal agent of branch dieback on Juniperus phoenicea.

    PubMed

    Evidente, Antonio; Masi, Marco; Linaldeddu, Benedetto T; Franceschini, Antonio; Scanu, Bruno; Cimmino, Alessio; Andolfi, Anna; Motta, Andrea; Maddau, Lucia

    2012-05-01

    Two phytotoxic dihydrofuropyran-2-ones, named afritoxinones A and B, were isolated from liquid culture of Diplodia africana, a fungal pathogen responsible for branch dieback of Phoenicean juniper in Italy. Additionally, six others known metabolites were isolated and characterized: oxysporone, sphaeropsidin A, epi-sphaeropsidone, R-(-)-mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein. The structures of afritoxinones A and B were established by spectroscopic and optical methods and determined to be as (3aS(*),6R(*),7aS)-6-methoxy-3a,7a-dihydro-3H,6H-furo[2,3-b]pyran-2-one and (3aR(*),6R(*),7aS)-6-methoxy-3a,7a-dihydro-3H,6H-furo[2,3-b]pyran-2-one, respectively. The phytotoxic activity of afritoxinones A and B and oxysporone was evaluated on host (Phoenicean juniper) and non-host plant (holm oak, cork oak and tomato) by cutting and leaf puncture assay. Oxysporone proved to be the most phytotoxic compound. This study represents the first report of secondary metabolites produced by D. africana. In addition, the taxonomic implications of secondary metabolites in Botryosphaeriaceae family studies are discussed.

  18. Xyleborus glabratus attacks and systemic colonization by Raffaelea lauricola associated with dieback of Cinnamomum camphora in the southeastern United States

    Treesearch

    S. W. Fraedrich; T. C. Harrington; G. S. Best

    2014-01-01

    Laurel wilt, caused by Raffaelea lauricola, is responsible for extensive mortality of redbay and other American members of the Lauraceae in the southeastern United States. Raffaelea lauricola is a mycangial symbiont of the redbay ambrosia beetle (Xyleborus glabratus), and the beetle and fungus were accidentally...

  19. When the forest dies: the response of forest soil fungi to a bark beetle-induced tree dieback.

    PubMed

    Stursová, Martina; Snajdr, Jaroslav; Cajthaml, Tomáš; Bárta, Jiří; Santrůčková, Hana; Baldrian, Petr

    2014-09-01

    Coniferous forests cover extensive areas of the boreal and temperate zones. Owing to their primary production and C storage, they have an important role in the global carbon balance. Forest disturbances such as forest fires, windthrows or insect pest outbreaks have a substantial effect on the functioning of these ecosystems. Recent decades have seen an increase in the areas affected by disturbances in both North America and Europe, with indications that this increase is due to both local human activity and global climate change. Here we examine the structural and functional response of the litter and soil microbial community in a Picea abies forest to tree dieback following an invasion of the bark beetle Ips typographus, with a specific focus on the fungal community. The insect-induced disturbance rapidly and profoundly changed vegetation and nutrient availability by killing spruce trees so that the readily available root exudates were replaced by more recalcitrant, polymeric plant biomass components. Owing to the dramatic decrease in photosynthesis, the rate of decomposition processes in the ecosystem decreased as soon as the one-time litter input had been processed. The fungal community showed profound changes, including a decrease in biomass (2.5-fold in the litter and 12-fold in the soil) together with the disappearance of fungi symbiotic with tree roots and a relative increase in saprotrophic taxa. Within the latter group, successive changes reflected the changing availability of needle litter and woody debris. Bacterial biomass appeared to be either unaffected or increased after the disturbance, resulting in a substantial increase in the bacterial/fungal biomass ratio.

  20. Structural overshoot of tree growth with climate variability and the global spectrum of drought-induced forest dieback.

    PubMed

    Jump, Alistair S; Ruiz-Benito, Paloma; Greenwood, Sarah; Allen, Craig D; Kitzberger, Thomas; Fensham, Rod; Martínez-Vilalta, Jordi; Lloret, Francisco

    2017-01-30

    Ongoing climate change poses significant threats to plant function and distribution. Increased temperatures and altered precipitation regimes amplify drought frequency and intensity, elevating plant stress and mortality. Large-scale forest mortality events will have far-reaching impacts on carbon and hydrological cycling, biodiversity, and ecosystem services. However, biogeographical theory and global vegetation models poorly represent recent forest die-off patterns. Furthermore, as trees are sessile and long-lived, their responses to climate extremes are substantially dependent on historical factors. We show that periods of favourable climatic and management conditions that facilitate abundant tree growth can lead to structural overshoot of aboveground tree biomass due to a subsequent temporal mismatch between water demand and availability. When environmental favourability declines, increases in water and temperature stress that are protracted, rapid, or both, drive a gradient of tree structural responses that can modify forest self-thinning relationships. Responses ranging from premature leaf senescence and partial canopy dieback to whole-tree mortality reduce canopy leaf area during the stress period and for a lagged recovery window thereafter. Such temporal mismatches of water requirements from availability can occur at local to regional scales throughout a species geographical range. As climate change projections predict large future fluctuations in both wet and dry conditions, we expect forests to become increasingly structurally mismatched to water availability and thus overbuilt during more stressful episodes. By accounting for the historical context of biomass development, our approach can explain previously problematic aspects of large-scale forest mortality, such as why it can occur throughout the range of a species and yet still be locally highly variable, and why some events seem readily attributable to an ongoing drought while others do not. This

  1. When the forest dies: the response of forest soil fungi to a bark beetle-induced tree dieback

    PubMed Central

    Štursová, Martina; Šnajdr, Jaroslav; Cajthaml, Tomáš; Bárta, Jiří; Šantrůčková, Hana; Baldrian, Petr

    2014-01-01

    Coniferous forests cover extensive areas of the boreal and temperate zones. Owing to their primary production and C storage, they have an important role in the global carbon balance. Forest disturbances such as forest fires, windthrows or insect pest outbreaks have a substantial effect on the functioning of these ecosystems. Recent decades have seen an increase in the areas affected by disturbances in both North America and Europe, with indications that this increase is due to both local human activity and global climate change. Here we examine the structural and functional response of the litter and soil microbial community in a Picea abies forest to tree dieback following an invasion of the bark beetle Ips typographus, with a specific focus on the fungal community. The insect-induced disturbance rapidly and profoundly changed vegetation and nutrient availability by killing spruce trees so that the readily available root exudates were replaced by more recalcitrant, polymeric plant biomass components. Owing to the dramatic decrease in photosynthesis, the rate of decomposition processes in the ecosystem decreased as soon as the one-time litter input had been processed. The fungal community showed profound changes, including a decrease in biomass (2.5-fold in the litter and 12-fold in the soil) together with the disappearance of fungi symbiotic with tree roots and a relative increase in saprotrophic taxa. Within the latter group, successive changes reflected the changing availability of needle litter and woody debris. Bacterial biomass appeared to be either unaffected or increased after the disturbance, resulting in a substantial increase in the bacterial/fungal biomass ratio. PMID:24671082

  2. Potential Effects of Drought on Tree Dieback in Great Britain and Implications for Forest Management in Adaptation to Climate Change

    NASA Astrophysics Data System (ADS)

    Yu, Jianjun; Berry, Pam

    2017-04-01

    The drought and heat stress has alerted the composition, structure and biogeography of forests globally, whilst the projected severe and widespread droughts are potentially increasing. This challenges the sustainable forest management to better cope with future climate and maintain the forest ecosystem functions and services. Many studies have investigated the climate change impacts on forest ecosystem but less considered the climate extremes like drought. In this study, we implement a dynamic ecosystem model based on a version of LPJ-GUESS parameterized with European tree species and apply to Great Britain at a finer spatial resolution of 5*5 km. The model runs for the baseline from 1961 to 2011 and projects to the latter 21st century using 100 climate scenarios generated from MaRIUS project to tackle the climate model uncertainty. We will show the potential impacts of climate change on forest ecosystem and vegetation transition in Great Britain by comparing the modelled conditions in the 2030s and the 2080s relative to the baseline. In particular, by analyzing the modelled tree mortality, we will show the tree dieback patterns in response to drought for various species, and assess their drought vulnerability across Great Britain. We also use species distribution modelling to project the suitable climate space for selected tree species using the same climate scenarios. Aided by these two modelling approaches and based on the corresponding modelling results, we will discuss the implications for adaptation strategy for forest management, especially in extreme drought conditions. The gained knowledge and lessons for Great Britain are considered to be transferable in many other regions.

  3. Developing publicly acceptable tree health policy: public perceptions of tree-breeding solutions to ash dieback among interested publics in the UK.

    PubMed

    Jepson, Paul R; Arakelyan, Irina

    2017-07-01

    The UK needs to develop effective policy responses to the spread of tree pathogens and pests. This has been given the political urgency following the media and other commentary associated with the arrival of a disease that causes 'dieback' of European Ash (Fraxinus excelsior) - a tree species with deep cultural associations. In 2014 the UK government published a plant biosecurity strategy and linked to this invested in research to inform policy. This paper reports the findings of a survey of informed UK publics on the acceptability of various potential strategies to deal with ash dieback, including "no action". During the summer of 2015, we conducted a face-to-face survey of 1152 respondents attending three major countryside events that attract distinct publics interested in the countryside: landowners & land managers; naturalists and gardeners. We found that UK publics who are likely to engage discursively and politically (through letter writing, petitions etc.) with the issue of ash dieback a) care about the issue, b) want an active response, c) do not really distinguish between ash trees in forestry or ecological settings, and d) prefer traditional breeding solutions. Further that e) younger people and gardeners are open to GM breeding techniques, but f) the more policy-empowered naturalists are more likely to be anti-GM. We suggest that these findings provide three 'steers' for science and policy: 1) policy needs to include an active intervention component involving the breeding of disease-tolerant trees, 2) that the development of disease tolerance using GM-technologies could be part of a tree-breeding policy, and 3) there is a need for an active dialogue with publics to manage expectations on the extent to which science and policy can control tree disease or, put another way, to build acceptability for the prospect that tree diseases may have to run their course.

  4. Strong nitrogen retention against the pine-stands dieback by pine-wilt disease in a temperate conifer-deciduous forest in central Japan: Budget and mechanisms

    NASA Astrophysics Data System (ADS)

    Ohte, N.; Tokuchi, N.; Katsuyama, M.; Osaka, K.; Yoneda, S.; Ochiai, N.

    2013-12-01

    Decreased N uptake by tree roots and increased N supply from the litter fall that occurred with the 1992-94 pine dieback caused by pine-wilt disease brought on a threefold and 10 years increase in nitrate concentrations in streamwater and subsurface groundwater in a conifer-deciduous mixed forest catchment (Kiryu Experimental Watershed) in central Japan. The disturbance also resulted in delayed changes of input-output nitrogen balances. The objectives of this study were 1) to evaluate the controls of the hydrological processes by which NO3- concentrations increase in streamwater, 2) to clarify the impacts of soil nitrogen transformation to the streamwater chemistry. It was found that, from 1992 to 1996, seasonal peaks occurred in the stream NO3- concentrations during the rainy season (July to August). This seasonal variation corresponded directly to groundwater levels in the riparian zone near the catchment outlet, suggesting that seasonal changes in groundwater levels were the dominant factor controlling temporal variation in stream NO3- concentrations. The annual N export was 110.0 mol N ha-1 year-1 in pre-disturbance condition and 749.8 mol N ha-1 year-1 in post-disturbance, and had decreased to 37.0 mol N ha-1 year-1 in 2005. N export under dieback influence was estimated to be 3697 mol N ha-1, and N loss due to pine dieback was 2810 mol N ha-1. This was three times larger than baseline N leakage for the disturbed period. The nitrogen contribution to dieback litter inputs was 7.39 kmol ha-1, and N loss from streamwater was less than 0.2-0.75 kmol ha-1 year-1 throughout the observation period. This large discrepancy suggested there was substantial nitrogen retaining mechanisms such as microbial immobilization. Measurements of nitrogen mineralization and nitrification potential of soil using 15N pool dilution method indicated that the soil in this site has very high NH4+ immobilization potential and low nitrification potential. This was one of the evidence

  5. Draft Genome Sequence of Pseudomonas syringae Pathovar Syringae Strain FF5, Causal Agent of Stem Tip Dieback Disease on Ornamental Pear

    PubMed Central

    Sohn, Kee Hoon; Jones, Jonathan D. G.

    2012-01-01

    Pseudomonas syringae FF5 causes stem tip dieback disease on ornamental pear (Pyrus calleryana). Its genome encodes a complete type III secretion system (T3SS) and HopAC1, HopM1, AvrE1, HopI1, HopAA1, HopJ1, HopAH2, HopAH1, HopAG1, and HopAZ1. Lacking detectable homologues of other T3SS effectors, it may encode novel, undiscovered effectors. PMID:22740663

  6. Temporal variability in the life history and reproductive biology of female dugongs in Torres Strait: The likely role of sea grass dieback

    NASA Astrophysics Data System (ADS)

    Marsh, Helene; Kwan, Donna

    2008-09-01

    The extensive sea grass meadows in Torres Strait enable it to be a globally important habitat for the dugong, Dugong dugon, a marine mammal of cultural and dietary significance to Torres Strait Islanders and the basis for the substantial island-based fishery in the Torres Strait Protected Zone. Torres Strait sea grass communities are subjected to episodic diebacks which are now believed to be largely natural events. Information on dugong life history was obtained from specimens obtained from female dugongs as they were butchered for food by Indigenous hunters at two major dugong hunting communities in Torres Strait: Daru (9.04°S, 143.21°E) in 1978-1982 (a time of sea grass dieback and recovery) and Mabuiag Island (9.95°S, 142.15°E) in 1997-1999 (when sea grasses were abundant). Dugongs sampled in 1997-1999 had their first calf at younger ages (minimum of 6 cf. 10 years), and more frequently (interbirth interval based on all possible pregnancies 2.6±0.4 (S.E.) yr cf. 5.8±1.0 yr) than the dugongs sampled in 1978-1982. Pregnancy rates increased monotonically during 1978-1982, coincident with sea grass recovery. The age distribution of the female dugongs collected in 1997-1999 also suggested a low birth rate between 1973 and 1983 and/or or a high level of mortality for animals born during this period. These results add to the evidence from other regions that the life history and reproductive rate of female dugongs are adversely affected by sea grass loss, the effect of which cannot be separated from a possible density-dependent response to changes in dugong population size. Many green turtles in Torres Strait were also in poor body condition coincident with the 1970s sea grass dieback. The impacts of future sea grass diebacks need to be anticipated when management options for the traditional Torres Strait fisheries for dugongs and green turtles are evaluated.

  7. Entomology: A Bee Farming a Fungus.

    PubMed

    Oldroyd, Benjamin P; Aanen, Duur K

    2015-11-16

    Farming is done not only by humans, but also by some ant, beetle and termite species. With the discovery of a stingless bee farming a fungus that provides benefits to its larvae, bees can be added to this list.

  8. Defense Responses in Grapevine (cv. Mourvèdre) after Inoculation with the Botryosphaeria Dieback Pathogens Neofusicoccum parvum and Diplodia seriata and Their Relationship with Flowering

    PubMed Central

    Spagnolo, Alessandro; Mondello, Vincenzo; Larignon, Philippe; Villaume, Sandra; Rabenoelina, Fanja; Clément, Christophe; Fontaine, Florence

    2017-01-01

    As a result of the increasing economic impact of grapevine trunk diseases on viticulture worldwide, efficient and viable control strategies are urgently needed. However, understanding both plant-pathogen interactions and plant physiological changes related to these diseases is fundamental to such an achievement. In this study, we analyzed the effect of inoculation with the Botryosphaeria dieback fungal agents, Neofusicoccum parvum and Diplodia seriata, with and without inflorescence removal at the onset of G stage (separated clusters), I stage (flowering) and M stage (veraison). A measure of lesion size and real-time reverse-transcription polymerase chain reaction-based analysis were carried out. The results clearly show the importance of inflorescences in the development of lesions associated with Botryosphaeria dieback pathogens inoculated on green stems of adult vines, especially at the onset of flowering. At flowering, the biggest necroses were observed with the inflorescences present, as well as an activation of the studied defense responses. Thus, an ineffective response to the pathogen could be consistent with a possible metabolic reprogramming linked to the host phenophase. PMID:28208805

  9. Drought-induced shoot dieback starts with massive root xylem embolism and variable depletion of nonstructural carbohydrates in seedlings of two tree species.

    PubMed

    Rodríguez-Calcerrada, Jesús; Li, Meng; López, Rosana; Cano, Francisco Javier; Oleksyn, Jacek; Atkin, Owen K; Pita, Pilar; Aranda, Ismael; Gil, Luis

    2017-01-01

    Combining hydraulic- and carbon-related measurements helps to understand drought-induced plant mortality. Here, we investigated the role that plant respiration (R) plays in determining carbon budgets under drought. We measured the hydraulic conductivity of stems and roots, and gas exchange and nonstructural carbohydrate (NSC) concentrations of leaves, stems and roots of seedlings of two resprouting species exposed to drought or well-watered conditions: Ulmus minor (riparian tree) and Quercus ilex (dryland tree). With increasing water stress (occurring more rapidly in larger U. minor), declines in leaf, stem and root R were less pronounced than that in leaf net photosynthetic CO2 uptake (Pn ). Daytime whole-plant carbon gain was negative below -4 and -6 MPa midday xylem water potential in U. minor and Q. ilex, respectively. Relative to controls, seedlings exhibiting shoot dieback suffered c. 80% loss of hydraulic conductivity in both species, and reductions in NSC concentrations in U. minor. Higher drought-induced depletion of NSC reserves in U. minor was related to higher plant R, faster stomatal closure, and premature leaf-shedding. Differences in drought resistance relied on the ability to maintain hydraulic conductivity during drought, rather than tolerating conductivity loss. Root hydraulic failure elicited shoot dieback and precluded resprouting without root NSC reserves being apparently limiting for R.

  10. Flowering as the Most Highly Sensitive Period of Grapevine (Vitis vinifera L. cv Mourvèdre) to the Botryosphaeria Dieback Agents Neofusicoccum parvum and Diplodia seriata Infection

    PubMed Central

    Spagnolo, Alessandro; Larignon, Philippe; Magnin-Robert, Maryline; Hovasse, Agnès; Cilindre, Clara; Van Dorsselaer, Alain; Clément, Christophe; Schaeffer-Reiss, Christine; Fontaine, Florence

    2014-01-01

    Botryosphaeria dieback is a fungal grapevine trunk disease that currently represents a threat for viticulture worldwide because of the important economical losses due to reduced yield of affected plants and their premature death. Neofusicoccum parvum and Diplodia seriata are among the causal agents. Vine green stems were artificially infected with N. parvum or D. seriata at the onset of three different phenological stages (G stage (separated clusters), flowering and veraison). Highest mean lesion lengths were recorded at flowering. Major proteome changes associated to artificial infections during the three different phenological stages were also reported using two dimensional gel electrophoresis (2D)-based analysis. Twenty (G stage), 15 (flowering) and 13 (veraison) differentially expressed protein spots were subjected to nanoLC-MS/MS and a total of 247, 54 and 25 proteins were respectively identified. At flowering, a weaker response to the infection was likely activated as compared to the other stages, and some defense-related proteins were even down regulated (e.g., superoxide dismutase, major latex-like protein, and pathogenesis related protein 10). Globally, the flowering period seemed to represent the period of highest sensitivity of grapevine to Botryosphaeria dieback agent infection, possibly being related to the high metabolic activity in the inflorescences. PMID:24886812

  11. Flowering as the most highly sensitive period of grapevine (Vitis vinifera L. cv Mourvèdre) to the Botryosphaeria dieback agents Neofusicoccum parvum and Diplodia seriata infection.

    PubMed

    Spagnolo, Alessandro; Larignon, Philippe; Magnin-Robert, Maryline; Hovasse, Agnès; Cilindre, Clara; Van Dorsselaer, Alain; Clément, Christophe; Schaeffer-Reiss, Christine; Fontaine, Florence

    2014-05-30

    Botryosphaeria dieback is a fungal grapevine trunk disease that currently represents a threat for viticulture worldwide because of the important economical losses due to reduced yield of affected plants and their premature death. Neofusicoccum parvum and Diplodia seriata are among the causal agents. Vine green stems were artificially infected with N. parvum or D. seriata at the onset of three different phenological stages (G stage (separated clusters), flowering and veraison). Highest mean lesion lengths were recorded at flowering. Major proteome changes associated to artificial infections during the three different phenological stages were also reported using two dimensional gel electrophoresis (2D)-based analysis. Twenty (G stage), 15 (flowering) and 13 (veraison) differentially expressed protein spots were subjected to nanoLC-MS/MS and a total of 247, 54 and 25 proteins were respectively identified. At flowering, a weaker response to the infection was likely activated as compared to the other stages, and some defense-related proteins were even down regulated (e.g., superoxide dismutase, major latex-like protein, and pathogenesis related protein 10). Globally, the flowering period seemed to represent the period of highest sensitivity of grapevine to Botryosphaeria dieback agent infection, possibly being related to the high metabolic activity in the inflorescences.

  12. Endophytic Association of Trichoderma asperellum within Theobroma cacao Suppresses Vascular Streak Dieback Incidence and Promotes Side Graft Growth

    PubMed Central

    Nasaruddin, Nasaruddin; Hendarto, Hendarto; Hakkar, Andi Akbar; Agriansyah, Nursalim

    2016-01-01

    Trichoderma species are able to persist on living sapwood and leaves of cacao (Theobroma cacao) in an endophytic relationship. In this research, we evaluated the ability of Trichodema asperellum introduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application of T. asperellum was 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mL T. asperellum, the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations of T. asperellum listed above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application of T. asperellum to cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches. PMID:27790069

  13. Exploring fungus-plant N transfer in a tripartite ant-plant-fungus mutualism.

    PubMed

    Leroy, Céline; Jauneau, Alain; Martinez, Yves; Cabin-Flaman, Armelle; Gibouin, David; Orivel, Jérôme; Séjalon-Delmas, Nathalie

    2017-09-01

    The plant Hirtella physophora, the ant Allomerus decemarticulatus and a fungus, Trimmatostroma sp., form a tripartite association. The ants manipulate both the plant trichomes and the fungus to build galleries under the stems of their host plant used to capture prey. In addition to its structural role, the fungus also improves nutrient uptake by the host plant. But it still remains unclear whether the fungus plays an indirect or a direct role in transferring nutrients to the plant. This study aimed to trace the transfer of N from the fungus to the plant's stem tissue. Optical microscopy and transmission electron microscopy (TEM) were used to investigate the presence of fungal hyphae in the stem tissues. Then, a 15N-labelling experiment was combined with a nanoscale secondary-ion mass spectrometry (NanoSIMS 50) isotopic imaging approach to trace the movement of added 15N from the fungus to plant tissues. The TEM images clearly showed hyphae inside the stem tissue in the cellular compartment. Also, fungal hyphae were seen perforating the wall of the parenchyma cell. The 15N provisioning of the fungus in the galleries resulted in significant enrichment of the 15N signature of the plant's leaves 1 d after the 15N-labelling solution was deposited on the fungus-bearing trap. Finally, NanoSIMS imaging proved that nitrogen was transferred biotrophically from the fungus to the stem tissue. This study provides evidence that the fungi are connected endophytically to an ant-plant system and actively transfer nitrogen from 15N-labelling solution to the plant's stem tissues. Overall, this study underlines how complex the trophic structure of ant-plant interactions is due to the presence of the fungus and provides insight into the possibly important nutritional aspects and tradeoffs involved in myrmecophyte-ant mutualisms.

  14. Grower perceptions of preventative practices for management of trunk diseases of grape

    USDA-ARS?s Scientific Manuscript database

    Trials on prevention of trunk diseases (e.g., Eutypa dieback) show that three practices [delayed pruning, double pruning, pruning-wound protectants] prevent pruning-wound infections by 25-100%. Nonetheless, they are often not adopted until disease incidence is >20% in mature vineyards. There are no ...

  15. Susceptibility of cultivated and wild Vitis to wood infection by fungal trunk pathogens

    USDA-ARS?s Scientific Manuscript database

    Cultivars of European grapevine, Vitis vinifera, show varying levels of susceptibility to Eutypa dieback and Esca, in terms of foliar symptoms. However, little is known regarding cultivar susceptibility of their woody tissues to canker formation. Accordingly, we evaluated the relative susceptibility...

  16. TrunkDiseaseID.org: A molecular database for fast and accurate identification of fungi commonly isolated from grapevine wood

    USDA-ARS?s Scientific Manuscript database

    The grapevine trunk-disease complex limits vineyard longevity in all major grape-growing regions. Although trunk diseases have been distinguished based on causal agents (aka trunk pathogens) and etiologies (e.g., Botryosphaeria-, Eutypa-, and Phomopsis diebacks, Esca), mixed infections are frequent ...

  17. Hypovirulence of the Phytopathogenic Fungus Botryosphaeria dothidea: Association with a Coinfecting Chrysovirus and a Partitivirus

    PubMed Central

    Wang, LiPing; Jiang, JingJing; Wang, YanFen; Hong, Ni; Zhang, Fangpeng

    2014-01-01

    ABSTRACT Botryosphaeria dothidea is an important pathogenic fungus causing fruit rot, leaf and stem ring spots and dieback, stem canker, stem death or stool mortality, and decline of pear trees. Seven double-stranded RNAs (dsRNAs; dsRNAs 1 to 7 with sizes of 3,654, 2,773, 2,597, 2,574, 1,823, 1,623, and 511 bp, respectively) were identified in an isolate of B. dothidea exhibiting attenuated growth and virulence and a sectoring phenotype. Characterization of the dsRNAs revealed that they belong to two dsRNA mycoviruses. The four largest dsRNAs (dsRNAs 1 to 4) are the genomic components of a novel member of the family Chrysoviridae (tentatively designated Botryosphaeria dothidea chrysovirus 1 [BdCV1]), a view supported by the morphology of the virions and phylogenetic analysis of the putative RNA-dependent RNA polymerases (RdRps). Two other dsRNAs (dsRNAs 5 and 6) are the genomic components of a novel member of the family Partitiviridae (tentatively designated Botryosphaeria dothidea partitivirus 1 [BdPV1]), which is placed in a clade distinct from other established partitivirus genera on the basis of the phylogenetic analysis of its RdRp. The smallest dsRNA, dsRNA7, seems to be a noncoding satellite RNA of BdPV1 on the basis of the conservation of its terminal sequences in BdPV1 genomic segments and its cosegregation with BdPV1 after horizontal transmission. This is the first report of a chrysovirus and a partitivirus infecting B. dothidea and of a chrysovirus associated with the hypovirulence of a phytopathogenic fungus. IMPORTANCE Our studies identified and characterized two novel mycoviruses, Botryosphaeria dothidea chrysovirus 1 (BdCV1) and Botryosphaeria dothidea partitivirus 1 (BdPV1), associated with the hypovirulence of an important fungus pathogenic to fruit trees. This is the first report of a chrysovirus and a partitivirus infecting B. dothidea and of a chrysovirus associated with the hypovirulence of a phytopathogenic fungus. BdCV1 appears to be a good

  18. Fungus-insect gall of Phlebopus portentosus.

    PubMed

    Zhang, Chun-Xia; He, Ming-Xia; Cao, Yang; Liu, Jing; Gao, Feng; Wang, Wen-Bing; Ji, Kai-Ping; Shao, Shi-Cheng; Wang, Yun

    2015-01-01

    Phlebopus portentosus is a popular edible wild mushroom found in the tropical Yunnan, China, and northern Thailand. In its natural habitats, a gall often has been found on some plant roots, around which fungal fruiting bodies are produced. The galls are different from common insect galls in that their cavity walls are not made from plant tissue but rather from the hyphae of P. portentosus. Therefore we have termed this phenomenon "fungus-insect gall". Thus far six root mealy bug species in the family Pseudococcidae that form fungus-insect galls with P. portentosus have been identified: Formicococcus polysperes, Geococcus satellitum, Planococcus minor, Pseudococcus cryptus, Paraputo banzigeri and Rastrococcus invadens. Fungus-insect galls were found on the roots of more than 21 plant species, including Delonix regia, Citrus maxima, Coffea arabica and Artocarpus heterophyllus. Greenhouse inoculation trials showed that fungus-insect galls were found on the roots of A. heterophyllus 1 mo after inoculation. The galls were subglobose to globose, fulvous when young and became dark brown at maturation. Each gall harbored one or more mealy bugs and had a chimney-like vent for ventilation and access to the gall. The cavity wall had three layers. Various shaped mealy bug wax deposits were found inside the wall. Fungal hyphae invaded the epidermis of plant roots and sometimes even the cortical cells during the late stage of gall development. The identity of the fungus inside the cavity was confirmed by molecular methods.

  19. High-resolution intravital imaging reveals that blood-derived macrophages but not resident microglia facilitate secondary axonal dieback in traumatic spinal cord injury.

    PubMed

    Evans, Teresa A; Barkauskas, Deborah S; Myers, Jay T; Hare, Elisabeth G; You, Jing Qiang; Ransohoff, Richard M; Huang, Alex Y; Silver, Jerry

    2014-04-01

    After traumatic spinal cord injury, functional deficits increase as axons die back from the center of the lesion and the glial scar forms. Axonal dieback occurs in two phases: an initial axon intrinsic stage that occurs over the first several hours and a secondary phase which takes place over the first few weeks after injury. Here, we examine the secondary phase, which is marked by infiltration of macrophages. Using powerful time-lapse multi-photon imaging, we captured images of interactions between Cx3cr1(+/GFP) macrophages and microglia and Thy-1(YFP) axons in a mouse dorsal column crush spinal cord injury model. Over the first few weeks after injury, axonal retraction bulbs within the lesion are static except when axonal fragments are lost by a blebbing mechanism in response to physical contact followed by phagocytosis by mobile Cx3Cr1(+/GFP) cells. Utilizing a radiation chimera model to distinguish marrow-derived cells from radio-resistant CNS-resident microglia, we determined that the vast majority of accumulated cells in the lesion are derived from the blood and only these are associated with axonal damage. Interestingly, CNS-resident Cx3Cr1(+/GFP) microglia did not increasingly accumulate nor participate in neuronal destruction in the lesion during this time period. Additionally, we found that the blood-derived cells consisted mainly of singly labeled Ccr2(+/RFP) macrophages, singly labeled Cx3Cr1(+/GFP) macrophages and a small population of double-labeled cells. Since all axon destructive events were seen in contact with a Cx3Cr1(+/GFP) cell, we infer that the CCR2 single positive subset is likely not robustly involved in axonal dieback. Finally, in our model, deletion of CCR2, a chemokine receptor, did not alter the position of axons after dieback. Understanding the in vivo cellular interactions involved in secondary axonal injury may lead to clinical treatment candidates involving modulation of destructive infiltrating blood monocytes. Copyright © 2014

  20. Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis.

    PubMed

    Oh, Dong-Chan; Poulsen, Michael; Currie, Cameron R; Clardy, Jon

    2009-06-01

    Fungus-growing ants engage in mutualistic associations with both the fungus they cultivate for food and actinobacteria (Pseudonocardia spp.) that produce selective antibiotics to defend that fungus from specialized fungal parasites. We have analyzed one such system at the molecular level and found that the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the associated parasitic fungus (Escovopsis sp.).

  1. White-Nose Syndrome Fungus (Geomyces destructans) in Bat, France

    PubMed Central

    Puechmaille, Sébastien J.; Verdeyroux, Pascal; Fuller, Hubert; Gouilh, Meriadeg Ar; Bekaert, Michaël

    2010-01-01

    White-nose syndrome is caused by the fungus Geomyces destructans and is responsible for the deaths of >1,000,000 bats since 2006. This disease and fungus had been restricted to the northeastern United States. We detected this fungus in a bat in France and assessed the implications of this finding. PMID:20113562

  2. White-nose syndrome fungus (Geomyces destructans) in bat, France.

    PubMed

    Puechmaille, Sebastien J; Verdeyroux, Pascal; Fuller, Hubert; Gouilh, Meriadeg Ar; Bekaert, Michael; Teeling, Emma C

    2010-02-01

    White-nose syndrome is caused by the fungus Geomyces destructans and is responsible for the deaths of >1,000,000 bats since 2006. This disease and fungus had been restricted to the northeastern United States. We detected this fungus in a bat in France and assessed the implications of this finding.

  3. Contamination of Pine Seeds by the Pitch Canker Fungus

    Treesearch

    L. David Dwinell; S.W. Fraedrich

    1999-01-01

    The pitch canker fungus, Fusarium subglutinans f. sp. pini, has been identified as a significant problem in man pine seed orchards and nursuries in the South. THe fungus causes strobilus mortality, seed deterioation, and cankers on the main stem, branches, and shoots of pines Dwinell and others 1985). The pitche canker fungus...

  4. Preliminary Effects of Fertilization on Ecochemical Soil Condition in Mature Spruce Stands Experiencing Dieback in the Beskid Śląski and Żywiecki Mountains, Poland.

    PubMed

    Małek, Stanisław; Januszek, Kazimierz; Keeton, William S; Barszcz, Józef; Kroczek, Marek; Błońska, Ewa; Wanic, Tomasz

    2014-01-01

    In recent years, there has been the phenomena of spruce dieback in Europe. Significant areas of spruce low mortality now cover both sides of the Polish southern border. We evaluated ecochemical parameters influencing the heavy dieback occurring in mature spruce stands in the Polish Carpathian Mountains. Dolomite, magnesite and serpentinite fertilizers were applied to experimental plots located in 100-year-old stands in the autumn of 2008. The experimental plots were located in the mid-elevational forest zone (900-950 m) on two nappes of the flysch Carpathians: Magura (Ujsoły Forest District) and Silesian (Wisła Forest District). The saturation of the studied soils demonstrates moderate resilience of soils in Wisła Forest District in relation to acid load and high flexibility of the Ujsoły soils. After application of the fertilizers, an increase of Mg, Ca and Mb was noted in the soil solution, determined in the overlaying highly acidic organic horizons through the ion-exchange buffering mechanism of highly protonated functional groups with high buffering capacity. Magnesium concentration increased following fertilization, presenting a potential improvement of forest growth capacity without the hazard of adverse side effects of liming. Aluminium stress in old spruce is unlikely, while trees in the control plots in Wisła Forest District may already be sensitive to aluminium stress. Serpentinite fertilization improved the supply of soils in magnesium without causing significant changes in the pH of the soil. Such changes in the pH were found in dolomite and magnesite fertilizer.

  5. High-resolution intravital imaging reveals that blood derived macrophages but not resident microglia facilitate secondary axonal dieback in traumatic spinal cord injury

    PubMed Central

    Evans, Teresa A.; Barkauskas, Deborah S.; Myers, Jay; Hare, Elisabeth G.; You, Jingquang; Ransohoff, Richard M.; Huang, Alex Y.; Silver, Jerry

    2014-01-01

    After traumatic spinal cord injury, functional deficits increase as axons die back from the center of the lesion and the glial scar forms. Axonal die back occurs in two phases: an initial axon intrinsic stage that occurs over the first several hours and a secondary phase which takes place over the first few weeks after injury. Here, we examine the secondary phase, which is marked by infiltration of macrophages. Using powerful time lapse multi-photon imaging, we captured images of interactions between Cx3cr1+/GFP macrophages and microglia and Thy-1YFP axons in a mouse dorsal column crush spinal cord injury model. Over the first few weeks after injury, axonal retraction bulbs within the lesion are static except when axonal fragments are lost by a blebbing mechanism in response to physical contact followed by phagocytosis by mobile Cx3Cr1+/GFP cells. Utilizing a radiation chimera model to distinguish marrow-derived cells from radio-resistant CNS resident microglia, we determined that the vast majority of accumulated cells in the lesion are derived from the blood and only these are associated with axonal damage. Interestingly, CNS-resident Cx3Cr1+/GFP microglia did not increasingly accumulate nor participate in neuronal destruction in the lesion during this time period. Additionally, we found that the blood-derived cells consisted mainly of singly labeled Ccr2+/RFP macrophages, singly labeled Cx3Cr1+/GFP macrophages and a small population of double-labeled cells. Since all axon destructive events were seen in contact with a Cx3Cr1+/GFP cell, we infer that the CCR2 single positive subset is likely not robustly involved in axonal dieback. Finally, in our model, deletion of CCR2, a chemokine receptor, did not alter the position of axons after dieback. Understanding the in vivo cellular interactions involved in secondary axonal injury may lead to clinical treatment candidates involving modulation of destructive infiltrating blood monocytes. PMID:24468477

  6. Global distribution of the pitch canker fungus

    Treesearch

    L. David Dwinell

    1998-01-01

    The pitch canker fungus, Fusarium subglutinans f. sp. pini, causes diseases of pines in the United States, Haiti, Japan, Mexico, Spain, and South Africa. Pitch canker was first reported in Virginia pine in North Carolina in 1946. Although the disease was reported in Haitian pine in 1953, pitch canker was generally considered a...

  7. Solanapyrone analogues from a Hawaiian fungicolous fungus

    USDA-ARS?s Scientific Manuscript database

    Four new solanayrone analogues (solanapyrones J-M; 1-4) have been isolated from an unidentified fungicolous fungus collected in Hawaii. The structures and relative configurations of these compounds were determined by analysis of ID NMR, 2D NMR, and MS data. Solanapyrone J(1) showed antifungal acti...

  8. Ant-fungus species combinations engineer physiological activity of fungus gardens.

    PubMed

    Seal, J N; Schiøtt, M; Mueller, U G

    2014-07-15

    Fungus-gardening insects are among the most complex organisms because of their extensive co-evolutionary histories with obligate fungal symbionts and other microbes. Some fungus-gardening insect lineages share fungal symbionts with other members of their lineage and thus exhibit diffuse co-evolutionary relationships, while others exhibit little or no symbiont sharing, resulting in host-fungus fidelity. The mechanisms that maintain this symbiont fidelity are currently unknown. Prior work suggested that derived leaf-cutting ants in the genus Atta interact synergistically with leaf-cutter fungi (Attamyces) by exhibiting higher fungal growth rates and enzymatic activities than when growing a fungus from the sister-clade to Attamyces (so-called 'Trachymyces'), grown primarily by the non-leaf cutting Trachymyrmex ants that form, correspondingly, the sister-clade to leaf-cutting ants. To elucidate the enzymatic bases of host-fungus specialization in leaf-cutting ants, we conducted a reciprocal fungus-switch experiment between the ant Atta texana and the ant Trachymyrmex arizonensis and report measured enzymatic activities of switched and sham-switched fungus gardens to digest starch, pectin, xylan, cellulose and casein. Gardens exhibited higher amylase and pectinase activities when A. texana ants cultivated Attamyces compared with Trachymyces fungi, consistent with enzymatic specialization. In contrast, gardens showed comparable amylase and pectinase activities when T. arizonensis cultivated either fungal species. Although gardens of leaf-cutting ants are not known to be significant metabolizers of cellulose, T. arizonensis were able to maintain gardens with significant cellulase activity when growing either fungal species. In contrast to carbohydrate metabolism, protease activity was significantly higher in Attamyces than in Trachymyces, regardless of the ant host. Activity of some enzymes employed by this symbiosis therefore arises from complex interactions between the

  9. Vegetation dieback as a proxy for temperature within a wet pyroclastic density current: A novel experiment and observations from the 6th of August 2012 Tongariro eruption

    NASA Astrophysics Data System (ADS)

    Efford, Jackson T.; Bylsma, Rebecca J.; Clarkson, Bruce D.; Pittari, Adrian; Mauriohooho, Kate; Moon, Vicki G.

    2014-10-01

    The 6th of August 2012 eruption of Te Maari (Mt Tongariro, New Zealand) generated wet pyroclastic density currents (PDCs) which caused widespread dieback of vegetation (singed, brown foliage) in their path. An absence of significant charcoal formation suggests that PDC temperatures were mostly below 250 °C. Textural evidence for liquid water being present in the matrices during emplacement (vesicles) suggests that temperatures were < 100 °C. We determined a probable minimum PDC temperature using an experiment replicating the critical temperatures required to induce foliar browning in seven species affected by the eruption. In locations where all species exhibited browned foliage (or were defoliated), temperatures were probably ≥ 64 °C assuming a PDC duration of 60 s. In the more distal areas, where only the most susceptible species were browned while others remained healthy and unaffected, temperatures were probably around 51-58 °C. These results have relevance to volcanic hazard mitigation and risk assessment, especially on the popular Tongariro Alpine Crossing.

  10. In Vivo Two-Photon Imaging of Axonal Dieback, Blood Flow, and Calcium Influx with Methylprednisolone Therapy after Spinal Cord Injury

    PubMed Central

    Tang, Peifu; Zhang, Yiling; Chen, Chao; Ji, Xinran; Ju, Furong; Liu, Xingyu; Gan, Wen-Biao; He, Zhigang; Zhang, Shengxiang; Li, Wei; Zhang, Lihai

    2015-01-01

    Severe spinal cord injury (SCI) can cause neurological dysfunction and paralysis. However, the early dynamic changes of neurons and their surrounding environment after SCI are poorly understood. Although methylprednisolone (MP) is currently the standard therapeutic agent for treating SCI, its efficacy remains controversial. The purpose of this project was to investigate the early dynamic changes and MP's efficacy on axonal damage, blood flow, and calcium influx into axons in a mouse SCI model. YFP H-line and Thy1-GCaMP transgenic mice were used in this study. Two-photon microscopy was used for imaging of axonal dieback, blood flow, and calcium influx post-injury. We found that MP treatment attenuated progressive damage of axons, increased blood flow, and reduced calcium influx post-injury. Furthermore, microglia/macrophages accumulated in the lesion site after SCI and expressed the proinflammatory mediators iNOS, MCP-1 and IL-1β. MP treatment markedly inhibited the accumulation of microglia/macrophages and reduced the expression of the proinflammatory mediators. MP treatment also improved the recovery of behavioral function post-injury. These findings suggest that MP exerts a neuroprotective effect on SCI treatment by attenuating progressive damage of axons, increasing blood flow, reducing calcium influx, and inhibiting the accumulation of microglia/macrophages after SCI. PMID:25989524

  11. In vivo two-photon imaging of axonal dieback, blood flow, and calcium influx with methylprednisolone therapy after spinal cord injury.

    PubMed

    Tang, Peifu; Zhang, Yiling; Chen, Chao; Ji, Xinran; Ju, Furong; Liu, Xingyu; Gan, Wen-Biao; He, Zhigang; Zhang, Shengxiang; Li, Wei; Zhang, Lihai

    2015-05-19

    Severe spinal cord injury (SCI) can cause neurological dysfunction and paralysis. However, the early dynamic changes of neurons and their surrounding environment after SCI are poorly understood. Although methylprednisolone (MP) is currently the standard therapeutic agent for treating SCI, its efficacy remains controversial. The purpose of this project was to investigate the early dynamic changes and MP's efficacy on axonal damage, blood flow, and calcium influx into axons in a mouse SCI model. YFP H-line and Thy1-GCaMP transgenic mice were used in this study. Two-photon microscopy was used for imaging of axonal dieback, blood flow, and calcium influx post-injury. We found that MP treatment attenuated progressive damage of axons, increased blood flow, and reduced calcium influx post-injury. Furthermore, microglia/macrophages accumulated in the lesion site after SCI and expressed the proinflammatory mediators iNOS, MCP-1 and IL-1β. MP treatment markedly inhibited the accumulation of microglia/macrophages and reduced the expression of the proinflammatory mediators. MP treatment also improved the recovery of behavioral function post-injury. These findings suggest that MP exerts a neuroprotective effect on SCI treatment by attenuating progressive damage of axons, increasing blood flow, reducing calcium influx, and inhibiting the accumulation of microglia/macrophages after SCI.

  12. Erythritol Production by a Yeastlike Fungus

    PubMed Central

    Hajny, G. J.; Smith, J. H.; Garver, J. C.

    1964-01-01

    A yeastlike fungus, probably belonging to the genus Torula, was isolated from fresh pollen and was shown to produce erythritol in yields of 35 to 40% of the sugar utilized. The ability to produce erythritol is an inherent characteristic of the isolate, but unfavorable fermentation conditions can lead to the production of glycerol at the expense of erythritol. By the use of a synthetic medium, it was shown that the concentrations of both nitrogen and phosphorous in the medium must be closely controlled to obtain satisfactory erythritol yields. PMID:14171841

  13. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe

    PubMed Central

    Spitzen-van der Sluijs, Annemarieke; Martel, An; Asselberghs, Johan; Bales, Emma K.; Beukema, Wouter; Bletz, Molly C.; Dalbeck, Lutz; Goverse, Edo; Kerres, Alexander; Kinet, Thierry; Kirst, Kai; Laudelout, Arnaud; Marin da Fonte, Luis F.; Nöllert, Andreas; Ohlhoff, Dagmar; Sabino-Pinto, Joana; Schmidt, Benedikt R.; Speybroeck, Jeroen; Spikmans, Frank; Steinfartz, Sebastian; Veith, Michael; Vences, Miguel; Wagner, Norman; Pasmans, Frank

    2016-01-01

    Emerging fungal diseases can drive amphibian species to local extinction. During 2010–2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity. PMID:27070102

  14. Metacridamides A and B from the biocontrol fungus metarhizium acridum

    USDA-ARS?s Scientific Manuscript database

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. As part of an effort to catalog the secondary metabolites of this fungus we discovered that its conidia produce two novel 17-membered macrocycl...

  15. Phomalactone from a phytopathogenic fungus infecting Zinnia elegans (Asteraceae) leaves

    USDA-ARS?s Scientific Manuscript database

    Zinnia elegans plants are infected by a fungus that causes necrosis with dark red spots particularly in late spring to the middle of summer in the Mid-South part of the United States. This fungal disease when untreated causes the leaves to wilt and eventually kills the plant. The fungus was isolated...

  16. Bacterial farming by the fungus Morchella crassipes.

    PubMed

    Pion, Martin; Spangenberg, Jorge E; Simon, Anaele; Bindschedler, Saskia; Flury, Coralie; Chatelain, Auriel; Bshary, Redouan; Job, Daniel; Junier, Pilar

    2013-12-22

    The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and (13)C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils.

  17. Bacterial farming by the fungus Morchella crassipes

    PubMed Central

    Pion, Martin; Spangenberg, Jorge E.; Simon, Anaele; Bindschedler, Saskia; Flury, Coralie; Chatelain, Auriel; Bshary, Redouan; Job, Daniel; Junier, Pilar

    2013-01-01

    The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and 13C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils. PMID:24174111

  18. Assembly of complex plant–fungus networks

    PubMed Central

    Toju, Hirokazu; Guimarães, Paulo R.; Olesen, Jens M.; Thompson, John N.

    2014-01-01

    Species in ecological communities build complex webs of interaction. Although revealing the architecture of these networks is fundamental to understanding ecological and evolutionary dynamics in nature, it has been difficult to characterize the structure of most species-rich ecological systems. By overcoming this limitation through next-generation sequencing technology, we herein uncover the network architecture of below-ground plant–fungus symbioses, which are ubiquitous to terrestrial ecosystems. The examined symbiotic network of a temperate forest in Japan includes 33 plant species and 387 functionally and phylogenetically diverse fungal taxa, and the overall network architecture differs fundamentally from that of other ecological networks. In contrast to results for other ecological networks and theoretical predictions for symbiotic networks, the plant–fungus network shows moderate or relatively low levels of interaction specialization and modularity and an unusual pattern of ‘nested’ network architecture. These results suggest that species-rich ecological networks are more architecturally diverse than previously recognized. PMID:25327887

  19. Population structure of dogwood anthracnose fungus.

    PubMed

    Zhang, Ning; Blackwell, Meredith

    2002-12-01

    ABSTRACT Dogwood anthracnose, caused by Discula destructiva, affects several native dogwood species in North America, especially flowering dogwood in the east and Pacific dogwood in the west. The fungus behaves as a recently introduced plant pathogen under episodic selection. Two distinct disjunct groups of fungal isolates corresponding to eastern and western groups were detected by amplified fragment length polymorphisms and sequences of the intergenic spacer (IGS) of the nuclear ribosomal DNA, translation elongation factor-1alpha, and beta-tubulin genes. Of 20 genotypes identified among 72 isolates, 17 genotypes were from the eastern United States (n = 50), but only three were present among the western isolates (n = 22), indicating that the eastern population may be more diverse. Most eastern and western isolates belonged to a few widespread clones, and the genetic variability of this apparently asexual fungus was remarkably low compared with that of many other asexual fungi. We conclude that D. destructiva is still under intense selection pressure and that episodic selection may still be in effect. The New York City area, a possible epidemic center in the east, had relatively higher genetic variability than samples from other areas.

  20. Hazardous waste treatment using fungus enters marketplace

    SciTech Connect

    Illman, D.L.

    1993-07-01

    When the announcement was made eight years ago that a common fungus had been found that could degrade a variety of environmental pollutants, the news stirred interest in the scientific community, the private sector, and the general public. Here was the promise of a new technology that might be effective and economical in treating hazardous waste, especially the most recalcitrant of toxic pollutants. Today, commercialization is beginning amid a mixture of optimism and skepticism. The organism in question is white rot fungus, or Phanerochaete chrysosporium, and it belongs to a family of woodrotting fungi common all over North America. The fungi secrete enzymes that break down lignin in wood to carbon dioxide and water--a process called mineralization. These lignin-degrading enzymes are not very discriminating, however. The white rot fungi have been shown to degrade such materials as DDT, the herbicide (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), 2,4,6-trinitrotoluene (TNT), pentachlorophenol (PCP), creosote, coal tars, and heavy fuels, in many cases mineralizing these pollutants to a significant extent.

  1. General metabolism of the dimorphic and pathogenic fungus Paracoccidioides brasiliensis.

    PubMed

    Arraes, Fabrício B M; Benoliel, Bruno; Burtet, Rafael T; Costa, Patrícia L N; Galdino, Alexandro S; Lima, Luanne H A; Marinho-Silva, Camila; Oliveira-Pereira, Luciana; Pfrimer, Pollyanna; Procópio-Silva, Luciano; Reis, Viviane Castelo-Branco; Felipe, Maria Sueli S

    2005-06-30

    Annotation of the transcriptome of the dimorphic fungus Paracoccidioides brasiliensis has set the grounds for a global understanding of its metabolism in both mycelium and yeast forms. This fungus is able to use the main carbohydrate sources, including starch, and it can store reduced carbons in the form of glycogen and trehalose; these provide energy reserves that are relevant for metabolic adaptation, protection against stress and infectivity mechanisms. The glyoxylate cycle, which is also involved in pathogenicity, is present in this fungus. Classical pathways of lipid biosynthesis and degradation, including those of ketone body and sterol production, are well represented in the database of P. brasiliensis. It is able to synthesize de novo all nucleotides and amino acids, with the sole exception of asparagine, which was confirmed by the fungus growth in minimal medium. Sulfur metabolism, as well as the accessory synthetic pathways of vitamins and co-factors, are likely to exist in this fungus.

  2. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus – A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species

    PubMed Central

    Baral, Hans-Otto; Bemmann, Martin

    2014-01-01

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  3. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus - A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species.

    PubMed

    Baral, Hans-Otto; Bemmann, Martin

    2014-10-02

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  4. Progression of ash canopy thinning and dieback outward from the initial infestation of emerald ash borer (Coleoptera: Buprestidae) in southeastern Michigan.

    PubMed

    Smitley, David; Davis, Terrance; Rebek, Eric

    2008-10-01

    Our objective was to characterize the rate at which ash (Fraxinus spp.) trees decline in areas adjacent to the leading edge of visible ash canopy thinning due to emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Trees in southeastern Michigan were surveyed from 2003 to 2006 for canopy thinning and dieback by comparing survey trees with a set of 11 standard photographs. Freeways stemming from Detroit in all directions were used as survey transects. Between 750 and 1,100 trees were surveyed each year. A rapid method of sampling populations of emerald ash borer was developed by counting emerald ash borer emergence holes with binoculars and then felling trees to validate binocular counts. Approximately 25% of the trees surveyed for canopy thinning in 2005 and 2006 also were sampled for emerald ash borer emergence holes using binoculars. Regression analysis indicates that 41-53% of the variation in ash canopy thinning can be explained by the number of emerald ash borer emergence holes per tree. Emerald ash borer emergence holes were found at every site where ash canopy thinning averaged > 40%. In 2003, ash canopy thinning averaged 40% at a distance of 19.3 km from the epicenter of the emerald ash borer infestation in Canton. By 2006, the point at which ash trees averaged 40% canopy thinning had increased to a distance of 51.2 km away from Canton. Therefore, the point at which ash trees averaged 40% canopy thinning, a state of decline clearly visible to the average person, moved outward at a rate of 10.6 km/yr during this period.

  5. A foam formulation of an entomopathogenic fungus for control of boring beetles in avocado orchards

    USDA-ARS?s Scientific Manuscript database

    A foam formulation of Beauveria bassiana was adapted to control boring beetles in avocado orchards. The two geographically independent avocado growing areas in the United States are threatened by emerging diseases vectored by boring beetles. In the California growing region, Fusarium dieback is vect...

  6. Chemical composition of metapleural gland secretions of fungus-growing and non-fungus-growing ants.

    PubMed

    Vieira, Alexsandro S; Morgan, E David; Drijfhout, Falko P; Camargo-Mathias, Maria I

    2012-10-01

    The metapleural gland is exclusive to ants, and unusual among exocrine glands in having no mechanism for closure and retention of secretion. As yet, no clear conclusion has been reached as to the function of metapleural gland secretion. Metapleural gland secretions were investigated for fungus-growing ants representing the derived attines Trachymyrmex fuscus, Atta laevigata, and Acromyrmex coronatus, the basal attines Apterostigma pilosum and Mycetarotes parallelus, and non-fungus-growing ants of the tribes Ectatommini (Ectatomma brunneum) and Myrmicini (Pogonomyrmex naegeli). Our results showed that the secretions of leaf-cutting ants (A. laevigata and A. coronatus) and the derived attine, T. fuscus, contain a greater variety and larger quantities of volatile compounds than those of myrmicine and ectatommine ants. The most abundant compounds found in the metapleural glands of A. laevigata and A. coronatus were hydroxyacids, and phenylacetic acid (only in A. laevigata). Indole was present in all groups examined, while skatole was found in large quantities only in attines. Ketones and aldehydes are present in the secretion of some attines. Esters are present in the metapleural gland secretion of all species examined, although mainly in A. laevigata, A. coronatus, and T. fuscus. Compared with basal attines and non-fungus-growing ants, the metapleural glands of leaf-cutting ants produce more acidic compounds that may have an antibiotic or antifungal function.

  7. Is the Fungus Magnaporthe Losing DNA Methylation?

    PubMed Central

    Ikeda, Ken-ichi; Van Vu, Ba; Kadotani, Naoki; Tanaka, Masaki; Murata, Toshiki; Shiina, Kohta; Chuma, Izumi; Tosa, Yukio; Nakayashiki, Hitoshi

    2013-01-01

    The long terminal repeat retrotransposon, Magnaporthe gypsy-like element (MAGGY), has been shown to be targeted for cytosine methylation in a subset of Magnaporthe oryzae field isolates. Analysis of the F1 progeny from a genetic cross between methylation-proficient (Br48) and methylation-deficient (GFSI1-7-2) isolates revealed that methylation of the MAGGY element was governed by a single dominant gene. Positional cloning followed by gene disruption and complementation experiments revealed that the responsible gene was the DNA methyltransferase, MoDMT1, an ortholog of Neurospora crassa Dim-2. A survey of MAGGY methylation in 60 Magnaporthe field isolates revealed that 42 isolates from rice, common millet, wheat, finger millet, and buffelgrass were methylation proficient while 18 isolates from foxtail millet, green bristlegrass, Japanese panicgrass, torpedo grass, Guinea grass, and crabgrass were methylation deficient. Phenotypic analyses showed that MoDMT1 plays no major role in development and pathogenicity of the fungus. Quantitative polymerase chain reaction analysis showed that the average copy number of genomic MAGGY elements was not significantly different between methylation-deficient and -proficient field isolates even though the levels of MAGGY transcript were generally higher in the former group. MoDMT1 gene sequences in the methylation-deficient isolates suggested that at least three independent mutations were responsible for the loss of MoDMT1 function. Overall, our data suggest that MoDMT1 is not essential for the natural life cycle of the fungus and raise the possibility that the genus Magnaporthe may be losing the mechanism of DNA methylation on the evolutionary time scale. PMID:23979580

  8. Specificity in the interaction between an epibiotic clavicipitalean fungus and its convolvulaceous host in a fungus/plant symbiotum

    PubMed Central

    Steiner, Ulrike; Hellwig, Sabine

    2008-01-01

    Ipomoea asarifolia and Turbina corymbosa (Convolvulaceae) are associated with epibiotic clavicipitalean fungi responsible for the presence of ergoline alkaloids in these plants. Experimentally generated plants devoid of these fungi were inoculated with different epibiotic and endophytic fungi resulting in a necrotic or commensal situation. A symbiotum of host plant and its respective fungus was best established by integration of the fungus into the morphological differentiation of the host plant. This led us to suppose that secretory glands on the leaf surface of the host plant may play an essential role in ergoline alkaloid biosynthesis which takes place in the epibiotic fungus. PMID:19704834

  9. An insect parasitoid carrying an ochratoxin producing fungus

    NASA Astrophysics Data System (ADS)

    Vega, Fernando E.; Posada, Francisco; Gianfagna, Thomas J.; Chaves, Fabio C.; Peterson, Stephen W.

    2006-06-01

    The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.

  10. An insect parasitoid carrying an ochratoxin producing fungus.

    PubMed

    Vega, Fernando E; Posada, Francisco; Gianfagna, Thomas J; Chaves, Fabio C; Peterson, Stephen W

    2006-06-01

    The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.

  11. Parasitic Aspects of a Fairy Ring Fungus, Marasmius oreades

    Treesearch

    T. H. Filer

    1965-01-01

    Marasmius oreades parasitizes Poa pratensis, Festuca rubra, and Agrostis tenuis. The fungus penetrates the root directly in all three species and does not require natural openings or wounds. The mycelium ramifies in the cortical cells and destroys the cell contents.

  12. FLUORESCENT-SERIOLOGICAL INVESTIGATIONS OF A PATHOGENIC FUNGUS (SPOROTRICHUM SCHENCKII),

    DTIC Science & Technology

    coloration of numerous other species of fungus no cross reactions with Sporotrichum schenkii were found. The use of this fluorescent coloring method for the diagnosis of Sporotrichosis is suggested. (Author)

  13. The role of mites in insect-fungus associations.

    PubMed

    Hofstetter, R W; Moser, J C

    2014-01-01

    The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on fungi for nutrients, and fungi benefit from them with regard to spore dispersal, habitat provision, or nutrient resources. Mites have important impacts on community dynamics, ecosystem processes, and biodiversity within many insect-fungus systems. Given that mites are understudied but highly abundant, they likely have bigger, more important, and more widespread impacts on communities than previously recognized. We describe mutualistic and antagonistic effects of mites on insect-fungus associations, explore the processes that underpin ecological and evolutionary patterns of these multipartite communities, review well-researched examples of the effects of mites on insect-fungus associations, and discuss approaches for studying mites within insect-fungus communities.

  14. Fungus Ball in Concha Bullosa: A Rare Case with Anosmia

    PubMed Central

    Özkırıs, Mahmut; Kapusuz, Zeliha; Seçkın, Selda; Saydam, Levent

    2013-01-01

    Concha bullosa is the pneumatization of the concha and is one of the most common variations of the sinonasal anatomy. The histopathological changes caused by the infections which arise from the impaired aeration of conchal cavity are frequently found. Fungus ball of the nasal cavity is an extremely rare, fungal infection with only three cases reported previously. In this paper, we present the fourth fungus ball case which developed within a concha bullosa and presented with anosmia. PMID:23936708

  15. Biological control of Ascaris suum eggs by Pochonia chlamydosporia fungus.

    PubMed

    Ferreira, Sebastião Rodrigo; de Araújo, Jackson Victor; Braga, Fábio Ribeiro; Araujo, Juliana Milani; Frassy, Luiza Neme; Ferreira, Aloízio Soares

    2011-12-01

    Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26 °C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs.

  16. Pathogenic nature of Syncephalastrum in Atta sexdens rubropilosa fungus gardens.

    PubMed

    Barcoto, Mariana O; Pedrosa, Felipe; Bueno, Odair C; Rodrigues, Andre

    2017-05-01

    Leaf-cutter ants are considered to be a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism responsible for a characteristic disease in fungus gardens. We also characterise the damage caused by this fungus by evaluating physiological and behavioural responses of Atta sexdens rubropilosa subcolonies infected with Syncephalastrum sp. Syncephalastrum sp. fulfils Koch's postulates characterising it as a pathogenic microorganism. Ant workers recognise the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, subcolony deterioration and an increase in the amount of waste generated, all resulting in subcolony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g. worker mortality caused by an entomopathogenic fungus). Syncephalastrum sp. treatment resulted in progressive damage in subcolonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf-cutter ants. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Secondary Metabolites from the Fungus Emericella nidulans

    PubMed Central

    Tarawneh, Amer H.; León, Francisco; Radwan, Mohamed M.; Rosa, Luiz H.

    2014-01-01

    A new polyketide derivative koninginin H (1), has been isolated from the fungus Emericella nidulans, together with koninginin E (2), koninginin A (3), trichodermatide B (4), citrantifidiol (5), (4S,5R)-4-hydroxy-5-methylfuran-2-one (6), the glycerol derivatives gingerglycolipid B (7), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-[α-d-galactopyranosyl-(1″→6′)β-d-galactopyranosyl]glycerol (8), (2S)-bis[9Z,12Z]-1-O, 2-O-dilinoleoyl-3-O-β-d-galactopyranosylglycerol (9), the cerebroside flavuside B (10), and the known sterols β-sitosterol glucoside and ergosta-5,7,22-trien-3-ol. Their structures were established by extensive NMR studies (1H NMR, 13C NMR, DEPT, 1H–1H COSY, HSQC, HMBC) and mass spectrometry. The antibacterial, antimalarial, antifungal and antileishmanial activities of compounds 1-10 were examined and the results indicated that compound 4 showed good antifungal activity against Cryptococcus neoformans with an IC50 value of 4.9 μg /mL. PMID:24273867

  18. Malaria Mosquitoes Attracted by Fatal Fungus

    PubMed Central

    George, Justin; Jenkins, Nina E.; Blanford, Simon; Thomas, Matthew B.; Baker, Thomas C.

    2013-01-01

    Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

  19. The agricultural pathology of ant fungus gardens

    PubMed Central

    Currie, Cameron R.; Mueller, Ulrich G.; Malloch, David

    1999-01-01

    Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission, Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more “primitive” (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens. PMID:10393936

  20. The first fossil fungus gardens of Isoptera: oldest evidence of symbiotic termite fungiculture (Miocene, Chad basin)

    NASA Astrophysics Data System (ADS)

    Duringer, Philippe; Schuster, Mathieu; Genise, Jorge F.; Likius, Andossa; Mackaye, Hassan Taisso; Vignaud, Patrick; Brunet, Michel

    2006-12-01

    Higher termites of the subfamily Macrotermitinae (fungus-growing termites) are known to build fungus gardens where a symbiotic fungus ( Termitomyces sp.) is cultivated. The fungus grows on a substrate called fungus comb, a structure built with the termites’ own faeces. Here we present the first fossil fungus combs ever found in the world. They were extracted from 7-million-year-old continental sandstone (Chad basin). Fossilized fungus combs have an ovoid morphology with a more or less flattened concave base and a characteristic general alveolar aspect. Under lens, they display a typical millimetre-scale pelletal structure. The latter, as well as the general shape and alveolar aspect, are similar to the morphology of fungus combs from extant fungus-growing termites.

  1. Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

    DOEpatents

    Lasure, Linda L [Fall City, WA; Dai, Ziyu [Richland, WA

    2008-10-21

    The invention includes isolated polynucleotide molecules that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention includes a method of enhancing a bioprocess utilizing a fungus. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to a promoter. The polynucleotide sequence is expressed to promote a first morphology. The first morphology of the transformed fungus enhances a bioprocess relative to the bioprocess utilizing a second morphology.

  2. Allergens of the entomopathogenic fungus Beauveria bassiana.

    PubMed

    Westwood, Greg S; Huang, Shih-Wen; Keyhani, Nemat O

    2005-01-11

    BACKGROUND: Beauveria bassiana is an important entomopathogenic fungus currently under development as a bio-control agent for a variety of insect pests. Although reported to be non-toxic to vertebrates, the potential allergenicity of Beauveria species has not been widely studied. METHODS: IgE-reactivity studies were performed using sera from patients displaying mould hypersensitivity by immunoblot and immunoblot inhibition. Skin reactivity to B. bassiana extracts was measured using intradermal skin testing. RESULTS: Immunoblots of fungal extracts with pooled as well as individual sera showed a distribution of IgE reactive proteins present in B. bassiana crude extracts. Proteinase K digestion of extracts resulted in loss of IgE reactive epitopes, whereas EndoH and PNGaseF (glycosidase) treatments resulted in minor changes in IgE reactive banding patterns as determined by Western blots. Immunoblot inhibitions experiments showed complete loss of IgE-binding using self protein, and partial inhibition using extracts from common allergenic fungi including; Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum, Candida albicans, Epicoccum purpurascens, and Penicillium notatum. Several proteins including a strongly reactive band with an approximate molecular mass of 35 kDa was uninhibited by any of the tested extracts, and may represent B. bassiana specific allergens. Intradermal skin testing confirmed the in vitro results, demonstrating allergenic reactions in a number of individuals, including those who have had occupational exposure to B. bassiana. CONCLUSIONS: Beauveria bassiana possesses numerous IgE reactive proteins, some of which are cross-reactive among allergens from other fungi. A strongly reactive potential B. bassiana specific allergen (35 kDa) was identified. Intradermal skin testing confirmed the allergenic potential of B. bassiana.

  3. Metabolite diversification by cultivation of the endophytic fungus Dothideomycete sp. in halogen containing media: Cultivation of terrestrial fungus in seawater.

    PubMed

    Wijesekera, Kanchana; Mahidol, Chulabhorn; Ruchirawat, Somsak; Kittakoop, Prasat

    2017-06-01

    The endophytic fungus, Dothideomycete sp. CRI7, isolated from the terrestrial plant, Tiliacora triandra, was salt tolerant, capable of growing in the culture medium prepared from seawater; salts in seawater did not have any effects on the fungal growth. Metabolite productions of the fungus CRI7 cultivated in media prepared from seawater (MSW), prepared from deionized water supplemented with potassium bromide (MKBr) or potassium iodide (MKI), and prepared from deionized water (MDW) were investigated. It was found that the cultivation of the fungus CRI7 in MKBr and MSW enabled the fungus to produce nine new metabolites (1-9). The production of an azaphilone, austdiol (10), of the fungus CRI7 grown in MDW was 0.04g/L, which was much lower than that grown in MSW, MKBr, and MKI media which provided the yields of 0.5, 0.9, and 1.2g/L, respectively, indicating that halogen salts significantly enhanced the production of the polyketide 10. The cultivation of terrestrial fungi in media containing halogen salts could therefore be useful for the metabolite diversification by one strain-many compounds (OSMAC) approach. Moreover, the isolated polyketides had significant biosynthetic relationship, suggesting that the cultivation of fungi in halogen containing media could provide the insights into certain polyketide biosynthesis. One of the isolated compounds exhibited antibacterial activity with the MIC value of 100μg/mL. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Phomalactone from a Phytopathogenic Fungus Infecting ZINNIA elegans (ASTERACEAE) Leaves.

    PubMed

    Meepagala, Kumudini M; Johnson, Robert D; Techen, Natascha; Wedge, David E; Duke, Stephen O

    2015-07-01

    Zinnia elegans Jacq. plants are infected by a fungus that causes dark red spots with necrosis on leaves, particularly in late spring to the middle of summer in the Mid-South of the United States. This fungal disease causes the leaves to wilt and eventually kills the plant. The fungus was isolated, cultured in potato dextrose broth, and identified as Nigrospora sphaerica by molecular techniques. Two major lactone metabolites (phomalactone and catenioblin A) were isolated from liquid culture of N. sphaerica isolated from Z. elegans. When injected into leaves of Z. elegans, phomalactone caused lesions similar to those of the fungus. The lesion sizes were proportional to the concentration of the phomalactone. Phomalactone, but not catenioblin A, was phytotoxic to Z. elegans and other plant species by inhibition of seedling growth and by causing electrolyte leakage from photosynthetic tissues of both Z. elegans leaves and cucumber cotyledons. This latter effect may be related to the wilting caused by the fungus in mature Z. elegans plants. Phomalactone was moderately fungicidal to Coletotrichum fragariae and two Phomopsis species, indicating that the compound may keep certain other fungi from encroaching into plant tissue that N. sphaerica has infected. Production of large amounts of phomalactone by N. sphaerica contributes to the pathogenic behavior of this fungus, and may have other ecological functions in the interaction of N. sphaerica with other fungi. This is the first report of isolation of catenioblin A from a plant pathogenic fungus. The function of catenioblin A is unclear, as it was neither significantly phyto- nor fungitoxic.

  5. Rust-red stringy white rot: The Indian paint fungus, Echinodontium tinctorium

    Treesearch

    A. D. Wilson

    1997-01-01

    Older trees are more susceptible to damage by this fungus, although even very young trees are susceptible to infection. Infections occur most frequently in dense stands where selfpruning creates infection courts for the fungus.

  6. Roles of Peroxisomes in the Rice Blast Fungus

    PubMed Central

    Liu, Caiyun

    2016-01-01

    The rice blast fungus, Magnaporthe oryzae, is a model plant pathogenic fungus and is a severe threat to global rice production. Over the past two decades, it has been found that the peroxisomes play indispensable roles during M. oryzae infection. Given the importance of the peroxisomes for virulence, we review recent advances of the peroxisomes roles during M. oryzae infection processes. We firstly introduce the molecular mechanisms and life cycles of the peroxisomes. And then, metabolic functions related to the peroxisomes are also discussed. Finally, we provide an overview of the relationship between peroxisomes and pathogenicity. PMID:27610388

  7. Patterns of functional enzyme activity in fungus farming ambrosia beetles

    PubMed Central

    2012-01-01

    Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose

  8. Detection of 3-hydroxykynurenine in a plant pathogenic fungus.

    PubMed Central

    Wilson, T J Greer; Thomsen, Karl Kristian; Petersen, Bent O; Duus, Jens Ø; Oliver, Richard P

    2003-01-01

    A redox-active compound has been purified from the barley powdery mildew fungus Blumeria ( Erysiphe ) graminis f. sp. hordei. A combination of spectrophotometry, MS and NMR has identified it as 3-hydroxykynurenine (3OHKyn). This compound, never previously detected in any fungus or pathogen, is best known for its role in vertebrate cataracts. It is found abundantly in developing and germinating spores and also in runner hyphae. Two roles for 3OHKyn are discussed: first, the presence of active oxygen species would enable 3OHKyn to cross-link the spore chemically with the plant. Secondly, it may be acting as an UV protectant and an antioxidant. PMID:12556224

  9. Patterns of functional enzyme activity in fungus farming ambrosia beetles.

    PubMed

    De Fine Licht, Henrik H; Biedermann, Peter H W

    2012-06-06

    In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose components of the ray

  10. Population genomics reveals that within-fungus polymorphism is common and maintained in populations of the mycorrhizal fungus Rhizophagus irregularis

    PubMed Central

    Wyss, Tania; Masclaux, Frédéric G; Rosikiewicz, Pawel; Pagni, Marco; Sanders, Ian R

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi are symbionts of most plants, increasing plant growth and diversity. The model AM fungus Rhizophagus irregularis (isolate DAOM 197198) exhibits low within-fungus polymorphism. In contrast, another study reported high within-fungus variability. Experiments with other R. irregularis isolates suggest that within-fungus genetic variation can affect the fungal phenotype and plant growth, highlighting the biological importance of such variation. We investigated whether there is evidence of differing levels of within-fungus polymorphism in an R. irregularis population. We genotyped 20 isolates using restriction site-associated DNA sequencing and developed novel approaches for characterizing polymorphism among haploid nuclei. All isolates exhibited higher within-isolate poly-allelic single-nucleotide polymorphism (SNP) densities than DAOM 197198 in repeated and non-repeated sites mapped to the reference genome. Poly-allelic SNPs were independently confirmed. Allele frequencies within isolates deviated from diploids or tetraploids, or that expected for a strict dikaryote. Phylogeny based on poly-allelic sites was robust and mirrored the standard phylogeny. This indicates that within-fungus genetic variation is maintained in AM fungal populations. Our results predict a heterokaryotic state in the population, considerable differences in copy number variation among isolates and divergence among the copies, or aneuploidy in some isolates. The variation may be a combination of all of these hypotheses. Within-isolate genetic variation in R. irregularis leads to large differences in plant growth. Therefore, characterizing genomic variation within AM fungal populations is of major ecological importance. PMID:26953600

  11. [Study of water-soluble compounds from fungus garden of Odontotermes formosanus].

    PubMed

    Xue, Dejun; Zhou, Hui; Zhang, Min; Xie, Kang; Zhang, Yong

    2005-10-01

    To study water-soluble compounds from fungus garden of Odontotermes formosanus. The chemical constituents of fungus garden were analyzed and identified by GC-MS. 28 compounds were separated and 11 chemical constituents were identified. The main constituents in water-solubles from fungus garden of Odontotermes formosanus are palmitic acid, linolei acid and oleic aid.

  12. Directed Evolution of a Filamentous Fungus for Thermotolerance

    USDA-ARS?s Scientific Manuscript database

    Filamentous fungi represent the most widely used eukaryotic biocatalysts in industrial and chemical applications. Metarhizium anisopliae is a broad-host-range entomopathogenic fungus currently under intensive investigation as a biologically based alternative to chemical pesticides. One of the most p...

  13. Using copper sulfate to control fungus on fish eggs

    USDA-ARS?s Scientific Manuscript database

    Copper sulfate (CuSO4) is widely used by the catfish industry as an economical treatment to control fungus (Saprolegnia spp.) on catfish eggs. This is an overview of our effectiveness and safety studies. Channel catfish spawns were 24 - 48 hrs old. Comparable portions of a single spawn were place...

  14. Asterogynins: Secondary Metabolites from a Costa Rican Endophytic Fungus

    PubMed Central

    2010-01-01

    An endophytic fungus isolated from the small palm Asterogyne martiana produced two unusual steroid-like metabolites, asterogynin A (1) and asterogynin B (2), along with the known compounds viridiol (3) and viridin (4). Asterogynins A and B were characterized by NMR and MS spectroscopic analysis. PMID:20839869

  15. Fun Microbiology: How To Measure Growth of a Fungus.

    ERIC Educational Resources Information Center

    Mitchell, James K.; And Others

    1997-01-01

    Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)

  16. A Brazilian social bee must cultivate fungus to survive.

    PubMed

    Menezes, Cristiano; Vollet-Neto, Ayrton; Marsaioli, Anita Jocelyne; Zampieri, Davila; Fontoura, Isabela Cardoso; Luchessi, Augusto Ducati; Imperatriz-Fonseca, Vera Lucia

    2015-11-02

    The nests of social insects provide suitable microenvironments for many microorganisms as they offer stable environmental conditions and a rich source of food [1-4]. Microorganisms in turn may provide several benefits to their hosts, such as nutrients and protection against pathogens [1, 4-6]. Several examples of symbiosis between social insects and microorganisms have been found in ants and termites. These symbioses have driven the evolution of complex behaviors and nest structures associated with the culturing of the symbiotic microorganisms [5, 7, 8]. However, while much is known about these relationships in many species of ants and termites, symbiotic relationships between microorganisms and social bees have been poorly explored [3, 4, 9, 10]. Here, we report the first case of an obligatory relationship between the Brazilian stingless bee Scaptotrigona depilis and a fungus of the genus Monascus (Ascomycotina). Fungal mycelia growing on the provisioned food inside the brood cell are eaten by the larva. Larvae reared in vitro on sterilized larval food supplemented with fungal mycelia had a much higher survival rate (76%) compared to larvae reared under identical conditions but without fungal mycelia (8% survival). The fungus was found to originate from the material from which the brood cells are made. Since the bees recycle and transport this material between nests, fungus would be transferred to newly built cells and also to newly founded nests. This is the first report of a fungus cultivation mutualism in a social bee. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Analysis of a Functional Lactate Permease in the Fungus Rhizopus

    USDA-ARS?s Scientific Manuscript database

    The fungus Rhizopus is frequently used for fermentative production of lactic acid, but little is known about the mechanisms or proteins for transporting this carboxylic acid. Since transport of the lactate anion across the plasma membrane is critical to prevent acidification of the cytoplasm, we ev...

  18. Lignocellulose pretreatment in a fungus-cultivating termite

    Treesearch

    Hongjie Li; Daniel J. Yelle; Chang Li; Mengyi Yang; Jing Ke; Ruijuan Zhang; Yu Liu; Na Zhu; Shiyou Liang; Xiaochang Mo; John Ralph; Cameron R. Currie; Jianchu Mo

    2017-01-01

    Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether– and carbon–carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating...

  19. Microsatellites from the charcoal rot fungus (Macrophomina phaseolina)

    USDA-ARS?s Scientific Manuscript database

    Microsatellite loci were identified from the charcoal rot fungus Macrophomina phaseolina. Primer pairs for 46 loci were developed and of these 13 were optimized and screened using genomic DNA from 44 fungal isolates collected predominantly from two soybean fields in MS. All optimized loci were poly...

  20. Fun Microbiology: How To Measure Growth of a Fungus.

    ERIC Educational Resources Information Center

    Mitchell, James K.; And Others

    1997-01-01

    Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  2. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    EPA Science Inventory

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  3. The development and endophytic nature of the fungus Heteroconium chaetospira.

    PubMed

    Hashiba, Teruyoshi; Narisawa, Kazuhiko

    2005-11-15

    The root endophytic fungus Heteroconium chaetospira was isolated from roots of Chinese cabbage grown in field soil in Japan. This fungus penetrates through the outer epidermal cells of its host, passes into the inner cortex, and grows throughout the cortical cells, including those of the root tip region, without causing apparent pathogenic symptoms. There are no ultrastructural signs of host resistance responses. H. chaetospira has been recovered from 19 plant species in which there was no disruption of host growth. H. chaetospira has a symbiotic association with Chinese cabbage. The fungus provides nitrogen in exchange for carbon. These associations are beneficial for the inoculated plants, as demonstrated by increased growth rate. When used as a preinoculum, H. chaetospira suppresses the incidence of clubroot and Verticillium yellows when the test plant is post-inoculated with the causal agents of these diseases. H. chaetospira is an effective biocontrol agent against clubroot in Chinese cabbage at a low to moderate soil moisture range and a pathogen resting spore density of 10(5) resting spores per gram of soil in situ. Disease caused by Pseudomonas syringae pv. macricola and Alternaria brassicae on leaves can be suppressed by treatment with H. chaetospira. The fungus persists in the roots and induces systemic resistance to the foliar disease.

  4. Inferring dispersal patterns of the generalist root fungus Armillaria mellea

    USDA-ARS?s Scientific Manuscript database

    Investigating the dispersal of the root-pathogenic fungus Armillaria mellea is necessary to understand its population biology. Such an investigation is complicated by both its subterranean habit and the persistence of genotypes over successive host generations. As such, host colonization by resident...

  5. Genomic sequence of the aflatoxigenic filamentous fungus Aspergillus nomius

    USDA-ARS?s Scientific Manuscript database

    Aspergillus nomius is an opportunistic pathogen and one of the three most important producers of aflatoxins in section Flavi. This fungus has been reported to contaminate agricultural commodities, but it has also been sampled in non-agricultural soils so the host range is not well known. Having a si...

  6. Diseases of pines caused by the pitch canker fungus

    Treesearch

    L. David Dwinell; Stephen W. Fraedrich; D. Adams

    2001-01-01

    Fusarium subglutinans f. sp. pini, the pitch canker fungus, causes a number of serious diseases of Pinus species. The pathogen infects a variety of vegetative and reproductive pine structures at different stages of maturity and produces a diversity of symptoms. When the pathogen infects the woody vegetative...

  7. [Modification of wood lignin by the fungus Panus tigrinus].

    PubMed

    Revin, V V; Kadimaliev, D A; Shutova, V V; Samuilov, V D

    2002-01-01

    The treatment of sawdust with the fungus Panus tigrinus VKM F-3616 D changed the contents of functional groups in lignin from wood raw material. These changes are accompanied by the release of carboxyl and phenyl hydroxyl groups involved in chemical bond formation between wood particles in pressed materials manufactured from wood wastes.

  8. Draft Genome Sequence of the Fungus Trametes hirsuta 072.

    PubMed

    Pavlov, Andrey R; Tyazhelova, Tatiana V; Moiseenko, Konstantin V; Vasina, Daria V; Mosunova, Olga V; Fedorova, Tatiana V; Maloshenok, Lilya G; Landesman, Elena O; Bruskin, Sergei A; Psurtseva, Nadezhda V; Slesarev, Alexei I; Kozyavkin, Sergei A; Koroleva, Olga V

    2015-11-19

    A standard draft genome sequence of the white rot saprotrophic fungus Trametes hirsuta 072 (Basidiomycota, Polyporales) is presented. The genome sequence contains about 33.6 Mb assembled in 141 scaffolds with a G+C content of ~57.6%. The draft genome annotation predicts 14,598 putative protein-coding open reading frames (ORFs). Copyright © 2015 Pavlov et al.

  9. Draft Genome Sequence of the Fungus Trametes hirsuta 072

    PubMed Central

    Tyazhelova, Tatiana V.; Moiseenko, Konstantin V.; Vasina, Daria V.; Mosunova, Olga V.; Fedorova, Tatiana V.; Maloshenok, Lilya G.; Landesman, Elena O.; Bruskin, Sergei A.; Psurtseva, Nadezhda V.; Slesarev, Alexei I.; Kozyavkin, Sergei A.; Koroleva, Olga V.

    2015-01-01

    A standard draft genome sequence of the white rot saprotrophic fungus Trametes hirsuta 072 (Basidiomycota, Polyporales) is presented. The genome sequence contains about 33.6 Mb assembled in 141 scaffolds with a G+C content of ~57.6%. The draft genome annotation predicts 14,598 putative protein-coding open reading frames (ORFs). PMID:26586872

  10. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    EPA Science Inventory

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  11. Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus.

    PubMed

    Mitchell, Angela M; Strobel, Gary A; Moore, Emily; Robison, Richard; Sears, Joe

    2010-01-01

    Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.

  12. Controlling fungus on channel catfish eggs with peracetic acid

    USDA-ARS?s Scientific Manuscript database

    There is much interest in the use of peracetic acid (PAA) to treat pathogens in aquaculture. It is a relatively new compound and is approved for use in Europe, but not in the United States. This study determined the effectiveness of PAA for fungus control on channel catfish Ictalurus punctatus egg...

  13. The origin of Ceratocystis fagacearum, the oak wilt fungus

    Treesearch

    Jennifer Juzwik; Thomas C. Harrington; William L. MacDonald; David N. Appel

    2008-01-01

    The oak wilt pathogen, Ceratocystis fagacearum, may be another example of a damaging, exotic species in forest ecosystems in the United States. Though C. fagacearum has received much research attention, the origin of the fungus is unknown. The pathogen may have been endemic at a low incidence until increased disturbances, changes...

  14. Endophytic fungus-vascular plant-insect interactions.

    PubMed

    Raman, A; Wheatley, W; Popay, A

    2012-06-01

    Insect association with fungi has a long history. Theories dealing with the evolution of insect herbivory indicate that insects used microbes including fungi as their principal food materials before flowering plants evolved. Subtlety and the level of intricacy in the interactions between insects and fungi indicate symbiosis as the predominant ecological pattern. The nature of the symbiotic interaction that occurs between two organisms (the insect and the fungus), may be either mutualistic or parasitic, or between these two extremes. However, the triangular relationship involving three organisms, viz., an insect, a fungus, and a vascular plant is a relationship that is more complicated than what can be described as either mutualism or parasitism, and may represent facets of both. Recent research has revealed such a complex relationship in the vertically transmitted type-I endophytes living within agriculturally important grasses and the pestiferous insects that attack them. The intricacy of the association depends on the endophytic fungus-grass association and the insect present. Secondary compounds produced in the endophytic fungus-grass association can provide grasses with resistance to herbivores resulting in mutualistic relationship between the fungus and the plant that has negative consequences for herbivorous insects. The horizontally transmitted nongrass type-II endophytes are far less well studied and as such their ecological roles are not fully understood. This forum article explores the intricacy of dependence in such complex triangular relationships drawing from well-established examples from the fungi that live as endophytes in vascular plants and how they impact on the biology and evolution of free-living as well as concealed (e.g., gall-inducing, gall-inhabiting) insects. Recent developments with the inoculation of strains of type-I fungal endophytes into grasses and their commercialization are discussed, along with the possible roles the endophytic

  15. Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non–Fungus-Growing Ants (Hymenoptera, Formicidae)

    PubMed Central

    Vieira, Alexsandro Santana; Bueno, Odair Correa; Camargo-Mathias, Maria Izabel

    2012-01-01

    The metapleural gland is an organ exclusive to ants. Its main role is to produce secretions that inhibit the proliferation of different types of pathogens. The aim of the present study was to examine the morphophysiological differences between the metapleural gland of 3 non–fungus-growing ants of the tribes Ectatommini, Myrmicini, and Blepharidattini and that of 5 fungus-growing ants from 2 basal and 3 derived attine genera. The metapleural gland of the non–fungus-growing ants and the basal attine ants has fewer secretory cells than that of the derived attine ants (leaf-cutting ants). In addition, the metapleural gland of the latter had more clusters of secretory cells and sieve plates, indicating a greater storage capacity and demand for secretion in these more advanced farming ants. The glands of the derived attine ants also produced higher levels of polysaccharides and acidic lipids than those of Myrmicini, Blepharidattini, and basal attines. Our results confirm morphophysiological differences between the metapleural glands of the derived attines and those of the basal attines and non–fungus-growing ants, suggesting that the metapleural glands of the derived attines (leaf-cutting ants) are more developed in morphology and physiology, with enhanced secretion production (acidic lipids and protein) to protect against the proliferation of unwanted fungi and bacteria in the fungal garden, it is possible that leaf-cutting ants may have evolved more developed metapleural glands in response to stronger pressure from parasites. PMID:22927993

  16. Morphophysiological differences between the metapleural glands of fungus-growing and non-fungus-growing ants (Hymenoptera, Formicidae).

    PubMed

    Vieira, Alexsandro Santana; Bueno, Odair Correa; Camargo-Mathias, Maria Izabel

    2012-01-01

    The metapleural gland is an organ exclusive to ants. Its main role is to produce secretions that inhibit the proliferation of different types of pathogens. The aim of the present study was to examine the morphophysiological differences between the metapleural gland of 3 non-fungus-growing ants of the tribes Ectatommini, Myrmicini, and Blepharidattini and that of 5 fungus-growing ants from 2 basal and 3 derived attine genera. The metapleural gland of the non-fungus-growing ants and the basal attine ants has fewer secretory cells than that of the derived attine ants (leaf-cutting ants). In addition, the metapleural gland of the latter had more clusters of secretory cells and sieve plates, indicating a greater storage capacity and demand for secretion in these more advanced farming ants. The glands of the derived attine ants also produced higher levels of polysaccharides and acidic lipids than those of Myrmicini, Blepharidattini, and basal attines. Our results confirm morphophysiological differences between the metapleural glands of the derived attines and those of the basal attines and non-fungus-growing ants, suggesting that the metapleural glands of the derived attines (leaf-cutting ants) are more developed in morphology and physiology, with enhanced secretion production (acidic lipids and protein) to protect against the proliferation of unwanted fungi and bacteria in the fungal garden, it is possible that leaf-cutting ants may have evolved more developed metapleural glands in response to stronger pressure from parasites.

  17. Draft genome of the fungus-growing termite pathogenic fungus Ophiocordyceps bispora (Ophiocordycipitaceae, Hypocreales, Ascomycota).

    PubMed

    Conlon, Benjamin H; Mitchell, Jannette; de Beer, Z Wilhelm; Carøe, Christian; Gilbert, M Thomas P; Eilenberg, Jørgen; Poulsen, Michael; de Fine Licht, Henrik H

    2017-04-01

    This article documents the public availability of genome sequence data and assembled contigs representing the partial draft genome of Ophiocordyceps bispora. As one of the few known pathogens of fungus-farming termites, a draft genome of O. bispora represents the opportunity to further the understanding of disease and resistance in these complex termite societies. With the ongoing attempts to resolve the taxonomy of the Hypocralaean family, more genetic data will also help to shed light on the phylogenetic relationship between sexual and asexual life stages. Next generation sequence data is available from the European Nucleotide Archive (ENA) under accession PRJEB13655; run numbers: ERR1368522, ERR1368523, and ERR1368524. Genome assembly available from ENA under accession numbers: FKNF01000001-FKNF01000302. Gene prediction available as protein fasta, nucleotide fasta and GFF file from Mendeley Data with accession doi:10.17632/r99fd6g3s4.2 (http://dx.doi.org/10.17632/r99fd6g3s4.2).

  18. Candicidin-producing Streptomyces support leaf-cutting ants to protect their fungus garden against the pathogenic fungus Escovopsis.

    PubMed

    Haeder, Susanne; Wirth, Rainer; Herz, Hubert; Spiteller, Dieter

    2009-03-24

    Leaf-cutting ants such as Acromyrmex octospinosus live in obligate symbiosis with fungi of the genus Leucoagaricus, which they grow with harvested leaf material. The symbiotic fungi, in turn, serve as a major food source for the ants. This mutualistic relation is disturbed by the specialized pathogenic fungus Escovopsis sp., which can overcome Leucoagaricus sp. and thus destroy the ant colony. Microbial symbionts of leaf-cutting ants have been suggested to protect the fungus garden against Escovopsis by producing antifungal compounds [Currie CR, Scott JA, Summerbell RC, Malloch D (1999) Fungus-growing ants use antibiotic-producing bacteria to control garden parasites. Nature 398:701-704.]. To date, however, the chemical nature of these compounds has remained elusive. We characterized 19 leaf-cutting ant-associated microorganisms (5 Pseudonocardia, 1 Dermacoccus, and 13 Streptomyces) from 3 Acromyrmex species, A. octospinosus, A. echinatior, and A. volcanus, using 16S-rDNA analysis. Because the strain Streptomyces sp. Ao10 proved highly active against the pathogen Escovopsis, we identified the molecular basis of its antifungal activity. Using bioassay-guided fractionation, high-resolution electrospray mass spectrometry (HR-ESI-MS), and UV spectroscopy, and comparing the results with an authentic standard, we were able identify candicidin macrolides. Candicidin macrolides are highly active against Escovopsis but do not significantly affect the growth of the symbiotic fungus. At least one of the microbial isolates from each of the 3 leaf-cutting ant species analyzed produced candicidin macrolides. This suggests that candicidins play an important role in protecting the fungus gardens of leaf-cutting ants against pathogenic fungi.

  19. Autofluorescence of the fungus Morchella conica var. rigida.

    PubMed

    Zižka, Z; Gabriel, J

    2011-03-01

    Autofluorescence (primary fluorescence (AF)) of fruiting bodies and stems of the fungus Morchella conica var. rigida was studied by fluorescence microscopy including sporangia and ascospores. The ascospores were characterized by a weak green-yellow AF at blue excitation. Using a green excitation, no AF was observed. The hyphae located under the layer of asci with ascospores exhibited a higher primary fluorescence, namely their walls that had green-yellow color at blue excitation. Also, their red AF observed when a green excitation was used was significant. Similarly, the hyphae located in the fungal stem exhibited a significant AF, especially their walls when the blue light was used for excitation. In addition, large, yellow-to-yellow/green, oval-to-round bodies with strong fluorescence were detected whose morphological equivalents were not clearly visible in the white halogen light. The AF of the fungus M. conica var. rigida was lower compared with the other higher fungi studied so far.

  20. Gaeumannomyces graminis, the take-all fungus and its relatives.

    PubMed

    Freeman, Jacqueline; Ward, Elaine

    2004-07-01

    SUMMARY Take-all, caused by the fungus Gaeumannomyces graminis var. tritici, is the most important root disease of wheat worldwide. Many years of intensive research, reflected by the large volume of literature on take-all, has led to a considerable degree of understanding of many aspects of the disease. However, effective and economic control of the disease remains difficult. The application of molecular techniques to study G. graminis and related fungi has resulted in some significant advances, particularly in the development of improved methods for identification and in elucidating the role of the enzyme avenacinase as a pathogenicity determinant in the closely related oat take-all fungus (G. graminis var. avenae). Some progress in identifying other factors that may be involved in determining host range and pathogenicity has been made, despite the difficulties of performing genetic analyses and the lack of a reliable transformation system.

  1. Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

    SciTech Connect

    Basavaraja, S.; Balaji, S.D.; Lagashetty, Arunkumar; Rajasab, A.H.; Venkataraman, A.

    2008-05-06

    Development of environmental friendly procedures for the synthesis of metal nanoparticles through biological processes is evolving into an important branch of nanobiotechnology. In this paper, we report on the use of fungus 'Fusarium semitectum' for the extracellular synthesis of silver nanoparticles from silver nitrate solution (i.e. through the reduction of Ag{sup +} to Ag{sup 0}). Highly stable and crystalline silver nanoparticles are produced in solution by treating the filtrate of the fungus F. semitectum with the aqueous silver nitrate solution. The formations of nanoparticles are understood from the UV-vis and X-ray diffraction studies. Transmission electron microscopy of the silver particles indicated that they ranged in size from 10 to 60 nm and are mostly spherical in shape. Interestingly the colloidal suspensions of silver nanoparticles are stable for many weeks. Possible medicinal applications of these silver nanoparticles are envisaged.

  2. White-nose syndrome fungus (Geomyces destructans) in bats, Europe.

    PubMed

    Wibbelt, Gudrun; Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans Peter; Seidl, Hans Peter; Blehert, David S

    2010-08-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

  3. Hormonemate Derivatives from Dothiora sp., an Endophytic Fungus.

    PubMed

    Pérez-Bonilla, Mercedes; González-Menéndez, Víctor; Pérez-Victoria, Ignacio; de Pedro, Nuria; Martín, Jesús; Molero-Mesa, Joaquín; Casares-Porcel, Manuel; González-Tejero, María Reyes; Vicente, Francisca; Genilloud, Olga; Tormo, José R; Reyes, Fernando

    2017-03-09

    A search for cytotoxic agents from cultures of the endophytic fungus Dothiora sp., isolated from the endemic plant Launaea arborescens, led to the isolation of six new compounds structurally related to hormonemate, with moderate cytotoxic activity against different cancer cell lines. By using a bioassay-guided fractionation approach, hormonemates A-D (1-4), hormonemate (5), and hormonemates E (6) and F (7) were obtained from the acetone extract of this fungus. Their structures were determined using a combination of HRMS, ESI-qTOF-MS/MS, 1D and 2D NMR experiments, and chemical degradation. The cytotoxic activities of these compounds were evaluated by microdilution colorimetric assays against human breast adenocarcinoma (MCF-7), human liver cancer cells (HepG2), and pancreatic cancer cells (MiaPaca_2). Most of the compounds displayed cytotoxic activity against this panel.

  4. Functional genome of the human pathogenic fungus Paracoccidioides brasiliensis.

    PubMed

    Felipe, Maria Sueli S; Torres, Fernando A G; Maranhão, Andrea Q; Silva-Pereira, Ildinete; Poças-Fonseca, Marcio J; Campos, Elida G; Moraes, Lídia M P; Arraes, Fabrício B M; Carvalho, Maria José A; Andrade, Rosângela V; Nicola, André M; Teixeira, Marcus M; Jesuíno, Rosália S A; Pereira, Maristela; Soares, Célia M A; Brígido, Marcelo M

    2005-09-01

    Paracoccidioides brasiliensis is a dimorphic and thermo-regulated fungus which is the causative agent of paracoccidioidomycosis, an endemic disease widespread in Latin America. Pathogenicity is assumed to be a consequence of the cellular differentiation process that this fungus undergoes from mycelium to yeast cells during human infection. In an effort to elucidate the molecular mechanisms involved in this process a network of Brazilian laboratories carried out a transcriptome project for both cell types. This review focuses on the data analysis yielding a comprehensive view of the fungal metabolism and the molecular adaptations during dimorphism in P. brasiliensis from analysis of 6022 groups, related to expressed genes, which were generated from both mycelium and yeast phases.

  5. Engineering a filamentous fungus for L-rhamnose extraction.

    PubMed

    Kuivanen, Joosu; Richard, Peter

    2016-03-01

    L-Rhamnose is a high value rare sugar that is used as such or after chemical conversions. It is enriched in several biomass fractions such as the pectic polysaccharides rhamnogalacturonan I and II and in naringin, hesperidin, rutin, quercitrin and ulvan. We engineered the filamentous fungus Aspergillus niger to not consume L-rhamnose, while it is still able to produce the enzymes for the hydrolysis of L-rhamnose rich biomass. As a result we present a strain that can be used for the extraction of L-rhamnose in a consolidated process. In the process the biomass is hydrolysed to the monomeric sugars which are consumed by the fungus leaving the L-rhamnose.

  6. Fungus-associated asthma: overcoming challenges in diagnosis and treatment.

    PubMed

    Ogawa, Haruhiko; Fujimura, Masaki; Ohkura, Noriyuki; Satoh, Kazuo; Makimura, Koichi

    2014-05-01

    With regard to fungal colonization and fungal sensitization, the goals of fungus-associated asthma management are as follows: 1) to survey fungi colonizing the airways of patients repeatedly; 2) to evaluate the tendency of the colonizing fungi to sensitize patients and the influence on clinical manifestations of asthma; 3) to follow disease development to allergic bronchopulmonary mycosis or sinobronchial allergic mycosis; and 4) to determine whether fungal eradication from the airway of patients is beneficial from the viewpoints of future risk factors. Recent developments in molecular biological analyses have facilitated the identification of basidiomycetous fungi that were not previously thought to be of concern in fungal allergy. The total control of fungus-associated asthma will be accomplished by environmental management established from the viewpoint of both the ecology and life cycle of the responsible fungi.

  7. Mycocrystallization of gold ions by the fungus Cylindrocladium floridanum.

    PubMed

    Narayanan, Kannan Badri; Sakthivel, Natarajan

    2013-11-01

    The size and morphology determines the thermodynamic, physical and electronic properties of metal nanoparticles. The extracellular synthesis of gold nanoparticles by fungus, Cylindrocladium floridanum, which acts as a source of reducing and stabilizing agent has been described. The synthesized nanoparticles were characterized using techniques such as UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray analysis (EDAX), and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical with an average size of 19.05 nm. Powder XRD pattern proved the formation of (111)-oriented face-centered cubic crystals of metallic gold. This microbial approach by fungus for the green synthesis of spherical gold nanoparticles has many advantages such as economic viability, scaling up and environment friendliness.

  8. White-nose syndrome fungus (Geomyces destructans) in bats, Europe

    USGS Publications Warehouse

    Wibbelt, G.; Kurth, A.; Hellmann, D.; Weishaar, M.; Barlow, A.; Veith, M.; Pruger, J.; Gorfol, T.; Grosche, T.; Bontadina, F.; Zophel, U.; Seidl, Hans-Peter; Cryan, P.M.; Blehert, D.S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.

  9. White-Nose Syndrome Fungus (Geomyces destructans) in Bats, Europe

    PubMed Central

    Kurth, Andreas; Hellmann, David; Weishaar, Manfred; Barlow, Alex; Veith, Michael; Prüger, Julia; Görföl, Tamás; Grosche, Lena; Bontadina, Fabio; Zöphel, Ulrich; Seidl, Hans-Peter; Cryan, Paul M.; Blehert, David S.

    2010-01-01

    White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus. PMID:20678317

  10. Cytochalasin derivatives from a jellyfish-derived fungus Phoma sp.

    PubMed

    Kim, Eun La; Wang, Haibo; Park, Ju Hee; Hong, Jongki; Choi, Jae Sue; Im, Dong Soon; Chung, Hae Young; Jung, Jee H

    2015-01-01

    Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116).

  11. Complete Genome Sequence of the Endophytic Fungus Diaporthe (Phomopsis) ampelina

    PubMed Central

    Bhargavi, S. D.; Praveen, V. K.

    2016-01-01

    Diaporthe ampelina was isolated as an endophytic fungus from the root of Commiphora wightii, a medicinal plant collected from Dhanvantri Vana, Bangalore University, Bangalore, India. The whole genome is 59 Mb, contains a total of 905 scaffolds, and has a G+C content of 51.74%. The genome sequence of D. ampelina shows a complete absence of lovastatin (an anticholesterol drug) gene cluster. PMID:27257198

  12. The yeast spectrum of the 'tea fungus Kombucha'.

    PubMed

    Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

    1995-01-01

    The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably

  13. Oxygenated lanostane-type triterpenoids from the fungus ganodermalucidum.

    PubMed

    Akihisa, Toshihiro; Tagata, Masaaki; Ukiya, Motohiko; Tokuda, Harukuni; Suzuki, Takashi; Kimura, Yumiko

    2005-04-01

    Two new triterpenoids, 20(21)-dehydrolucidenic acid A (1) and methyl 20(21)-dehydrolucidenate A (2), and five new 20-hydroxylucidenic acids, 20-hydroxylucidenic acid D(2) (3), 20-hydroxylucidenic acid F (4), 20-hydroxylucidenic acid E(2) (5), 20-hydroxylucidenic acid N (6), and 20-hydroxylucidenic acid P (7), were isolated from the fruiting body of the fungus Ganoderma ludicum, and their structures were established on the basis of spectroscopic methods.

  14. The Kinome of Edible and Medicinal Fungus Wolfiporia cocos.

    PubMed

    Wei, Wei; Shu, Shaohua; Zhu, Wenjun; Xiong, Ying; Peng, Fang

    2016-01-01

    Wolfiporia cocos is an edible and medicinal fungus that grows in association with pine trees, and its dried sclerotium, known as Fuling in China, has been used as a traditional medicine in East Asian countries for centuries. Nearly 10% of the traditional Chinese medicinal preparations contain W. cocos. Currently, the commercial production of Fuling is limited because of the lack of pine-based substrate and paucity of knowledge about the sclerotial development of the fungus. Since protein kinase (PKs) play significant roles in the regulation of growth, development, reproduction, and environmental responses in filamentous fungi, the kinome of W. cocos was analyzed by identifying the PKs genes, studying transcript profiles and assigning PKs to orthologous groups. Of the 10 putative PKs, 11 encode atypical PKs, and 13, 10, 2, 22, and 11 could encoded PKs from the AGC, CAMK, CK, CMGC, STE, and TLK Groups, respectively. The level of transcripts from PK genes associated with sclerotia formation in the mycelium and sclerotium stages were analyzed by qRT-PCR. Based on the functions of the orthologs in Sclerotinia sclerotiorum (a sclerotia-formation fungus) and Saccharomyces cerevisiae, the potential roles of these W. cocos PKs were assigned. To the best of our knowledge, our study is the first identification and functional discussion of the kinome in the edible and medicinal fungus W. cocos. Our study systematically suggests potential roles of W. cocos PKs and provide comprehensive and novel insights into W. cocos sclerotial development and other economically important traits. Additionally, based on our result, genetic engineering can be employed for over expression or interference of some significant PKs genes to promote sclerotial growth and the accumulation of active compounds.

  15. Pseudocopulatory Pollination in Lepanthes (Orchidaceae: Pleurothallidinae) by Fungus Gnats

    PubMed Central

    BLANCO, MARIO A.; BARBOZA, GABRIEL

    2005-01-01

    • Background and Aims Lepanthes is one of the largest angiosperm genera (>800 species). Their non-rewarding, tiny and colourful flowers are structurally complex. Their pollination mechanism has hitherto remained unknown, but has been subject of ample speculation; the function of the minuscule labellum appendix is especially puzzling. Here, the pollination of L. glicensteinii by sexually deceived male fungus gnats is described and illustrated. • Methods Visitors to flowers of L. glicensteinii were photographed and their behaviour documented; some were captured for identification. Occasional visits to flowers of L. helleri, L. stenorhyncha and L. turialvae were also observed. Structural features of flowers and pollinators were studied with SEM. • Key Results Sexually aroused males of the fungus gnat Bradysia floribunda (Diptera: Sciaridae) were the only visitors and pollinators of L. glicensteinii. The initial long-distance attractant seems to be olfactory. Upon finding a flower, the fly curls his abdomen under the labellum and grabs the appendix with his genitalic claspers, then dismounts the flower and turns around to face away from it. The pollinarium attaches to his abdomen during this pivoting manoeuvre. Pollinia are deposited on the stigma during a subsequent flower visit. The flies appear to ejaculate during pseudocopulation. The visitors of L. helleri, L. stenorhyncha and L. turialvae are different species of fungus gnats that display a similar behaviour. • Conclusions Lepanthes glicensteinii has genitalic pseudocopulatory pollination, the first case reported outside of the Australian orchid genus Cryptostylis. Since most species of Lepanthes have the same unusual flower structure, it is predicted that pollination by sexual deception is prevalent in the genus. Several morphological and phenological traits in Lepanthes seem well suited for exploiting male fungus gnats as pollinators. Correspondingly, some demographic trends common in Lepanthes are

  16. Biotransformation of Malachite Green by the Fungus Cunninghamella elegans

    PubMed Central

    Cha, Chang-Jun; Doerge, Daniel R.; Cerniglia, Carl E.

    2001-01-01

    The filamentous fungus Cunninghamella elegans ATCC 36112 metabolized the triphenylmethane dye malachite green with a first-order rate constant of 0.029 μmol h−1 (mg of cells)−1. Malachite green was enzymatically reduced to leucomalachite green and also converted to N-demethylated and N-oxidized metabolites, including primary and secondary arylamines. Inhibition studies suggested that the cytochrome P450 system mediated both the reduction and the N-demethylation reactions. PMID:11526047

  17. The Kinome of Edible and Medicinal Fungus Wolfiporia cocos

    PubMed Central

    Wei, Wei; Shu, Shaohua; Zhu, Wenjun; Xiong, Ying; Peng, Fang

    2016-01-01

    Wolfiporia cocos is an edible and medicinal fungus that grows in association with pine trees, and its dried sclerotium, known as Fuling in China, has been used as a traditional medicine in East Asian countries for centuries. Nearly 10% of the traditional Chinese medicinal preparations contain W. cocos. Currently, the commercial production of Fuling is limited because of the lack of pine-based substrate and paucity of knowledge about the sclerotial development of the fungus. Since protein kinase (PKs) play significant roles in the regulation of growth, development, reproduction, and environmental responses in filamentous fungi, the kinome of W. cocos was analyzed by identifying the PKs genes, studying transcript profiles and assigning PKs to orthologous groups. Of the 10 putative PKs, 11 encode atypical PKs, and 13, 10, 2, 22, and 11 could encoded PKs from the AGC, CAMK, CK, CMGC, STE, and TLK Groups, respectively. The level of transcripts from PK genes associated with sclerotia formation in the mycelium and sclerotium stages were analyzed by qRT-PCR. Based on the functions of the orthologs in Sclerotinia sclerotiorum (a sclerotia-formation fungus) and Saccharomyces cerevisiae, the potential roles of these W. cocos PKs were assigned. To the best of our knowledge, our study is the first identification and functional discussion of the kinome in the edible and medicinal fungus W. cocos. Our study systematically suggests potential roles of W. cocos PKs and provide comprehensive and novel insights into W. cocos sclerotial development and other economically important traits. Additionally, based on our result, genetic engineering can be employed for over expression or interference of some significant PKs genes to promote sclerotial growth and the accumulation of active compounds. PMID:27708635

  18. Fungus mediated synthesis of biomedically important cerium oxide nanoparticles

    SciTech Connect

    Khan, Shadab Ali; Ahmad, Absar

    2013-10-15

    Graphical abstract: - Highlights: • First time biological synthesis of cerium oxide oxide nanoparticles using fungus Humicola sp. • Complete characterization of cerium oxide nanoparticles. • Biosynthesis of naturally protein capped, luminescent and water dispersible CeO{sub 2} nanoparticles. • Biosynthesized CeO{sub 2} nanoparticles can be used for many biomedical applications. - Abstract: Nanomaterials can be synthesized by chemical, physical and the more recently discovered biological routes. The biological routes are advantageous over the chemical and physical ones as unlike these, the biological synthesis protocols occur at ambient conditions, are cheap, non-toxic and eco-friendly. Although purely biological and bioinspired methods for the synthesis of nanomaterials are environmentally benign and energy conserving processes, their true potential has not been explored yet and attempts are being made to extend the formation of technologically important nanoparticles using microorganisms like fungi. Though there have been reports on the biosynthesis of oxide nanoparticles by our group in the past, no attempts have been made to employ fungi for the synthesis of nanoparticles of rare earth metals or lanthanides. Here we report for the first time, the bio-inspired synthesis of biomedically important cerium oxide (CeO{sub 2}) nanoparticles using the thermophilic fungus Humicola sp. The fungus Humicola sp. when exposed to aqueous solutions of oxide precursor cerium (III) nitrate hexahydrate (CeN{sub 3}O{sub 9}·6H{sub 2}O) results in the extracellular formation of CeO{sub 2} nanoparticles containing Ce (III) and Ce (IV) mixed oxidation states, confirmed by X-ray Photoemission Spectroscopy (XPS). The formed nanoparticles are naturally capped by proteins secreted by the fungus and thus do not agglomerate, are highly stable, water dispersible and are highly fluorescent as well. The biosynthesized nanoparticles were characterized by UV–vis spectroscopy

  19. Decomposition of Plant Debris by the Nematophagous Fungus ARF

    PubMed Central

    Wang, Kening; Riggs, R. D.; Crippen, Devany

    2004-01-01

    In the study of the biological control of plant-parasitic nematodes, knowledge of the saprophytic ability of a nematophagous fungus is necessary to understand its establishment and survival in the soil. The objectives of this study were (i) to determine if the nematophagous fungus ARF (Arkansas Fungus) shows differential use of plant residues; and (ii) to determine if ARF still existed in the soil of a field in which ARF was found originally and in which the population level of Heterodera glycines had remained very low, despite 15 years of continuous, susceptible soybean. Laboratory studies of the decomposition of wheat straw or soybean root by ARF were conducted in two separate experiments, using a CO₂ collection apparatus, where CO₂-free air was passed through sterilized cotton to remove the microorganisms in the air and then was passed over the samples, and evolved CO₂ was trapped by KOH. Milligrams of C as CO₂ was used to calculate the percentage decomposition of the plant debris by ARF. Data indicated ARF decomposed 11.7% of total organic carbon of the wheat straw and 20.1% of the soybean roots in 6 weeks. In the field soil study, 21 soil samples were taken randomly from the field. Only 3 months after the infestation of the soil with H. glycines, the percentage of parasitized eggs of H. glycines reached 64 ± 19%, and ARF was isolated from most parasitized eggs of H. glycines. Research results indicated ARF could use plant residues to survive. PMID:19262814

  20. Symbiotic Fungus of Marine Sponge Axinella sp. Producing Antibacterial Agent

    NASA Astrophysics Data System (ADS)

    Trianto, A.; Widyaningsih, S.; Radjasa, OK; Pribadi, R.

    2017-02-01

    The emerging of multidrug resistance pathogenic bacteria cause the treatment of the diseaseshave become ineffective. There for, invention of a new drug with novel mode of action is an essential for curing the disease caused by an MDR pathogen. Marine fungi is prolific source of bioactive compound that has not been well explored. This study aim to obtain the marine sponges-associated fungus that producing anti-MDR bacteria substaces. We collected the sponge from Riung water, NTT, Indonesia. The fungus was isolated with affixed method, followed with purification with streak method. The overlay and disk diffusion agar methods were applied for bioactivity test for the isolate and the extract, respectively. Molecular analysis was employed for identification of the isolate. The sponge was identified based on morphological and spicular analysis. The ovelay test showed that the isolate KN15-3 active against the MDR Staphylococcus aureus and Eschericia coli. The extract of the cultured KN15-3 was also inhibited the S. aureus and E. coli with inhibition zone 2.95 mm and 4.13 mm, respectively. Based on the molecular analysis, the fungus was identified as Aspergillus sydowii. While the sponge was identified as Axinella sp.

  1. Biodegradation of polyethylene microplastics by the marine fungus Zalerion maritimum.

    PubMed

    Paço, Ana; Duarte, Kátia; da Costa, João P; Santos, Patrícia S M; Pereira, R; Pereira, M E; Freitas, Ana C; Duarte, Armando C; Rocha-Santos, Teresa A P

    2017-05-15

    Plastic yearly production has surpassed the 300milliontons mark and recycling has all but failed in constituting a viable solution for the disposal of plastic waste. As these materials continue to accumulate in the environment, namely, in rivers and oceans, in the form of macro-, meso-, micro- and nanoplastics, it becomes of the utmost urgency to find new ways to curtail this environmental threat. Multiple efforts have been made to identify and isolate microorganisms capable of utilizing synthetic polymers and recent results point towards the viability of a solution for this problem based on the biodegradation of plastics resorting to selected microbial strains. Herein, the response of the fungus Zalerion maritimum to different times of exposition to polyethylene (PE) pellets, in a minimum growth medium, was evaluated, based on the quantified mass differences in both the fungus and the microplastic pellets used. Additionally, molecular changes were assessed through attenuated total reflectance Fourier transform Infrared Spectroscopy (FTIR-ATR) and Nuclear Magnetic Resonance (NMR). Results showed that, under the tested conditions, Z. maritimum is capable of utilizing PE, resulting in the decrease, in both mass and size, of the pellets. These results indicate that this naturally occurring fungus may actively contribute to the biodegradation of microplastics, requiring minimum nutrients.

  2. Efficient xylose fermentation by the brown rot fungus Neolentinus lepideus.

    PubMed

    Okamoto, Kenji; Kanawaku, Ryuichi; Masumoto, Masaru; Yanase, Hideshi

    2012-02-10

    The efficient production of bioethanol on an industrial scale requires the use of renewable lignocellulosic biomass as a starting material. A limiting factor in developing efficient processes is identifying microorganisms that are able to effectively ferment xylose, the major pentose sugar found in hemicellulose, and break down carbohydrate polymers without pre-treatment steps. Here, a basidiomycete brown rot fungus was isolated as a new biocatalyst with unprecedented fermentability, as it was capable of converting not only the 6-carbon sugars constituting cellulose, but also the major 5-carbon sugar xylose in hemicelluloses, to ethanol. The fungus was identified as Neolentinus lepideus and was capable of assimilating and fermenting xylose to ethanol in yields of 0.30, 0.33, and 0.34 g of ethanol per g of xylose consumed under aerobic, oxygen-limited, and anaerobic conditions, respectively. A small amount of xylitol was detected as the major by-product of xylose metabolism. N. lepideus produced ethanol from glucose, mannose, galactose, cellobiose, maltose, and lactose with yields ranging from 0.34 to 0.38 g ethanol per g sugar consumed, and also exhibited relatively favorable conversion of non-pretreated starch, xylan, and wheat bran. These results suggest that N. lepideus is a promising candidate for cost-effective and environmentally friendly ethanol production from lignocellulosic biomass. To our knowledge, this is the first report on efficient ethanol fermentation from various carbohydrates, including xylose, by a naturally occurring brown rot fungus.

  3. New and poorly known Palaearctic fungus gnats (Diptera, Sciaroidea)

    PubMed Central

    Kolcsár, Levente-Péter

    2017-01-01

    Abstract Background Fungus gnats (Sciaroidea) are a globally species rich group of lower Diptera. In Europe, Fennoscandian peninsula in particular holds a notable diversity, ca. 1000 species, of which 10 % are still unnamed. Fungus gnats are predominantly terrestrial insects, but some species dwell in wetland habitats. New information Eight new fungus gnat species, belonging to the families Keroplatidae (Orfelia boreoalpina Salmela sp.n.) and Mycetophilidae (Sciophila holopaineni Salmela sp.n., S. curvata Salmela sp.n., Boletina sasakawai Salmela & Kolcsár sp.n., B. norokorpii Salmela & Kolcsár sp.n., Phronia sompio Salmela sp.n., P. reducta Salmela sp.n., P. prolongata Salmela sp.n.), are described. Four of the species are known from Fennoscandia only whilst two are supposed to have boreo-alpine disjunct ranges, i.e. having populations in Fennoscandia and the Central European Alps. One of the species probably has a boreal range (Finnish Lapland and Central Siberia). Type material of Boletina curta Sasakawa & Kimura from Japan was found to consist of two species, and a further species close to these taxa is described from Finland. Phronia elegantula Hackman is redescribed and reported for the first time from Norway. DNA barcodes are provided for the first time for five species. PMID:28325987

  4. Evolutionary transitions in enzyme activity of ant fungus gardens.

    PubMed

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G; Boomsma, Jacobus J

    2010-07-01

    Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens are targeted primarily toward partial degradation of plant cell walls, reflecting a plesiomorphic state of nondomesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major breakdown of cell walls. The adaptive significance of the lower-attine symbiont shifts remains unclear. One of these shifts was obligate, but digestive advantages remained ambiguous, whereas the other remained facultative despite providing greater digestive efficiency.

  5. Relationships between Swiss needle cast and ectomycorrhizal fungus diversity.

    PubMed

    Luoma, Daniel L; Eberhart, Joyce L

    2014-01-01

    Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R(2) = 0.93) and EM density (R(2) = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R(2) = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas.

  6. Fungus dose-dependent primary pulmonary aspergillosis in immunosuppressed mice.

    PubMed Central

    Dixon, D M; Polak, A; Walsh, T J

    1989-01-01

    We report on a model of primary pulmonary aspergillosis occurring after intranasal instillation of concentrated suspensions of conidia of Aspergillus fumigatus in immunocompromised mice. Unconcentrated suspensions of inoculum contained ca. 2 x 10(7) conidia per ml (1x). These suspensions were concentrated by centrifugation, adjusted to give ca. 2 x 10(8) (10x) or 2 x 10(9) (100x) conidia per ml, and delivered in 30-microliters droplets to the nares of anesthetized mice. Mice were untreated or injected with cortisone acetate (CA) or cyclophosphamide (CY) in various dosage regimens. It was not possible to obtain mortality of more than 50% with sublethal immunosuppressive treatment and 1x fungus. In contrast, mortality followed a fungus dose response in mice receiving sublethal immunosuppression with either CA or CY. Mortality rates of up to 100% were obtained with 100x fungus and a single dose of CY (200 mg/kg) or CA (250 mg/kg) or three alternate doses (125 mg/kg per day) of CA prior to infection. This model is applicable to the study of acute, fatal primary pulmonary aspergillosis and chemotherapy trials. PMID:2651308

  7. Datasheet: Pseudogymnoascus destructans (white-nose syndrome fungus)

    USGS Publications Warehouse

    Blehert, David; Lankau, Emily

    2017-01-01

    Pseudogymnoascus destructans is a psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), an emerging disease of North American bats that has caused unprecedented population declines. The fungus is believed to have been introduced to North America from Europe or Asia (where it is present but does not cause significant mortality), but the full extent of its native range is unknown. The route of introduction is also unknown. In North America, hibernating bats become infected with P. destructans when body temperature decreases during winter torpor into the range permissive for growth of this fungus. Infected bats may develop visible fungal growth on the nose or wings, awaken more frequently from torpor, and experience a cascade of physiologic changes that result in weight loss, dehydration, electrolyte imbalances, and death. P. destructans persists in the environments of underground bat hibernation sites (hibernacula) and is believed to spread primarily by natural movements of infected bats. The first evidence of WNS in North America is from a photograph of a hibernating bat taken during winter of 2005-2006 in a hibernaculum near Albany, New York. P. destructans subsequently spread rapidly from the northeastern United States throughout much of the eastern portions of the United States and Canada, and most recently (as of May 2017) was detected in Washington State. It has killed millions of bats, threatening some species with regional extirpation and putting at risk the valuable environmental services that bats provide by eating harmful insects.

  8. Removal of phenanthrene in contaminated soil by combination of alfalfa, white-rot fungus, and earthworms.

    PubMed

    Deng, Shuguang; Zeng, Defang

    2017-03-01

    The aim of this study was to investigate the removal of phenanthrene by combination of alfalfa, white-rot fungus, and earthworms in soil. A 60-day experiment was conducted. Inoculation with earthworms and/or white-rot fungus increased alfalfa biomass and phenanthrene accumulation in alfalfa. However, inoculations of alfalfa and white-rot fungus can significantly decrease the accumulation of phenanthrene in earthworms. The removal rates for phenanthrene in soil were 33, 48, 66, 74, 85, and 93% under treatments control, only earthworms, only alfalfa, earthworms + alfalfa, alfalfa + white-rot fungus, and alfalfa + earthworms + white-rot fungus, respectively. The present study demonstrated that the combination of alfalfa, earthworms, and white-rot fungus is an effective way to remove phenanthrene in the soil. The removal is mainly via stimulating both microbial development and soil enzyme activity.

  9. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L; Magnuson, Jon K

    2014-05-27

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  10. Isolated fungal promoters and gene transcription terminators and methods of protein and chemical production in a fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  11. Isolated Fungal Promoters and Gene Transcription Terminators and Methods of Protein and Chemical Production in a Fungus

    DOEpatents

    Dai, Ziyu; Lasure, Linda L.; Magnuson, Jon K.

    2008-11-11

    The present invention encompasses isolated gene regulatory elements and gene transcription terminators that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention also encompasses a method of utilizing a fungus for protein or chemical production. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to another molecule comprising a coding region of a gene of interest. The gene regulatory element and gene transcription terminator may temporally and spatially regulate expression of particular genes for optimum production of compounds of interest in a transgenic fungus.

  12. Carbon dioxide sensing in an obligate insect-fungus symbiosis: CO2 preferences of leaf-cutting ants to rear their mutualistic fungus

    PubMed Central

    Bollazzi, Martin; Roces, Flavio

    2017-01-01

    Defense against biotic or abiotic stresses is one of the benefits of living in symbiosis. Leaf-cutting ants, which live in an obligate mutualism with a fungus, attenuate thermal and desiccation stress of their partner through behavioral responses, by choosing suitable places for fungus-rearing across the soil profile. The underground environment also presents hypoxic (low oxygen) and hypercapnic (high carbon dioxide) conditions, which can negatively influence the symbiont. Here, we investigated whether workers of the leaf-cutting ant Acromyrmex lundii use the CO2 concentration as an orientation cue when selecting a place to locate their fungus garden, and whether they show preferences for specific CO2 concentrations. We also evaluated whether levels preferred by workers for fungus-rearing differ from those selected for themselves. In the laboratory, CO2 preferences were assessed in binary choices between chambers with different CO2 concentrations, by quantifying number of workers in each chamber and amount of relocated fungus. Leaf-cutting ants used the CO2 concentration as a spatial cue when selecting places for fungus-rearing. A. lundii preferred intermediate CO2 levels, between 1 and 3%, as they would encounter at soil depths where their nest chambers are located. In addition, workers avoided both atmospheric and high CO2 levels as they would occur outside the nest and at deeper soil layers, respectively. In order to prevent fungus desiccation, however, workers relocated fungus to high CO2 levels, which were otherwise avoided. Workers’ CO2 preferences for themselves showed no clear-cut pattern. We suggest that workers avoid both atmospheric and high CO2 concentrations not because they are detrimental for themselves, but because of their consequences for the symbiotic partner. Whether the preferred CO2 concentrations are beneficial for symbiont growth remains to be investigated, as well as whether the observed preferences for fungus-rearing influences the ants

  13. Carbon dioxide sensing in an obligate insect-fungus symbiosis: CO2 preferences of leaf-cutting ants to rear their mutualistic fungus.

    PubMed

    Römer, Daniela; Bollazzi, Martin; Roces, Flavio

    2017-01-01

    Defense against biotic or abiotic stresses is one of the benefits of living in symbiosis. Leaf-cutting ants, which live in an obligate mutualism with a fungus, attenuate thermal and desiccation stress of their partner through behavioral responses, by choosing suitable places for fungus-rearing across the soil profile. The underground environment also presents hypoxic (low oxygen) and hypercapnic (high carbon dioxide) conditions, which can negatively influence the symbiont. Here, we investigated whether workers of the leaf-cutting ant Acromyrmex lundii use the CO2 concentration as an orientation cue when selecting a place to locate their fungus garden, and whether they show preferences for specific CO2 concentrations. We also evaluated whether levels preferred by workers for fungus-rearing differ from those selected for themselves. In the laboratory, CO2 preferences were assessed in binary choices between chambers with different CO2 concentrations, by quantifying number of workers in each chamber and amount of relocated fungus. Leaf-cutting ants used the CO2 concentration as a spatial cue when selecting places for fungus-rearing. A. lundii preferred intermediate CO2 levels, between 1 and 3%, as they would encounter at soil depths where their nest chambers are located. In addition, workers avoided both atmospheric and high CO2 levels as they would occur outside the nest and at deeper soil layers, respectively. In order to prevent fungus desiccation, however, workers relocated fungus to high CO2 levels, which were otherwise avoided. Workers' CO2 preferences for themselves showed no clear-cut pattern. We suggest that workers avoid both atmospheric and high CO2 concentrations not because they are detrimental for themselves, but because of their consequences for the symbiotic partner. Whether the preferred CO2 concentrations are beneficial for symbiont growth remains to be investigated, as well as whether the observed preferences for fungus-rearing influences the ants

  14. Secretome analysis of the fungus Trichoderma harzianum grown on cellulose.

    PubMed

    Do Vale, Luis H F; Gómez-Mendoza, Diana P; Kim, Min-Sik; Pandey, Akhilesh; Ricart, Carlos A O; Ximenes F Filho, Edivaldo; Sousa, Marcelo V

    2012-08-01

    Trichoderma harzianum is a mycoparasitic filamentous fungus that produces and secretes a wide range of extracellular hydrolytic enzymes used in cell wall degradation. Due to its potential in biomass conversion, T. harzianum draws great attention from biofuel and biocontrol industries and research. Here, we report an extensive secretome analysis of T. harzianum. The fungus was grown on cellulose medium, and its secretome was analyzed by a combination of enzymology, 2DE, MALDI-MS and -MS/MS (Autoflex II), and LC-MS/MS (LTQ-Orbitrap XL). A total of 56 proteins were identified using high-resolution MS. Interestingly, although cellulases were found, the major hydrolytic enzymes secreted in the cellulose medium were chitinases and endochitinases, which may reflect the biocontrol feature of T. harzianum. The glycoside hydrolase family, including chitinases (EC 3.2.1.14), endo-N-acetylglucosaminidases (EC 3.2.1.96), hexosaminidases (EC 3.2.1.52), galactosidases (EC 3.2.1.23), xylanases (EC 3.2.1.8), exo-1,3-glucanases (EC 3.2.1.58), endoglucanases (EC 3.2.1.4), xylosidases (EC 3.2.1.37), α-L-arabinofuranosidase (EC 3.2.1.55), N-acetylhexosaminidases (EC 3.2.1.52), and other enzymes represented 51.36% of the total secretome. Few representatives were classified in the protease family (8.90%). Others (17.60%) are mostly intracellular proteins. A considerable part of the secretome was composed of hypothetical proteins (22.14%), probably because of the absence of an annotated T. harzianum genome. The T. harzianum secretome composition highlights the importance of this fungus as a rich source of hydrolytic enzymes for bioconversion and biocontrol applications.

  15. Novel 11-norbetaenone isolated from an entomopathogenic fungus Lecanicillium antillanum.

    PubMed

    Li, Chi-Ying; Lo, I-Wen; Wang, Shih-Wei; Hwang, Tsong-Long; Chung, Yu-Ming; Cheng, Yuan-Bin; Tseng, Sung-Pin; Liu, Yi-Hung; Hsu, Yu-Ming; Chen, Shu-Rong; Hu, Hao-Chun; Chang, Fang-Rong; Wu, Yang-Chang

    2017-05-01

    A novel nor-betaenone compound, 11-norbetaenone (1), was isolated from the culture broth of an entomopathogenic fungus Lecanicillium antillanum. The structure was determined on the basis of 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was further confirmed by X-ray single crystallography analysis. It is the first secondary metabolite reported from the species Lecanicillium antillanum. And it is also the first time that a betaenone-type compound was isolated from the genus Lecanicillium. Furthermore, 11-norbetaenone (1) displayed significant anti-angiogenic effect by suppressing tube formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Pimarane diterpenes from the Arctic fungus Eutypella sp. D-1.

    PubMed

    Lu, Xiao-Ling; Liu, Jing-Tang; Liu, Xiao-Yu; Gao, Yun; Zhang, Jianpeng; Jiao, Bing-Hua; Zheng, Heng

    2014-02-01

    Two new diterpenes, libertellenone G(1) and libertellenone H(2) were isolated from the fungus Eutypella sp. D-1 isolated from the soil of high latitude of Arctic, together with two known pimarane diterpenes (3-4). The structures of 1 and 2 were elucidated from spectroscopic data (nuclear magnetic resonance, mass spectrometry and infrared). These compounds were evaluated for cytotoxic activity against seven human tumor cell lines. Compound 2 showed a range of cytotoxicity between 3.31 and 44.1 μM. Compound 1 exhibited antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus.

  17. Microsatellites from the charcoal rot fungus (Macrophomina phaseolina).

    PubMed

    Baird, Richard E; Wadl, Phillip A; Wang, Xinwang; Johnson, Denita H; Rinehart, Timothy A; Abbas, Hamed K; Shier, Thomas; Trigiano, Robert N

    2009-05-01

    Microsatellite loci were identified from the charcoal rot fungus (Macrophomina phaseolina). Primer pairs for 46 loci were developed, and of these, 13 were optimized and screened using genomic DNA from 55 fungal isolates collected predominantly from two soybean fields in Mississippi. Twelve of the optimized loci were polymorphic and the number of alleles per locus ranged from 6 to 22. These microsatellites will be useful in population and pathogenicity studies to correspond with development of potential disease-resistant soybean and other susceptible crops. © 2009 Blackwell Publishing Ltd. No claim to original US government works.

  18. Two new terpenoids from endophytic fungus Periconia sp. F-31.

    PubMed

    Ge, Han-Lin; Zhang, De-Wu; Li, Li; Xie, Dan; Zou, Jian-Hua; Si, Yi-Kang; Dai, Jungui

    2011-01-01

    Two new terpenoids, (+)-(3S,6S,7R,8S)-periconone A (1) and (-)-(1R,4R,6S,7S)-2-caren-4,8-olide (2), have been isolated from an endophytic fungus Periconia sp., which was collected from the plant Annona muricata. Their structures were elucidated on the basis of extensive spectroscopic analyses. In the in vitro assays, the two compounds showed low cytotoxic activities against six human tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, A2780 and MCF-7) with IC(50)>10(-5) M.

  19. Extracellular oxidases of the lignin-degrading fungus Panus tigrinus.

    PubMed

    Cadimaliev, D A; Revin, V V; Atykyan, N A; Samuilov, V D

    2005-06-01

    Two extracellular oxidases (laccases) were isolated from the extracellular fluid of the fungus Panus (Lentinus) tigrinus cultivated in low-nitrogen medium supplemented with birch sawdust. The enzymes were purified by successive chromatography on columns with TEAE-cellulose and DEAE-Toyopearl 650M. Both oxidases catalyze oxidation of pyrocatechol and ABTS. Moreover, oxidase 1 also catalyzes oxidation of guaiacol, o-phenylenediamine, and syringaldazine. The enzymes have identical pH (7.0) and temperature (60-65 degrees C) optimums. Absorption spectra of the oxidases differ from the spectra of typical "blue" laccases and are similar to the spectrum of yellow oxidase.

  20. Bioactive compounds from the endophytic fungus Fusarium proliferatum.

    PubMed

    Dame, Zerihun T; Silima, Beauty; Gryzenhout, Marieka; van Ree, Teunis

    2016-06-01

    The crude extract of an endophytic fungus isolated from Syzygium cordatum and identified as Fusarium proliferatum showed 100% cytotoxicity against the brine shrimp Artemia salina at 100 μg/mL. Seven coloured, biologically active metabolites - including ergosta-5,7,22-trien-3β-ol, nectriafurone-8-methyl ether, 9-O-methyl fusarubin, bostrycoidin, bostrycoidin-9-methyl ether and 8-hydroxy-5,6-dimethoxy-2-methyl-3-(2-oxo-propyl)-1,4-naphthoquinone- were isolated from the extract.

  1. Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

    PubMed Central

    de Prince, Karina Andrade; Sordi, Renata; Pavan, Fernando Rogério; Barreto Santos, Adolfo Carlos; Araujo, Angela R.; Leite, Sergio R.A.; Leite, Clarice Q. F.

    2012-01-01

    Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib.) B. Sutton, (Diaporthaceae), cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA) and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC) and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties. PMID:24031821

  2. Cepstrum based feature extraction method for fungus detection

    NASA Astrophysics Data System (ADS)

    Yorulmaz, Onur; Pearson, Tom C.; Çetin, A. Enis

    2011-06-01

    In this paper, a method for detection of popcorn kernels infected by a fungus is developed using image processing. The method is based on two dimensional (2D) mel and Mellin-cepstrum computation from popcorn kernel images. Cepstral features that were extracted from popcorn images are classified using Support Vector Machines (SVM). Experimental results show that high recognition rates of up to 93.93% can be achieved for both damaged and healthy popcorn kernels using 2D mel-cepstrum. The success rate for healthy popcorn kernels was found to be 97.41% and the recognition rate for damaged kernels was found to be 89.43%.

  3. Dihydroisocoumarins from the Mangrove-Derived Fungus Penicillium citrinum

    PubMed Central

    Huang, Guo-Lei; Zhou, Xue-Ming; Bai, Meng; Liu, Yu-Xin; Zhao, Yan-Lei; Luo, You-Ping; Niu, Yan-Yan; Zheng, Cai-Juan; Chen, Guang-Ying

    2016-01-01

    Three new dihydroisocoumarin penicimarins G–I (1–3), together with one known dihydroisocoumarin (4) and three known meroterpenoids (5–7), were obtained from a fungus Penicillium citrinum isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of spectroscopic data. The absolute configuration of 1 was determined by the X-ray diffraction analysis using Cu Kα radiation. The absolute configurations of 2 and 3 were determined by comparison of their circular dichroism (CD) spectra with the literature. All compounds were evaluated for their antibacterial activities and cytotoxic activities. PMID:27735855

  4. Biological activities of ophiobolin K and 6-epi-ophiobolin K produced by the endophytic fungus Aspergillus calidoustus

    USDA-ARS?s Scientific Manuscript database

    The endophytic fungus, Aspergillus calidoustus, was isolated from the plant species Acanthospermum australe (Asteraceae). A dichloromethane extract of the fungus displayed antifungal, antiprotozoal, and cytotoxic activities. Aspergillus calidoustus was identified using molecular, physiological and m...

  5. Specificity in the symbiotic association between fungus-growing ants and protective Pseudonocardia bacteria

    PubMed Central

    Cafaro, Matías J.; Poulsen, Michael; Little, Ainslie E. F.; Price, Shauna L.; Gerardo, Nicole M.; Wong, Bess; Stuart, Alison E.; Larget, Bret; Abbot, Patrick; Currie, Cameron R.

    2011-01-01

    Fungus-growing ants (tribe Attini) engage in a mutualism with a fungus that serves as the ants' primary food source, but successful fungus cultivation is threatened by microfungal parasites (genus Escovopsis). Actinobacteria (genus Pseudonocardia) associate with most of the phylogenetic diversity of fungus-growing ants; are typically maintained on the cuticle of workers; and infection experiments, bioassay challenges and chemical analyses support a role of Pseudonocardia in defence against Escovopsis through antibiotic production. Here we generate a two-gene phylogeny for Pseudonocardia associated with 124 fungus-growing ant colonies, evaluate patterns of ant–Pseudonocardia specificity and test Pseudonocardia antibiotic activity towards Escovopsis. We show that Pseudonocardia associated with fungus-growing ants are not monophyletic: the ants have acquired free-living strains over the evolutionary history of the association. Nevertheless, our analysis reveals a significant pattern of specificity between clades of Pseudonocardia and groups of related fungus-growing ants. Furthermore, antibiotic assays suggest that despite Escovopsis being generally susceptible to inhibition by diverse Actinobacteria, the ant-derived Pseudonocardia inhibit Escovopsis more strongly than they inhibit other fungi, and are better at inhibiting this pathogen than most environmental Pseudonocardia strains tested. Our findings support a model that many fungus-growing ants maintain specialized Pseudonocardia symbionts that help with garden defence. PMID:21106596

  6. Detection of fungus-infected corn kernels using near-infrared reflectance spectroscopy and color imaging

    USDA-ARS?s Scientific Manuscript database

    Contamination of grain products by fungus can lead to economic losses and is deleterious to human and livestock health. Detection and quantification of fungus-infected corn kernels would be adventitious for producers and breeders in evaluating quality and in selecting hybrids with resistance to inf...

  7. Using copper sulfate to control egg fungus at Keo Fish Farm

    USDA-ARS?s Scientific Manuscript database

    Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab has been working on gaining FDA-approval to use copper sulfate to control fungus on catfish eggs, so we were con...

  8. Naphthalene, an insect repellent, is produced by Muscodor vitigenus, a novel endophytic fungus

    Treesearch

    Bryn H. Daisy; Gary A. Strobel; Uvidelio Castillo; David Ezra; Joe Sears; David K. Weaver; Justin B. Runyon

    2002-01-01

    Muscodor vitigenus is a recently described endophytic fungus of Paullinia paullinioides, a liana growing in the understorey of the rainforests of the Peruvian Amazon. This fungus produces naphthalene under certain cultural conditions. Naphthalene produced by M. vitigenus was identified by gas chromatography/mass...

  9. White-Nose Syndrome Fungus in a 1918 Bat Specimen from France.

    PubMed

    Campana, Michael G; Kurata, Naoko P; Foster, Jeffrey T; Helgen, Lauren E; Reeder, DeeAnn M; Fleischer, Robert C; Helgen, Kristofer M

    2017-09-01

    White-nose syndrome, first diagnosed in North America in 2006, causes mass deaths among bats in North America. We found the causative fungus, Pseudogymnoascus destructans, in a 1918 sample collected in Europe, where bats have now adapted to the fungus. These results are consistent with a Eurasian origin of the pathogen.

  10. Serpula lacrymans, the dry rot fungus and tolerance towards copper-based wood preservatives

    Treesearch

    Anne Christine Steenkjaer Hastrup; Frederick Green; Carol Clausen; Bo Jensen

    2005-01-01

    Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a...

  11. Association of the Pitch Canker Fungus with Cones and Seeds of Pines

    Treesearch

    L. David Dwinell

    1998-01-01

    The pitch canker fungus, Fusarium subglutinans f. sp.pini, causes the mortality of female flowers and mature cones, and can infect and destroy gametophyte tissues of seeds of several pine species in the southeastern U.S. The fungus can also be associated with the seed coats of apparently healthy, viable pine seeds. The pitch canker...

  12. Bioproducts and morphological features of diverse isolates of the fungus Aureobasidium pullulans

    USDA-ARS?s Scientific Manuscript database

    Aureobasidium pullulans is a fungus included among the “black yeasts.” Although many strains are predominantly yeast-like, the species is actually polymorphic, exhibiting a variety of complex forms. The fungus is ubiquitous, routinely found on the surface of leaves, wood, painted walls, etc. We rece...

  13. White-Nose Syndrome Fungus in a 1918 Bat Specimen from France

    PubMed Central

    Campana, Michael G.; Kurata, Naoko P.; Foster, Jeffrey T.; Helgen, Lauren E.; Reeder, DeeAnn M.; Fleischer, Robert C.

    2017-01-01

    White-nose syndrome, first diagnosed in North America in 2006, causes mass deaths among bats in North America. We found the causative fungus, Pseudogymnoascus destructans, in a 1918 sample collected in Europe, where bats have now adapted to the fungus. These results are consistent with a Eurasian origin of the pathogen. PMID:28820367

  14. Fun Microbiology: Using a Plant Pathogenic Fungus To Demonstrate Koch's Postulates.

    ERIC Educational Resources Information Center

    Mitchell, James K.; Orsted, Kathy M.; Warnes, Carl E.

    1997-01-01

    Describes an experiment using a plant pathogenic fungus in which students learn to follow aseptic techniques, grow and produce spores of a fungus, use a hemacytometer for enumerating spores, prepare serial dilutions, grow and inoculate plants, isolate a pure culture using agar streak plates, and demonstrate the four steps of Koch's postulates.…

  15. Mating and Progeny Isolation in The Corn Smut Fungus Ustilago maydis

    USDA-ARS?s Scientific Manuscript database

    The corn smut pathogen, Ustilago maydis (U. maydis) (DC.) Corda, is a semi-obligate plant pathogenic fungus in the phylum Basidiomycota (Alexopoulos, Mims and Blackwell, 1996). The fungus can be easily cultured in its haploid yeast phase on common laboratory media. However, to complete its sexual cy...

  16. Fungus gnats and Pythium in the attack on greenhouse plants: conspirators or just cohabitants

    USDA-ARS?s Scientific Manuscript database

    Research conducted by collaborating Cornell University and USDA-ARS scientists investigated the potential for fungus gnats to vector Pythium root-rot pathogens. Fungus gnat larvae readily consumed Pythium oospores; the spores survived passage through the larval gut and, upon defecation, were able to...

  17. Fun Microbiology: Using a Plant Pathogenic Fungus To Demonstrate Koch's Postulates.

    ERIC Educational Resources Information Center

    Mitchell, James K.; Orsted, Kathy M.; Warnes, Carl E.

    1997-01-01

    Describes an experiment using a plant pathogenic fungus in which students learn to follow aseptic techniques, grow and produce spores of a fungus, use a hemacytometer for enumerating spores, prepare serial dilutions, grow and inoculate plants, isolate a pure culture using agar streak plates, and demonstrate the four steps of Koch's postulates.…

  18. Reproduction of a woodwasp, Urocerus japonicus (Hymenoptera: Siricidae) using no maternal symbiotic fungus

    Treesearch

    Hideshi Fukuda

    2003-01-01

    Most woodwasps (Siricidae) are symbiotically associated with the specific fungus, Amylostereum spp. Female adults inoculate the fungus during their oviposition in sapwood of the host trees (Morgan 1968). Woodwasp larvae can digest sapwood with low nutritional quality with the aid of symbiosis (Kukor and Martin 1983). In the earlier study, we...

  19. Genome Sequence of the Mucoromycotina Fungus Umbelopsis isabellina, an Effective Producer of Lipids

    SciTech Connect

    Takeda, Itaru; Tamano, Koichi; Yamane, Noriko; Ishii, Tomoko; Miura, Ai; Umemura, Myco; Terai, Goro; Baker, Scott E.; Koike, Hideaki; Machida, Masayuki

    2014-02-27

    Umbelopsis isabellina is a fungus in the subdivision Mucoromycotina, many members of which have been shown to be oleaginous and have become important organisms for producing oil because of their high level of intracellular lipid accumulation from various feedstocks. The genome sequence of U. isabellina NBRC 7884 was determined and annotated, and this information might provide insights into the oleaginous properties of this fungus.

  20. Specificity in the symbiotic association between fungus-growing ants and protective Pseudonocardia bacteria.

    PubMed

    Cafaro, Matías J; Poulsen, Michael; Little, Ainslie E F; Price, Shauna L; Gerardo, Nicole M; Wong, Bess; Stuart, Alison E; Larget, Bret; Abbot, Patrick; Currie, Cameron R

    2011-06-22

    Fungus-growing ants (tribe Attini) engage in a mutualism with a fungus that serves as the ants' primary food source, but successful fungus cultivation is threatened by microfungal parasites (genus Escovopsis). Actinobacteria (genus Pseudonocardia) associate with most of the phylogenetic diversity of fungus-growing ants; are typically maintained on the cuticle of workers; and infection experiments, bioassay challenges and chemical analyses support a role of Pseudonocardia in defence against Escovopsis through antibiotic production. Here we generate a two-gene phylogeny for Pseudonocardia associated with 124 fungus-growing ant colonies, evaluate patterns of ant-Pseudonocardia specificity and test Pseudonocardia antibiotic activity towards Escovopsis. We show that Pseudonocardia associated with fungus-growing ants are not monophyletic: the ants have acquired free-living strains over the evolutionary history of the association. Nevertheless, our analysis reveals a significant pattern of specificity between clades of Pseudonocardia and groups of related fungus-growing ants. Furthermore, antibiotic assays suggest that despite Escovopsis being generally susceptible to inhibition by diverse Actinobacteria, the ant-derived Pseudonocardia inhibit Escovopsis more strongly than they inhibit other fungi, and are better at inhibiting this pathogen than most environmental Pseudonocardia strains tested. Our findings support a model that many fungus-growing ants maintain specialized Pseudonocardia symbionts that help with garden defence.

  1. Differential response by Melaleuca quinquenervia trees to attack by the rust fungus Puccinia psidii in Florida

    USDA-ARS?s Scientific Manuscript database

    Melaleuca quinquenervia (melaleuca, paperbark tree) is an exotic invasive tree in Florida, Hawaii, and some Caribbean islands. Puccinia psidii (guava rust-fungus) is a Neotropical rust fungus, reported to attack many species in the Myrtaceae and one genus in the Heteropyxidaceae, both members of the...

  2. [Fungus, Metarrhizium anisopliae, as a possible regulator of the number of horseflies].

    PubMed

    Saubenova, O G

    1976-01-01

    In water bodies of the flood-plains of the Ili and Turgen rivers (Alma-Ata district) there were found larvae of Tabanus autumnalis infected with the fungus Metarrhizium anisopliae. Experiments on the infection of T. autumnalis with this fungus yielded 100% mortality of larvae and adult insects. The possibility of creation of an artificial infection nidus under natural conditions was established.

  3. Nigrosphaerin A., a new isachromene derivative from the endophytic fungus Nigrospora sphaerica

    USDA-ARS?s Scientific Manuscript database

    Nigrosphaerin A, a new isochromene derivative (1) was isolated from the endophytic fungus Nigrospora sphaerica and chemically identified as 3-(3,4-dihydroxyphenyl)-4,6,8-trihydroxy-1H-isochromen-1-one-6-O-ß-D- glucopyranoside. In addition nineteen known compounds (2-20) isolated from the same fungus...

  4. Biotransformation of an africanane sesquiterpene by the fungus Mucor plumbeus.

    PubMed

    Fraga, Braulio M; Díaz, Carmen E; Amador, Leonardo J; Reina, Matías; López-Rodriguez, Matías; González-Coloma, Azucena

    2017-03-01

    Biotransformation of 8β-hydroxy-african-4(5)-en-3-one angelate by the fungus Mucor plumbeus afforded as main products 6α,8β-dihydroxy-african-4(5)-en-3-one 8β-angelate and 1α,8β-dihydroxy-african-4(5)-en-3-one 8β-angelate, which had been obtained, together with the substrate, from transformed root cultures of Bethencourtia hermosae. This fact shows that the enzyme system involved in these hydroxylations in both organisms, the fungus and the plant, acts with the same regio- and stereospecificity. In addition another twelve derivatives were isolated in the incubation of the substrate, which were identified as the (2'R,3'R)- and (2'S,3'S)-epoxy derivatives of the substrate and of the 6α- and 1α-hydroxy alcohols, the 8β-(2'R,3'R)- and 8β-(2'S,3'S)-epoxyangelate of 8β,15-dihydroxy-african-4(5)-en-3-one, the hydrolysis product of the substrate, and three isomers of 8β-hydroxy-african-4(5)-en-3-one 2ξ,3ξ-dihydroxy-2-methylbutanoate. The insect antifeedant effects of the pure compounds were tested against chewing and sucking insect species along with their selective cytotoxicity against insect (Sf9) and mammalian (CHO) cell lines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Transformation of Metalaxyl by the Fungus Syncephalastrum racemosum†

    PubMed Central

    Zheng, Zhong; Liu, Shu-Yen; Freyer, Alan J.; Bollag, Jean-Marc

    1989-01-01

    The fungus Syncephalastrum racemosum (Cohn) Schroeter was found to transform the fungicide metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester] in pure culture. After 21 days of incubation in a basal medium amended with 5 μg of metalaxyl per ml, more than 80% of the compound was transformed by the fungus. The transformation rates decreased as the concentrations of metalaxyl increased from 5 to 100 μg/ml. No transformation was observed when the concentration of metalaxyl was higher than 200 μg/ml. Two isomeric metabolites and a mixture of two other isomeric metabolites were isolated from the organic extract of the growth medium and identified as N-(2-methyl-6-hydroxymethylphenyl)-N- and N-(2-hydroxymethyl-6-methylphenyl)-N-(methoxyacetyl)-alanine methyl ester and N-(3-hydroxy- and N-(5-hydroxy-2,6-dimethyl-phenyl)-N-(methoxyacetyl)-alanine methyl ester according to their mass-spectral and nuclear magnetic resonance-spectral characteristics. Benzylic hydroxylation of the methyl side chains and/or aromatic hydroxylation appeared to be the major reactions involved in the metabolism of metalaxyl. PMID:16347836

  6. The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus

    SciTech Connect

    Ellstrom, Magnus; Shah, Firoz; Johansson, Tomas; Ahren, Dag; Persson, Per; Tunlid, Anders

    2015-03-16

    The amounts of carbon allocated to the fungal partner in ectomycorrhizal associations can vary substantially depending on the plant growth and the soil nutrient conditions, and the fungus may frequently be confronted with limitations in carbon. We used chemical analysis and transcriptome profiling to examine the physiological response of the ectomycorrhizal fungus Paxillus involutus to carbon starvation during axenic cultivation. Carbon starvation induced a decrease in the biomass. Concomitantly, ammonium, cell wall material (chitin) and proteolytic enzymes were released into the medium, which suggest autolysis. Compared with the transcriptome of actively growing hyphae, about 45% of the transcripts analyzed were differentially regulated during C-starvation. Induced during starvation were transcripts encoding extracellular enzymes such as peptidases, chitinases and laccases. In parallel, transcripts of N-transporters were upregulated, which suggest that some of the released nitrogen compounds were re-assimilated by the mycelium. The observed changes suggest that the carbon starvation response in P. involutus is associated with complex cellular changes that involves autolysis, recycling of intracellular compounds by autophagy and reabsorption of the extracellular released material. The study provides molecular markers that can be used to examine the role of autolysis for the turnover and survival of the ectomycorrhizal mycelium in soils.

  7. The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus

    DOE PAGES

    Ellstrom, Magnus; Shah, Firoz; Johansson, Tomas; ...

    2015-03-16

    The amounts of carbon allocated to the fungal partner in ectomycorrhizal associations can vary substantially depending on the plant growth and the soil nutrient conditions, and the fungus may frequently be confronted with limitations in carbon. We used chemical analysis and transcriptome profiling to examine the physiological response of the ectomycorrhizal fungus Paxillus involutus to carbon starvation during axenic cultivation. Carbon starvation induced a decrease in the biomass. Concomitantly, ammonium, cell wall material (chitin) and proteolytic enzymes were released into the medium, which suggest autolysis. Compared with the transcriptome of actively growing hyphae, about 45% of the transcripts analyzed weremore » differentially regulated during C-starvation. Induced during starvation were transcripts encoding extracellular enzymes such as peptidases, chitinases and laccases. In parallel, transcripts of N-transporters were upregulated, which suggest that some of the released nitrogen compounds were re-assimilated by the mycelium. The observed changes suggest that the carbon starvation response in P. involutus is associated with complex cellular changes that involves autolysis, recycling of intracellular compounds by autophagy and reabsorption of the extracellular released material. The study provides molecular markers that can be used to examine the role of autolysis for the turnover and survival of the ectomycorrhizal mycelium in soils.« less

  8. [Chemical constituents of an endophytic fungus from Annona muricata].

    PubMed

    Ge, Hanlin; Dai, Jungui

    2010-12-01

    To investigate the chemical constituents of an endophytic fungus, F-31, from Annona muricata and search antitumor natural products. After scaling up, the fermentation broth and mycelia were extracted by macroporous resin and chromatographied by silica gel column, Sephadex LH-20 gel column and semi-preparative HPLC. The structures of compounds were determined by the means of extensive spectroscopic data The activity of the compounds were evaluated through MTT assay. Six compounds were isolated from the fermentation broth and mycelia of this fungus, their structures were identified as 5-(3-hydroxybutyl)furan-2(5H)-one(1), chloranthalactone E(2), 5, 7-dimethyl-6-hydroxycoumarin(3), 1, 2, 4-triazole-(1'R, 2'R, 3'R, 4'R)-nucleosides(4), L-tryptophan(5), L-phenylalanine(6). The in vitro pharmalogical evaluation results displayed that the above compounds exhibited no inhibitory effects on the proliferation of six tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, A2780 and MCF-7). Among these obtained compounds, compound 1 was a new compound.

  9. Biosolubilization of coal by a genetically characterized fungus

    SciTech Connect

    Odom, C.B.

    1990-01-01

    Biosolubilization of lignite at ambient temperatures and pressure by the genetically well characterized fungus Neurospora crassa is reported. The fungus also demonstrates the ability to survive on media containing solubilized coal compounds as the sole carbon source. An extracellular protein with an apparent molecular weight of approximately 84,000 daltons that functions in the biosolubilizations process has been isolated and purified to apparent homogeneity. Enhanced secretions of this protein can be induced by the treatment of the growing culture with the protein synthesis inhibitor cycloheximide. Characterization of the heat stability of the solubilizing agent led to the discovery of another, more heat stable, putative solubilization factor having a molecular weight of less than 10,000 daltons. This factor is remarkably similar to a factor that has been previously discovered in another microbial system. Several sources of non-biological solubilization activity were discovered and examined, as well as finding that a common extracellular enzyme, laccase, has the apparent ability to heighten the degree of biosolubilization brought about by the purified solubilizing factor. The amino acid composition of the biologically active protein was determined and found to be distinct from that of laccase. Finally, electrophoretic separation of the products of solubilized lignite indicate a possible difference in breakdown products between coal treated with different chemical and biological agents.

  10. Homoharringtonine production by endophytic fungus isolated from Cephalotaxus hainanensis Li.

    PubMed

    Hu, Xiaoping; Li, Wu; Yuan, Mu; Li, Congfa; Liu, Sixin; Jiang, Chunjie; Wu, Yanchun; Cai, Kun; Liu, Yan

    2016-07-01

    Homoharringtonine (HHT), a natural plant alkaloid derived from Cephalotaxus, has demonstrated to have a broad antitumor activity and efficacy in treating human chronic myeloid leukemia. An alternative source is required to substitute for the slow-growing and scarce Cephalotaxus to meet the increasing demand of the drug market. The objective of this study was to screen HHT-producing endophytic fungi from Cephalotaxus hainanensis Li. By screening 213 fungal isolates obtained from the bark parts of Cephalotaxus hainanensis Li, one isolate was found to be capable of biosynthesizing HHT. The fungus was identified as Alternaria tenuissima by morphological characteristics and internal transcribed spacer (ITS) sequence analysis and was named as CH1307. HHT obtained from CH1307 was analyzed through the HPLC and LC-MS/MS and NMR spectroscopy. The extract of the fermentation broth of CH1307 showed antiproliferative activities against K562 (chronic myelocytic leukemia), NB4 (acute promyelocytic leukemia), and HL-60 (promyelocytic leukemia) human cancer cell lines with IC50 values of 67.25 ± 4.26, 65.02 ± 4.75, and 99.23 ± 4.26 μg/mL, respectively. The findings suggest that HHT-producing endophytic fungus, Alternaria tenuissima CH1307 might provide a promising source for the research and application of HHT.

  11. Secondary metabolite arsenal of an opportunistic pathogenic fungus.

    PubMed

    Bignell, Elaine; Cairns, Timothy C; Throckmorton, Kurt; Nierman, William C; Keller, Nancy P

    2016-12-05

    Aspergillus fumigatus is a versatile fungus able to successfully exploit diverse environments from mammalian lungs to agricultural waste products. Among its many fitness attributes are dozens of genetic loci containing biosynthetic gene clusters (BGCs) producing bioactive small molecules (often referred to as secondary metabolites or natural products) that provide growth advantages to the fungus dependent on environment. Here we summarize the current knowledge of these BGCs-18 of which can be named to product-their expression profiles in vivo, and which BGCs may enhance virulence of this opportunistic human pathogen. Furthermore, we find extensive evidence for the presence of many of these BGCs, or similar BGCs, in distantly related genera including the emerging pathogen Pseudogymnoascus destructans, the causative agent of white-nose syndrome in bats, and suggest such BGCs may be predictive of pathogenic potential in other fungi.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  12. The response of filamentous fungus Rhizopus nigricans to flavonoids.

    PubMed

    Slana, Marko; Zigon, Dušan; Makovec, Tomaž; Lenasi, Helena

    2011-08-01

    The saprophytic fungus Rhizopus nigricans constitutes a serious problem when thriving on gathered crops. The identification of any compounds, especially natural ones, that inhibit fungal growth, may therefore be important. During its life cycle, Rhizopus nigricans encounters many compounds, among them the flavonoids, plant secondary metabolites that are involved in plant defense against pathogenic microorganisms. Although not being a plant pathogen, Rhizopus nigricans may interact with these compounds in the same way as plant pathogens--in response to the fungitoxic effect of flavonoids the fungi transform them into less toxic metabolites. We have studied the interaction of R. nigricans with some flavonoids. Inhibition of hyphal spreading (from 3% to 100%) was observed by 300 μM flavones, flavanones and isoflavones, irrespective of their basic structure, oxidized or reduced C-ring, and orientation of the B-ring. However, a hydrophobic A-ring was important for the toxicity. R. nigricans transformed some of the flavonoids into glucosylated products. Recognition of substrates for glucosylating enzyme(s) did not correlate with their fungitoxic effect but depended exclusively on the presence of a free -OH group in the flavonoid A-ring and of a hydrophobic B-ring. Although the fungus produced glucosyltransferase constitutively, an additional amount of the enzyme was induced by the substrate flavonoid. Moreover, effective detoxification was shown to require the presence of glucose.

  13. Oxidative degradation of phenanthrene by the ligininolytic fungus Phanerochaete chrysosporium

    SciTech Connect

    Hammel, K.E.; Moen, M.A. ); Wen Zhigai; Green, B. )

    1992-06-01

    The ligninolytic fungus Phanerochaete chrysosporium oxidized phenanthrene and phenanthrene-9,10-quinone (PQ) at their C-9 and C-10 positions to give a ring-fission product, 2,2[prime]-diphenic acid (DPA), which was identified in chromatographic and isotope dilution experiments. DPA formation from phenanthrene was somewhat greater in low-nitrogen cultures than in high-nitrogen cultures and did not occur in uninoculated cultures. The oxidation of PQ to DPA involved both fungal and abiotic mechanisms, was unaffected by the level of nitrogen added, and was significantly faster than the cleavage of phenanthrene to DPA. Phenanthrene-trans-9,10-dihydrodiol, which was previously shown to be the principal phenathrene metabolite in nonligninolytic P. chrysosporium cultures, was not formed in the ligninolytic cultures employed here. These results suggest that phenanthrene degradation by ligninolytic P. chrysosporium proceeds in order from phenanthrene [yields] PQ [yields] DPA, involves both ligninolytic and nonligninolytic enzymes, and is not initiated by a classical microsomal cytochrome P-450. The extracellular lignin peroxidases of P. chrysosporium were not able to oxidize phenanthrene in vitro and therefore are also unlikely to catalyze the first step of phenanthrene degradation in vivo. Both phenanthrene and PQ were mineralized to similar extents by the fungus, which supports the intermediacy of PQ in phenanthrene degradation, but both compounds were mineralized significantly less than the structurally related lignin peroxidase substrate pyrene was.

  14. Oxidative degradation of phenanthrene by the ligninolytic fungus phanerochaete chrysosposium

    SciTech Connect

    Hammel, K.E.; Gai, W.Z.; Green, B.; Moen, M.A.

    1992-01-01

    The ligninolytic fungus Phanerochaete chrysosporium oxidized phenanthrene and phenanthrene-9,10-quinone (PQ) at their C-9 and C-10 positions to give a ring-fission product, 2,2'-diphenic acid (DPA), which was identified in chromatographic and isotope dilution experiments. DPA formation from phenanthrene was somewhat greater in low-nitrogen (ligninolytic) cultures than in high-nitrogen (nonligninolytic) cultures and did not occur in uninoculated cultures. The oxidation of PQ to DPA involved both fungal and abiotic mechanisms, was unaffected by the level of nitrogen added, and was significantly faster than the cleavage of phenanthrene to DPA. Phenanthrene-trans-9,10-dihydrodiol, which was previously shown to be the principal phenanthrene metabolite in nonligninolytic P. chrysosporium cultures, was not formed in the ligninolytic cultures employed here. These results suggest that phenanthrene degradation by ligninolytic P. chrysosporium proceeds in order from phenanthrene -> PQ -> DPA, involves both ligninolytic and nonligninolytic enzymes, and is not initiated by a classical microsomal cytochrome P-450. The extracellular lignin peroxidases of P. chrysosporium were not able to oxidize phenanthrene in vitro and therefore are also unlikely to catalyze the first step of phenanthrene degradation in vivo. Both phenanthrene and PQ were mineralized to similar extents by the fungus, which supports the intermediacy of PQ in phenanthrene degradation, but both compounds were mineralized significantly less than the structurally related lignin peroxidase substrate pyrene was.

  15. The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus.

    PubMed

    Ellström, Magnus; Shah, Firoz; Johansson, Tomas; Ahrén, Dag; Persson, Per; Tunlid, Anders

    2015-04-01

    The amounts of carbon allocated to the fungal partner in ectomycorrhizal associations can vary substantially depending on the plant growth and the soil nutrient conditions, and the fungus may frequently be confronted with limitations in carbon. We used chemical analysis and transcriptome profiling to examine the physiological response of the ectomycorrhizal fungus Paxillus involutus to carbon starvation during axenic cultivation. Carbon starvation induced a decrease in the biomass. Concomitantly, ammonium, cell wall material (chitin) and proteolytic enzymes were released into the medium, which suggest autolysis. Compared with the transcriptome of actively growing hyphae, about 45% of the transcripts analyzed were differentially regulated during C-starvation. Induced during starvation were transcripts encoding extracellular enzymes such as peptidases, chitinases and laccases. In parallel, transcripts of N-transporters were upregulated, which suggest that some of the released nitrogen compounds were re-assimilated by the mycelium. The observed changes suggest that the carbon starvation response in P. involutus is associated with complex cellular changes that involves autolysis, recycling of intracellular compounds by autophagy and reabsorption of the extracellular released material. The study provides molecular markers that can be used to examine the role of autolysis for the turnover and survival of the ectomycorrhizal mycelium in soils.

  16. No sex in fungus-farming ants or their crops

    PubMed Central

    Himler, Anna G.; Caldera, Eric J.; Baer, Boris C.; Fernández-Marín, Hermógenes; Mueller, Ulrich G.

    2009-01-01

    Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent–offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant–fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii. PMID:19369264

  17. The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus

    PubMed Central

    Ellström, Magnus; Shah, Firoz; Johansson, Tomas; Ahrén, Dag; Persson, Per; Tunlid, Anders

    2015-01-01

    The amounts of carbon allocated to the fungal partner in ectomycorrhizal associations can vary substantially depending on the plant growth and the soil nutrient conditions, and the fungus may frequently be confronted with limitations in carbon. We used chemical analysis and transcriptome profiling to examine the physiological response of the ectomycorrhizal fungus Paxillus involutus to carbon starvation during axenic cultivation. Carbon starvation induced a decrease in the biomass. Concomitantly, ammonium, cell wall material (chitin) and proteolytic enzymes were released into the medium, which suggest autolysis. Compared with the transcriptome of actively growing hyphae, about 45% of the transcripts analyzed were differentially regulated during C-starvation. Induced during starvation were transcripts encoding extracellular enzymes such as peptidases, chitinases and laccases. In parallel, transcripts of N-transporters were upregulated, which suggest that some of the released nitrogen compounds were re-assimilated by the mycelium. The observed changes suggest that the carbon starvation response in P. involutus is associated with complex cellular changes that involves autolysis, recycling of intracellular compounds by autophagy and reabsorption of the extracellular released material. The study provides molecular markers that can be used to examine the role of autolysis for the turnover and survival of the ectomycorrhizal mycelium in soils. PMID:25778509

  18. Expression of organophosphate hydrolase in the filamentous fungus Gliocladium virens.

    PubMed

    Dave, K I; Lauriano, C; Xu, B; Wild, J R; Kenerley, C M

    1994-05-01

    The broad-spectrum organophosphate hydrolase (OPH; EC 3.1.8.1) encoded by the organophosphate-degrading gene (opd) from Pseudomonas diminuta MG and Flavobacterium sp. ATCC 27551 possesses capabilities of both P-O bond hydrolysis (e.g. paraoxon) and P-F bond hydrolysis [e.g. sarin and diisopropylfluorophosphate (DFP)]. In the present study a 9.4-kb plasmid, pCL1, was used to transform the saprophytic fungus Gliocladium virens. pCL1 was derived from pJS294 by placing the fungal promoter (prom1) from Cochliobolus heterostrophus upstream and the trpC terminator from Aspergillus nidulans down-stream of the opd gene. Southern analysis of restricted genomic DNA from various transformants indicated that integration occurred non-specifically at multiple sites. Western blot analysis of mycelial extracts from transformants confirmed the production of a processed form of the enzyme in the fungus. Maximal levels of OPH activity (rate of p-nitrophenol production from paraoxon) were observed after 168 h of culture and activity levels correlated with biomass production in mature vegetative growth.

  19. One fungus, one name promotes progressive plant pathology.

    PubMed

    Wingfield, Michael J; De Beer, Z Wilhelm; Slippers, Bernard; Wingfield, Brenda D; Groenewald, Johannes Z; Lombard, Lorenzo; Crous, Pedro W

    2012-08-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms, for which the taxonomy and, in particular, a dual nomenclature system have frustrated and confused practitioners of plant pathology. The emergence of DNA sequencing has revealed cryptic taxa and revolutionized our understanding of relationships in the fungi. The impacts on plant pathology at every level are already immense and will continue to grow rapidly as new DNA sequencing technologies continue to emerge. DNA sequence comparisons, used to resolve a dual nomenclature problem for the first time only 19 years ago, have made it possible to approach a natural classification for the fungi and to abandon the confusing dual nomenclature system. The journey to a one fungus, one name taxonomic reality has been long and arduous, but its time has come. This will inevitably have a positive impact on plant pathology, plant pathologists and future students of this hugely important discipline on which the world depends for food security and plant health in general. This contemporary review highlights the problems of a dual nomenclature, especially its impact on plant pathogenic fungi, and charts the road to a one fungus, one name system that is rapidly drawing near. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

  20. Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus

    PubMed Central

    Bracarense, Adriana A.P.; Takahashi, Jacqueline A.

    2014-01-01

    Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 22 full factorial planning (ANOVA) and on a 23 factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC. PMID:24948950

  1. The Phosphatome of Medicinal and Edible Fungus Wolfiporia cocos.

    PubMed

    Zhu, Wenjun; Wei, Wei; Zhang, Shaopeng; Zheng, Yonglian; Chen, Ping; Xu, Xiaowen

    2017-09-12

    Wolfiporia cocos is an important medicinal and edible fungus that grows in association with pine trees, and its dried sclerotium has been used as a traditional medicine in China for centuries. However, the commercial production of W. cocos sclerotia is currently limited by shortages in pine wood resources. Since protein phosphatases (PPs) play significant roles in growth, signal transduction, development, metabolism, sexual reproduction, cell cycle, and environmental stress responses in fungi, the phosphatome of W. cocos was analyzed in this study by identifying PP genes, studying transcript profiles and assigning PPs to orthologous groups. Fifty-four putative PP genes were putatively identified in W. cocos genome based on homologous sequences searching using BLASTx program against the Saccharomyces cerevisiae, Fusarium graminearum, and Sclerotinia sclerotiorum databases. Based on known and presumed functions of orthologues of these PP genes found in other fungi, the putative roles of these W. cocos PPs in colonization, hyphal growth, sclerotial formation, secondary metabolism, and stress tolerance to environment were discussed in this study. And the level of transcripts from PP genes in the mycelium and sclerotium stages was also analyzed by qRT-PCR. Our study firstly identified and functional discussed the phosphatome in the medicinal and edible fungus W. cocos. The data from our study contribute to a better understanding of PPs potential roles in various cellar processes of W. cocos, and systematically provide comprehensive and novel insights into W. cocos economically important traits that could be extended to other fungi.

  2. Cytotoxic acyl amides from the soil fungus Gymnascella dankaliensis.

    PubMed

    Hammerschmidt, Lena; Aly, Amal H; Abdel-Aziz, Mohammed; Müller, Werner E G; Lin, Wenhan; Daletos, Georgios; Proksch, Peter

    2015-02-15

    The soil fungus Gymnascella dankaliensis was collected in the vicinity of the Giza pyramids, Egypt. When grown on solid rice medium the fungus yielded four new compounds including 11'-carboxygymnastatin N (1), gymnastatin S (2), dankamide (3), and aranorosin-2-methylether (4), the latter having been reported previously only as a semisynthetic compound. In addition, six known metabolites (5-10) were isolated. Addition of NaCl or KBr to the rice medium resulted in the accumulation of chlorinated or brominated compounds as indicated by LC-MS analysis due to the characteristic isotope patterns observed. From the rice medium spiked with 3.5% NaCl the known chlorinated compounds gymnastatin A (11) and gymnastatin B (12) were obtained. All isolated compounds were unambiguously structurally elucidated on the basis of comprehensive spectral analysis (1D and 2D NMR, and mass spectrometry), as well as by comparison with the literature. Compounds 4, 7 and 11 showed potent cytotoxicity against the murine lymphoma cell line L5178Y (IC50 values 0.44, 0.58 and 0.64μM, respectively), whereas 12 exhibited moderate activity with an IC50 value of 5.80μM.

  3. Reciprocal genomic evolution in the ant–fungus agricultural symbiosis

    PubMed Central

    Nygaard, Sanne; Hu, Haofu; Li, Cai; Schiøtt, Morten; Chen, Zhensheng; Yang, Zhikai; Xie, Qiaolin; Ma, Chunyu; Deng, Yuan; Dikow, Rebecca B.; Rabeling, Christian; Nash, David R.; Wcislo, William T.; Brady, Seán G.; Schultz, Ted R.; Zhang, Guojie; Boomsma, Jacobus J.

    2016-01-01

    The attine ant–fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cultivars. We show that ant subsistence farming probably originated in the early Tertiary (55–60 MYA), followed by further transitions to the farming of fully domesticated cultivars and leaf-cutting, both arising earlier than previously estimated. Evolutionary modifications in the ants include unprecedented rates of genome-wide structural rearrangement, early loss of arginine biosynthesis and positive selection on chitinase pathways. Modifications of fungal cultivars include loss of a key ligninase domain, changes in chitin synthesis and a reduction in carbohydrate-degrading enzymes as the ants gradually transitioned to functional herbivory. In contrast to human farming, increasing dependence on a single cultivar lineage appears to have been essential to the origin of industrial-scale ant agriculture. PMID:27436133

  4. Accumulation and chemical states of radiocesium by fungus Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Yamasaki, Shinya; Yu, Qianqian

    2014-05-01

    After accident of Fukushima Daiichi Nuclear Power Plant, the fall-out radiocesium was deposited on the ground. Filamentous fungus is known to accumulate radiocesium in environment, even though many minerals are involved in soil. These facts suggest that fungus affect the migration behavior of radiocesium in the environment. However, accumulation mechanism of radiocesium by fungus is not understood. In the present study, accumulation and chemical states change of Cs by unicellular fungus of Saccharomyces cerevisiae have been studied to elucidate the role of microorganisms in the migration of radiocesium in the environment. Two different experimental conditions were employed; one is the accumulation experiments of radiocesium by S. cerevisiae from the agar medium containing 137Cs and a mineral of zeolite, vermiculite, smectite, mica, or illite. The other is the experiments using stable cesium to examine the chemical states change of Cs. In the former experiment, the cells were grown on membrane filter of 0.45 μm installed on the agar medium. After the grown cells were weighed, radioactivity in the cells was measured by an autoradiography technique. The mineral weight contents were changed from 0.1% to 1% of the medium. In the latter experiment, the cells were grown in the medium containing stable Cs between 1 mM and 10mM. The Cs accumulated cells were analyzed by SEM-EDS and EXAFS. The adsorption experiments of cesium by the cells under resting condition were also conducted to test the effect of cells metabolic activity. Without mineral in the medium, cells of S. cerevisiae accumulated 1.5x103 Bq/g from the medium containing 137Cs of 2.6x102 Bq/g. When mineral was added in the medium, concentration of 137Cs in the cells decreased. The concentration of 137Cs in the cells from the medium containing different minerals were in the following order; smectite, illite, mica > vermiculite > zeolite. This order was nearly the same as the inverse of distribution coefficient of

  5. Host deception: Predaceous fungus, esteya vermicola, entices pine wood nematode by mimicking the scent of its host pine for nutrient

    USDA-ARS?s Scientific Manuscript database

    A nematophagous fungus, Esteya vermicola, is recorded as the first endoparasitic fungus of pine wood nematode (PWN), Burasphelenchus xylophilus, in the last century. E. vermicola exhibited high infectivity toward PWN in the laboratory conditions and conidia spraying of this fungus on Japanese red pi...

  6. Evidence refuting the contribution of the fungus Aspergillus penicillioides to the allergenicity of the house dust mite Dermatophagoides pteronyssinus.

    PubMed

    Hay, D B; Hart, B J; Douglas, A E

    1992-01-01

    This communication demonstrates unequivocally that the fungi associated with house dust mites do not contribute to mite allergenicity. The evidence is twofold: first, larval mites which lack fungi have allergen profiles indistinguishable from fungus-bearing adult mites. Second, the allergen profile of experimentally-derived fungus-free adult mites and mites re-fed the fungus Aspergillus penicillioides are identical.

  7. Towards an integrated understanding of the consequences of fungus domestication on the fungus-growing termite gut microbiota.

    PubMed

    Poulsen, Michael

    2015-08-01

    Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some of the functional implications of this shift have recently been established. I review reports on the composition of the Macrotermitinae gut microbiota, evidence for a subfamily core gut microbiota, and the first insight into functional complementarity between fungal and gut symbionts. In addition, I argue that we need to explore the capacities of all members of the symbiotic communities, including better solidifying Termitomyces role(s) in order to understand putative complementary gut bacterial contributions. Approaches that integrate natural history and sequencing data to elucidate symbiont functions will be powerful, particularly if executed in comparative analyses across the well-established congruent termite-fungus phylogenies. This will allow for testing if gut communities have evolved in parallel with their hosts, with implications for our general understanding of the evolution of gut symbiont communities with hosts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Quantitative proteomic analysis of the response of the wood-rot fungus, Schizophyllum commune, to the biocontrol fungus, Trichoderma viride.

    PubMed

    Ujor, V C; Peiris, D G; Monti, M; Kang, A S; Clements, M O; Hedger, J N

    2012-04-01

    Investigation of changes in the protein profile of the wood-rot fungus, Schizophyllum commune, when paired against the biocontrol fungus, Trichoderma viride, for 48 h. Variations in protein profile resulting from contact with T. viride were assessed by spot separation using 2 dimensional protein gel electrophoresis followed by MALDI-TOF-TOF MS/MS protein identification. Contact with T. viride elicited a systematic response in S. commune, characterized by marked increases in proteins involved for transcription and translation (61%) and cell wall/hyphal biogenesis and stabilization (17%), whereas metabolism-associated proteins decreased in amounts (64%). Trichoderma viride, however, exhibited typical mycoparasitic behaviour with increases in the amounts of proteins involved in proteolysis and carbohydrate metabolism. The protein profile of S. commune confronted by T. viride indicates the up-regulation of mechanisms specifically targeted at the mycoparasitic machinery of T. viride, particularly cell wall lysis and antibiosis. The proteomic responses observed in S. commune may occur in natural environments, providing an insight to the mechanism involved in conferring resistance to mycoparasitic attack. This study, therefore, warrants further investigation for the targeted design of more robust biocontrol agents. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  9. Protein profiling of the dimorphic, pathogenic fungus, Penicillium marneffei

    PubMed Central

    Chandler, Julie M; Treece, Erin R; Trenary, Heather R; Brenneman, Jessica L; Flickner, Tressa J; Frommelt, Jonathan L; Oo, Zaw M; Patterson, Megan M; Rundle, William T; Valle, Olga V; Kim, Thomas D; Walker, Gary R; Cooper, Chester R

    2008-01-01

    Background Penicillium marneffei is a pathogenic fungus that afflicts immunocompromised individuals having lived or traveled in Southeast Asia. This species is unique in that it is the only dimorphic member of the genus. Dimorphism results from a process, termed phase transition, which is regulated by temperature of incubation. At room temperature, the fungus grows filamentously (mould phase), but at body temperature (37°C), a uninucleate yeast form develops that reproduces by fission. Formation of the yeast phase appears to be a requisite for pathogenicity. To date, no genes have been identified in P. marneffei that strictly induce mould-to-yeast phase conversion. In an effort to help identify potential gene products associated with morphogenesis, protein profiles were generated from the yeast and mould phases of P. marneffei. Results Whole cell proteins from the early stages of mould and yeast development in P. marneffei were resolved by two-dimensional gel electrophoresis. Selected proteins were recovered and sequenced by capillary-liquid chromatography-nanospray tandem mass spectrometry. Putative identifications were derived by searching available databases for homologous fungal sequences. Proteins found common to both mould and yeast phases included the signal transduction proteins cyclophilin and a RACK1-like ortholog, as well as those related to general metabolism, energy production, and protection from oxygen radicals. Many of the mould-specific proteins identified possessed similar functions. By comparison, proteins exhibiting increased expression during development of the parasitic yeast phase comprised those involved in heat-shock responses, general metabolism, and cell-wall biosynthesis, as well as a small GTPase that regulates nuclear membrane transport and mitotic processes in fungi. The cognate gene encoding the latter protein, designated RanA, was subsequently cloned and characterized. The P. marneffei RanA protein sequence, which contained the

  10. Directed evolution of a filamentous fungus for thermotolerance

    PubMed Central

    de Crecy, Eudes; Jaronski, Stefan; Lyons, Benjamin; Lyons, Thomas J; Keyhani, Nemat O

    2009-01-01

    Background Filamentous fungi are the most widely used eukaryotic biocatalysts in industrial and chemical applications. Consequently, there is tremendous interest in methodology that can use the power of genetics to develop strains with improved performance. For example, Metarhizium anisopliae is a broad host range entomopathogenic fungus currently under intensive investigation as a biologically based alternative to chemical pesticides. However, it use is limited by the relatively low tolerance of this species to abiotic stresses such as heat, with most strains displaying little to no growth between 35–37°C. In this study, we used a newly developed automated continuous culture method called the Evolugator™, which takes advantage of a natural selection-adaptation strategy, to select for thermotolerant variants of M. anisopliae strain 2575 displaying robust growth at 37°C. Results Over a 4 month time course, 22 cycles of growth and dilution were used to select 2 thermotolerant variants of M. anisopliae. Both variants displayed robust growth at 36.5°C, whereas only one was able to grow at 37°C. Insect bioassays using Melanoplus sanguinipes (grasshoppers) were also performed to determine if thermotolerant variants of M. anisopliae retained entomopathogenicity. Assays confirmed that thermotolerant variants were, indeed, entomopathogenic, albeit with complex alterations in virulence parameters such as lethal dose responses (LD50) and median survival times (ST50). Conclusion We report the experimental evolution of a filamentous fungus via the novel application of a powerful new continuous culture device. This is the first example of using continuous culture to select for complex phenotypes such as thermotolerance. Temperature adapted variants of the insect-pathogenic, filamentous fungus M. anisopliae were isolated and demonstrated to show vigorous growth at a temperature that is inhibitory for the parent strain. Insect virulence assays confirmed that pathogenicity

  11. Maxillary fungus ball: zinc-oxide endodontic materials as a risk factor.

    PubMed

    Nicolai, P; Mensi, M; Marsili, F; Piccioni, M; Salgarello, S; Gilberti, E; Apostoli, P

    2015-04-01

    The objective of this study was to demonstrate the correlation between endodontic treatment on maxillary teeth and fungus ball with inductively coupled plasma mass spectrometry measurement of zinc and other metals (barium, lead and copper) in fungus ball samples. Samples of normal maxillary mucosa were used as comparison. Metal concentration was also measured in several endodontic materials. A significant difference was found between the concentration of zinc and copper in fungus ball compared to normal mucosa. Metal distribution was more similar in fungus ball and in the endodontic materials tested than normal mucosa. The similar metal concentration in the endodontic materials and fungus ball suggests that endodontic materials play a role in the pathogenesis of fungus ball. Endodontic materials accidentally pushed into the maxillary sinus during endodontic treatments may play a crucial role. Dentists should be as careful as possible when treating maxillary teeth to avoid perforating the maxillary sinus floor; the use of zinc-free endodontic materials, as zinc is a metal that plays a pivotal role in fungus growth, should be encouraged.

  12. Molecular characterization of a seed transmitted clavicipitaceous fungus occurring on dicotyledoneous plants (Convolvulaceae).

    PubMed

    Steiner, Ulrike; Ahimsa-Müller, Mahalia A; Markert, Anne; Kucht, Sabine; Gross, Julia; Kauf, Nicole; Kuzma, Monika; Zych, Monika; Lamshöft, Marc; Furmanowa, Miroslawa; Knoop, Volker; Drewke, Christel; Leistner, Eckhard

    2006-08-01

    Ergoline alkaloids (syn. ergot alkaloids) are constituents of clavicipitaceous fungi (Ascomycota) and of one particular dicotyledonous plant family, the Convolvulaceae. While the biology of fungal ergoline alkaloids is rather well understood, the evolutionary and biosynthetic origin of ergoline alkaloids within the family Convolvulaceae is unknown. To investigate the possible origin of ergoline alkaloids from a plant-associated fungus, 12 endophytic fungi and one epibiotic fungus were isolated from an ergoline alkaloid-containing Convolvulaceae plant, Ipomoea asarifolia Roem. & Schult. Phylogenetic trees constructed from 18S rDNA genes as well as internal transcribed spacer (ITS) revealed that the epibiotic fungus belongs to the family Clavicipitaceae (Ascomycota) whereas none of the endophytic fungi does. In vitro and in vivo cultivation on intact plants gave no evidence that the endophytic fungi are responsible for the accumulation of ergoline alkaloids in I. asarifolia whereas the epibiotic clavicipitaceous fungus very likely is equipped with the genetic material to synthesize these compounds. This fungus resisted in vitro and in vivo cultivation and is seed transmitted. Several observations strongly indicate that this plant-associated fungus and its hitherto unidentified relatives occurring on different Convolvulaceae plants are responsible for the isolated occurrence of ergoline alkaloids in Convolvulaceae. This is the first report of an ergot alkaloid producing clavicipitaceous fungus associated with a dicotyledonous plant.

  13. Two new triterpenoids from fruiting bodies of fungus Ganoderma lucidum.

    PubMed

    Zhao, Zhen-Zhu; Yin, Rong-Hua; Chen, He-Ping; Feng, Tao; Li, Zheng-Hui; Dong, Ze-Jun; Cui, Bao-Kai; Liu, Ji-Kai

    2015-01-01

    Two new triterpenoids, (24E)-9α,11α-epoxy-3β-hydroxylanosta-7,24-dien-26-al (1) and (22Z,24Z)-13-hydroxy-3-oxo-14(13 → 12)abeo-lanosta-8,22,24-trien-26,23-olide (2) were isolated from dried fruiting bodies of fungus Ganoderma lucidum. The structures of these two new compounds were elucidated on the basis of extensive spectroscopic analyses. Compound 1 possessed a lanostane skeleton, while compound 2 was based on a rare 14 (13 → 12)abeo-lanostane skeleton with a 26,23-olide moiety. Both of them were evaluated for their antifungal and cytotoxic activities. Neither of them displayed obvious inhibition on Candida albicans and five human cancer cell lines.

  14. Cadmium-Responsive Thiols in the Ectomycorrhizal Fungus Paxillus involutus

    PubMed Central

    Courbot, Mikael; Diez, Laurent; Ruotolo, Roberta; Chalot, Michel; Leroy, Pierre

    2004-01-01

    Molecular and cellular mechanisms underlying the sustained metal tolerance of ectomycorrhizal fungi are largely unknown. Some of the main mechanisms involved in metal detoxification appear to involve the chelation of metal ions in the cytosol with thiol-containing compounds, such as glutathione, phytochelatins, or metallothioneins. We used an improved high-performance liquid chromatography method for the simultaneous measurement of thiol-containing compounds from cysteine and its derivatives (γ-glutamylcysteine, glutathione) to higher-molecular-mass compounds (phytochelatins). We found that glutathione and γ-glutamylcysteine contents increased when the ectomycorrhizal fungus Paxillus involutus was exposed to cadmium. An additional compound with a 3-kDa molecular mass, most probably related to a metallothionein, increased drastically in mycelia exposed to cadmium. The relative lack of phytochelatins and the presence of a putative metallothionein suggest that ectomycorrhizal fungi may use a different means to tolerate heavy metals, such as Cd, than do their plant hosts. PMID:15574943

  15. Molecular Karyotype of the White Rot Fungus Pleurotus ostreatus

    PubMed Central

    Larraya, Luis M.; Pérez, Gumer; Peñas, María M.; Baars, Johan J. P.; Mikosch, Thomas S. P.; Pisabarro, Antonio G.; Ramírez, Lucía

    1999-01-01

    The white rot fungus Pleurotus ostreatus is an edible basidiomycete with increasing agricultural and biotechnological importance. Genetic manipulation and breeding of this organism are restricted because of the lack of knowledge about its genomic structure. In this study, we analyzed the genomic constitution of P. ostreatus by using pulsed-field gel electrophoresis optimized for the separation of its chromosomes. We have determined that it contains 11 pairs of chromosomes with sizes ranging from 1.4 to 4.7 Mbp. In addition to chromosome separation, the use of single-copy DNA probes allowed us to resolve the ambiguities caused by chromosome comigration. When the two nuclei present in the dikaryon were separated by protoplasting, analysis of their karyotypes revealed length polymorphisms affecting various chromosomes. This is, to our knowledge, the clearest chromosome separation available for this species. PMID:10427028

  16. The invasive chytrid fungus of amphibians paralyzes lymphocyte responses.

    PubMed

    Fites, J Scott; Ramsey, Jeremy P; Holden, Whitney M; Collier, Sarah P; Sutherland, Danica M; Reinert, Laura K; Gayek, A Sophia; Dermody, Terence S; Aune, Thomas M; Oswald-Richter, Kyra; Rollins-Smith, Louise A

    2013-10-18

    The chytrid fungus, Batrachochytrium dendrobatidis, causes chytridiomycosis and is a major contributor to global amphibian declines. Although amphibians have robust immune defenses, clearance of this pathogen is impaired. Because inhibition of host immunity is a common survival strategy of pathogenic fungi, we hypothesized that B. dendrobatidis evades clearance by inhibiting immune functions. We found that B. dendrobatidis cells and supernatants impaired lymphocyte proliferation and induced apoptosis; however, fungal recognition and phagocytosis by macrophages and neutrophils was not impaired. Fungal inhibitory factors were resistant to heat, acid, and protease. Their production was absent in zoospores and reduced by nikkomycin Z, suggesting that they may be components of the cell wall. Evasion of host immunity may explain why this pathogen has devastated amphibian populations worldwide.

  17. Garden sharing and garden stealing in fungus-growing ants

    NASA Astrophysics Data System (ADS)

    Adams, Rachelle M. M.; Mueller, U. G.; Holloway, Alisha K.; Green, Abigail M.; Narozniak, Joanie

    Fungi cultivated by fungus-growing ants (Attini: Formicidae) are passed on between generations by transfer from maternal to offspring nest (vertical transmission within ant species). However, recent phylogenetic analyses revealed that cultivars are occasionally also transferred between attine species. The reasons for such lateral cultivar transfers are unknown. To investigate whether garden loss may induce ants to obtain a replacement cultivar from a neighboring colony (lateral cultivar transfer), pairs of queenright colonies of two Cyphomyrmex species were set up in two conjoined chambers; the garden of one colony was then removed to simulate the total crop loss that occurs naturally when pathogens devastate gardens. Garden-deprived colonies regained cultivars through one of three mechanisms: joining of a neighboring colony and cooperation in a common garden; stealing of a neighbor's garden; or aggressive usurpation of a neighbor's garden. Because pathogens frequently devastate attine gardens under natural conditions, garden joining, stealing and usurpation emerge as critical behavioral adaptations to survive garden catastrophes.

  18. A new cytotoxic cytochalasin from the endophytic fungus Trichoderma harzianum.

    PubMed

    Chen, Huiqin; Daletos, Georgios; Okoye, Festus; Lai, Daowan; Dai, Haofu; Proksch, Peter

    2015-04-01

    The new natural product 4]-hydroxy-deacetyl-18-deoxycytochalasin H (1), together with the known deacetyl-18-deoxycytochalasin H (2) and 18-deoxycytochalasin H (3) were obtained from the endophytic fungus Trichoderma harzianum isolated from leaves of Cola nitida. The structure of the new compound was unambiguously determined by 1D and 2D NMR spectroscopy, and by HRESIMS measurements, as well as by comparison with the literature. Compounds 1-3 showed potent cytotoxic activity against the murine lymphoma (L5178Y) cell line and against human ovarian cancer (A2780 sens and A2780 CisR) cell lines (IC50 0.19-6.97 µM). The A2780 cell lines included cisplatin-sensitive (sens) and -resistant (R) cells.

  19. Developmental modulation of DNA methylation in the fungus Phycomyces blakesleeanus.

    PubMed Central

    Antequera, F; Tamame, M; Vilanueva, J R; Santos, T

    1985-01-01

    DNA methylation is a rather sparse event among fungi. Phycomyces blakesleeanus seems to be one of the few exceptions in this context. 5-Methylcytosine represents 2.9% of the total cytosine in spore DNA and is located in approximately the same amount at any of the four CA, CT, CC or CG dinucleotides. A progressive and gradual drop in total 5-methylcytosine parallels the development of the fungus. This demethylation is non random but sequence specific and is not accounted for equally by the four different methylated dinucleotides, CG being much less affected (20% demethylated) than CA, CT and CC (more than 90% demethylated at the same time). "De novo" methylation to restore the initial pattern probably takes place during spore maturation. By using specific hybridization probes we have been able to show that the rRNA genes are not significantly methylated at any stage of development, regardless of their transcription status. Images PMID:2997714

  20. New secondary metabolites from the marine endophytic fungus Apiospora montagnei.

    PubMed

    Klemke, Christine; Kehraus, Stefan; Wright, Anthony D; König, Gabriele M

    2004-06-01

    The marine fungus Apiospora montagnei was isolated from the inner tissue of the North Sea alga Polysiphonia violacea. Cultivation of this fungal strain led to the isolation of several new secondary metabolites, including the diterpene myrocin A (1) and the polyketide apiosporic acid (2). Furthermore the new monomethyl ester of 9-hydroxyhexylitaconic acid (3) and the (-)-enantiomer (4) of the known (+)-hexylitaconic acid were found together with the known (+)-epiepoxydon (5), (+)-epoxydon monoacetate, R-mellein, R-8-methoxymellein, 5-hydroxymethylfuran-2-carboxylic acid, and the xanthone derivative anomalin A. The structures were elucidated mainly by 1D and 2D NMR, MS, UV, and IR spectral data. Compound 5 exhibited significant cytoxicity against human cancer cell lines.

  1. Fungal keratitis due to Schizophyllum commune: an emerging pathogenic fungus.

    PubMed

    Reddy, Ashok Kumar; Ashok, Rangaiahgari; Majety, Madhavi; Chitta, Megharaj; Narayen, Nitesh

    2016-07-12

    Fungal keratitis due to Schizophyllum commune is very rare. In this study, we report the clinical and microbiological profile of five patients with fungal keratitis due to S. commune. Direct microscopic examination of corneal scrapings from all five patients showed septate branching hyaline fungal filaments. Similarly, in all five patients Sabouraud dextrose agar (SDA) plates inoculated with corneal scrapings showed white, cottony colonies on the second day of incubation. Lactophenol cotton blue stained wet preparation of 7-day-old colonies on SDA revealed clamp connections and no spores. The fungus was identified by its characteristic clamp connections, fan-shaped bracket fruiting body with pinkish-grey longitudinally split-radiating gills. The phenotypic identification of one of the five isolates further conformed by ITS sequencing. Treatment outcome was available for two of the five patients; in these two patients, the keratitis resolved with topical natamycin. © 2016 Blackwell Verlag GmbH.

  2. Amphibian chytrid fungus Batrachochytrium dendrobatidis in Cusuco National Park, Honduras.

    PubMed

    Kolby, Jonathan E; Padgett-Flohr, Gretchen E; Field, Richard

    2010-11-01

    Amphibian population declines in Honduras have long been attributed to habitat degradation and pollution, but an increasing number of declines are now being observed from within the boundaries of national parks in pristine montane environments. The amphibian chytrid fungus Batrachochytrium dendrobatidis has been implicated in these declines and was recently documented in Honduras from samples collected in Pico Bonito National Park in 2003. This report now confirms Cusuco National Park, a protected cloud forest reserve with reported amphibian declines, to be the second known site of infection for Honduras. B. dendrobatidis infection was detected in 5 amphibian species: Craugastor rostralis, Duellmanohyla soralia, Lithobates maculata, Plectrohyla dasypus, and Ptychohyla hypomykter. D. soralia, P. dasypus, and P. hypomykter are listed as critically endangered in the IUCN Red List of Threatened Species and have severely fragmented or restricted distributions. Further investigations are necessary to determine whether observed infection levels indicate an active B. dendrobatidis epizootic with the potential to cause further population declines and extinction.

  3. Waterfowl: potential environmental reservoirs of the chytrid fungus Batrachochytrium dendrobatidis.

    PubMed

    Garmyn, An; Van Rooij, Pascale; Pasmans, Frank; Hellebuyck, Tom; Van Den Broeck, Wim; Haesebrouck, Freddy; Martel, An

    2012-01-01

    Infections with Batrachochytrium dendrobatidis (B. dendrobatidis), the causal agent of chytridiomycosis, have been shown to play an important role in the decline of amphibians worldwide. Spread of the fungus is poorly understood. Bird movement might possibly contribute to the spread of B. dendrobatidis in the environment. Therefore, 397 wild geese in Belgium were screened for presence of B. dendrobatidis on their toes using real-time quantitative PCR (qPCR). In addition, chemotaxis towards, adhesion, survival after desiccation and proliferation of B. dendrobatidis on keratinous toe scales from waterfowl were examined in vitro. qPCR revealed that 76 geese (15%) were positive for B. dendrobatidis. Results of the in vitro tests showed that B. dendrobatidis is attracted to the keratinous toes of aquatic birds on which they can adhere and even proliferate. However, desiccation is poorly tolerated. This suggests waterfowl are potential environmental reservoirs for B. dendrobatidis.

  4. Waterfowl: Potential Environmental Reservoirs of the Chytrid Fungus Batrachochytrium dendrobatidis

    PubMed Central

    Pasmans, Frank; Hellebuyck, Tom; Van Den Broeck, Wim; Haesebrouck, Freddy; Martel, An

    2012-01-01

    Infections with Batrachochytrium dendrobatidis (B. dendrobatidis), the causal agent of chytridiomycosis, have been shown to play an important role in the decline of amphibians worldwide. Spread of the fungus is poorly understood. Bird movement might possibly contribute to the spread of B. dendrobatidis in the environment. Therefore, 397 wild geese in Belgium were screened for presence of B. dendrobatidis on their toes using real-time quantitative PCR (qPCR). In addition, chemotaxis towards, adhesion, survival after desiccation and proliferation of B. dendrobatidis on keratinous toe scales from waterfowl were examined in vitro. qPCR revealed that 76 geese (15%) were positive for B. dendrobatidis. Results of the in vitro tests showed that B. dendrobatidis is attracted to the keratinous toes of aquatic birds on which they can adhere and even proliferate. However, desiccation is poorly tolerated. This suggests waterfowl are potential environmental reservoirs for B. dendrobatidis. PMID:22514705

  5. Population genetics of the frog-killing fungus Batrachochytrium dendrobatidis

    PubMed Central

    Morgan, Jess A. T.; Vredenburg, Vance T.; Rachowicz, Lara J.; Knapp, Roland A.; Stice, Mary J.; Tunstall, Tate; Bingham, Rob E.; Parker, John M.; Longcore, Joyce E.; Moritz, Craig; Briggs, Cheryl J.; Taylor, John W.

    2007-01-01

    Global amphibian decline by chytridiomycosis is a major environmental disaster that has been attributed to either recent fungal spread or environmental change that promotes disease. Here, we present a population genetic comparison of Batrachochytrium dendrobatidis isolates from an intensively studied region of frog decline, the Sierra Nevada of California. In support of a novel pathogen, we find low diversity, no amphibian-host specificity, little correlation between fungal genotype and geography, local frog extirpation by a single fungal genotype, and evidence of human-assisted fungus migration. In support of endemism, at a local scale, we find some diverse, recombining populations. Therefore neither epidemic spread nor endemism alone explains this particular amphibian decline. Recombination raises the possibility of resistant sporangia and a mechanism for rapid spread as well as persistence that could greatly complicate global control of the pathogen. PMID:17693553

  6. Arbuscular mycorrhizal fungus responses to disturbance are context-dependent.

    PubMed

    van der Heyde, Mieke; Ohsowski, Brian; Abbott, Lynette K; Hart, Miranda

    2017-01-24

    Anthropogenic disturbance is one of the most important forces shaping soil ecosystems. While organisms that live in the soil, such as arbuscular mycorrhizal (AM) fungi, are sensitive to disturbance, their response is not always predictable. Given the range of disturbance types and differences among AM fungi in their growth strategies, the unpredictability of the responses of AM fungi to disturbance is not surprising. We investigated the role of disturbance type (i.e., soil disruption, agriculture, host perturbation, and chemical disturbance) and fungus identity on disturbance response in the AM symbiosis. Using meta-analysis, we found evidence for differential disturbance response among AM fungal species, as well as evidence that particular fungal species are especially susceptible to certain disturbance types, perhaps because of their life history strategies.

  7. Chemically armed mercenary ants protect fungus-farming societies

    PubMed Central

    Adams, Rachelle M. M.; Liberti, Joanito; Illum, Anders A.; Jones, Tappey H.; Nash, David R.; Boomsma, Jacobus J.

    2013-01-01

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies. PMID:24019482

  8. Disposable diapers biodegradation by the fungus Pleurotus ostreatus.

    PubMed

    Espinosa-Valdemar, Rosa María; Turpin-Marion, Sylvie; Delfín-Alcalá, Irma; Vázquez-Morillas, Alethia

    2011-08-01

    This research assesses the feasibility of degrading used disposable diapers, an important component (5-15% in weight) of urban solid waste in Mexico, by the activity of the fungus Pleurotus ostreatus, also known as oyster mushroom. Disposable diapers contain polyethylene, polypropylene and a super absorbent polymer. Nevertheless, its main component is cellulose, which degrades slowly. P. ostreatus has been utilized extensively to degrade cellulosic materials of agroindustrial sources, using in situ techniques. The practice has been extended to the commercial farming of the mushroom. This degradation capacity was assayed to reduce mass and volume of used disposable diapers. Pilot laboratory assays were performed to estimate the usefulness of the following variables on conditioning of used diapers before they act as substrate for P. ostreatus: (1) permanence vs removal of plastic cover; (2) shredding vs grinding; (3) addition of grape wastes to improve structure, nitrogen and trace elements content. Wheat straw was used as a positive control. After 68 days, decrease of the mass of diapers and productivity of fungus was measured. Weight and volume of degradable materials was reduced up to 90%. Cellulose content was diminished in 50% and lignine content in 47%. The highest efficiency for degradation of cellulosic materials corresponded to the substrates that showed highest biological efficiency, which varied from 0% to 34%. Harvested mushrooms had good appearance and protein content and were free of human disease pathogens. This research indicates that growing P. ostreatus on disposable diapers could be a good alternative for two current problems: reduction of urban solid waste and availability of high protein food sources. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. An extracellular glucoamylase produced by endophytic fungus EF6.

    PubMed

    Tangngamsakul, P; Karnchanatat, A; Sihanonth, P; Sangvanich, P

    2011-01-01

    A strain of endophytic fungus EF6 isolated from Thai medicinal plants was found to produce higher levels of extracellular glucoamylase. This strain produced glucoamylase of culture filtrate when grown on 1% soluble starch. The enzyme was purified and characterized. Purification steps involved (NH4)2SO4 precipitation, anion exchange, and gel filtration chromatography. Final purification fold was 14.49 and the yield obtained was 9.15%. The enzyme is monomeric with a molecular mass of 62.2 kDa as estimated by SDS-PAGE, and with a molecular mass of 62.031 kDa estimated by MALDI-TOF spectrometry. The temperature for maximum activity was 60 degrees C. After 30 min for incubation, glucoamylase was found to be stable lower than 50 degrees C. The activity decrease rapidly when residual activity was retained about 45% at 55 degrees C. The pH optimum of the enzyme activity was 6.0, and it was stable over a pH range of 4.0-7.0 at 50 degrees C. The activity of glucoamylase was stimulated by Ca2+, Co2+, Mg2+, Mn2+, glycerol, DMSO, DTT and EDTA, and strongly inhibited by Hg2+. Various types of starch were test, soluble starch proved to be the best substrate for digestion process. The enzyme catalyzes the hydrolysis of soluble starch and maltose as the substrate, the enzyme had Km values of 2.63, and 1.88 mg/ml and Vmax, values of 1.25, and 2.54 U/min/mg protein, and Vmax/Km values of 0.48 and 1.35, respectively. The internal amino acid sequences of endophytic fungus EF6 glucoamylase; RALAN HKQVV DSFRS have similarity to the sequence of the glucoamylase purified form Thermomyces lanuginosus. From all results indicated that this enzyme is a glucoamylase (1,4-alpha-D-glucan glucanohydrolase).

  10. Chemically armed mercenary ants protect fungus-farming societies.

    PubMed

    Adams, Rachelle M M; Liberti, Joanito; Illum, Anders A; Jones, Tappey H; Nash, David R; Boomsma, Jacobus J

    2013-09-24

    The ants are extraordinary in having evolved many lineages that exploit closely related ant societies as social parasites, but social parasitism by distantly related ants is rare. Here we document the interaction dynamics among a Sericomyrmex fungus-growing ant host, a permanently associated parasitic guest ant of the genus Megalomyrmex, and a raiding agro-predator of the genus Gnamptogenys. We show experimentally that the guest ants protect their host colonies against agro-predator raids using alkaloid venom that is much more potent than the biting defenses of the host ants. Relatively few guest ants are sufficient to kill raiders that invariably exterminate host nests without a cohabiting guest ant colony. We also show that the odor of guest ants discourages raider scouts from recruiting nestmates to host colonies. Our results imply that Sericomyrmex fungus-growers obtain a net benefit from their costly guest ants behaving as a functional soldier caste to meet lethal threats from agro-predator raiders. The fundamentally different life histories of the agro-predators and guest ants appear to facilitate their coexistence in a negative frequency-dependent manner. Because a guest ant colony is committed for life to a single host colony, the guests would harm their own interests by not defending the host that they continue to exploit. This conditional mutualism is analogous to chronic sickle cell anemia enhancing the resistance to malaria and to episodes in human history when mercenary city defenders offered either net benefits or imposed net costs, depending on the level of threat from invading armies.

  11. Cladosporium sp. , a potential fungus for bioremediation of wood-treating wastes

    SciTech Connect

    Borazjani, H.; Ferguson, B.; Hendrix, F.; McFarland, L.; McGinnis, G.; Pope, D.; Strobel, D.; Wagner, J. )

    1989-01-01

    A fungus, Cladosporium sp., was isolated from a very old wood-treating plant sludge pond in Weed, California. A preliminary study showed no inhibition of mycelial growth at 5,500 {mu}g polycyclic aromatic hydrocarbons (PAH) per ml of potato dextrose agar (PDA). Pentachlorophenol (PCP) inhibited mycelial growth at 10 {mu}g/ml of PDA. Rates of breakdown of both PAHs and PCP in the soil and water system were studied using this fungus. The results of this study and the application of this fungus for cleaning up contaminated sites will be discussed.

  12. Bioremediation with white rot fungus. (Latest citations from Pollution Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-10-01

    The bibliography contains citations concerning the use of white rot fungus to degrade a variety of hazardous materials. The citations examine the application of the fungus to the remediation of petroleum hydrocarbons, polychlorinated biphenyls, 2,4,6-trinitrotoluene (TNT), pentachlorophenol, herbicides, insecticides, and other environmentally persistent organic compounds. The results of laboratory and field studies are presented. The use of white rot fungus in biological pulping and delignification is also discussed. (Contains a minimum of 50 citations and includes a subject term index and title list.)

  13. Maxillary reconstruction and placement of dental implants after treatment of a maxillary sinus fungus ball.

    PubMed

    Colletti, Giacomo; Felisati, Giovanni; Biglioli, Federico; Tintinelli, Roberto; Valassina, Davide

    2010-01-01

    A fungus ball is one of the fungal diseases that can affect the paranasal sinuses. It requires surgical treatment. Because there is only one previously reported case of dental implant placement after treatment of a maxillary sinus fungus ball, the authors here report on a case of a maxillary sinus fungus ball with bone erosion that was treated surgically with a combined endoscopic endonasal and endoral (Caldwell-Luc) approach. One year later, a graft from the ilium was obtained and a sinus elevation was performed to allow the placement of dental implants. Three months later, the dental implants were placed, and they were all osseointegrated at the 9-month follow-up.

  14. The response of the grape berry moth (Lobesia botrana) to a dietary phytopathogenic fungus (Botrytis cinerea): the significance of fungus sterols.

    PubMed

    Mondy; Corio-Costet

    2000-12-01

    A Tortricidae (Lobesia botrana) has a mutualistic relationship with the fungus (Botrytis cinerea). In this study, we investigated the growth, survival, fecundity and amount of sterols and steroids in larvae of this vineyard pest reared on artificial diets containing mycelium (3%) or purified sterols (0.01%) of the phytopathogenic fungus. Two principal questions related to the physiological and biochemical basis of this mutualistic relationship were addressed: (1) how the fungus influences growth, survival, fecundity, sterol and steroid contents of the insect and (2) are fungal sterols involved in the biochemical basis of mutualism? The presence of fungus in the diet led to a decrease of total duration of larval development (mean gain 5.1-9.4 days compared to the total duration in control of 42.9 days), an increase in survival (mean gain 50-76.3%) and fecundity (gain of 94-102%). These positive effects of the fungus on the biology and physiology of the insect were directly correlated to the presence of fungal sterols in the diet. Fungal sterols are one of the biochemical basis of the mutualistic relationship between L. botrana and B. cinerea.

  15. Development of 11 polymorphic microsatellite markers for the blackberry rust fungus Phragmidium violaceum

    USDA-ARS?s Scientific Manuscript database

    Eleven polymorphic microsatellite markers were developed for the Uredinales fungus Phragmidium violaceum, which causes leaf rust on European blackberry (Rubus fruticosus L. aggregate). Allele frequency ranged between two and seventeen alleles per locus with no evidence of linkage disequilibrium amon...

  16. Inferring outcrossing in the homothallic fungus Sclerotinia sclerotiorum using linkage disequilibrium decay

    USDA-ARS?s Scientific Manuscript database

    The occurrence and frequency of outcrossing in homothallic fungal species in nature is an unresolved question. Here we report detection of frequent outcrossing in the homothallic fungus Sclerotinia sclerotiorum. In using multilocus linkage disequilibrium (LD) to infer recombination among microsatell...

  17. Deciphering the molecular mechanisms behind cellulase production in Trichoderma reesei, the hyper-cellulolytic filamentous fungus.

    PubMed

    Shida, Yosuke; Furukawa, Takanori; Ogasawara, Wataru

    2016-09-01

    The filamentous fungus Trichoderma reesei is a potent cellulase producer and the best-studied cellulolytic fungus. A lot of investigations not only on glycoside hydrolases produced by T. reesei, but also on the machinery controlling gene expression of these enzyme have made this fungus a model organism for cellulolytic fungi. We have investigated the T. reesei strain including mutants developed in Japan in detail to understand the molecular mechanisms that control the cellulase gene expression, the biochemical and morphological aspects that could favor this phenotype, and have attempted to generate novel strains that may be appropriate for industrial use. Subsequently, we developed recombinant strains by combination of these insights and the heterologous-efficient saccharifing enzymes. Resulting enzyme preparations were highly effective for saccharification of various biomass. In this review, we present some of the salient findings from the recent biochemical, morphological, and molecular analyses of this remarkable cellulase hyper-producing fungus.

  18. Limited transmission of the ectoparasitic fungus Hesperomyces virescens between lady beetles

    USDA-ARS?s Scientific Manuscript database

    The ectoparasitic fungus Hesperomyces virescens Thaxter (Ascomycota: Laboulbeniales) commonly infects the invasive lady beetle Harmonia axyridis (Pallas) and several other aphidophagous lady beetles in North America and Europe. We tested the hypothesis that bodily contact between adults of differen...

  19. Lovastatin-producing endophytic fungus isolated from a medicinal plant Solanum xanthocarpum.

    PubMed

    Parthasarathy, Ramalingam; Sathiyabama, Muthukrishnan

    2015-01-01

    Lovastatin is a potent drug for lowering blood cholesterol. An endophytic fungus Phomopsis vexans was isolated from the healthy leaf tissues of Solanum xanthocarpum, a medicinal plant, and screened for lovastatin production. The fungus was identified by their characteristic cultural morphology and molecular analysis. The strain had a component with the same TLC Rf value and HPLC retention time as authentic lovastatin. The presence of lovastatin was further confirmed by FT-IR, UV, (1)H, (13)C NMR and LC-MS analyses. The amount of lovastatin produced by this endophytic fungus was quantified to be 550 mg/L, and thus the fungus can serve as a potential material to improve the production of lovastatin.

  20. An endophytic fungus, Gibberella moniliformis from Lawsonia inermis L. produces lawsone, an orange-red pigment.

    PubMed

    Sarang, Hatnagar; Rajani, Pijakala; Vasanthakumari, Madhugiri Mallaiah; Kumara, Patel Mohana; Siva, Ramamoorthy; Ravikanth, Gudasalamani; Uma Shaanker, R

    2017-07-01

    Lawsone (2-hydroxy-1, 4-napthoquinone), also known as hennotannic acid, is an orange red dye used as a popular skin and hair colorant. The dye is produced in the leaves of Lawsonia inermis L, often referred to as the "henna" tree. In this study, we report the production of lawsone by an endophytic fungus, Gibberella moniliformis isolated from the leaf tissues of Lawsonia inermis. The fungus produced the orange-red dye in potato dextrose agar and broth, independent of the host tissue. Presence of lawsone was confirmed spectrometrically using HPLC and ESI-MS/MS analysis. The fragmentation pattern of lawsone was identical to both standard lawsone and that extracted from plant tissue. This is a first report of lawsone being produced by an endophytic fungus, independent of the host tissue. The study opens up interesting questions on the possible biosynthetic pathway through which lawsone is produced by the fungus.

  1. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    SciTech Connect

    Luey, J.; Brouns, T.M.; Elliott, M.L.

    1990-11-01

    The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs.

  2. Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites.

    PubMed

    Visser, Anna A; Nobre, Tânia; Currie, Cameron R; Aanen, Duur K; Poulsen, Michael

    2012-05-01

    In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus-growing termites, indicating lack of specificity. Antibiotic-activity screening of 288 isolates against the fungal cultivar and competitor revealed that most of the Actinobacteria-produced molecules with antifungal activity. A more detailed bioassay on 53 isolates, to test the specificity of antibiotics, showed that many Actinobacteria inhibit both Pseudoxylaria and Termitomyces, and that the cultivar fungus generally is more susceptible to inhibition than the competitor. This suggests that either defensive symbionts are not present in the system or that they, if present, represent a subset of the community isolated. If so, the antibiotics must be used in a targeted fashion, being applied to specific areas by the termites. We describe the first discovery of an assembly of antibiotic-producing Actinobacteria occurring in fungus-growing termite nests. However, due to the diversity found, and the lack of both phylogenetic and bioactivity specificity, further work is necessary for a better understanding of the putative role of antibiotic-producing bacteria in the fungus

  3. New Filamentous Fungus Sagenomella chlamydospora Responsible for a Disseminated Infection in a Dog

    PubMed Central

    Gené, Josepa; Blanco, José L.; Cano, Josep; García, Marta E.; Guarro, Josep

    2003-01-01

    A filamentous fungus that caused a fatal systemic infection in a dog has been identified as the new species Sagenomella chlamydospora. When the case was initially reported, the fungus was identified as Paecilomyces sp. This study emphasizes how difficult can be the identification of the causative agent of an infection when an uncommon microorganism is involved. This is the first time that this genus has been involved in animal infections, including humans. PMID:12682169

  4. Rapid dereplication and identification of the bioactive constituents from the fungus, Leucocoprinus birnbaumii.

    PubMed

    Brkljača, Robert; Urban, Sylvia

    2015-01-01

    A series of fatty acids were rapidly dereplicated and partially identified from the flowerpot fungus, Leucocoprinus birnbaumii using HPLC-NMR and HPLC-MS. Subsequent off-line isolation unequivocally established the structures, and anti-microbial testing concluded that the fatty acids displayed moderate but selective anti-microbial activity. This represents the first report of these compounds occurring in this particular terrestrial fungus.

  5. Microalgae harvesting via co-culture with filamentous fungus

    NASA Astrophysics Data System (ADS)

    Gultom, Sarman Oktovianus

    Microalgae harvesting is a labor- and energy-intensive process. For instance, classical harvesting technologies such as chemical addition and mechanical separation are economically prohibiting for biofuel production. Newer approaches to harvest microalgae have been developed in order to decrease costs. Among these new methods, fungal co-pelletization seems to be a promising technology. By co-culturing filamentous fungi with microalgae, it is possible to form pellets, which can easily be separated. In this study, different parameters for the cultivation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to efficiently form cell pellets were evaluated under heterotrophic and phototrophic conditions, including organic carbon source (glucose, glycerol and sodium acetate) concentration, pH, initial concentration of fungal spores, initial concentration of microalgal cells, concentration of ionic strength (Calcium and Magnesium) and concentration of salinity (NaCl). In addition, zeta-potential measurements were carried out in order to get a better understanding of the mechanism of attraction. It was found that 2 g/L of glucose, a fungus to microalgae ratio of 1:300, and uncontrolled pH (around 7) are the best culturing conditions for co-pelletization. Under these conditions, it was possible to achieve a high harvesting performance (>90%). In addition, it was observed that most pellets formed in the co-culture were spherical with an average diameter of 3.5 mm and in concentrations of about 5 pellets per mL of culture media. Under phototrophic conditions, co-pelletization required the addition of glucose as organic carbon source to sustain the growth of fungi and to allow the harvesting of microalgae. Zeta-potential measurements indicated that (i) both microalgae and fungi have low zeta-potential values regardless of the pH on the bulk (i.e. <-10 mV) (ii) fungi can have a positive electric charge at low pH (ie. pH=3). These values suggest that it

  6. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

    PubMed

    Moller, Isabel E; De Fine Licht, Henrik H; Harholt, Jesper; Willats, William G T; Boomsma, Jacobus J

    2011-03-10

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

  7. Fungal Garden Making inside Bamboos by a Non-Social Fungus-Growing Beetle

    PubMed Central

    Toki, Wataru; Takahashi, Yukiko; Togashi, Katsumi

    2013-01-01

    In fungus-growing mutualism, it is indispensable for host animals to establish gardens of the symbiotic fungus as rapidly as possible. How to establish fungal gardens has been well-documented in social fungus-farming insects, whereas poorly documented in non-social fungus-farming insects. Here we report that the non-social, fungus-growing lizard beetle Doubledaya bucculenta (Coleoptera: Erotylidae: Languriinae) transmits the symbiotic yeast Wickerhamomyces anomalus from the ovipositor-associated mycangium into bamboo internode cavities and disperses the yeast in the cavities to make gardens. Microbial isolation and cryo-scanning electron microscopy observation revealed that W. anomalus was constantly located on the posterior ends of eggs, where larvae came out, and on the inner openings of oviposition holes. Direct observation of oviposition behavior inside internodes revealed that the distal parts of ovipositors showed a peristaltic movement when they were in contact with the posterior ends of eggs. Rearing experiments showed that W. anomalus was spread much more rapidly and widely on culture media and internodes in the presence of the larvae than in the absence. These results suggest that the ovipositors play a critical role in vertical transmission of W. anomalus and that the larvae contribute actively to the garden establishment, providing a novel case of fungal garden founding in non-social insect-fungus mutualism. PMID:24223958

  8. The Dynamics of Plant Cell-Wall Polysaccharide Decomposition in Leaf-Cutting Ant Fungus Gardens

    PubMed Central

    Harholt, Jesper; Willats, William G. T.; Boomsma, Jacobus J.

    2011-01-01

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants. PMID:21423735

  9. Identification and evaluation of SERI-NF1 fungus for ethanol production from xylose fermentation

    SciTech Connect

    Antonopoulos, A.A.

    1989-01-01

    This work aimed at identifying the SERI-NF1 fungus isolated by Solar Energy Research Institute investigators, as well as evaluating the fungus as an ethanol producer from xylose fermentations. Microscopic and physiological observations led to the conclusion that the fungus is Paecilomyces varioti Bainier 1907. The fungus grows relatively fast in PDA plates, and its cultures release a light sweet aromatic odor. In liquid cultures the fungus forms round mycelial balls (1--12 mm in diameter). It showed to be thermophilic (grown well at 26--36/degree/C) and thermotolerant (exposed for two hours to 60/degree/C resumed its growth), and to prefer pH levels close to neutrality. Cultures of the fungus were tested (in 125 ml flasks) for fermenting xylose to ethanol. Its growth in the liquid cultures was slow and formed mycelial balls. The yield of ethanol production was low. The amount of fungal mass has to be more than a few mycelial balls per flask to get a reasonable yield of ethanol. 17 refs., 1 fig.

  10. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

    SciTech Connect

    Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M.; Nicora, Carrie D.; Hu, Zeping; Metz, Thomas O.; Lipton, Mary S.; Smith, Richard D.; Currie, Cameron R.; Burnum-Johnson, Kristin E.

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics. Rather than directly consuming the fresh foliar biomass they harvest, these ants use it to cultivate specialized fungus gardens. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metametabolomics and metaproteomics techniques, we examine the dynamics of nutrient turnover and biosynthesis in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous findings of cellulases and laccases produced by Leucoagaricus gongylophorus, the fungus cultivated by leaf-cutter ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metametabolomics experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in the fungus garden. These results provide new insights into the dynamics of nutrient cycling that underlie this important ant-fungus symbiosis.

  11. Deciphering the salinity adaptation mechanism in Penicilliopsis clavariiformis AP, a rare salt tolerant fungus from mangrove.

    PubMed

    Kashyap, Prem Lal; Rai, Anuradha; Singh, Ruchi; Chakdar, Hillol; Kumar, Sudheer; Srivastava, Alok Kumar

    2016-07-01

    Penicilliopsis clavariiformis AP, a rare salt tolerant fungus reported for the first time from India was identified through polyphasic taxonomy. Scanning electron microscopy showed that the fungus has unique features such as biverticillate penicilli bearing masses of oval to ellipsoidal conidia. The fungus has been characterized for salt tolerance and to understand the relevance of central carbon metabolism in salt stress adaptation. It showed optimal growth at 24 °C and able to tolerate up to 10% (w/v) NaCl. To understand the mechanism of adaptation to high salinity, activities of the key enzymes regulating glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle were investigated under normal (0% NaCl) and saline stress environment (10% NaCl). The results revealed a re-routing of carbon metabolism away from glycolysis to the pentose phosphate pathway (PPP), served as a cellular stress-resistance mechanism in fungi under saline environment. The detection and significant expression of fungus genes (Hsp98, Hsp60, HTB, and RHO) under saline stress suggest that these halotolerance conferring genes from the fungus could have a role in fungus protection and adaptation under saline environment. Overall, the present findings indicate that the rearrangement of the metabolic fluxes distribution and stress related genes play an important role in cell survival and adaptation under saline environment.

  12. Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants

    PubMed Central

    Ruiz-González, Mario X.; Malé, Pierre-Jean G.; Leroy, Céline; Dejean, Alain; Gryta, Hervé; Jargeat, Patricia; Quilichini, Angélique; Orivel, Jérôme

    2011-01-01

    Ant–fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant–fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures on their myrmecophytic hosts in order to ambush prey. We show that this association is not opportunistic because the ants select from a monophyletic group of closely related fungal haplotypes of an ascomycete species from the order Chaetothyriales that consistently grows on and has been isolated from the galleries. Both the ants' behaviour and an analysis of the genetic population structure of the ants and the fungus argue for host specificity in this interaction. The ants' behaviour reveals a major investment in manipulating, growing and cleaning the fungus. A molecular analysis of the fungus demonstrates the widespread occurrence of one haplotype and many other haplotypes with a lower occurrence, as well as significant variation in the presence of these fungal haplotypes between areas and ant species. Altogether, these results suggest that such an interaction might represent an as-yet undescribed type of specific association between ants and fungus in which the ants cultivate fungal mycelia to strengthen their hunting galleries. PMID:21084334

  13. Insect symbioses: a case study of past, present, and future fungus-growing ant research.

    PubMed

    Caldera, Eric J; Poulsen, Michael; Suen, Garret; Currie, Cameron R

    2009-02-01

    Fungus-growing ants (Attini: Formicidae) engage in an obligate mutualism with fungi they cultivate for food. Although biologists have been fascinated with fungus-growing ants since the resurgence of natural history in the modern era, the early stages of research focused mainly on the foraging behavior of the leaf-cutters (the most derived attine lineage). Indeed, the discovery that the ants actually use leaf fragments to manure a fungus did not come until the 1800s. More recently, three additional microbial symbionts have been described, including specialized microfungal parasites of the ant's fungus garden, antibiotic-producing actinobacteria that help protect the fungus garden from the parasite, and a black yeast that parasitizes the ant-actinobacteria mutualism. The fungus-growing ant symbiosis serves as a particularly useful model system for studying insect-microbe symbioses, because, to date, it contains four well-characterized microbial symbionts, including mutualists and parasites that encompass micro-fungi, macro-fungi, yeasts, and bacteria. Here, we discuss approaches for studying insect-microbe symbioses, using the attine ant-microbial symbiosis as our framework. We draw attention to particular challenges in the field of symbiosis, including the establishment of symbiotic associations and symbiont function. Finally, we discuss future directions in insect-microbe research, with particular focus on applying recent advances in DNA sequencing technologies.

  14. Starch metabolism in Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants.

    PubMed

    Silva, A; Bacci, M; Pagnocca, F C; Bueno, O C; Hebling, M J A

    2006-01-01

    Leucoagaricus gongylophorus, the symbiotic fungus of the leaf-cutting ants, degrades starch, this degradation being supposed to occur in the plant material which leafcutters forage to the nests, generating most of the glucose which the ants utilize for food. In the present investigation, we show that laboratory cultures of L. gongylophorus produce extracellular alpha-amylase and maltase which degrade starch to glucose, reinforcing that the ants can obtain glucose from starch through the symbiotic fungus. Glucose was found to repress alpha-amylase and, more severely, maltase activity, thus repressing starch degradation by L. gongylophorus, so that we hypothesize that: (1) glucose down-regulation of starch degradation also occurs in the Atta sexdens fungus garden; (2) glucose consumption from the fungus garden by A. sexdens stimulates degradation of starch from plant material by L. gongylophorus, which may represent a mechanism by which leafcutters can control enzyme production by the symbiotic fungus. Since glucose is found in the fungus garden inside the nests, down-regulation of starch degradation by glucose is supposed to occur in the nest and play a part in the control of fungal enzyme production by leafcutters.

  15. Nature of the interactions between hypocrealean fungi and the mutualistic fungus of leaf-cutter ants.

    PubMed

    Varanda-Haifig, Sadala Schmidt; Albarici, Tatiane Regina; Nunes, Pablo Henrique; Haifig, Ives; Vieira, Paulo Cezar; Rodrigues, Andre

    2017-04-01

    Leaf-cutter ants cultivate and feed on the mutualistic fungus, Leucoagaricus gongylophorus, which is threatened by parasitic fungi of the genus Escovopsis. The mechanism of Escovopsis parasitism is poorly understood. Here, we assessed the nature of the antagonism of different Escovopsis species against its host. We also evaluated the potential antagonism of Escovopsioides, a recently described fungal genus from the attine ant environment whose role in the colonies of these insects is unknown. We performed dual-culture assays to assess the interactions between L. gongylophorus and both fungi. We also evaluated the antifungal activity of compounds secreted by the latter on L. gongylophorus growth using crude extracts of Escovopsis spp. and Escovopsioides nivea obtained either in (1) absence or (2) presence of the mutualistic fungus. The physical interaction between these fungi and the mutualistic fungus was examined under scanning electron microscopy (SEM). Escovopsis spp. and E. nivea negatively affected the growth of L. gongylophorus, which was also significantly inhibited by both types of crude extract. These results indicate that Escovopsis spp. and E. nivea produce antifungal metabolites against the mutualistic fungus. SEM showed that Escovopsis spp. and E. nivea maintained physical contact with the mutualistic fungus, though no specialised structures related to mycoparasitism were observed. These results showed that Escovopsis is a destructive mycoparasite that needs physical contact for the death of the mutualistic fungus to occur. Also, our findings suggest that E. nivea is an antagonist of the ant fungal cultivar.

  16. Mutualistic fungus promotes plant invasion into diverse communities.

    PubMed

    Rudgers, Jennifer A; Mattingly, W Brett; Koslow, Jennifer M

    2005-07-01

    Reducing the biological diversity of a community may decrease its resistance to invasion by exotic species. Manipulative experiments typically support this hypothesis but have focused mainly on one trophic level (i.e., primary producers). To date, we know little about how positive interactions among species may influence the relationship between diversity and invasibility, which suggests a need for research that addresses the question: under what conditions does diversity affect resistance to invasion? We used experimental manipulations of both plant diversity and the presence of an endophytic fungus to test whether a fungal mutualist of an invasive grass species (Lolium arundinaceum) switches the relationship between plant community diversity and resistance to invasion. Association with the fungal endophyte (Neotyphodium coenophialum) increased the ability of L. arundinaceum to invade communities with greater species diversity. In the absence of the endophyte, the initial diversity of the community significantly reduced the establishment of L. arundinaceum. However, establishment was independent of initial diversity in the presence of the endophyte. Fungal symbionts, like other key species, are often overlooked in studies of plant diversity, yet their presence may explain variation among studies in the effect of diversity on resistance to invasion.

  17. Purification of an Inducible DNase from a Thermophilic Fungus

    PubMed Central

    Landry, Kyle S.; Vu, Andrea; Levin, Robert E.

    2014-01-01

    The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 μm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the presence of DNA and/or deoxyribose. Static growth of the organism resulted in significantly higher DNase production than agitated growth. The DNase was purified 145-fold using a novel affinity membrane purification system with 25% of the initial enzyme activity remaining. Electrophoresis of the purified enzyme resulted in a single protein band, indicating DNase homogeneity. PMID:24447923

  18. Bioturbation by the Fungus-Gardening Ant, Trachymyrmex septentrionalis.

    PubMed

    Tschinkel, Walter R; Seal, Jon N

    2016-01-01

    Soil invertebrates such as ants are thought to be important manipulators of soils in temperate and tropical ecosystems. The fungus gardening ant, Trachymyrmex septentrionalis, is an important agent of biomantling, that is, of depositing soil excavated from below onto the surface, and has been suggested as an agent of bioturbation (moving soil below ground) as well. The amount of bioturbation by this ant was quantified by planting queenright colonies in sand columns consisting of 5 layers of different colored sand. The amount of each color of sand deposited on the surface was determined from April to November 2015. In November, colonies were excavated and the color and amount of sand deposited below ground (mostly as backfill in chambers) was determined. Extrapolated to one ha, T. septentrionalis deposited 800 kg of sand per annum on the surface, and an additional 200 kg (17% of the total excavated) below ground. On average, this mixes 1.3% of the sand from other layers within the top meter of soil per millennium, but this mixing is unlikely to be homogeneous, and probably occurs as "hotspots" in both horizontal and vertical space. Such mixing is discussed as a challenge to sediment dating by optically stimulated luminescence (OSL).

  19. Fungus mediated biosynthesis and characterization of zinc oxide nanorods

    NASA Astrophysics Data System (ADS)

    Venkatesh, K. S.; Palani, N. S.; Krishnamoorthi, S. R.; Thirumal, V.; Ilangovan, R.

    2013-06-01

    Recently nanomaterials have been synthesized through biological approach due to its biocompatibility, inexpensive, eco friendly and it offers easiest experimental protocol and so on. ZnO can be potentially used in various applications. This present study reports the fungus mediated extra-cellular bio synthesis of ZnO nanorods using Fusarium Solani. The dried powder was calcined at 350°C for 1 hour in air. The thermal property of the as synthesized ZnO nanopowder was analyzed through Thermo gravimetric /Differential Thermo gravimetric (TGA / DTG) analysis. The structural and morphological properties of the calcined ZnO nanopowder were studied by XRD and SEM analysis respectively. X ray diffraction result revealed that a peak located at 2θ = 36.2° with (101) plane confirms the presence of Zinc oxide with Hexagonal crystal system. The morphology of the calcined ZnO powder was analyzed by Scanning Electron Microscopy and it clearly indicates the presence of ZnO nanorods. The diameter of the nanorods is in the range of 60 to 95 nm.

  20. Pulmonary echinococcal cyst with a filamentous fungus co-infection.

    PubMed

    Pandey, P; Dixit, A K; Tanwar, A; Mahajan, N C

    2013-09-01

    Fungal infections are known to colonize the pre-existing lung cavities formed as a result of diseases like tuberculosis, sarcoidosis, bronchiectasis and cavitatary neoplasia, mostly encountered in immunocompromised patients. Pulmonary echinococcal cysts have been reported coexistent with cryptococcosis and other saprophytic mycosis, but the coexistence of aspergillosis and echinococcal cyst is extremely rare and occasionally been reported in English literature. Active invasion and proliferation of the fungi in the laminated ectocyst of the echinococcal cyst is very unusual. We report a case of 60 years old immunocompetent female, presented with cough, chest pain and shortness of breath. The chest X-ray showed a large thick walled cavity in the lower and mid zone of right lung with positive water lily sign. Surgical enucleation of the echinococcal cyst revealed aspergilloma involving the cavity with massive invasion of laminated ectocyst by filamentous fungus, morphologically resembling an Aspergillus species and was further treated with Itraconazole for 3 months. This unique coexistence of active pulmonary echinococcosis and aspergillosis is being reported because of its rarity and clinical importance for its management.

  1. Acrophialophora, a Poorly Known Fungus with Clinical Significance

    PubMed Central

    Sandoval-Denis, Marcelo; Sutton, Deanna A.; Wiederhold, Nathan P.; Guarro, Josep

    2015-01-01

    Acrophialophora fusispora is an emerging opportunistic fungus capable of causing human infections. The taxonomy of the genus is not yet resolved and, in order to facilitate identification of clinical specimens, we have studied a set of clinical and environmental Acrophialophora isolates by morphological and molecular analyses. This set included the available type strains of Acrophialophora species and similar fungi, some of which were considered by various authors to be synonyms of A. fusispora. Sequence analysis of the large subunit (LSU) and internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA and a fragment of the β-tubulin (Tub) gene revealed that Acrophialophora belongs in the family Chaetomiaceae and comprises three different species, i.e., A. fusispora, Acrophialophora levis, and Acrophialophora seudatica; the latter was previously included in the genus Ampullifera. The most prevalent species among clinical isolates was A. levis (72.7%), followed by A. fusispora (27.3%), both of which were isolated mostly from respiratory specimens (72.7%), as well as subcutaneous and corneal tissue samples. In general, of the eight antifungal drugs tested, voriconazole had the greatest in vitro activity, while all other agents showed poor in vitro activity against these fungi. PMID:25716450

  2. Biodegradation of ciprofloxacin by white rot fungus Pleurotus ostreatus.

    PubMed

    Singh, Sushil Kumar; Khajuria, Robinka; Kaur, Loveleen

    2017-05-01

    Unrestricted and reckless use of antibiotics has resulted in their accumulation in environment. This, in turn, has led to the emergence of multiple drug-resistant microbes. The present study focuses on degradation of ciprofloxacin (CIP) by an edible white rot fungus Pleurotus ostreatus. Effect of CIP was determined on radial growth and biomass of P. ostreatus. Titrimetric and spectrophotometric assays were carried out to assess the degrading potential of P. ostreatus towards CIP. It was found that CIP has a stimulatory effect on growth and enzyme activity of P. ostreatus. Maximum enzyme (glucanase, ligninases, laccase) production was observed at the highest concentration of CIP (500 ppm). Antibiotic degradation of about 68.8, 94.25 and 91.34% was estimated after 14 days of incubation at 500 ppm CIP using Titrimetric, Indigo carmine and Methyl orange assay, respectively. Degradation of CIP was further validated by high performance liquid chromatography (HPLC) and microbiological analysis. HPLC analysis revealed 95.07% degradation while microbiological test also exhibited a decreased antimicrobial activity of degraded products against Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes. To the best of our knowledge, this is the first study wherein P. ostreatus was used for the degradation of ciprofloxacin.

  3. Characterization of Transposable Elements in the Ectomycorrhizal Fungus Laccaria bicolor

    SciTech Connect

    Labbe, Jessy L; Murat, Claude; Morin, Emmanuelle; Tuskan, Gerald A; Le Tacon, F; Martin, Francis

    2012-01-01

    Background: The publicly available Laccaria bicolor genome sequence has provided a considerable genomic resource allowing systematic identification of transposable elements (TEs) in this symbiotic ectomycorrhizal fungus. Using a TEspecific annotation pipeline we have characterized and analyzed TEs in the L. bicolor S238N-H82 genome. Methodology/Principal Findings: TEs occupy 24% of the 60 Mb L. bicolor genome and represent 25,787 full-length and partial copy elements distributed within 171 families. The most abundant elements were the Copia-like. TEs are not randomly distributed across the genome, but are tightly nested or clustered. The majority of TEs exhibits signs of ancient transposition except some intact copies of terminal inverted repeats (TIRS), long terminal repeats (LTRs) and a large retrotransposon derivative (LARD) element. There were three main periods of TE expansion in L. bicolor: the first from 57 to 10 Mya, the second from 5 to 1 Mya and the most recent from 0.5 Mya ago until now. LTR retrotransposons are closely related to retrotransposons found in another basidiomycete, Coprinopsis cinerea. Conclusions: This analysis 1) represents an initial characterization of TEs in the L. bicolor genome, 2) contributes to improve genome annotation and a greater understanding of the role TEs played in genome organization and evolution and 3) provides a valuable resource for future research on the genome evolution within the Laccaria genus.

  4. Eosinophils in Fungus-Associated Allergic Pulmonary Disease

    PubMed Central

    Ghosh, Sumit; Hoselton, Scott A.; Dorsam, Glenn P.; Schuh, Jane M.

    2013-01-01

    Asthma is frequently caused and/or exacerbated by sensitization to fungal allergens, which are ubiquitous in many indoor and outdoor environments. Severe asthma with fungal sensitization is characterized by airway hyperresponsiveness and bronchial constriction in response to an inhaled allergen that is worsened by environmental exposure to airborne fungi and which leads to a disease course that is often very difficult to treat with standard asthma therapies. As a result of complex interactions among inflammatory cells, structural cells, and the intercellular matrix of the allergic lung, patients with sensitization to fungal allergens may experience a greater degree of airway wall remodeling and progressive, accumulated pulmonary dysfunction as part of the disease sequela. From their development in the bone marrow to their recruitment to the lung via chemokine and cytokine networks, eosinophils form an important component of the inflammatory milieu that is associated with this syndrome. Eosinophils are recognized as complex multi-factorial leukocytes with diverse functions in the context of allergic fungal asthma. In this review, we will consider recent advances in our understanding of the molecular mechanisms that are associated with eosinophil development and migration to the allergic lung in response to fungal inhalation, along with the eosinophil’s function in the immune response to and the immunopathology attributed to fungus-associated allergic pulmonary disease. PMID:23378838

  5. Structural analysis of fungus-derived FAD glucose dehydrogenase

    PubMed Central

    Yoshida, Hiromi; Sakai, Genki; Mori, Kazushige; Kojima, Katsuhiro; Kamitori, Shigehiro; Sode, Koji

    2015-01-01

    We report the first three-dimensional structure of fungus-derived glucose dehydrogenase using flavin adenine dinucleotide (FAD) as the cofactor. This is currently the most advanced and popular enzyme used in glucose sensor strips manufactured for glycemic control by diabetic patients. We prepared recombinant nonglycosylated FAD-dependent glucose dehydrogenase (FADGDH) derived from Aspergillus flavus (AfGDH) and obtained the X-ray structures of the binary complex of enzyme and reduced FAD at a resolution of 1.78 Å and the ternary complex with reduced FAD and D-glucono-1,5-lactone (LGC) at a resolution of 1.57 Å. The overall structure is similar to that of fungal glucose oxidases (GOxs) reported till date. The ternary complex with reduced FAD and LGC revealed the residues recognizing the substrate. His505 and His548 were subjected for site-directed mutagenesis studies, and these two residues were revealed to form the catalytic pair, as those conserved in GOxs. The absence of residues that recognize the sixth hydroxyl group of the glucose of AfGDH, and the presence of significant cavity around the active site may account for this enzyme activity toward xylose. The structural information will contribute to the further engineering of FADGDH for use in more reliable and economical biosensing technology for diabetes management. PMID:26311535

  6. ENTOMOPATHOGENIC FUNGUS ENTOMOPHAGA MAIMAIGA AND INTEGRATED PEST MANAGEMENT IN SERBIA.

    PubMed

    Tabaković-Tosić, Mara

    2015-01-01

    During the latest outbreak of the gypsy moth in Serbia (2009-2014), some areas of Central Serbia were particularly endangered, and one of them was Krusevac region, where the forests give way to orchards in the pattern resembling the tiger's skin. Since the number of the laid egg masses in the autumn 2013 guaranteed the defoliation of both forest tree species and agricultural crops, and the presence of E. maimaigo, in Central Serbia had already been determined, at 30 selected plots the assisted spread of it was performed, through the introduction of the infectious inoculum in the beech and oak forests which border the orchards. Since there was dealt with the living organism--fungus, which is particularly susceptible to the weather conditions (temperature and air humidity, as well as the precipitation), and under the conditions of the global warming and great drought, the special recipe for the preparation of inoculum was made. In the following year the mass epizootic of the gypsy moth caterpillars, of the younger instars (L2 and L3), occurred, which implies that E. maimaiga caused the crash of the outbreak of this most harmful species of the defoliating insects of the forests and orchards.

  7. Bioturbation by the Fungus-Gardening Ant, Trachymyrmex septentrionalis

    PubMed Central

    Tschinkel, Walter R.; Seal, Jon N.

    2016-01-01

    Soil invertebrates such as ants are thought to be important manipulators of soils in temperate and tropical ecosystems. The fungus gardening ant, Trachymyrmex septentrionalis, is an important agent of biomantling, that is, of depositing soil excavated from below onto the surface, and has been suggested as an agent of bioturbation (moving soil below ground) as well. The amount of bioturbation by this ant was quantified by planting queenright colonies in sand columns consisting of 5 layers of different colored sand. The amount of each color of sand deposited on the surface was determined from April to November 2015. In November, colonies were excavated and the color and amount of sand deposited below ground (mostly as backfill in chambers) was determined. Extrapolated to one ha, T. septentrionalis deposited 800 kg of sand per annum on the surface, and an additional 200 kg (17% of the total excavated) below ground. On average, this mixes 1.3% of the sand from other layers within the top meter of soil per millennium, but this mixing is unlikely to be homogeneous, and probably occurs as "hotspots" in both horizontal and vertical space. Such mixing is discussed as a challenge to sediment dating by optically stimulated luminescence (OSL). PMID:27391485

  8. Genetic dissection of PARylation in the filamentous fungus Neurospora crassa.

    PubMed

    Kothe, Gregory O

    2011-01-01

    PARylation is a posttranslational protein modification carried out by PAR polymerases (PARPs). These enzymes function as ADP-ribose transferases that add polymers of ADP-ribose (PAR) to target proteins. PARP proteins have critical functions impacting the aspects of normal human health, such as aging, as well as disease development, particularly cancer. Recently, the powerful antitumor PARP inhibitor Olaparib was shown to be effective in blocking the progression of BRCA1/2-associated tumors, prompting Bruce Alberts to call for an expansion of cancer research beyond utilization of cancer cell lines to include model organisms, such as bacteria, yeast, worms, flies, and mice. Although Dr. Alberts did not specifically mention the filamentous fungus Neurospora crassa, it is now known that Neurospora is the only genetically tractable model eukaryote with completely dispensable PARylation. PARylation in Neurospora can be entirely eliminated by disruption of a single predicted ORF, encoding a nuclear localized PARP protein termed Neurospora PARP ortholog (NPO). We, thus, present this initial genetic characterization of PARylation in N. crassa as evidence of the supreme advantage of using Neurospora as a tool for the genetic dissection of PARP and PARylation and emphasize the power of this system to advance unparalleled contributions to knowledge in this field.

  9. Acrophialophora, a poorly known fungus with clinical significance.

    PubMed

    Sandoval-Denis, Marcelo; Gené, Josepa; Sutton, Deanna A; Wiederhold, Nathan P; Guarro, Josep

    2015-05-01

    Acrophialophora fusispora is an emerging opportunistic fungus capable of causing human infections. The taxonomy of the genus is not yet resolved and, in order to facilitate identification of clinical specimens, we have studied a set of clinical and environmental Acrophialophora isolates by morphological and molecular analyses. This set included the available type strains of Acrophialophora species and similar fungi, some of which were considered by various authors to be synonyms of A. fusispora. Sequence analysis of the large subunit (LSU) and internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA and a fragment of the β-tubulin (Tub) gene revealed that Acrophialophora belongs in the family Chaetomiaceae and comprises three different species, i.e., A. fusispora, Acrophialophora levis, and Acrophialophora seudatica; the latter was previously included in the genus Ampullifera. The most prevalent species among clinical isolates was A. levis (72.7%), followed by A. fusispora (27.3%), both of which were isolated mostly from respiratory specimens (72.7%), as well as subcutaneous and corneal tissue samples. In general, of the eight antifungal drugs tested, voriconazole had the greatest in vitro activity, while all other agents showed poor in vitro activity against these fungi.

  10. Genes involved in virulence of the entomopathogenic fungus Beauveria bassiana.

    PubMed

    Valero-Jiménez, Claudio A; Wiegers, Harm; Zwaan, Bas J; Koenraadt, Constantianus J M; van Kan, Jan A L

    2016-01-01

    Pest insects cause severe damage to global crop production and pose a threat to human health by transmitting diseases. Traditionally, chemical pesticides (insecticides) have been used to control such pests and have proven to be effective only for a limited amount of time because of the rapid spread of genetic insecticide resistance. The basis of this resistance is mostly caused by (co)dominant mutations in single genes, which explains why insecticide use alone is an unsustainable solution. Therefore, robust solutions for insect pest control need to be sought in alternative methods such as biological control agents for which single-gene resistance is less likely to evolve. The entomopathogenic fungus Beauveria bassiana has shown potential as a biological control agent of insects, and insight into the mechanisms of virulence is essential to show the robustness of its use. With the recent availability of the whole genome sequence of B. bassiana, progress in understanding the genetics that constitute virulence toward insects can be made more quickly. In this review we divide the infection process into distinct steps and provide an overview of what is currently known about genes and mechanisms influencing virulence in B. bassiana. We also discuss the need for novel strategies and experimental methods to better understand the infection mechanisms deployed by entomopathogenic fungi. Such knowledge can help improve biocontrol agents, not only by selecting the most virulent genotypes, but also by selecting the genotypes that use combinations of virulence mechanisms for which resistance in the insect host is least likely to develop.

  11. Bioactive Chaetoglobosins from the Mangrove Endophytic Fungus Penicillium chrysogenum

    PubMed Central

    Huang, Song; Chen, Haiyan; Li, Wensheng; Zhu, Xinwei; Ding, Weijia; Li, Chunyuan

    2016-01-01

    A novel chaetoglobosin named penochalasin I (1) with a unprecedented six-cyclic 6/5/6/5/6/13 fused ring system, and another new chaetoglobosin named penochalasin J (2), along with chaetoglobosins G, F, C, A, E, armochaetoglobosin I, and cytoglobosin C (3–9) were isolated from the culture of Penicillium chrysogenum V11. Their structures were elucidated by 1D, 2D NMR spectroscopic analysis and high resolution mass spectroscopic data. The absolute configuration of compounds 1 and 2 were determined by comparing the theoretical electronic circular dichroism (ECD) calculation with the experimental CD. Compound 1 was the first example, with a six-cyclic fused ring system formed by the connection of C-5 and C-2′ of the chaetoglobosin class. Compounds 5–8 remarkably inhibited the plant pathogenic fungus R. solani (minimum inhibitory concentrations (MICs) = 11.79–23.66 μM), and compounds 2, 6, and 7 greatly inhibited C. gloeosporioides (MICs = 23.58–47.35 μM), showing an antifungal activity higher than that of carbendazim. Compound 1 exhibited marked cytotoxicity against MDA-MB-435 and SGC-7901 cells (IC50 < 10 μM), and compounds 6 and 9 showed potent cytotoxicity against SGC-7901 and A549 cells (IC50 < 10 μM). PMID:27690061

  12. Transcriptional response to hypoxia in the aquatic fungus Blastocladiella emersonii.

    PubMed

    Camilo, César M; Gomes, Suely L

    2010-06-01

    Global gene expression analysis was carried out with Blastocladiella emersonii cells subjected to oxygen deprivation (hypoxia) using cDNA microarrays. In experiments of gradual hypoxia (gradual decrease in dissolved oxygen) and direct hypoxia (direct decrease in dissolved oxygen), about 650 differentially expressed genes were observed. A total of 534 genes were affected directly or indirectly by oxygen availability, as they showed recovery to normal expression levels or a tendency to recover when cells were reoxygenated. In addition to modulating many genes with no putative assigned function, B. emersonii cells respond to hypoxia by readjusting the expression levels of genes responsible for energy production and consumption. At least transcriptionally, this fungus seems to favor anaerobic metabolism through the upregulation of genes encoding glycolytic enzymes and lactate dehydrogenase and the downregulation of most genes coding for tricarboxylic acid (TCA) cycle enzymes. Furthermore, genes involved in energy-costly processes, like protein synthesis, amino acid biosynthesis, protein folding, and transport, had their expression profiles predominantly downregulated during oxygen deprivation, indicating an energy-saving effort. Data also revealed similarities between the transcriptional profiles of cells under hypoxia and under iron(II) deprivation, suggesting that Fe(2+) ion could have a role in oxygen sensing and/or response to hypoxia in B. emersonii. Additionally, treatment of fungal cells prior to hypoxia with the antibiotic geldanamycin, which negatively affects the stability of mammalian hypoxia transcription factor HIF-1alpha, caused a significant decrease in the levels of certain upregulated hypoxic genes.

  13. The genome sequence of the model ascomycete fungus Podospora anserina.

    PubMed

    Espagne, Eric; Lespinet, Olivier; Malagnac, Fabienne; Da Silva, Corinne; Jaillon, Olivier; Porcel, Betina M; Couloux, Arnaud; Aury, Jean-Marc; Ségurens, Béatrice; Poulain, Julie; Anthouard, Véronique; Grossetete, Sandrine; Khalili, Hamid; Coppin, Evelyne; Déquard-Chablat, Michelle; Picard, Marguerite; Contamine, Véronique; Arnaise, Sylvie; Bourdais, Anne; Berteaux-Lecellier, Véronique; Gautheret, Daniel; de Vries, Ronald P; Battaglia, Evy; Coutinho, Pedro M; Danchin, Etienne Gj; Henrissat, Bernard; Khoury, Riyad El; Sainsard-Chanet, Annie; Boivin, Antoine; Pinan-Lucarré, Bérangère; Sellem, Carole H; Debuchy, Robert; Wincker, Patrick; Weissenbach, Jean; Silar, Philippe

    2008-01-01

    The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina transcription/splicing machinery generates numerous non-conventional transcripts. Comparison of the P. anserina genome and orthologous gene set with the one of its close relatives, Neurospora crassa, shows that synteny is poorly conserved, the main result of evolution being gene shuffling in the same chromosome. The P. anserina genome contains fewer repeated sequences and has evolved new genes by duplication since its separation from N. crassa, despite the presence of the repeat induced point mutation mechanism that mutates duplicated sequences. We also provide evidence that frequent gene loss took place in the lineages leading to P. anserina and N. crassa. P. anserina contains a large and highly specialized set of genes involved in utilization of natural carbon sources commonly found in its natural biotope. It includes genes potentially involved in lignin degradation and efficient cellulose breakdown. The features of the P. anserina genome indicate a highly dynamic evolution since the divergence of P. anserina and N. crassa, leading to the ability of the former to use specific complex carbon sources that match its needs in its natural biotope.

  14. The genome sequence of the model ascomycete fungus Podospora anserina

    PubMed Central

    Espagne, Eric; Lespinet, Olivier; Malagnac, Fabienne; Da Silva, Corinne; Jaillon, Olivier; Porcel, Betina M; Couloux, Arnaud; Aury, Jean-Marc; Ségurens, Béatrice; Poulain, Julie; Anthouard, Véronique; Grossetete, Sandrine; Khalili, Hamid; Coppin, Evelyne; Déquard-Chablat, Michelle; Picard, Marguerite; Contamine, Véronique; Arnaise, Sylvie; Bourdais, Anne; Berteaux-Lecellier, Véronique; Gautheret, Daniel; de Vries, Ronald P; Battaglia, Evy; Coutinho, Pedro M; Danchin, Etienne GJ; Henrissat, Bernard; Khoury, Riyad EL; Sainsard-Chanet, Annie; Boivin, Antoine; Pinan-Lucarré, Bérangère; Sellem, Carole H; Debuchy, Robert; Wincker, Patrick; Weissenbach, Jean; Silar, Philippe

    2008-01-01

    Background The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. Results We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina transcription/splicing machinery generates numerous non-conventional transcripts. Comparison of the P. anserina genome and orthologous gene set with the one of its close relatives, Neurospora crassa, shows that synteny is poorly conserved, the main result of evolution being gene shuffling in the same chromosome. The P. anserina genome contains fewer repeated sequences and has evolved new genes by duplication since its separation from N. crassa, despite the presence of the repeat induced point mutation mechanism that mutates duplicated sequences. We also provide evidence that frequent gene loss took place in the lineages leading to P. anserina and N. crassa. P. anserina contains a large and highly specialized set of genes involved in utilization of natural carbon sources commonly found in its natural biotope. It includes genes potentially involved in lignin degradation and efficient cellulose breakdown. Conclusion The features of the P. anserina genome indicate a highly dynamic evolution since the divergence of P. anserina and N. crassa, leading to the ability of the former to use specific complex carbon sources that match its needs in its natural biotope. PMID:18460219

  15. Adhesion of the entomopathogenic fungus Beauveria (Cordyceps) bassiana to substrata.

    PubMed

    Holder, Diane J; Keyhani, Nemat O

    2005-09-01

    The entomopathogenic fungus Beauveria bassiana produces at least three distinct single-cell propagules, aerial conidia, vegetative cells termed blastospores, and submerged conidia, which can be isolated from agar plates, from rich broth liquid cultures, and under nutrient limitation conditions in submerged cultures, respectively. Fluorescently labeled fungal cells were used to quantify the kinetics of adhesion of these cell types to surfaces having various hydrophobic or hydrophilic properties. Aerial conidia adhered poorly to weakly polar surfaces and rapidly to both hydrophobic and hydrophilic surfaces but could be readily washed off the latter surfaces. In contrast, blastospores bound poorly to hydrophobic surfaces, forming small aggregates, bound rapidly to hydrophilic surfaces, and required a longer incubation time to bind to weakly polar surfaces than to hydrophilic surfaces. Submerged conidia displayed the broadest binding specificity, adhering to hydrophobic, weakly polar, and hydrophilic surfaces. The adhesion of the B. bassiana cell types also differed in sensitivity to glycosidase and protease treatments, pH, and addition of various carbohydrate competitors and detergents. The outer cell wall layer of aerial conidia contained sodium dodecyl sulfate-insoluble, trifluoroacetic acid-soluble proteins (presumably hydrophobins) that were not present on either blastospores or submerged conidia. The variations in the cell surface properties leading to the different adhesion qualities of B. bassiana aerial conidia, blastospores, and submerged conidia could lead to rational design decisions for improving the efficacy and possibly the specificity of entomopathogenic fungi for host targets.

  16. Zosteropenillines: Polyketides from the Marine-Derived Fungus Penicillium thomii

    PubMed Central

    Afiyatullov, Shamil Sh.; Leshchenko, Elena V.; Berdyshev, Dmitrii V.; Sobolevskaya, Maria P.; Antonov, Alexandr S.; Denisenko, Vladimir A.; Popov, Roman S.; Pivkin, Mikhail V.; Udovenko, Anatoly A.; Pislyagin, Evgeny A.; von Amsberg, Gunhild; Dyshlovoy, Sergey A.

    2017-01-01

    Twelve new polyketides, zosteropenillines A–L (1–12), together with known polyketide pallidopenilline A (13), were isolated from the ethylacetate extract of the fungus Penicillium thomii associated with the seagrass Zostera marina. Their structures were established based on spectroscopic methods. The absolute configuration of zosteropenilline A (1) as 4R, 5S, 8S, 9R, 10R, and 13S was determined by a combination of the modified Mosher’s method, X-ray analysis, and NOESY data. Absolute configurations of zosteropenillines B–D (2–4) were determined by time-dependent density functional theory (TD-DFT) calculations of ECD spectra. The effect of compounds 1–3, 7, 8, 10, and 11 on the viability of human drug-resistant prostate cancer cells PC3 as well as on autophagy in these cancer cells and inhibitory effects of compounds 1, 2, and 8–10 on NO production in LPS-induced RAW 264.7 murine macrophages were examined. PMID:28218691

  17. Devonian landscape heterogeneity recorded by a giant fungus

    NASA Astrophysics Data System (ADS)

    Boyce, C. Kevin; Hotton, Carol L.; Fogel, Marilyn L.; Cody, George D.; Hazen, Robert M.; Knoll, Andrew H.; Hueber, Francis M.

    2007-05-01

    The enigmatic Paleozoic fossil Prototaxites Dawson 1859 consists of tree-like trunks as long as 8 m constructed of interwoven tubes <50 mm in diameter. Prototaxites specimens from five localities differ from contemporaneous vascular plants by exhibiting a carbon isotopic range, within and between localities, of as much as 13‰ δ13C. Pyrolysis gas chromatography mass spectrometry highlights compositional differences between Prototaxites and co-occurring plant fossils and supports interpretation of isotopic distinctions as biological rather than diagenetic in origin. Such a large isotopic range is difficult to reconcile with an autotrophic metabolism, suggesting instead that, consistent with anatomy-based interpretation as a fungus, Prototaxites was a heterotroph that lived on isotopically heterogeneous substrates. Light isotopic values of Prototaxites approximate those of vascular plants from the same localities; in contrast, heavy extremes seen in the Lower Devonian appear to reflect consumption of primary producers with carbon-concentrating mechanisms, such as cryptobiotic soil crusts, or possibly bryophytes. Prototaxites biogeochemistry thus suggests that a biologically heterogeneous mosaic of primary producers characterized land surfaces well into the vascular plant era.

  18. Adhesion of the Entomopathogenic Fungus Beauveria (Cordyceps) bassiana to Substrata†

    PubMed Central

    Holder, Diane J.; Keyhani, Nemat O.

    2005-01-01

    The entomopathogenic fungus Beauveria bassiana produces at least three distinct single-cell propagules, aerial conidia, vegetative cells termed blastospores, and submerged conidia, which can be isolated from agar plates, from rich broth liquid cultures, and under nutrient limitation conditions in submerged cultures, respectively. Fluorescently labeled fungal cells were used to quantify the kinetics of adhesion of these cell types to surfaces having various hydrophobic or hydrophilic properties. Aerial conidia adhered poorly to weakly polar surfaces and rapidly to both hydrophobic and hydrophilic surfaces but could be readily washed off the latter surfaces. In contrast, blastospores bound poorly to hydrophobic surfaces, forming small aggregates, bound rapidly to hydrophilic surfaces, and required a longer incubation time to bind to weakly polar surfaces than to hydrophilic surfaces. Submerged conidia displayed the broadest binding specificity, adhering to hydrophobic, weakly polar, and hydrophilic surfaces. The adhesion of the B. bassiana cell types also differed in sensitivity to glycosidase and protease treatments, pH, and addition of various carbohydrate competitors and detergents. The outer cell wall layer of aerial conidia contained sodium dodecyl sulfate-insoluble, trifluoroacetic acid-soluble proteins (presumably hydrophobins) that were not present on either blastospores or submerged conidia. The variations in the cell surface properties leading to the different adhesion qualities of B. bassiana aerial conidia, blastospores, and submerged conidia could lead to rational design decisions for improving the efficacy and possibly the specificity of entomopathogenic fungi for host targets. PMID:16151112

  19. [Furfural degradation by filamentous fungus Amorphotheca resinae ZN1].

    PubMed

    Wang, Xiaofeng; Zhang, Jian; Xin, Xiujuan; Bao, Jie

    2012-09-01

    Some degradation products from lignocellulose pretreatment strongly inhibit the activities of cellulolytic enzymes and ethanol fermentation strains, thus the efficient removal of the inhibitor substances ("detoxification") is the inevitable step for the biotransformation processes. In this study, the biological detoxification of furfural by a newly isolated fungus, Amorphotheca resinae ZN1, was studied and the metabolic pathways of furfural degradation was analyzed. The metabolic pathway of furfural degradation in A. resinae ZN1 was described as follows: first, furfural was quickly converted into the low toxic furfuryl alcohol; then the furfuryl alcohol was gradually converted into furfural again but under the low concentration under aerobic condition, which was not lethal to the growth of the fungi; furfural continued to be oxidized to furoic acid by A. resinae ZN1. It is likely that furoic acid was further degraded in the TCA cycle to complete the biological degradation of furfural. The present study provided the important experimental basis for speeding up the biodetoxification of furfural by A. resinae ZN1 and the rate-limiting step in the lignocellulose biotransformation to ethanol.

  20. Identification of naphthalene metabolism by white rot fungus Pleurotus eryngii.

    PubMed

    Hadibarata, Tony; Teh, Zee Chuang; Rubiyatno; Zubir, Meor Mohd Fikri Ahmad; Khudhair, Ameer Badr; Yusoff, Abdull Rahim Mohd; Salim, Mohd Razman; Hidayat, Topik

    2013-10-01

    The use of biomaterials or microorganisms in PAHs degradation had presented an eye-catching performance. Pleurotus eryngii is a white rot fungus, which is easily isolated from the decayed woods in the tropical rain forest, used to determine the capability to utilize naphthalene, a two-ring polycyclic aromatic hydrocarbon as source of carbon and energy. In the meantime, biotransformation of naphthalene to intermediates and other by-products during degradation was investigated in this study. Pleurotus eryngii had been incubated in liquid medium formulated with naphthalene for 14 days. The presence of metabolites of naphthalene suggests that Pleurotus eryngii begin the ring cleavage by dioxygenation on C1 and C4 position to give 1,4-naphthaquinone. 1,4-Naphthaquinone was further degraded to benzoic acid, where the proposed terepthalic acid is absent in the cultured extract. Further degradation of benzoic acid by Pleurotus eryngii shows the existence of catechol as a result of the combination of decarboxylation and hydroxylation process. Unfortunately, phthalic acid was not detected in this study. Several enzymes, including manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase are enzymes responsible for naphthalene degradation. Reduction of naphthalene and the presence of metabolites in liquid medium showed the ability of Pleurotus eryngii to utilize naphthalene as carbon source instead of a limited glucose amount.

  1. The mitochondrial genome from the thermal dimorphic fungus Paracoccidioides brasiliensis.

    PubMed

    Cardoso, Maria Angélica G; Tambor, José Humberto M; Nobrega, Francisco G

    2007-07-01

    We present here the sequence of the mitochondrial DNA of the pathogenic thermodimorphic fungus Paracoccidioides brasiliensis, agent of an endemic disease in most South American countries. The sequenced genome has 71 334 bp and is organized as a circular molecule with two gaps of unknown size flanking the middle exon of the nad5 gene. We located genes coding for the three subunits of the ATP synthase (atp6, atp8 and atp9), the apocytochrome b (cob), three subunits of the cytochrome c oxidase enzyme complex (cox1, cox2 and cox3), seven subunits of the reduced nicotinamide adenine dinucleotide ubiquinone oxidoreductase (nad1, nad2, nad3, nad4, nad5, nad6 and nad4L) and the large (rnl) and small (rns) subunits of ribosomal RNA. Two maturases and a ribosomal protein (rms5) are located inside introns. Twenty-five tRNAs were identified with acceptors for all 20 amino acids. Seven polypurine/polypyrimidine tracts (140-240 bp) have been found in this genome. All genes are in the same orientation over the genome, while their order is closest to the mitochondrial genomes from Penicillium marneffei and Aspergillus nidulans.

  2. Biological control of cyathostomin (Nematoda: Cyathostominae) with nematophagous fungus Monacrosporium thaumasium in tropical southeastern Brazil.

    PubMed

    Tavela, Alexandre de Oliveira; Araújo, Jackson Victor; Braga, Fábio Ribeiro; Silva, André Ricardo; Carvalho, Rogério Oliva; Araujo, Juliana Milani; Ferreira, Sebastião Rodrigo; Carvalho, Giovanni Ribeiro

    2011-01-10

    Horses are hosts to a wide variety of helminthes; the most important are the cyathostomin, or small strongyles. The viability of a fungal formulation (pellets) using the nematode-trapping fungus Monacrosporium thaumasium was assessed in biological control of horse cyathostomin. Two groups (fungus-treated and control) consisted of six mares in each group, crossbred (ages of 2.5 and 3.5 years), were placed in pastures of Cynodon sp. naturally infected with horse cyathostomin larvae. In the treated group, each animal received 1g/10 kg body weight (0.2g/10 kg live weight of fungus) of pellets of sodium alginate matrix containing the fungus M. thaumasium orally, twice a week for 6 months. In the control group, animals received (1g/10 kg body weight) of pellets without fungus. The egg count per gram of feces showed difference (p<0.01) in the animals treated with the fungus in relation to the control animals during all months of the experiment. The EPG percentage decrease were 87.5%, 89.7%, 68.3%, 58.7%, 52.5% and 35.2% during June, July, August, September, October and November, respectively. In faecal cultures, there was difference (p<0.05) among animals treated with fungus was found in relation to the control animals during all the experiment month, with percentage reduction of 67.5%, 61.4% and 31.8% in September, October and November, respectively. Difference (p<0.01) was observed in the recovery of infective larvae from pastures that were collected up to 20 cm from the dung pats in pastures in the group treated with the fungus in relation to the control group with a reduction of 60.9% and between 0-20 and 0-40 cm from the faecal pat reduction (p<0.01) was about 56% in the group treated with the fungus M. thaumasium in relation to the control group pasture. There was no difference (p>0.05) between the average weight gains in both animal groups. The treatment of horses with pellets containing the nematophagous fungus M. thaumasium can be effective in controlling

  3. Characterization of fungus-specific microsatellite markers in the lichen-forming fungus Parmelina carporrhizans (Parmeliaceae)1

    PubMed Central

    Alors, David; Dal Grande, Francesco; Schmitt, Imke; Kraichak, Ekaphan; Lumbsch, H. Thorsten; Crespo, Ana; Divakar, Pradeep K.

    2014-01-01

    • Premise of the study: Microsatellite loci were developed to study the lichen-forming fungus Parmelina (Parmeliaceae) in different habitats of western Europe and the Mediterranean for baseline studies to understand the effects of climate change on its distribution. • Methods and Results: We cultured P. carporrhizans from ascospores for genomic sequencing with Illumina HiSeq. We successfully developed 11 polymorphic microsatellite markers and associated primer sets and assessed them with 30 individuals from two of the Canary Islands. The average number of alleles per locus was 8.8. Nei’s unbiased gene diversity of these loci ranged from 0.53 to 0.91 in the tested populations. Amplification in two closely related species (P. tiliacea, P. cryptotiliacea) yielded only limited success. • Conclusions: The new microsatellite markers will allow the study of genetic diversity and population structure in P. carporrhizans. We propose eight markers to combine in two multiplex reactions for further studies on a larger set of populations. PMID:25506522

  4. Slope aspect influences arbuscular mycorrhizal fungus communities in arid ecosystems of the Daqingshan Mountains, Inner Mongolia, North China.

    PubMed

    Liu, Min; Zheng, Rong; Bai, Shulan; Bai, Yv E; Wang, Jugang

    2017-04-01

    Arbuscular mycorrhizal (AM) symbiosis plays an important role in ecosystem functioning, particularly in fragile environments. Little is known, however, about how AM fungus community composition responds to slope aspect. Our objective was to compare the AM fungus communities between sunny and shady slopes and to detect factors that influenced the distributions of AM fungi in arid ecosystems of the Daqingshan Mountains, Inner Mongolia, North China. AM fungus communities were evaluated based on small subunit ribosomal RNA genes (SSUs) using Illumina MiSeq sequencing. AM fungus community composition differed significantly between slope aspects, and sunny slopes had significantly higher AM fungus diversity and richness as well as spore density, total root colonization, arbuscule abundance, vesicle abundance, and hyphal colonization than shady slopes. Structural equation modeling (SEM) illustrated that the effects of slope aspect on AM fungus richness likely were mediated by available phosphorus, soil organic carbon, plant cover, and plant diversity. Available phosphorus was the principal factor that influenced AM fungus species richness, and soil organic carbon was the principal factor influencing spore density and total root colonization, suggesting that these factors especially might be responsible for differences between the AM fungus communities of different slope aspects. These findings elucidate the influence of slope aspect on AM fungus communities and may inform use of AM fungi in protection and restoration of vegetation with different slope aspects in arid ecosystems.

  5. Peroxisome dynamics during development of the fungus Podospora anserina.

    PubMed

    Takano-Rojas, Harumi; Zickler, Denise; Peraza-Reyes, Leonardo

    2016-01-01

    Peroxisomes are versatile and dynamic organelles that are required for the development of diverse eukaryotic organisms. We demonstrated previously that in the fungus Podospora anserina different peroxisomal functions are required at distinct stages of sexual development, including the initiation and progression of meiocyte (ascus) development and the differentiation and germination of sexual spores (ascospores). Peroxisome assembly during these processes relies on the differential activity of the protein machinery that drives the import of proteins into the organelle, indicating a complex developmental regulation of peroxisome formation and activity. Here we demonstrate that peroxisome dynamics is also highly regulated during development. We show that peroxisomes in P. anserina are highly dynamic and respond to metabolic and environmental cues by undergoing changes in size, morphology and number. In addition, peroxisomes of vegetative and sexual cell types are structurally different. During sexual development peroxisome number increases at two stages: at early ascus differentiation and during ascospore formation. These processes are accompanied by changes in peroxisome structure and distribution, which include a cell-polarized concentration of peroxisomes at the beginning of ascus development, as well as a morphological transition from predominantly spherical to elongated shapes at the end of the first meiotic division. Further, the mostly tubular peroxisomes present from second meiotic division to early ascospore formation again become rounded during ascospore differentiation. Ultimately the number of peroxisomes dramatically decreases upon ascospore maturation. Our results reveal a precise regulation of peroxisome dynamics during sexual development and suggest that peroxisome constitution and function during development is defined by the coordinated regulation of the proteins that control peroxisome assembly and dynamics.

  6. Trade-offs in an ant-plant-fungus mutualism.

    PubMed

    Orivel, Jérôme; Malé, Pierre-Jean; Lauth, Jérémie; Roux, Olivier; Petitclerc, Frédéric; Dejean, Alain; Leroy, Céline

    2017-03-15

    Species engaged in multiple, simultaneous mutualisms are subject to trade-offs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species.

  7. Genomic insight into pathogenicity of dematiaceous fungus Corynespora cassiicola.

    PubMed

    Looi, Hong Keat; Toh, Yue Fen; Yew, Su Mei; Na, Shiang Ling; Tan, Yung-Chie; Chong, Pei-Sin; Khoo, Jia-Shiun; Yee, Wai-Yan; Ng, Kee Peng; Kuan, Chee Sian

    2017-01-01

    Corynespora cassiicola is a common plant pathogen that causes leaf spot disease in a broad range of crop, and it heavily affect rubber trees in Malaysia (Hsueh, 2011; Nghia et al., 2008). The isolation of UM 591 from a patient's contact lens indicates the pathogenic potential of this dematiaceous fungus in human. However, the underlying factors that contribute to the opportunistic cross-infection have not been fully studied. We employed genome sequencing and gene homology annotations in attempt to identify these factors in UM 591 using data obtained from publicly available bioinformatics databases. The assembly size of UM 591 genome is 41.8 Mbp, and a total of 13,531 (≥99 bp) genes have been predicted. UM 591 is enriched with genes that encode for glycoside hydrolases, carbohydrate esterases, auxiliary activity enzymes and cell wall degrading enzymes. Virulent genes comprising of CAZymes, peptidases, and hypervirulence-associated cutinases were found to be present in the fungal genome. Comparative analysis result shows that UM 591 possesses higher number of carbohydrate esterases family 10 (CE10) CAZymes compared to other species of fungi in this study, and these enzymes hydrolyses wide range of carbohydrate and non-carbohydrate substrates. Putative melanin, siderophore, ent-kaurene, and lycopene biosynthesis gene clusters are predicted, and these gene clusters denote that UM 591 are capable of protecting itself from the UV and chemical stresses, allowing it to adapt to different environment. Putative sterigmatocystin, HC-toxin, cercosporin, and gliotoxin biosynthesis gene cluster are predicted. This finding have highlighted the necrotrophic and invasive nature of UM 591.

  8. Host Specialization in the Charcoal Rot Fungus, Macrophomina phaseolina.

    PubMed

    Su, G; Suh, S O; Schneider, R W; Russin, J S

    2001-02-01

    ABSTRACT To investigate host specialization in Macrophomina phaseolina, the fungus was isolated from soybean, corn, sorghum, and cotton root tissue and soil from fields cropped continuously to these species for 15 years in St. Joseph, LA. Chlorate phenotype of each isolate was determined after growing on a minimal medium containing 120 mM potassium chlorate. Consistent differences in chlorate sensitivity were detected among isolates from different hosts and from soil versus root. To further explore genetic differentiation among fungal isolates from each host, these isolates were examined by restriction fragment length polymorphism and random amplified polymorphic DNA (RAPD) analysis. No variations were observed among isolates in restriction patterns of DNA fragments amplified by polymerase chain reaction covering the internal transcribed spacer region, 5.8S rRNA and part of 25S rRNA, suggesting that M. phaseolina constitutes a single species. Ten random primers were used to amplify the total DNA of 45 isolates, and banding patterns resulting from RAPD analysis were compared with the neighbor-joining method. Isolates from a given host were genetically similar to each other but distinctly different from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. In greenhouse tests, soybean, sorghum, corn, and cotton were grown separately in soil infested with individual isolates of M. phaseolina that were chosen based on their host of origin and chlorate phenotype. Root colonization and plant weight were measured after harvesting. More colonization of corn roots occurred when corn was grown in soil containing corn isolates compared with isolates from other hosts. However, there was no host specialization in isolates from soybean, sorghum, or cotton. More root colonization in soybean occurred with chlorate-sensitive than with chlorate-resistant isolates.

  9. Pathogenic Fungus Microsporum canis Activates the NLRP3 Inflammasome

    PubMed Central

    Mao, Liming; Zhang, Liping; Li, Hua; Chen, Wei; Wang, Hongbin; Wu, Shuxian; Guo, Caiqin; Lu, Ailing; Yang, Guiwen; An, Liguo

    2014-01-01

    Microsporum canis is a pathogenic fungus with worldwide distribution that causes tinea capitis in animals and humans. M. canis also causes invasive infection in immunocompromised patients. To defy pathogenic fungal infection, the host innate immune system is the first line of defense. As an important arm of innate immunity, the inflammasomes are intracellular multiprotein complexes that control the activation of caspase-1, which cleaves proinflammatory cytokine pro-interleukin-1β (IL-1β) into its mature form. To determine whether the inflammasome is involved in the host defense against M. canis infection, we challenged human monocytic THP-1 cells and mouse dendritic cells with a clinical strain of M. canis isolated from patients with tinea capitis. We found that M. canis infection triggered rapid secretion of IL-1β from both THP-1 cells and mouse dendritic cells. Moreover, by using gene-specific shRNA and competitive inhibitors, we determined that M. canis-induced IL-1β secretion was dependent on NLRP3. The pathways proposed for NLRP3 inflammasome activation, namely, cathepsin B activity, K+ efflux, and reactive oxygen species production, were all required for the inflammasome activation triggered by M. canis. Meanwhile, Syk, Dectin-1, and Card9 were found to be involved in M. canis-induced IL-1β secretion via regulation of pro-IL-1β transcription. More importantly, our data revealed that M. canis-induced production of IL-1β was dependent on the NLRP3 inflammasome in vivo. Together, this study unveils that the NLRP3 inflammasome exerts a critical role in host innate immune responses against M. canis infection, and our data suggest that diseases that result from M. canis infection might be controlled by regulating the activation of inflammasomes. PMID:24478101

  10. Lactic acid production from xylose by the fungus Rhizopus oryzae.

    PubMed

    Maas, Ronald H W; Bakker, Robert R; Eggink, Gerrit; Weusthuis, Ruud A

    2006-10-01

    Lignocellulosic biomass is considered nowadays to be an economically attractive carbohydrate feedstock for large-scale fermentation of bulk chemicals such as lactic acid. The filamentous fungus Rhizopus oryzae is able to grow in mineral medium with glucose as sole carbon source and to produce optically pure L(+)-lactic acid. Less is known about the conversion by R. oryzae of pentose sugars such as xylose, which is abundantly present in lignocellulosic hydrolysates. This paper describes the conversion of xylose in synthetic media into lactic acid by ten R. oryzae strains resulting in yields between 0.41 and 0.71 g g(-1). By-products were fungal biomass, xylitol, glycerol, ethanol and carbon dioxide. The growth of R. oryzae CBS 112.07 in media with initial xylose concentrations above 40 g l(-1) showed inhibition of substrate consumption and lactic acid production rates. In case of mixed substrates, diauxic growth was observed where consumption of glucose and xylose occurred subsequently. Sugar consumption rate and lactic acid production rate were significantly higher during glucose consumption phase compared to xylose consumption phase. Available xylose (10.3 g l(-1)) and glucose (19.2 g l(-1)) present in a mild-temperature alkaline treated wheat straw hydrolysate was converted subsequently by R. oryzae with rates of 2.2 g glucose l(-1) h(-1) and 0.5 g xylose l(-1) h(-1). This resulted mainly into the product lactic acid (6.8 g l(-1)) and ethanol (5.7 g l(-1)).

  11. Genomic insight into pathogenicity of dematiaceous fungus Corynespora cassiicola

    PubMed Central

    Looi, Hong Keat; Toh, Yue Fen; Yew, Su Mei; Na, Shiang Ling; Tan, Yung-Chie; Chong, Pei-Sin; Khoo, Jia-Shiun; Yee, Wai-Yan; Ng, Kee Peng

    2017-01-01

    Corynespora cassiicola is a common plant pathogen that causes leaf spot disease in a broad range of crop, and it heavily affect rubber trees in Malaysia (Hsueh, 2011; Nghia et al., 2008). The isolation of UM 591 from a patient’s contact lens indicates the pathogenic potential of this dematiaceous fungus in human. However, the underlying factors that contribute to the opportunistic cross-infection have not been fully studied. We employed genome sequencing and gene homology annotations in attempt to identify these factors in UM 591 using data obtained from publicly available bioinformatics databases. The assembly size of UM 591 genome is 41.8 Mbp, and a total of 13,531 (≥99 bp) genes have been predicted. UM 591 is enriched with genes that encode for glycoside hydrolases, carbohydrate esterases, auxiliary activity enzymes and cell wall degrading enzymes. Virulent genes comprising of CAZymes, peptidases, and hypervirulence-associated cutinases were found to be present in the fungal genome. Comparative analysis result shows that UM 591 possesses higher number of carbohydrate esterases family 10 (CE10) CAZymes compared to other species of fungi in this study, and these enzymes hydrolyses wide range of carbohydrate and non-carbohydrate substrates. Putative melanin, siderophore, ent-kaurene, and lycopene biosynthesis gene clusters are predicted, and these gene clusters denote that UM 591 are capable of protecting itself from the UV and chemical stresses, allowing it to adapt to different environment. Putative sterigmatocystin, HC-toxin, cercosporin, and gliotoxin biosynthesis gene cluster are predicted. This finding have highlighted the necrotrophic and invasive nature of UM 591. PMID:28149676

  12. Ethanol physiology in the warehouse-staining fungus, Baudoinia compniacensis.

    PubMed

    Ewaze, Juliet O; Summerbell, Richard C; Scott, James A

    2008-11-01

    The fungus Baudoinia compniacensis colonizes the exterior surfaces of a range of materials, such as buildings, outdoor furnishings, fences, signs, and vegetation, in regions subject to periodic exposure to low levels of ethanol vapour, such as those in the vicinity of distillery aging warehouses and commercial bakeries. Here we investigated the basis of ethanol metabolism in Baudoinia and investigate the role of ethanol in cell germination and growth. Germination of mycelia of Baudoinia was enhanced by up to roughly 1d exposure to low ethanol concentrations, optimally 10ppm when delivered in vapour form and 5mm in liquid form. However, growth was strongly inhibited following exposure to higher ethanol concentrations for shorter durations (e.g., 1.7m for 6h). We found that ethanol was catabolized into central metabolism via alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ACDH). Isocitrate dehydrogenases (IDHs) were active in cells grown on glucose, but these enzymes were not expressed when ethanol was provided as a sole or companion carbon source. The glyoxylate cycle enzymes isocitrate lyase (ICL) and malate synthase (MS) activities observed in cells grown on acetate were comparable to those reported for other microorganisms. By replenishing tricarboxylic acid (TCA) cycle intermediates, it is likely that the functionality of the glyoxylate cycle is important in the establishment of luxuriant growth of Baudoinia compniacensis on ethanol-exposed, nutrient-deprived, exposed surfaces. In other fungi, such as Saccharomyces cerevisiae, ADH II catalyses the conversion of ethanol to acetaldehyde, which then can be metabolized via the TCA cycle. ADH II is known to be strongly repressed in the presence of glucose.

  13. Five New Cytotoxic Metabolites from the Marine Fungus Neosartorya pseudofischeri

    PubMed Central

    Lan, Wen-Jian; Fu, Sheng-Jiao; Xu, Meng-Yang; Liang, Wan-Ling; Lam, Chi-Keung; Zhong, Guo-Hua; Xu, Jun; Yang, De-Po; Li, Hou-Jin

    2016-01-01

    The marine fungus Neosartorya pseudofischeri was isolated from Acanthaster planci from the South China Sea. In a preliminary bioactivity screening, the crude methanol extract of the fungal mycelia showed significant inhibitory activity against the Sf9 cell line from the fall armyworm Spodoptera frugiperda. Five novel compounds, including 5-olefin phenylpyropene A (1), 13-dehydroxylpyripyropene A (4), deacetylsesquiterpene (7), 5-formyl-6-hydroxy-8-isopropyl-2- naphthoic acid (9) and 6,8-dihydroxy-3-((1E,3E)-penta-1,3-dien-1-yl)isochroman-1-one (10), together with eleven known compounds, phenylpyropene A (2) and C (3), pyripyropene A (5), 7-deacetylpyripyropene A (6), (1S,2R,4aR,5R,8R,8aR)-1,8a-dihydroxy-2-acetoxy-3,8-dimethyl-5- (prop-1-en-2-yl)-1,2,4a, 5,6,7,8,8a-octahydronaphthalene (8), isochaetominine C (11), trichodermamide A (12), indolyl-3-acetic acid methyl ester (13), 1-acetyl-β-carboline (14), 1,2,3,4-tetrahydro-6-hydroxyl-2-methyl-l,3,4-trioxopyrazino[l,2-a]-indole (15) and fumiquinazoline F (16), were obtained. The structures of these compounds were determined mainly by MS and NMR data. The absolute configuration of 9 was assigned by the single-crystal X-ray diffraction studies. Compounds 1–11 and 15 showed significant cytotoxicity against the Sf9 cells from S. frugiperda. PMID:26771621

  14. Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species and concentration) and environmental effects (exposure duration and food availability) influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR) <1) compared to Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR < 1). The effect of increase in fungus concentration on larval mortality was influenced by spore clumping. One day exposure to fungal spores was found to be equally effective as seven days exposure. In different exposure time treatments 0 - 4.9% of the total larvae, exposed to fungus, showed infection at either the pupal or adult stage. Mortality rate increased with increasing larval density and amount of available food. Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional

  15. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

    SciTech Connect

    Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.; Suen, Garret; Tringe, Susannah G.; Adams, Sandra M.; Barry, Kerrie W.; Nicora, Carrie D.; Piehowski, Paul D.; Purvine, Samuel O.; Starrett, Gabriel J.; Goodwin, Lynne A.; Smith, Richard D.; Lipton, Mary S.; Currie, Cameron R.

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.

  16. The hidden habit of the entomopathogenic fungus Beauveria bassiana: first demonstration of vertical plant transmission.

    PubMed

    Quesada-Moraga, Enrique; López-Díaz, Cristina; Landa, Blanca Beatriz

    2014-01-01

    Beauveria bassiana strain 04/01-Tip, obtained from a larva of the opium poppy stem gall wasp Iraella luteipes (Hymenoptera; Cynipidae), endophytically colonizes opium poppy (Papaver somniferum L.) plants and protects them against this pest. The goal of this study was to monitor the dynamics of endophytic colonization of opium poppy by B. bassiana after the fungus was applied to the seed and to ascertain whether the fungus is transmitted vertically via seeds. Using a species-specific nested PCR protocol and DNA extracted from surface-sterilised leaf pieces or seeds of B. bassiana-inoculated opium poppy plants, the fungus was detected within the plant beginning at the growth stage of rosette building and them throughout the entire plant growth cycle (about 120-140 days after sowing). The fungus was also detected in seeds from 50% of the capsules sampled. Seeds that showed positive amplification for B. bassiana were planted in sterile soil and the endophyte was again detected in more than 42% of the plants sampled during all plant growth stages. Beauveria bassiana was transmitted to seeds in 25% of the plants from the second generation that formed a mature capsule. These results demonstrate for the first time the vertical transmission of an entomopathogenic fungus from endophytically colonised maternal plants. This information is crucial to better understand the ecological role of entomopathogenic fungi as plant endophytes and may allow development of a sustainable and cost effective strategy for I. luteipes management in P. somniferum.

  17. The nematophagous fungus Monacrosporium thaumasium and its nematicidal activity on Angiostrongylus vasorum.

    PubMed

    Soares, Filippe Elias de Freitas; Braga, Fabio Ribeiro; de Araújo, Jackson Victor; Lima, Walter dos Santos; de Queiroz, José Humberto

    2015-01-01

    The dog acts as a reservoir and environmental disseminator of potentially zoonotic parasites. The objective of this work was to study the fungus Monacrosporium thaumasium regarding its nematicidal potential in laboratory trials and its proteolytic profile. The in vitro test was carried out through two assays (A and B). In assay A, conidia of the fungus N34a were added in positive coprocultures for Angiostrongylus vasorum. In assay B, crude extract (treated group) and distilled water (control group) were added to coprocultures. Next, the proteolytic profile of crude extract of the nematophagous fungus M. thaumasium (NF34a) was revealed by performing a zymogram. There was a reduction (p<0.01) in the averages of larvae recovered from the treated groups (conidia and crude extract) in relation to control groups. The zymogram suggested that the nematophagous fungus M. thaumasium produces a protease of approximately 40 kDa. The results of this work confirm that the conidia as well as the crude extract of the fungus M. thaumasium may be used to control A. vasorum L1. The proteolytic profile suggested the presence of one protease (Mt1) of approximately 40 kDa that in the future may be used in biological control of L1 of this nematode. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  18. Fungus ball and emphysematous cystitis secondary to Candida tropicalis: A case report

    PubMed Central

    Wang, Lei; Ji, Xiang; Sun, Guo-feng; Qin, Ying-chao; Gong, Miao-zi; Zhang, Jin-xia; Li, Ning-chen; Na, Yan-qun

    2015-01-01

    Fungus ball and fungal emphysematous cystitis are two rare complications of fungal urinary tract infection. A 53-year-old male patient presented with these complications caused by Candida tropicalis simultaneously. The predisposing factors were diabetes mellitus and usage of broad-spectrum antibiotics. The fungus ball, measuring 3.5 × 2.0 cm on the left wall of the urinary bladder, shrank significantly to 1.6 × 0.8 cm after 5 days of intermittent irrigation with saline before surgery. With transurethral removal of the fungus ball and antifungal treatment with fluconazole, the patient fully recovered. We conclude that a bladder fungus ball and fungal emphysematous cystitis should always be suspected in patients with diabetes mellitus with uncontrolled funguria and abnormal imaging. Treatment should include a systemic antifungal therapy and thorough surgical removal of the fungus ball. A systemic antifungal therapy combined with a local irrigation with saline or antifungal drugs might help decrease the dissemination of fungemia during an invasive manipulation. PMID:26425243

  19. Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens.

    PubMed

    Aylward, Frank O; Burnum, Kristin E; Scott, Jarrod J; Suen, Garret; Tringe, Susannah G; Adams, Sandra M; Barry, Kerrie W; Nicora, Carrie D; Piehowski, Paul D; Purvine, Samuel O; Starrett, Gabriel J; Goodwin, Lynne A; Smith, Richard D; Lipton, Mary S; Currie, Cameron R

    2012-09-01

    Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant neotropical herbivores cultivate symbiotic fungus gardens on large quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers. Using metagenomic and metaproteomic techniques, we characterize the bacterial diversity and physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter and Escherichia. We show that these bacterial communities possess genes associated with lignocellulose degradation and diverse biosynthetic pathways, suggesting that they play a role in nutrient cycling by converting the nitrogen-poor forage of the ants into B-vitamins, amino acids and other cellular components. Our metaproteomic analysis confirms that bacterial glycosyl hydrolases and proteins with putative biosynthetic functions are produced in both field-collected and laboratory-reared colonies. These results are consistent with the hypothesis that fungus gardens are specialized fungus-bacteria communities that convert plant material into energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities in the ecology and evolution of herbivorous metazoans.

  20. The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation.

    PubMed

    Huang, Eric L; Aylward, Frank O; Kim, Young-Mo; Webb-Robertson, Bobbie-Jo M; Nicora, Carrie D; Hu, Zeping; Metz, Thomas O; Lipton, Mary S; Smith, Richard D; Currie, Cameron R; Burnum-Johnson, Kristin E

    2014-08-01

    Leaf-cutter ants are dominant herbivores in ecosystems throughout the Neotropics that feed on fungus gardens cultivated on fresh foliar biomass. Although recent investigations have shed light on how plant biomass is degraded in fungus gardens, the cycling of nutrients that takes place in these specialized microbial ecosystems is still not well understood. Here, using metabolomic and metaproteomic techniques, we examine the dynamics of nutrient turnover in these gardens. Our results reveal that numerous free amino acids and sugars are depleted throughout the process of biomass degradation, indicating that easily accessible nutrients from plant material are readily consumed by microbes in these ecosystems. Accumulation of cellobiose and lignin derivatives near the end of the degradation process is consistent with previous characterization of lignocellulases produced by the fungal cultivar of the ants. Our results also suggest that ureides may be an important source of nitrogen in fungus gardens, especially during nitrogen-limiting conditions. No free arginine was detected in our metabolomic experiments despite evidence that the host ants cannot produce this amino acid, suggesting that biosynthesis of this metabolite may be tightly regulated in fungus gardens. These results provide new insights into microbial community-level processes that underlie this important ant-fungus symbiosis.

  1. Potential for Nitrogen Fixation in the Fungus-Growing Termite Symbiosis

    PubMed Central

    Sapountzis, Panagiotis; de Verges, Jane; Rousk, Kathrin; Cilliers, Magdeleen; Vorster, Barend J.; Poulsen, Michael

    2016-01-01

    Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2 fixation in fungus-growing and other termites. PMID:28018322

  2. Effect of the oyster fungus on glycaemia and cholesterolaemia in rats with insulin-dependent diabetes.

    PubMed

    Chorváthová, V; Bobek, P; Ginter, E; Klvanová, J

    1993-01-01

    We have investigated the effect of a diet containing of 4% oyster fungus (Pleurotus ostreatus) and 0.1% cholesterol on glycaemia and hyperlipoproteinaemia in rats with insulin-dependent diabetes (streptozotocin 45 mg/kg). After two months, the rats with diabetes kept on the oyster fungus diet, had a significantly lower basal and postprandial glycaemia, the insulinaemia remained unchanged. The cholesterol concentration was decreased by more than 40%, the lipoprotein profile was upgraded by the decrease of the cholesterol in both the low density and very low density lipoproteins. The oyster fungus decreased the cholesterol accumulation in the liver and had no significant effects on the levels of serum and liver triacylglycerols.

  3. Transgenic assessment of CFP-mediated cercosporin export and resistance in a cercosporin-sensitive fungus.

    PubMed

    Upchurch, Robert G; Rose, Mark S; Eweida, Mohamed; Callahan, Terrence M

    2002-04-01

    Cercosporin is a toxic polyketide produced by many phytopathogenic members of the fungal genus Cercospora. Cercospora species, themselves, exhibit the highest level of self-resistance to this almost universally toxic photosensitizer. Although the mechanism of cercosporin self-resistance is multi-faceted, partial resistance does appear to be provided by the encoded product of CFP ( cercosporin facilitator protein), a gene recently isolated from the pathogen of soybean, C. kikuchii. CFP has significant similarity to the major facilitator superfamily of integral membrane transport proteins. We expressed CFP in the cercosporin non-producing, cercosporin-sensitive fungus, Cochliobolus heterostrophus, in order to assess the transport activity of CFP and the contribution of CFP to cercosporin resistance in a fungal species free of endogenous toxin production. Expression of the CFP transgene in this fungus results in increased resistance to cercosporin due, apparently, to its export out of the fungus.

  4. Comparative mitochondrial genomics toward exploring molecular markers in the medicinal fungus Cordyceps militaris.

    PubMed

    Zhang, Shu; Hao, Ai-Jing; Zhao, Yu-Xiang; Zhang, Xiao-Yu; Zhang, Yong-Jie

    2017-01-10

    Cordyceps militaris is a fungus used for developing health food, but knowledge about its intraspecific differentiation is limited due to lack of efficient markers. Herein, we assembled the mitochondrial genomes of eight C. militaris strains and performed a comparative mitochondrial genomic analysis together with three previously reported mitochondrial genomes of the fungus. Sizes of the 11 mitochondrial genomes varied from 26.5 to 33.9 kb mainly due to variable intron contents (from two to eight introns per strain). Nucleotide variability varied according to different regions with non-coding regions showing higher variation frequency than coding regions. Recombination events were identified between some locus pairs but seemed not to contribute greatly to genetic variations of the fungus. Based on nucleotide diversity fluctuations across the alignment of all mitochondrial genomes, molecular markers with the potential to be used for future typing studies were determined.

  5. Antifungal Depsidone Metabolites from Cordyceps dipterigena, an Endophytic Fungus Antagonistic to the Phytopathogen Gibberella fujikuroi

    PubMed Central

    Varughese, Titto; Riosa, Nivia; Higginbotham, Sarah; Arnold, A. Elizabeth; Coley, Phyllis D.; Kursar, Thomas A.; Gerwick, William H.; Cubilla Rios, L.

    2012-01-01

    Among thirty four endophytic fungal strains screened for in vitro antagonism, the endophytic fungus Cordyceps dipterigena was found to strongly inhibit mycelial growth of the plant pathogenic fungus Gibberella fujikuroi. Two new depsidone metabolites, cordycepsidone A (1) and cordycepsidone B (2), were isolated from the PDA culture extract of C. dipterigena and identified as being responsible for the antifungal activity. Elucidation of their chemical structures was carried out using 1D and 2D NMR spectroscopy in combination with IR and MS spectroscopic data. Cordycepsidone A displayed strong and dose-dependent antifungal activity against the plant pathogenic fungus Gibberella fujikuroi. The isolates were inactive in bioassays for malaria (Plasmodium falciparum), leishmaniasis (Leishmania donovani), Chagas’s disease (Trypanosoma cruzi), and cytotoxicity at 10 μg/mL. The compounds were also found to be inactive against several bacterial strains at 50 μg/mL. PMID:22707798

  6. Potential for Nitrogen Fixation in the Fungus-Growing Termite Symbiosis.

    PubMed

    Sapountzis, Panagiotis; de Verges, Jane; Rousk, Kathrin; Cilliers, Magdeleen; Vorster, Barend J; Poulsen, Michael

    2016-01-01

    Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues of research that may lead to a better understanding of N2 fixation in fungus-growing and other termites.

  7. The role of glycerol in the pathogenic lifestyle of the rice blast fungus Magnaporthe oryzae.

    PubMed

    Foster, Andrew J; Ryder, Lauren S; Kershaw, Michael J; Talbot, Nicholas J

    2017-03-01

    The rice blast fungus Magnaporthe oryzae elaborates a specialized cell called an appressorium, which is used to breach the tough outer cuticle of a rice leaf, enabling the fungus entry to host plant cells. The appressorium generates enormous turgor by accumulating glycerol to very high concentrations within the cell. Glycerol accumulation and melanization of the appressorium cell wall collectively drive turgor-mediated penetration of the rice leaf. In this review, we discuss the potential metabolic sources of glycerol in the rice blast fungus and how appressorium turgor is focused as physical force at the base of the infection cell, leading to the formation of a rigid penetration peg. We review recent studies of M. oryzae and other relevant appressorium-forming fungi which shed light on how glycerol is synthesized and how appressorium turgor is regulated. Finally, we provide some questions to guide avenues of future research that will be important in fully understanding the role of glycerol in rice blast disease.

  8. Sorption of cadmium, copper, and zinc onto soft coal and the fungus Rhizopus javanicus

    SciTech Connect

    Watts, H.D.; Chapman, S.K.

    1993-12-31

    Experiments involved testing the sorption properties of soft coal and the fungus Rhizopus javanicus to evaluate the feasibility of using these materials for acid mine reclamation. The metals cadmium, copper, and zinc were chosen since they are generally present in sulfide mine waste and are toxic. Their toxicity warrants their removal. To appropriate sulfide mine conditions, solutions of individual metals were prepared with concentrations between five and fifty milligrams/Liter and pH levels between three and seven. Results show forty to seventy percent metal removal for the fungus, and seventy-five to one-hundred percent removal by the coal. The pH of all the metal solutions equilibrated to between four and six when the fungus was used, and between five and seven for the coal. Sorption kinetics studies are currently underway and will be reported.

  9. Comparative mitochondrial genomics toward exploring molecular markers in the medicinal fungus Cordyceps militaris

    PubMed Central

    Zhang, Shu; Hao, Ai-Jing; Zhao, Yu-Xiang; Zhang, Xiao-Yu; Zhang, Yong-Jie

    2017-01-01

    Cordyceps militaris is a fungus used for developing health food, but knowledge about its intraspecific differentiation is limited due to lack of efficient markers. Herein, we assembled the mitochondrial genomes of eight C. militaris strains and performed a comparative mitochondrial genomic analysis together with three previously reported mitochondrial genomes of the fungus. Sizes of the 11 mitochondrial genomes varied from 26.5 to 33.9 kb mainly due to variable intron contents (from two to eight introns per strain). Nucleotide variability varied according to different regions with non-coding regions showing higher variation frequency than coding regions. Recombination events were identified between some locus pairs but seemed not to contribute greatly to genetic variations of the fungus. Based on nucleotide diversity fluctuations across the alignment of all mitochondrial genomes, molecular markers with the potential to be used for future typing studies were determined. PMID:28071691

  10. Advanced digital image analysis method dedicated to the characterization of the morphology of filamentous fungus.

    PubMed

    Hardy, N; Moreaud, M; Guillaume, D; Augier, F; Nienow, A; Béal, C; Ben Chaabane, F

    2017-02-06

    Filamentous fungi have a complex morphology that induces fermentation process development issues, as a consequence of viscosity increase and diffusion limitations. In order to better understand the relationship between viscosity changes and fungus morphology during fermentations of Trichoderma reesei, an accurate image analysis method has been developed to provide quantitative and representative data for morphological analysis. This method consisted of a new algorithm called FACE that allowed sharp images to be created at all positions, segmentation of fungus, and morphological analysis using skeleton and topological approaches. It was applied and validated by characterizing samples of an industrial strain of Trichoderma reesei that had or had not been exposed to an extreme shear stress. This method allowed many morphological characteristics to be identified, among which nine relevant criteria were extracted, regarding the impact of shear stress on the fungus and on the viscosity of the fermentation medium.

  11. A case of fungus ball type pansinusitis caused by Schizophillum commune.

    PubMed

    Nazeri, Mehdi; Mohammadi Ardehali, Mojtaba; Moazeni, Maryam; Jamal Hashemi, Seyed; Fallahi, Ali Akbar; Ehteram, Hassan; Rezaie, Sassan

    2012-01-01

    Schizophillum commune has been increasingly reported from allergic bronchopulmonary mycosis (ABPM) as well as fungus ball, brain abscess and several cases of maxillary or allergic fungal sinusitis. In the present study, we reported a case of fungus ball type pansinusitis from a 32-year-old woman in Iran. According to computed tomography (CT) scan, fungus ball type pan-sinusitis was likely to be the first diagnosis. Mycological examination revealed hyaline hyphae with small projection and also clamp connection structures on PDA medium. To identify the obtained isolate properly, molecular analysis of the internal transcribed spacer region was performed and indicated that the causing agent of the infection is surely Schizophillum commune. The patient completely recovered after surgical endoscopic operation and consequent post-operation MRI revealed clearance of sinuses.

  12. A case of fungus ball type pansinusitis caused by Schizophillum commune

    PubMed Central

    Nazeri, Mehdi; Mohammadi Ardehali, Mojtaba; Moazeni, Maryam; Jamal Hashemi, Seyed; Fallahi, Ali akbar; Ehteram, Hassan; Rezaie, Sassan

    2012-01-01

    Schizophillum commune has been increasingly reported from allergic bronchopulmonary mycosis (ABPM) as well as fungus ball, brain abscess and several cases of maxillary or allergic fungal sinusitis. In the present study, we reported a case of fungus ball type pansinusitis from a 32-year-old woman in Iran. According to computed tomography (CT) scan, fungus ball type pan-sinusitis was likely to be the first diagnosis. Mycological examination revealed hyaline hyphae with small projection and also clamp connection structures on PDA medium. To identify the obtained isolate properly, molecular analysis of the internal transcribed spacer region was performed and indicated that the causing agent of the infection is surely Schizophillum commune. The patient completely recovered after surgical endoscopic operation and consequent post-operation MRI revealed clearance of sinuses. PMID:24371755

  13. Fungus symbionts colonizing the galleries of the ambrosia beetle Platypus quercivorus.

    PubMed

    Endoh, Rikiya; Suzuki, Motofumi; Okada, Gen; Takeuchi, Yuko; Futai, Kazuyoshi

    2011-07-01

    Isolations were made to determine the fungal symbionts colonizing Platypus quercivorus beetle galleries of dead or dying Quercus laurifolia, Castanopsis cuspidata, Quercus serrata, Quercus crispula, and Quercus robur. For these studies, logs from oak wilt-killed trees were collected from Kyoto Prefecture, Japan. Fungi were isolated from the: (1) entrances of beetle galleries, (2) vertical galleries, (3) lateral galleries, and (4) the larval cradle of P. quercivorus in each host tree. Among the fungus colonies which appeared on YM agar plates, 1,219 were isolated as the representative isolates for fungus species inhabiting in the galleries based on their cultural characteristics. The validity of the visual classification of the fungus colonies was checked and if necessary properly corrected using microsatellite-primed PCR fingerprints. The nucleotide sequence of the D1/D2 region of the large subunit nuclear rRNA gene detected 38 fungus species (104 strains) of which three species, i.e., Candida sp. 3, Candida kashinagacola (both yeasts), and the filamentous fungus Raffaelea quercivora were isolated from all the tree species. The two yeasts were most prevalent in the interior of galleries, regardless of host tree species, suggesting their close association with the beetle. A culture-independent method, terminal restriction fragment length polymorphism (T-RFLP) analysis was also used to characterize the fungus flora of beetle galleries. T-RFLP patterns showed that yeast species belonging to the genus Ambrosiozyma frequently occurred on the gallery walls along with the two Candida species. Ours is the first report showing the specific fungi inhabiting the galleries of a platypodid ambrosia beetle.

  14. Effects of different ratios of pig manure to fungus residue on physicochemical parameters during composting.

    PubMed

    Zhou, Jiangming; Wang, Litong; Wang, Houming; Jiang, Long; Jiang, Xinyou

    2016-05-01

    This study examined physicochemical parameters to assess their effectiveness as stability and maturity indicators during the process of composting pig manure and fungus residue at different ratios. The results showed that composting mixtures with all ratios of pig manure to fungus residue maintained a temperature exceeding 50 °C for more than 10 days during composting and met the requirement for pathogen destruction. The treatment containing mainly pig manure showed higher nitrogen loss and a shorter thermophilic phase and maturity time than the treatment containing mainly fungus residue. The germination index (GI) values indicated that compost maturity was achieved in the final compost with initial ratios of pig manure to fungus residue of 9:1-7:3 (GIs of 101.4%, 91.2%, and 81.3%); the ratio of 6:4 did not reach compost maturity (GI of 63.8%) and had an inhibitory effect on seed germination. The results of this study suggest that a ratio of pig manure to fungus residue of approximately 8:2 can be considered suitable for the efficient and quality composting of pig manure and fungus residue. Co-composting of pig manure and edible fungi residue with appropriate proportion can effectively reduce the risk of environmental pollution caused by agricultural wastes, as well as achieve a safer and high-quality organic fertilizer, which can be used to improve physical and chemical properties of the soil, increase crop yields, and promote agricultural sustainable development. Therefore, technique of co-composting of pig manure and edible fungi residue has a wide prospect of application in practical production all over the world.

  15. Extraction of DNA from plant and fungus tissues in situ

    PubMed Central

    2012-01-01

    Background When samples are collected in the field and transported to the lab, degradation of the nucleic acids contained in the samples is frequently observed. Immediate extraction and precipitation of the nucleic acids reduces degradation to a minimum, thus preserving accurate sequence information. An extraction method to obtain high quality DNA in field studies is described. Findings DNA extracted immediately after sampling was compared to DNA extracted after allowing the sampled tissues to air dry at 21°C for 48 or 72 hours. While DNA extracted from fresh tissues exhibited little degradation, DNA extracted from all tissues exposed to 21°C air for 48 or 72 hours exhibited varying degrees of degradation. Yield was higher for extractions from fresh tissues in most cases. Four microcentrifuges were compared for DNA yield: one standard electric laboratory microcentrifuge (max rcf = 16,000×g), two battery-operated microcentrifuges (max rcf = 5,000 and 3,000 ×g), and one manually-operated microcentrifuge (max rcf = 120×g). Yields for all centrifuges were similar. DNA extracted under simulated field conditions was similar in yield and quality to DNA extracted in the laboratory using the same equipment. Conclusions This CTAB (cetyltrimethylammonium bromide) DNA extraction method employs battery-operated and manually-operated equipment to isolate high quality DNA in the field. The method was tested on plant and fungus tissues, and may be adapted for other types of organisms. The method produced high quality DNA in laboratory tests and under simulated field conditions. The field extraction method should prove useful for working in remote sites, where ice, dry ice, and liquid nitrogen are unavailable; where degradation is likely to occur due to the long distances between the sample site and the laboratory; and in instances where other DNA preservation and transportation methods have been unsuccessful. It may be possible to adapt this method for genomic

  16. Temperature Modulates the Secretome of the Phytopathogenic Fungus Lasiodiplodia theobromae

    PubMed Central

    Félix, Carina; Duarte, Ana S.; Vitorino, Rui; Guerreiro, Ana C. L.; Domingues, Pedro; Correia, António C. M.; Alves, Artur; Esteves, Ana C.

    2016-01-01

    Environmental alterations modulate host–microorganism interactions. Little is known about how climate changes can trigger pathogenic features on symbiont or mutualistic microorganisms. Current climate models predict increased environmental temperatures. The exposing of phytopathogens to these changing conditions can have particularly relevant consequences for economically important species and for humans. The impact on pathogen/host interaction and the shift on their biogeographical range can induce different levels of virulence in new hosts, allowing massive losses in agricultural and health fields. Lasiodiplodia theobromae is a phytopathogenic fungus responsible for a number of diseases in various plants. It has also been described as an opportunist pathogen in humans, causing infections with different levels of severity. L. theobromae has a high capacity of adaptation to different environments, such as woody plants, moist argillaceous soils, or even humans, being able to grow and infect hosts in a wide range of temperatures (9–39°C). Nonetheless, the effect of an increase of temperature, as predicted in climate change models, on L. theobromae is unknown. Here we explore the effect of temperature on two strains of L. theobromae – an environmental strain, CAA019, and a clinical strain, CBS339.90. We show that both strains are cytotoxic to mammalian cells but while the environmental strain is cytotoxic mainly at 25°C, the clinical strain is cytotoxic mainly at 30 and 37°C. Extracellular gelatinolytic, xylanolytic, amylolytic, and cellulolytic activities at 25 and 37°C were characterized by zymography and the secretome of both strains grown at 25, 30, and 37°C were characterized by electrophoresis and by Orbitrap LC-MS/MS. More than 75% of the proteins were identified, mostly enzymes (glycosyl hydrolases and proteases). The strains showed different protein profiles, which were affected by growth temperature. Also, strain specific proteins were identified

  17. Temperature Modulates the Secretome of the Phytopathogenic Fungus Lasiodiplodia theobromae.

    PubMed

    Félix, Carina; Duarte, Ana S; Vitorino, Rui; Guerreiro, Ana C L; Domingues, Pedro; Correia, António C M; Alves, Artur; Esteves, Ana C

    2016-01-01

    Environmental alterations modulate host-microorganism interactions. Little is known about how climate changes can trigger pathogenic features on symbiont or mutualistic microorganisms. Current climate models predict increased environmental temperatures. The exposing of phytopathogens to these changing conditions can have particularly relevant consequences for economically important species and for humans. The impact on pathogen/host interaction and the shift on their biogeographical range can induce different levels of virulence in new hosts, allowing massive losses in agricultural and health fields. Lasiodiplodia theobromae is a phytopathogenic fungus responsible for a number of diseases in various plants. It has also been described as an opportunist pathogen in humans, causing infections with different levels of severity. L. theobromae has a high capacity of adaptation to different environments, such as woody plants, moist argillaceous soils, or even humans, being able to grow and infect hosts in a wide range of temperatures (9-39°C). Nonetheless, the effect of an increase of temperature, as predicted in climate change models, on L. theobromae is unknown. Here we explore the effect of temperature on two strains of L. theobromae - an environmental strain, CAA019, and a clinical strain, CBS339.90. We show that both strains are cytotoxic to mammalian cells but while the environmental strain is cytotoxic mainly at 25°C, the clinical strain is cytotoxic mainly at 30 and 37°C. Extracellular gelatinolytic, xylanolytic, amylolytic, and cellulolytic activities at 25 and 37°C were characterized by zymography and the secretome of both strains grown at 25, 30, and 37°C were characterized by electrophoresis and by Orbitrap LC-MS/MS. More than 75% of the proteins were identified, mostly enzymes (glycosyl hydrolases and proteases). The strains showed different protein profiles, which were affected by growth temperature. Also, strain specific proteins were identified, such

  18. Cytotoxic effects of oosporein isolated from endophytic fungus Cochliobolus kusanoi

    PubMed Central

    Ramesha, Alurappa; Venkataramana, M.; Nirmaladevi, Dhamodaran; Gupta, Vijai K.; Chandranayaka, S.; Srinivas, Chowdappa

    2015-01-01

    In the present study, oosporein, a fungal toxic secondary metabolite known to be a toxic agent causing chronic disorders in animals, was isolated from fungus Cochliobolus kusanoi of Nerium oleander L. Toxic effects of oosporein and the possible mechanisms of cytotoxicity as well as the role of oxidative stress in cytotoxicity to Madin-Darby canine kidney kidney cells and RAW 264.7 splene cells were evaluated in vitro. Also to know the possible in vivo toxic effects of oosporein on kidney and spleen, Balb/C mouse were treated with different concentrations of oosporein ranging from 20 to 200 μM). After 24 h of exposure histopathological observations were made to know the effects of oosporein on target organs. Oosporein induced elevated levels of reactive oxygen species (ROS) generation and high levels of malondialdehyde, loss of mitochondrial membrane potential, induced glutathione hydroxylase (GSH) production was observed in a dose depended manner. Effects oosporein on chromosomal DNA damage was assessed by Comet assay, and increase in DNA damage were observed in both the studied cell lines by increasing the oosporein concentration. Further, oosporein treatment to studied cell lines indicated significant suppression of oxidative stress related gene (Superoxide dismutase1 and Catalase ) expression, and increased levels of mRNA expression in apoptosis or oxidative stress inducing genes HSP70, Caspase3, Caspase6, and Caspase9 as measured by quantitative real time-PCR assay. Histopathological examination of oosporein treated mouse kidney and splenocytes further revealed that, oosporein treated target mouse tissues were significantly damaged with that of untreated sam control mice and these effects were in directly proportional to the the toxin dose. Results of the present study reveals that, ROS is the principle event prompting increased oosporein toxicity in studied in vivio and in vitro animal models. The high previlance of these fungi in temperate climates further

  19. Transcriptional responses in Honey Bee larvae infected with chalkbrood fungus

    PubMed Central

    2010-01-01

    Background Diseases and other stress factors working synergistically weaken honey bee health and may play a major role in the losses of bee populations in recent years. Among a large number of bee diseases, chalkbrood has been on the rise. We present here the experimental identification of honey bee genes that are differentially expressed in response to infection of honey bee larvae with the chalkbrood fungus, Ascosphaera apis. Results We used cDNA-AFLP ®Technology to profile transcripts in infected and uninfected bee larvae. From 64 primer combinations, over 7,400 transcriptionally-derived fragments were obtained A total of 98 reproducible polymorphic cDNA-AFLP fragments were excised and sequenced, followed by quantitative real-time RT-PCR (qRT-PCR) analysis of these and additional samples. We have identified a number of differentially-regulated transcripts that are implicated in general mechanisms of stress adaptation, including energy metabolism and protein transport. One of the most interesting differentially-regulated transcripts is for a chitinase-like enzyme that may be linked to anti-fungal activities in the honey bee larvae, similarly to gut and fat-body specific chitinases found in mosquitoes and the red flour beetle. Surprisingly, we did not find many components of the well-characterized NF-κB intracellular signaling pathways to be differentially-regulated using the cDNA-AFLP approach. Therefore, utilizing qRT-PCR, we probed some of the immune related genes to determine whether the lack of up-regulation of their transcripts in our analysis can be attributed to lack of immune activation or to limitations of the cDNA-AFLP approach. Conclusions Using a combination of cDNA-AFLP and qRT-PCR analyses, we were able to determine several key transcriptional events that constitute the overall effort in the honey bee larvae to fight natural fungal infection. Honey bee transcripts identified in this study are involved in critical functions related to

  20. Do novel genotypes drive the success of an invasive bark beetle–fungus complex? Implications for potential reinvasion

    Treesearch

    Min Lu; Michael J. Wingfield; Nancy Gillette; Jiang-Hua Sun

    2011-01-01

    Novel genotypes often arise during biological invasions, but their role in invasion success has rarely been elucidated. Here we examined the population genetics and behavior of the fungus, Leptographium procerum, vectored by a highly invasive bark beetle, Dendroctonus valens, to determine whether genetic changes in the fungus...

  1. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    EPA Science Inventory

    The white-rot fungus Phanrochaete chrysosporium has the ability to degrade a wide variety of structurally diverse organic compounds, including a number of environmentally persistent organopollutants. The unique biodegradative abilities of this fungus appears to be depend...

  2. Symbiosis-regulated expression of an acetyl-CoA acetyltransferase gene in the ectomycorrhizal fungus Laccaria bicolor

    Treesearch

    Shiv T. Hiremath; Sujata Balasubramanian; Jun Zheng; Gopi K. Podila

    2006-01-01

    The ectomycorrhiza is a symbiotic organ generated from the intricate association of fungal hyphae and plant root. The establishment of the ectomycorrhiza is a coordinated process of cross-talk between plant and fungus, followed by metabolic, developmental, and structural changes in the fungus, resulting in its growth toward the root. The initial stages of the symbiotic...

  3. Seasonal prevalence of the insect pathogenic fungus Colletotrichum nymphaeae in Brazilian citrus groves under different chemical pesticide regimes

    USDA-ARS?s Scientific Manuscript database

    In a field study, we identified an endemic fungal entomopathogen, known as the 'salmão' fungus infecting populations of citrus scale, Praelongorthezia praelonga Douglas. The identification of this fungus is close to Colletotrichum nymphaeae (Sordariomycetes: Glomerellales) based on morphological sim...

  4. Genetic diversity and population structure of Raffaelea quercus-mongolicae, a fungus associated with oak mortality in South Korea

    Treesearch

    M. -S. Kim; P. A. Hohenlohe; K. -H. Kim; S. -T. Seo; Ned Klopfenstein

    2016-01-01

    Raffaelea quercus-mongolicae is a fungus associated with oak wilt and deemed to cause extensive oak mortality in South Korea. Since the discovery of this fungus on a dead Mongolian oak (Quercus mongolica) in 2004, the mortality continued to spread southwards in South Korea. Despite continued expansion of the disease and associated significant impacts on forest...

  5. Fingerprints of a forest fungus: Swiss needle cast, carbon isotopes, carbohydrates, and growth in Douglas-fir

    Treesearch

    Andrea Watts; Frederick Meinzer; Brandy J. Saffell

    2014-01-01

    Swiss needle cast is caused by a fungus native to the Pacific Northwest. Its host is Douglas-fir, an iconic evergreen tree in the region. The fungus does not kill its host, but it adversely affects the tree's growth. The fungal fruiting bodies block the stomata, small openings on the underside of the needle where carbon dioxide, water vapor, and other gases are...

  6. Characterization and host range of the symbiotic fungus Fusarium euwallaceae sp. nov., vectored by the invasive ambrosia beetle Euwallacea sp.

    USDA-ARS?s Scientific Manuscript database

    A novel symbiotic Fusarium euwallaceae fungus that serves as a specific nutritional source for the invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) is farmed in the galleries of host plants. This beetle-fungus complex, which has invaded Israel and California, is clo...

  7. Effect of fungus gnat Bradysia impatiens (Diptera: Sciaridae) feeding on subsequent Pythium aphanidermatum infection of geranium seedlings (Pelargonium x hortorum)

    USDA-ARS?s Scientific Manuscript database

    Dark-winged fungus gnats in the genus Bradysia (Diptera: Sciaridae) and root rot pathogens in the genus Pythium (Oomycetes) are important pests of greenhouse floriculture. Observations have pointed to a possible correlation between Pythium root rot disease and fungus gnat infestations; however, inte...

  8. Biological control of horse cyathostomin (Nematoda: Cyathostominae) using the nematophagous fungus Duddingtonia flagrans in tropical southeastern Brazil.

    PubMed

    Braga, Fabio Ribeiro; Araújo, Jackson Victor; Silva, André Ricardo; Araujo, Juliana Milani; Carvalho, Rogério Oliva; Tavela, Alexandre Oliveira; Campos, Artur Kanadani; Carvalho, Giovanni Ribeiro

    2009-08-26

    The viability of a fungal formulation using the nematode-trapping fungus Duddingtonia flagrans was assessed for the biological control of horse cyathostomin. Two groups (fungus-treated and control without fungus treatment), consisting of eight crossbred mares (3-18 years of age) were fed on Cynodon sp. pasture naturally infected with equine cyathostome larvae. Each animal of the treated group received oral doses of sodium alginate mycelial pellets (1g/(10 kg live weight week)), during 6 months. Significant reduction (p<0.01) in the number of eggs per gram of feces and coprocultures was found for animals of the fungus-treated group compared with the control group. There was difference (p<0.01) of 78.5% reduction in herbage samples collected up to (0-20 cm) between the fungus-treated group and the control group, during the experimental period (May-October). Difference of 82.5% (p<0.01) was found between the fungus-treated group and the control group in the sampling distance (20-40 cm) from fecal pats. During the last 3 months of the experimental period (August, September and October), fungus-treated mares had significant weight gain (p<0.01) compared with the control group, an increment of 38 kg. The treatment with sodium alginate pellets containing the nematode-trapping fungus D. flagrans reduced cyathostomin in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode in horses.

  9. Draft Genome Sequence of Two Monosporidial Lines of the Karnal Bunt Fungus Tilletia indica Mitra (PSWKBGH-1 and PSWKBGH-2)

    PubMed Central

    Sharma, Pradeep; Saharan, M. S.; Sharma, Indu; Kumar, Jitender; Mishra, Shefali; Muthusamy, Senthilkumar K.; Gupta, R. K.; Jaiswal, Sarika; Iquebal, M. A.; Angadi, U. B.; Kumar, Neeraj; Fatma, Samar; Rai, Anil; Kumar, Dinesh

    2016-01-01

    Karnal bunt disease caused by the fungus Tilletia indica Mitra is a serious concern due to strict quarantines affecting international trade of wheat. We announce here the first draft assembly of two monosporidial lines, PSWKBGH-1 and -2, of this fungus, having approximate sizes of 37.46 and 37.21 Mbp, respectively. PMID:27634992

  10. Speciation despite globally overlapping distributions in Penicillium chrysogenum: the population genetics of Alexander Fleming’s lucky fungus

    USDA-ARS?s Scientific Manuscript database

    Eighty years ago, Alexander Fleming described the antibiotic effects of a fungus that had contaminated his bacterial culture, kick starting the antimicrobial revolution. The fungus was later ascribed to a globally distributed asexual species, Penicillium chrysogenum. Recently, the species has been...

  11. The most relictual fungus-farming ant species cultivates the most recently evolved and highly domesticated fungal symbiont species.

    PubMed

    Schultz, Ted R; Sosa-Calvo, Jeffrey; Brady, Seán G; Lopes, Cauê T; Mueller, Ulrich G; Bacci, Mauricio; Vasconcelos, Heraldo L

    2015-05-01

    Fungus-farming (attine) ant agriculture is made up of five known agricultural systems characterized by remarkable symbiont fidelity in which five phylogenetic groups of ants faithfully cultivate five phylogenetic groups of fungi. Here we describe the first case of a lower-attine ant cultivating a higher-attine fungus based on our discovery of a Brazilian population of the relictual fungus-farming ant Apterostigma megacephala, known previously from four stray specimens from Peru and Colombia. We find that A. megacephala is the sole surviving representative of an ancient lineage that diverged ∼39 million years ago, very early in the ∼55-million-year evolution of fungus-farming ants. Contrary to all previously known patterns of ant-fungus symbiont fidelity, A. megacephala cultivates Leucoagaricus gongylophorus, a highly domesticated fungal cultivar that originated only 2-8 million years ago in the gardens of the highly derived and recently evolved (∼12 million years ago) leaf-cutting ants. Because no other lower fungus-farming ant is known to cultivate any of the higher-attine fungi, let alone the leaf-cutter fungus, A. megacephala may provide important clues about the biological mechanisms constraining the otherwise seemingly obligate ant-fungus associations that characterize attine ant agriculture.

  12. Complete Genome of Serratia sp. Strain FGI 94, a Strain Associated with Leaf-Cutter Ant Fungus Gardens.

    PubMed

    Aylward, Frank O; Tremmel, Daniel M; Starrett, Gabriel J; Bruce, David C; Chain, Patrick; Chen, Amy; Davenport, Karen W; Detter, Chris; Han, Cliff S; Han, James; Huntemann, Marcel; Ivanova, Natalia N; Kyrpides, Nikos C; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Teshima, Hazuki; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja; Currie, Cameron R

    2013-03-14

    Serratia sp. strain FGI 94 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its 4.86-Mbp chromosome will help advance our knowledge of symbiotic interactions and plant biomass degradation in this ancient ant-fungus mutualism.

  13. Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens.

    PubMed

    Aylward, Frank O; Tremmel, Daniel M; Bruce, David C; Chain, Patrick; Chen, Amy; Walston Davenport, Karen; Detter, Chris; Han, Cliff S; Han, James; Huntemann, Marcel; Ivanova, Natalia N; Kyrpides, Nikos C; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja; Currie, Cameron R

    2013-01-01

    The Enterobacteriaceae bacterium strain FGI 57 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its single 4.76-Mbp chromosome will shed light on community dynamics and plant biomass degradation in ant fungus gardens.

  14. Phytotoxins produced by fungi associated with grapevine trunk diseases.

    PubMed

    Andolfi, Anna; Mugnai, Laura; Luque, Jordi; Surico, Giuseppe; Cimmino, Alessio; Evidente, Antonio

    2011-12-01

    Up to 60 species of fungi in the Botryosphaeriaceae family, genera Cadophora, Cryptovalsa, Cylindrocarpon, Diatrype, Diatrypella, Eutypa, Eutypella, Fomitiporella, Fomitiporia, Inocutis, Phaeoacremonium and Phaeomoniella have been isolated from decline-affected grapevines all around the World. The main grapevine trunk diseases of mature vines are Eutypa dieback, the esca complex and cankers caused by the Botryospheriaceae, while in young vines the main diseases are Petri and black foot diseases. To understand the mechanism of these decline-associated diseases and the symptoms associated with them, the toxins produced by the pathogens involved in these diseases were isolated and characterised chemically and biologically. So far the toxins of only a small number of these decline fungi have been studied. This paper presents an overview of the toxins produced by the most serious of these vine wood pathogens: Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and some taxa in the Botryosphaeriaceae family, and examines how these toxins produce decline symptoms. The chemical structure of these metabolites and in some cases their vivotoxin nature are also discussed.

  15. Phytotoxins Produced by Fungi Associated with Grapevine Trunk Diseases

    PubMed Central

    Andolfi, Anna; Mugnai, Laura; Luque, Jordi; Surico, Giuseppe; Cimmino, Alessio; Evidente, Antonio

    2011-01-01

    Up to 60 species of fungi in the Botryosphaeriaceae family, genera Cadophora, Cryptovalsa, Cylindrocarpon, Diatrype, Diatrypella, Eutypa, Eutypella, Fomitiporella, Fomitiporia, Inocutis, Phaeoacremonium and Phaeomoniella have been isolated from decline-affected grapevines all around the World. The main grapevine trunk diseases of mature vines are Eutypa dieback, the esca complex and cankers caused by the Botryospheriaceae, while in young vines the main diseases are Petri and black foot diseases. To understand the mechanism of these decline-associated diseases and the symptoms associated with them, the toxins produced by the pathogens involved in these diseases were isolated and characterised chemically and biologically. So far the toxins of only a small number of these decline fungi have been studied. This paper presents an overview of the toxins produced by the most serious of these vine wood pathogens: Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and some taxa in the Botryosphaeriaceae family, and examines how these toxins produce decline symptoms. The chemical structure of these metabolites and in some cases their vivotoxin nature are also discussed. PMID:22295177

  16. Superoxide dismutase transgenes in sugarbeets confer resistance to oxidative agents and the fungus C. beticola.

    PubMed

    Tertivanidis, Konstantinos; Goudoula, Catherine; Vasilikiotis, Christos; Hassiotou, Efthymia; Perl-Treves, Rafael; Tsaftaris, Athanasios

    2004-06-01

    Sugarbeets carrying superoxide dismutase transgenes were developed in order to investigate the possibility of enhancing their resistance to oxidative stress. Binary T-DNA vectors carrying the chloroplastic and cytosolic superoxide dismutase genes from tomato, were used for Agrobacterium-mediated transformation of sugarbeet petioles. The transgenic plants were subjected to treatments known to cause oxidative stress, such as the herbicide methyl viologen and a natural photosensitizer toxin produced by the fungus Cercospora beticola, namely cercosporin. The transgenic plants exhibited increased tolerance to methyl viologen, to pure cercosporin, as well as to leaf infection with the fungus C. beticola.

  17. Process for producing ethanol from plant biomass using the fungus Paecilomyces sp

    DOEpatents

    Wu, J.F.

    1985-08-08

    A process for producing ethanol from plant biomass is disclosed. The process includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the fungus Paecilomyces which has the ability to ferment both cellobiose and xylose to ethanol is then selected and isolated. The substrate is inoculated with this fungus, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. Finally, ethanol is recovered from the fermented substrate. 5 figs., 3 tabs.

  18. Process for producing ethanol from plant biomass using the fungus paecilomyces sp.

    DOEpatents

    Wu, Jung Fu

    1989-01-01

    A process for producing ethanol from plant biomass is disclosed. The process in cludes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the fungus Paecilomyces, which has the ability to ferment both cellobiose and xylose to ethanol, is then selected and isolated. The substrate is inoculated with this fungus, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. Finally, ethanol is recovered from the fermented substrate.

  19. Laboratory evaluation of three strains of the entomopathogenic fungus Metarhizium anisopliae for controlling Dermanyssus gallinae.

    PubMed

    Tavassoli, M; Ownag, A; Pourseyed, S H; Mardani, K

    2008-06-01

    The pathogenicity of three strains of the entomopathogenic fungus Metarhizium anisopliae on different life stages of Dermanyssus gallinae was evaluated in the laboratory. All the strains tested were virulent to D. gallinae but pathogenicity varied among the strains. Strain V245 induced a higher mortality rate using different concentrations than other two strains. The estimated median lethal concentration of different strains of M. anisopliae against D. gallinae varied depending on the exposure time of D. gallinae to M. anisopliae. It was concluded that the pathogenicity of the entomopathogenic fungus M. anisopliae on different life stages of D. gallinae was concentration and time dependent.

  20. Regulation of the growth of cotton bollworms by metabolites from an entomopathogenic fungus Paecilomyces cateniobliquus.

    PubMed

    Wu, Hong-Yang; Wang, Yan-Li; Tan, Jian-Lin; Zhu, Chun-Yan; Li, Dong-Xian; Huang, Rong; Zhang, Ke-Qin; Niu, Xue-Mei

    2012-06-06

    Chemical investigation of one entomopathogenic fungus Paecilomyces cateniobliquus YMF1.01799 led to the isolation and identification of six metabolites, which include three new compounds (2-3, and 5) and three known metabolites. Their structures were established by spectroscopic studies such as 1D and 2D NMR and MS analysis. Insect growth experiments suggested that polyketide-derived compound 1 showed significant inhibitory effect on the growth of cotton bollworm Helicoverpa armigera, while terpenoid-derived metabolite 5 promoted the growth of the larvae. The findings revealed that the entomopathogenic fungus P. cateniobliquus could produce different types of metabolites to regulate growth of the insect.

  1. The research of using Co-60 γ ray to sterilize different mediums for edible fungus

    NASA Astrophysics Data System (ADS)

    Guozhu, Li; Zhenqian, Guan; Hengshou, Zhao

    1993-10-01

    The present experiment has been carried out by using different dosage of Co—60 γ ray for radiation sterilization of five kinds of cultural materials of edible fungus, The results indicated that sterilization dosage of sawdust is 22 kGy. that of cotton—seed shell and the rest are 26 kGy. We conclude that using Co-60 γ ray to sterilize the cultura 1 materials of edible fungus is a secure and saving labor and energy new method which could sterilize thoroughly.

  2. Labeling of Peroxisomes for Live Cell Imaging in the Filamentous Fungus Ustilago maydis.

    PubMed

    Guimarães, Sofia C; Kilaru, Sreedhar; Schrader, Michael; Schuster, Martin

    2017-01-01

    The basidiomycete fungus Ustilago maydis has emerged as a powerful model organism to study fundamental biological processes. U. maydis shares many important features with human cells but provides the technical advantages of yeast. Recently, U. maydis has also been used to investigate fundamental processes in peroxisome biology. Here, we present an efficient yeast recombination-based cloning method to construct and express fluorescent fusion proteins (or conditional mutant protein alleles) which target peroxisomes in the fungus U. maydis. In vivo analysis is pivotal for understanding the underlying mechanisms of organelle motility. We focus on the in vivo labeling of peroxisomes in U. maydis and present approaches to analyze peroxisomal motility.

  3. The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus.

    PubMed

    Lötters, Stefan; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Veith, Michael; Walker, Susan F; Fisher, Matthew C; Rödder, Dennis

    2009-09-01

    Amphibians are globally declining and approximately one-third of all species are threatened with extinction. Some of the most severe declines have occurred suddenly and for unknown reasons in apparently pristine habitats. It has been hypothesized that these "rapid enigmatic declines" are the result of a panzootic of the disease chytridiomycosis caused by globally emerging amphibian chytrid fungus. In a Species Distribution Model, we identified the potential distribution of this pathogen. Areas and species from which rapid enigmatic decline are known significantly overlap with those of highest environmental suitability to the chytrid fungus. We confirm the plausibility of a link between rapid enigmatic decline in worldwide amphibian species and epizootic chytridiomycosis.

  4. Bio-liquefaction/solubilization of lignitic humic acids by white-rot fungus (Phanerochaete chrysosporium)

    SciTech Connect

    Elbeyli, I.Y.; Palantoken, A.; Piskin, S.; Peksel, A.; Kuzu, H.

    2006-08-15

    Humic acid samples obtained from lignite were liquefied/solubilized by using white-rot fungus, and chemical characterization of the products was investigated by FTIR and GC-MS techniques. Prior to the microbial treatment, raw lignite was oxidized with hydrogen peroxide and nitric acid separately, and then humic acids were extracted by alkali solution. The prepared humic acid samples were placed on the agar surface of the fungus and liquid products formed by microbial affects were collected. The products were analyzed and the chemical properties were compared. The results show that oxidation agent and oxidation degree affect composition of the liquid products formed by microbial attack.

  5. A virus in a fungus in a plant: Three-way symbiosis required for thermal tolerance

    USGS Publications Warehouse

    Marquez, L.M.; Redman, R.S.; Rodriguez, R.J.; Roossinck, M.J.

    2007-01-01

    A mutualistic association between a fungal endophyte and a tropical panic grass allows both organisms to grow at high soil temperatures. We characterized a virus from this fungus that is involved in the mutualistic interaction. Fungal isolates cured of the virus are unable to confer heat tolerance, but heat tolerance is restored after the virus is reintroduced. The virus-infected fungus confers heat tolerance not only to its native monocot host but also to a eudicot host, which suggests that the underlying mechanism involves pathways conserved between these two groups of plants.

  6. Modification of Prenylated Stilbenoids in Peanut (Arachis hypogaea) Seedlings by the Same Fungi That Elicited Them: The Fungus Strikes Back.

    PubMed

    Aisyah, Siti; Gruppen, Harry; Slager, Mathijs; Helmink, Bianca; Vincken, Jean-Paul

    2015-10-28

    Aspergillus oryzae and Rhizopus oryzae were compared for inducing the production of prenylated stilbenoids in peanut seedlings. The fungus was applied at two different time points: directly after soaking (day 1) or after 2 days of germination (day 3). Aspergillus- and Rhizopus-elicited peanut seedlings accumulated an array of prenylated stilbenoids, with overlap in compounds induced, but also with compounds specific to the fungal treatment. The differences were confirmed to be due to modification of prenylated stilbenoids by the fungus itself. Each fungus appeared to deploy different strategies for modification. The content of prenylated stilbenoids modified by fungi accounted for around 8% to 49% (w/w) of total stilbenoids. The contents of modified prenylated stilbenoids were higher when the fungus was applied on day 1 instead of day 3. Altogether, type of fungus and time point of inoculation appeared to be crucial parameters for optimizing accumulation of prenylated stilbenoids in peanut seedlings.

  7. Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

    PubMed Central

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes. PMID:25296285

  8. Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies

    PubMed Central

    Cloyd, Raymond A.

    2015-01-01

    Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems. PMID:26463188

  9. Nothing special in the specialist? Draft genome sequence of Cryomyces antarcticus, the most extremophilic fungus from Antarctica.

    PubMed

    Sterflinger, Katja; Lopandic, Ksenija; Pandey, Ram Vinay; Blasi, Barbara; Kriegner, Albert

    2014-01-01

    The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.

  10. Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies.

    PubMed

    Cloyd, Raymond A

    2015-04-09

    Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

  11. Novel fungus-Fe3O4 bio-nanocomposites as high performance adsorbents for the removal of radionuclides.

    PubMed

    Ding, Congcong; Cheng, Wencai; Sun, Yubing; Wang, Xiangke

    2015-09-15

    The bio-nanocomposites of fungus-Fe3O4 were successfully synthesized using a low-cost self-assembly technique. SEM images showed uniform decoration of nano-Fe3O4 particles on fungus surface. The FTIR analysis indicated that nano-Fe3O4 was combined to the fungus surface by chemical bonds. The sorption ability of fungus-Fe3O4 toward Sr(II), Th(IV) and U(VI) was evaluated by batch techniques. Radionuclide sorption on fungus-Fe3O4 was independent of ionic strength, indicating that inner-sphere surface complexion dominated their sorption. XPS analysis indicated that the inner-sphere radionuclide complexes were formed by mainly bonding with oxygen-containing functional groups (i.e., alcohol, acetal and carboxyl) of fungus-Fe3O4. The maximum sorption capacities of fungus-Fe3O4 calculated from Langmuir isotherm model were 100.9, 223.9 and 280.8 mg/g for Sr(II) and U(VI) at pH 5.0, and Th(IV) at pH 3.0, respectively, at 303 K. Fungus-Fe3O4 also exhibited excellent regeneration performance for the preconcentration of radionuclides. The calculated thermodynamic parameters showed that the sorption of radionuclides on fungus-Fe3O4 was a spontaneous and endothermic process. The findings herein highlight the novel synthesis method of fungus-Fe3O4 and its high sorption ability for radionuclides.

  12. Nest Enlargement in Leaf-Cutting Ants: Relocated Brood and Fungus Trigger the Excavation of New Chambers

    PubMed Central

    Römer, Daniela; Roces, Flavio

    2014-01-01

    During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density-dependent digging behavior

  13. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

    PubMed

    Römer, Daniela; Roces, Flavio

    2014-01-01

    During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density-dependent digging behavior

  14. Co-evolutionary patterns and diversification of ant-fungus associations in the asexual fungus-farming ant Mycocepurus smithii in Panama.

    PubMed

    Kellner, K; Fernández-Marín, H; Ishak, H D; Sen, R; Linksvayer, T A; Mueller, U G

    2013-06-01

    Partner fidelity through vertical symbiont transmission is thought to be the primary mechanism stabilizing cooperation in the mutualism between fungus-farming (attine) ants and their cultivated fungal symbionts. An alternate or additional mechanism could be adaptive partner or symbiont choice mediating horizontal cultivar transmission or de novo domestication of free-living fungi. Using microsatellite genotyping for the attine ant Mycocepurus smithii and ITS rDNA sequencing for fungal cultivars, we provide the first detailed population genetic analysis of local ant-fungus associations to test for the relative importance of vertical vs. horizontal transmission in a single attine species. M. smithii is the only known asexual attine ant, and it is furthermore exceptional because it cultivates a far greater cultivar diversity than any other attine ant. Cultivar switching could permit the ants to re-acquire cultivars after garden loss, to purge inferior cultivars that are locally mal-adapted or that accumulated deleterious mutations under long-term asexuality. Compared to other attine ants, symbiont choice and local adaptation of ant-fungus combinations may play a more important role than partner-fidelity feedback in the co-evolutionary process of M. smithii and its fungal symbionts.

  15. Treatment of a textile effluent from dyeing with cochineal extracts using Trametes versicolor fungus.

    PubMed

    Arroyo-Figueroa, Gabriela; Ruiz-Aguilar, Graciela M L; López-Martínez, Leticia; González-Sánchez, Guillermo; Cuevas-Rodríguez, Germán; Rodríguez-Vázquez, Refugio

    2011-05-05

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in the presence or absence of Kirk's medium, glucose, and fungus, with an addition of 50% (v v-1) of nonsterilized effluent were performed. Physicochemical characterization was performed at the start and end of the treatment. Degradation kinetics were determined. A direct relationship was found between the dry weight of fungi, pH, and the decolorization system, with higher decolorization at lower pH levels (pH ~4.3). High decolorization (81% ± 0.09; 88% ± 0.17; and 99% ± 0.04) for three of the eight treatments (Kirk's medium without glucose, Kirk's medium with glucose, and without medium with glucose, respectively) was found. Toxicity tests determined an increase in the initial effluent toxicity (7.33 TU) compared with the final treatment (47.73 TU) in a period of 11 days. For this system, a degradation sequence of the carminic acid structure present in the effluent by the Tv fungus is suggested, in which it is seen that metabolites still containing aromatic structures are generated.

  16. The rust fungus Gymnosporangium in Korea including two new species, G. monticola and G. unicorne

    USDA-ARS?s Scientific Manuscript database

    A survey was conducted of species of the rust fungus Gymnosporangium in Korea. The previously known species were recollected, namely Gymnosporangium asiaticum, G. clavariiforme, G. globosum, G. japonicum, and G. yamadae. Although G. cornutum was reported from Korea, collections similar to that speci...

  17. Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?

    PubMed Central

    Nobre, T.; Eggleton, P.; Aanen, D. K.

    2010-01-01

    The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance colonization may have been severely constrained by the obligate interaction of the termites with fungal symbionts and the need to acquire these symbionts secondarily from the environment for most species (horizontal symbiont transmission). Consistent with this hypothesis, we show that all extant species of fungus-growing termites of Madagascar are the result of a single colonization event of termites belonging to one of the only two groups with vertical symbiont transmission, and we date this event at approximately 13 Mya (Middle/Upper Miocene). Vertical symbiont transmission may therefore have facilitated long-distance dispersal since both partners disperse together. In contrast to their termite hosts, the fungal symbionts have colonized Madagascar multiple times, suggesting that the presence of fungus-growing termites may have facilitated secondary colonizations of the symbiont. Our findings indicate that the absence of the right symbionts in a new environment can prevent long-distance dispersal of symbioses relying on horizontal symbiont acquisition. PMID:19828546

  18. Draft Genome Sequence of Sorghum Grain Mold Fungus Epicoccum sorghinum, a Producer of Tenuazonic Acid

    PubMed Central

    Oliveira, Rodrigo C.; Davenport, Karen W.; Hovde, Blake; Silva, Danielle; Chain, Patrick S. G.; Correa, Benedito

    2017-01-01

    ABSTRACT The facultative plant pathogen Epicoccum sorghinum is associated with grain mold of sorghum and produces the mycotoxin tenuazonic acid. This fungus can have serious economic impact on sorghum production. Here, we report the draft genome sequence of E. sorghinum (USPMTOX48). PMID:28126937

  19. Draft Genome Sequence of the Root-Colonizing Fungus Trichoderma harzianum B97

    PubMed Central

    Compant, Stéphane; Gerbore, Jonathan; Antonielli, Livio; Brutel, Aline

    2017-01-01

    ABSTRACT Trichoderma harzianum is one of the most beneficial microorganisms applied on diverse crops against biotic and abiotic stresses and acts also as a plant growth-promoting fungus. Here, we report the genome of T. harzianum B97, originating from a French agricultural soil and used as a biofertilizer that can tolerate abiotic stresses. PMID:28360171

  20. Differential gene expression during conidiation in the grape powdery mildew fungus, Erysiphe necator

    USDA-ARS?s Scientific Manuscript database

    Asexual sporulation (conidiation) is coordinately regulated in the grape powdery mildew fungus Erysiphe necator, but nothing is known about its genetic regulation. We hypothesized that genes required for conidiation in other fungi would be up-regulated at conidiophore initiation and/or full conidia...

  1. Control of common bunt of wheat under field conditions with the biofumigant fungus Muscodor albus.

    USDA-ARS?s Scientific Manuscript database

    Field experiments were conducted to evaluate the biological control potential of the fungus Muscodor albus, when applied as a seed treatment or an in furrow soil treatment, for control of common bunt (CB) of wheat caused by Tilletia caries. For seed treatments, dry rye grain culture of M. albus wa...

  2. Naphthoquinone spiroketal with allelochemical activity from the new endophytic fungus Edenia gomezpompae

    USDA-ARS?s Scientific Manuscript database

    Bioassay-guided isolation from the culture of Edenia gomezpompae, a new endophytic fungus isolated from the leaves of Callicarpa acuminata (Verbenaceae) from the ecological reserve El Eden, Quintana Roo, Mexico, led to the isolation of four naphthoquinone spiroketals, including three new compounds. ...

  3. Using copper sulfate to control egg fungus at Keo Fish Farm

    USDA-ARS?s Scientific Manuscript database

    Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab had just successfully completed an effectiveness study that was needed in our pursuit of gaining FDA-approval to...

  4. Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival

    USDA-ARS?s Scientific Manuscript database

    A major obstacle in fish hatcheries is the inevitable fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in channel catfish hatcheries that use troughs, but effectiveness on fish eggs hatched using different systems has only recently been investigated. Fish were spawn...

  5. Sulfuryl fluoride fumigation of red oak logs eradicates the oak wilt fungus

    Treesearch

    Elmer L. Schmidt; Jennifer Juzwik; Brian Schneider

    1997-01-01

    Preliminary field trials using red oak logs from trees dying from oak wilt disease were successful in eliminating oak wilt fungus from sapwood after fumigation with sulfuryl fluoride for 72 h under tarp. These results support earlier laboratory data on the fungitoxicity of sulfuryl fluoride as a potential replacement for methyl bromide of exported red oak veneer logs....

  6. Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival

    USDA-ARS?s Scientific Manuscript database

    A major obstacle in fish hatcheries is reduced hatch rates due to fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in catfish hatcheries that use troughs, but effectiveness on other species of fish eggs in different hatching systems has only recently been investigat...

  7. Ascospore dispersal of Ceratocystiopsis ranaculosus, a mycangial fungus of the southern pine beetle

    Treesearch

    John C. Moser; Thelma J. Perry; J. Robert Bridges; Hui-Fen Yin

    1995-01-01

    Ascospores of the heterothallic fungus Ceratocystiopsis ranaculosus were found in the sporothecae of three mite species of the genus Tarsonemus.These mites were phoretic on the coniferous bark beetles Dendroctonus frontalis, D. brevicomis, and Ips acuminatus.Ceratocystiopsis ranaculosus inhabits the mycangium of both Dendroctonus species as conidia in a budding yeast-...

  8. De novo genome assembly of the soil-borne fungus and tomato pathogen Pyrenochaeta lycopersici

    PubMed Central

    2014-01-01

    Background Pyrenochaeta lycopersici is a soil-dwelling ascomycete pathogen that causes corky root rot disease in tomato (Solanum lycopersicum) and other Solanaceous crops, reducing fruit yields by up to 75%. Fungal pathogens that infect roots receive less attention than those infecting the aerial parts of crops despite their significant impact on plant growth and fruit production. Results We assembled a 54.9Mb P. lycopersici draft genome sequence based on Illumina short reads, and annotated approximately 17,000 genes. The P. lycopersici genome is closely related to hemibiotrophs and necrotrophs, in agreement with the phenotypic characteristics of the fungus and its lifestyle. Several gene families related to host–pathogen interactions are strongly represented, including those responsible for nutrient absorption, the detoxification of fungicides and plant cell wall degradation, the latter confirming that much of the genome is devoted to the pathogenic activity of the fungus. We did not find a MAT gene, which is consistent with the classification of P. lycopersici as an imperfect fungus, but we observed a significant expansion of the gene families associated with heterokaryon incompatibility (HI). Conclusions The P. lycopersici draft genome sequence provided insight into the molecular and genetic basis of the fungal lifestyle, characterizing previously unknown pathogenic behaviors and defining strategies that allow this asexual fungus to increase genetic diversity and to acquire new pathogenic traits. PMID:24767544

  9. Biodegradation of pentachlorophenol by the white rot fungus Phanerochaete chrysosporium (1988)

    EPA Science Inventory

    Extensive biodegradation of pentachlorophenol (PCP) by the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance and mineralization of [14C]PCP in nutrient nitrogen-limited culture. Mass balance analyses demonstrated the formation of water-soluble met...

  10. Fungus cultivation by ambrosia beetles: Behavior and laboratory breeding success in three Xyleborine species

    Treesearch

    Peter Biedermann; Kier Klepzig; Taborsky Michael

    2009-01-01

    Fungus cultivation by ambrosia beetles is one of the four independently evolved cases of agriculture known in animals. Such cultivation is most advanced in the highly social subtribe Xyleborina (Scolytinae), which is characterized by haplodiploidy and extreme levels of inbreeding. Despite their ubiquity in forests worldwide, the behavior of these beetles remains poorly...

  11. Development and characterization of microsatellites for switchgrass rust fungus (Puccinia emaculata)

    USDA-ARS?s Scientific Manuscript database

    Ten polymorphic microsatellite loci from the fungus Puccinia emaculata, responsible for rust disease of switchgrass (Panicum virgatum) were developed. Loci were characterized using 20 single-pustule derived isolates of P. emaculata collected from switchgrass plants growing in the southeastern US. Th...

  12. Characteristics of uranium biosorption from aqueous solutions on fungus Pleurotus ostreatus.

    PubMed

    Zhao, Changsong; Liu, Jun; Tu, Hong; Li, Feize; Li, Xiyang; Yang, Jijun; Liao, Jiali; Yang, Yuanyou; Liu, Ning; Sun, Qun

    2016-12-01

    Uranium(VI) biosorption from aqueous solutions was investigated in batch studies by using fungus Pleurotus ostreatus biomass. The optimal biosorption conditions were examined by investigating the reaction time, biomass dosage, pH, temperature, and uranium initial concentration. The interaction between fungus biomass and uranium was confirmed using Fourier transformed infrared (FT-IR), scanning electronic microscopy energy dispersive X-ray (SEM-EDX), and X-ray photoelectron spectroscopy (XPS) analysis. Results exhibited that the maximum biosorption capacity of uranium on P. ostreatus was 19.95 ± 1.17 mg/g at pH 4.0. Carboxylic, amine, as well as hydroxyl groups were involved in uranium biosorption according to FT-IR analysis. The pseudo-second-order model properly evaluated the U(VI) biosorption on fungus P. ostreatus biomass. The Langmuir equation provided better fitting in comparison with Freundlich isotherm models. The obtained thermodynamic parameters suggested that biosorption is feasible, endothermic, and spontaneous. SEM-EDX and XPS were additionally conducted to comprehend the biosorption process that could be described as a complex process involving several mechanisms of physical adsorption, chemisorptions, and ion exchange. Results obtained from this work indicated that fungus P. ostreatus biomass can be used as potential biosorbent to eliminate uranium or other radionuclides from aqueous solutions.

  13. Microsatellite loci for the fungus, Ascosphaera apis, cause of honey bee chalkbrood disease

    USDA-ARS?s Scientific Manuscript database

    The fungus Ascosphaera apis (Ascomycota:Ascosphaeriaceae) is a worldwide fungal pathogen of honey bees. To provide tools for understanding the dispersal history of this pathogen, strain differences in virulence, and host-pathogen interactions, we developed and tested microsatellite loci for this sp...

  14. Mechanisms of resistance to an azole fungicide in the grapevine powdery mildew fungus, Erysiphe necator

    USDA-ARS?s Scientific Manuscript database

    We studied the mechanisms of azole resistance in the grapevine powdery mildew fungus, Erysiphe necator, by quantifying the sensitivity to myclobutanil (EC50) in 65 isolates from the eastern U.S. and 12 from Chile. From each isolate, we sequenced the gene for sterol 14a-demethylase (CYP51), and measu...

  15. Polymorphic sequence-characterized codominant loci in the chestnut blight fungus, Cryphonectria parasitica

    Treesearch

    J. E. Davis; Thomas L. Kubisiak; M. G. Milgroom

    2005-01-01

    Studies on the population biology of the chestnut blight fungus, Cryphonectria parasitica, have previously been carried out with dominant restriction fragment length polymorphism (RFLP) fingerprinting markers. In this study, we described the development of 11 condominant markers from randomly amplified polymorphic DNAs (RAPDs). RAPD fragments were...

  16. Heterogeneous occupancy and density estimates of the pathogenic fungus Batrachochytrium dendrobatidis in waters of North America

    Treesearch

    Tara Chestnut; Chauncey Anderson; Radu Popa; Andrew R. Blaustein; Mary Voytek; Deanna H. Olson; Julie. Kirshtein

    2014-01-01

    Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd), is a contributor to amphibian declines...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  18. Biodegradation of pentachlorophenol by the white rot fungus Phanerochaete chrysosporium (1988)

    EPA Science Inventory

    Extensive biodegradation of pentachlorophenol (PCP) by the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance and mineralization of [14C]PCP in nutrient nitrogen-limited culture. Mass balance analyses demonstrated the formation of water-soluble met...

  19. Metabolites from the endophytic fungus Sporormiella minimoides isolated from Hintonia latiflora

    USDA-ARS?s Scientific Manuscript database

    An extract of the solid cultures of Sporormiella minimoides (Sporormiaceae) isolated as an endophytic fungus from Hintonia latiflora (Rubiaceae), yielded three polyketides, 3,6-dimethoxy-8-methyl-1H,6H-benzo[de]isochromene-1,9-dione, 3-hydroxy-1,6,10-trimethoxy-8-methyl-1H,3H-benzo[de]isochromen-9-o...

  20. Greater taxol yield of fungus Pestalotiopsis hainanensis from dermatitic scurf of the giant panda (Ailuropoda melanoleuca).

    PubMed

    Gu, Yu; Wang, Yanlin; Ma, Xiaoping; Wang, Chengdong; Yue, Guizhou; Zhang, Yuetian; Zhang, Yunyan; Li, Shanshan; Ling, Shanshan; Liu, Xiaomin; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Deng, Junliang; Zuo, Zhicai; Yu, Shumin; Shen, Liuhong; Wu, Rui

    2015-01-01

    While taxol yields of fungi from non-animal sources are still low, whether Pestalotiopsis hainanensis isolated from the scurf of a dermatitic giant panda, Ailuropoda melanoleuca, provides a greater taxol yield remains unknown. The objective of the study was to determine the corresponding taxol yield. The structure of the taxol produced by the fungus was evaluated by thin layer chromatography (TLC), ultraviolet (UV) spectroscopy, high-performance liquid chromatography (HPLC), (1)H and (13)C nuclear magnetic resonance spectroscopy ((1)H-NMR and (13)C-NMR), and time-of-flight mass spectrometry (TOF-MS), with standard taxol as a control. The results demonstrated that the P. hainanensis fungus produced taxol, which had the same structure as the standard taxol and yield of 1,466.87 μg/L. This fungal taxol yield from the dermatitic giant panda was significantly greater than those of fungus from non-animal sources. The taxol-producing fungus may be a potential candidate for the production of taxol on an industrial scale.