Detection and Management of Mango Dieback Disease in the United Arab Emirates

PubMed Central

Saeed, Esam Eldin; Sham, Arjun; A. Al Shurafa, Khawla; S. Al Naqbi, Tahra; Iratni, Rabah; El-Tarabily, Khaled; F. AbuQamar, Synan

2017-01-01

Mango is affected by different decline disorders causing significant losses to mango growers. In the United Arab Emirates (UAE), the pathogen was isolated from all tissues sampled from diseased trees affected by Lasiodiplodia theobromae. Symptoms at early stages of the disease included general wilting appearance of mango trees, and dieback of twigs. In advanced stages, the disease symptoms were also characterized by the curling and drying of leaves, leading to complete defoliation of the tree and discolouration of vascular regions of the stems and branches. To substantially reduce the devastating impact of dieback disease on mango, the fungus was first identified based on its morphological and cultural characteristics. Target regions of 5.8S rRNA (ITS) and elongation factor 1-α (EF1-α) genes of the pathogen were amplified and sequenced. We also found that the systemic chemical fungicides, Score®, Cidely® Top, and Penthiopyrad®, significantly inhibited the mycelial growth of L. theobromae both in vitro and in the greenhouse. Cidely® Top proved to be a highly effective fungicide against L. theobromae dieback disease also under field conditions. Altogether, the morphology of the fruiting structures, molecular identification and pathogenicity tests confirm that the causal agent of the mango dieback disease in the UAE is L. theobromae. PMID:29053600

Lettuce dieback

USDA-ARS?s Scientific Manuscript database

Two related viruses, Tomato bushy stunt virus (TBSV) and Moroccan pepper virus (MPV) cause a disease known as lettuce dieback in California and Arizona. Lettuce dieback is characterized by yellowing, necrosis, stunting and death of lettuce plants, and often occurs in low lying areas with poor drain...

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

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...

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...

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...

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 ...

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

First Report of the Ash Dieback Pathogen Hymenoscyphus fraxineus in Korea

PubMed Central

Han, Jae-Gu; Shrestha, Bhushan; Hosoya, Tsuyoshi; Lee, Kang-Hyo

2014-01-01

In the past two decades, European ash trees (Fraxinus spp.) have been severely damaged due to ash dieback disease, which is caused by the fungal species Hymenoscyphus fraxineus (Chalara fraxinea in the anamorphic stage). Recent molecular phylogenetic and population genetic studies have suggested that this fungus has been introduced from Asia to Europe. During a fungal survey in Korea, H. fraxineus-like apothecia were collected from fallen leaves, rachises, and petioles of Korean ash and Manchurian ash trees. The morphological and ecological traits of these materials are described with the internal transcribed spacer rDNA sequence comparison of H. fraxineus strains collected from Korea, China and Japan. PMID:25606012

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

PubMed

Ibarra-Laclette, Enrique; 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

2017-08-31

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. Copyright © 2017 Ibarra-Laclette et al.

Response and resilience of Spartina alterniflora to sudden dieback

USGS Publications Warehouse

Marsh, Amanda; Blum, Linda K.; Christian, Robert R.; Ramsey, 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.

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...

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

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...

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.

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...

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

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.

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

Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease.

PubMed

Sambles, Christine M; Salmon, Deborah L; Florance, Hannah; Howard, Thomas P; Smirnoff, Nicholas; Nielsen, Lene R; McKinney, Lea V; Kjær, Erik D; Buggs, Richard J A; Studholme, David J; Grant, Murray

2017-12-19

European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples.

Patterns and correlates of giant sequoia foliage dieback during California’s 2012–2016 hotter drought

USGS Publications Warehouse

Stephenson, Nathan L.; Das, Adrian J.; Ampersee, Nicholas J.; Cahill, Kathleen G.; Caprio, Anthony C.; Sanders, John E.; Williams, A. Park

2018-01-01

Hotter droughts – droughts in which unusually high temperatures exacerbate the effects of low precipitation – are expected to increase in frequency and severity in coming decades, challenging scientists and managers to identify which parts of forested landscapes may be most vulnerable. In 2014, in the middle of California’s historically unprecedented 2012–2016 hotter drought, we noticed apparently drought-induced foliage dieback in giant sequoias (Sequoiadendron giganteum Lindl. [Buchholz]) in Sequoia and Kings Canyon national parks, California. Characteristics of the dieback were consistent with a controlled process of drought-induced senescence: younger (distal) shoots remained green while older (proximal) shoots were preferentially shed. As part of an ongoing interdisciplinary effort to understand and map sequoia vulnerability to hotter droughts, we reviewed historical records for evidence of previous foliage dieback events, surveyed dieback along trail corridors in eight sequoia groves, and analyzed tree-ring data from a high- and a low-foliage-dieback area. In sharp contrast to the greatly elevated mortality of other coniferous species found at low and middle elevations, we estimate that <1% of sequoias died during the drought. Foliage dieback was notably elevated in 2014 – the most severe single drought year in our 122-year record – but much lower in subsequent years. We found no historical records of similar foliage dieback during previous droughts. Dieback in 2014 was highly variable both within and among groves, ranging from virtually no dieback in some areas to nearly 50% in others. Dieback was highest (1) at low elevations, probably due to higher temperatures, reduced snowpack, and earlier snowmelt; (2) in areas of low adult sequoia densities, which likely reflect intrinsically more stressful sites; and (3) on steep slopes, probably reflecting reduced water availability. Average sequoia ring widths were narrower at the high-dieback than the

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.

Ash dieback in the Northeast

Treesearch

Robert W. Brandt

1961-01-01

A dieback condition among our ash trees is causing great concern among foresters and forest industries in the northeastern United States. There is good cause for concern. For example, a recent survey made by the New York Conservation Department in 18 eastern counties of the State revealed that about 70 percent of the woodland ash trees are dead or dying.

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

Biological Control of Mango Dieback Disease Caused by Lasiodiplodia theobromae Using Streptomycete and Non-streptomycete Actinobacteria in the United Arab Emirates

PubMed Central

Kamil, Fatima H.; Saeed, Esam E.; El-Tarabily, Khaled A.; AbuQamar, Synan F.

2018-01-01

Dieback caused by the fungus Lasiodiplodia theobromae is an important disease on mango plantations in the United Arab Emirates (UAE). In this study, 53 actinobacterial isolates were obtained from mango rhizosphere soil in the UAE, of which 35 (66%) were classified as streptomycetes (SA) and 18 (34%) as non-streptomycetes (NSA). Among these isolates, 19 (12 SA and 7 NSA) showed antagonistic activities against L. theobromae associated with either the production of diffusible antifungal metabolites, extracellular cell-wall-degrading enzymes (CWDEs), or both. Using a “novel” mango fruit bioassay, all isolates were screened in vivo for their abilities to reduce lesion severity on fruits inoculated with L. theobromae. Three isolates, two belonging to Streptomyces and one to Micromonospora spp., showed the strongest inhibitory effect against this pathogen in vitro and were therefore selected for tests on mango seedlings. Our results revealed that the antifungal action of S. samsunensis UAE1 was related to antibiosis, and the production of CWDEs (i.e., chitinase) and siderophores; whilst S. cavourensis UAE1 and M. tulbaghiae UAE1 were considered to be associated with antibiotic- and CWDE-production, respectively. Pre-inoculation in greenhouse experiments with the most promising actinobacterial isolates resulted in very high levels of disease protection in mango seedlings subsequently inoculated with the pathogen. This was evident by the dramatic reduction in the estimated disease severity indices of the mango dieback of individual biocontrol agent (BCA) applications compared with the pathogen alone, confirming their potential in the management of mango dieback disease. L. theobromae-infected mango seedlings treated with S. samsunensis showed significantly reduced number of defoliated leaves and conidia counts of L. theobromae by 2- and 4-fold, respectively, in comparison to the other two BCA applications. This indicates that the synergistic antifungal effects of S

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...

Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease

PubMed Central

Sambles, Christine M.; Salmon, Deborah L.; Florance, Hannah; Howard, Thomas P.; Smirnoff, Nicholas; Nielsen, Lene R.; McKinney, Lea V.; Kjær, Erik D.; Buggs, Richard J. A.; Studholme, David J.; Grant, Murray

2017-01-01

European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. PMID:29257137

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.

Using a GCM analogue model to investigate the potential for Amazonian forest dieback

NASA Astrophysics Data System (ADS)

Huntingford, C.; Harris, P. P.; Gedney, N.; Cox, P. M.; Betts, R. A.; Marengo, J. A.; Gash, J. H. C.

A combined GCM analogue model and GCM land surface representation is used to investigate the influences of climatology and land surface parameterisation on modelled Amazonian vegetation change. This modelling structure (called IMOGEN) captures the main features of the changes in surface climate as estimated by a GCM with enhanced atmospheric greenhouse gas concentrations. Advantage is taken of IMOGEN's computational speed which allows multiple simulations to be carried out to assess the robustness of the GCM results. The timing of forest dieback is found to be sensitive to the initial ``pre-industrial'' climate, as well as uncertainties in the representation of land-atmosphere CO2 exchange. Changing from a Q10 form for plant dark and maintanence respiration (as used in the coupled GCM runs) to a respiration proportional to maximum photosynthesis, reduces the biomass lost from Amazonia in the 21st century. Replacing the GCM control climate (which has about 25% too little rain in the annual mean over Amazonia) with an observed climatology increases the CO2 concentration at which rainfall drops to critical levels, and thereby further delays the dieback. On the other hand, calibration of the canopy photosynthesis model against Amazonian flux data tends to lead to earlier forest dieback. Further advances are required in both GCM rainfall simulation and land-surface process representation before a clearer picture will emerge on the timing of possible Amazonian forest dieback. However, it seems likely that these advances will overall lead to projections of later forest dieback as GCM control climates become more realistic.

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

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...

Climate-induced forest dieback: An escalating global phenomenon?

USGS Publications Warehouse

Allen, Craig D.

2009-01-01

Forests, which today cover 30 percent of the world’s land surface (FAO, 2006), are being rapidly and directly transformed in many areas by the impacts of expanding human populations and economies. Less evident are the pervasive effects of ongoing climatic changes on the condition and status of forests around the world. Recent examples of drought and heat-related forest stress and dieback (defined here as tree mortality noticeably above usual mortality levels) are being documented from all forested continents, making it possible to begin to see global patterns. This article introduces these patterns and considers the possibility that many forests and woodlands today are at increasing risk of climate-induced dieback. A more comprehensive article (Allen et al., 2009) addresses this topic in considerably greater detail. While climate events can damage forests in many ways ranging from ice storms to tornadoes and hurricanes, the emphasis here is on climatic water stress, driven by drought and warm temperatures.

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

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.

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)...

Preventative Disease Management and Grower Decision Making: A Case Study of California Wine-Grape Growers.

PubMed

Hillis, Vicken; Lubell, Mark; Kaplan, Jonathan; Baumgartner, Kendra

2017-06-01

Preventative disease management is challenging to farmers because it requires paying immediate costs in the hopes of returning uncertain future benefits. Understanding farmer decision making about prevention has the potential to reduce disease incidence and minimize the need for more costly postinfection practices. For example, the grapevine trunk-disease complex (esca, Botryosphaeria dieback, Eutypa dieback, and Phomopsis dieback) significantly affects vineyard productivity and longevity. Given the chronic nature of the infections and inability to eradicate the fungal pathogens, the preventative practices of delayed pruning, applications of pruning-wound protectants, and double pruning (also known as prepruning) are the most effective means of management. We surveyed wine-grape growers in six regions of California on their use of these three practices. In spite of acknowledging the yield impacts of trunk diseases, a substantial number of respondents either choose not to use preventative practices or incorrectly adopted them in mature vineyards, too late in the disease cycle to be effective. Growers with more negative perceptions of cost efficacy were less likely to adopt preventative practices or were more likely to time adoption incorrectly in mature vineyards. In general, preventative management may require strong intervention in the form of policy or extension to motivate behavioral change.

The Role of Pest Control Advisers in Preventative Management of Grapevine Trunk Diseases.

PubMed

Hillis, Vicken; Lubell, Mark; Kaplan, Jonathan; Doll, David; Baumgartner, Kendra

2016-04-01

Vineyards with trunk diseases (Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback) can have negative returns in the long run. Minimizing economic impacts depends on effective management, but adopting a preventative practice after infection occurs may not improve yields. Pest control advisers may reduce grower uncertainty about the efficacy of and need for prevention, which often entails future and unobservable benefits. Here, we surveyed advisers in California to examine their influence over grower decision-making, in the context of trunk diseases, which significantly limit grape production and for which curative practices are unavailable. Our online survey revealed adviser awareness of high disease incidence, and reduced yields and vineyard lifespan. Advisers rated both preventative and postinfection practices positively. Despite higher cost estimates given to postinfection practices, advisers did not recommend preventative practices at higher rates. High recommendation rates were instead correlated with high disease incidence for both preventative and postinfection practices. Recommendation rates declined with increasing cost for preventative, but not for postinfection, practices. Our findings suggest that even when advisers acknowledge the risks of trunk diseases, they may not recommend preventative practices before infection occurs. This underscores the importance of clear outreach, emphasizing both the need for prevention and its long-term cost efficacy.

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.

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.

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...

Assessment of abiotic and biotic factors associated with eastern white pine ( Pinus strobus L.) dieback in the Southern Appalachian Mountains

Treesearch

Ashley N. Schulz; Angela M. Mech; Christopher Asaro; David R. Coyle; Michelle M. Cram; Rima D. Lucardi; Kamal J.K. Gandhi

2018-01-01

A novel and emerging eastern white pine (Pinus strobus L.) dieback phenomenon is occurring in the Southern Appalachian Mountains in the eastern United States. Symptomatic eastern white pine trees exhibit canopy thinning, branch dieback, and cankers on the branches and bole. These symptoms are often associated with the presence of a scale insect, Matsucoccus...

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…

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.

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.

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...

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. © 2013 John Wiley & Sons Ltd.

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

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

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.

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

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...

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

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...

Secondary metabolites of the grapevine pathogen Eutypa lata inhibit mitochondrial respiration, based on a model bioassay using the yeast Saccharomyces cerevisiae.

PubMed

Kim, Jong H; Mahoney, Noreen; Chan, Kathleen L; Molyneux, Russell J; Campbell, Bruce C

2004-10-01

Acetylenic phenols and a chromene isolated from the grapevine fungal pathogen Eutypa lata were examined for mode of toxicity. The compounds included eutypine (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl aldehyde), eutypinol (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl alcohol), eulatachromene, 2- isoprenyl-5-formyl-benzofuran, siccayne, and eulatinol. A bioassay using the yeast Saccharomyces cerevisiae showed that all compounds were either lethal or inhibited growth. A respiratory assay using 2,3,5-triphenyltetrazolium (TTC) indicated that eutypinol and eulatachromene inhibited mitochondrial respiration in wild-type yeast. Bioassays also showed that 2- isoprenyl-5-formyl-benzofuran and siccayne inhibited mitochondrial respiration in the S. cerevisiae deletion mutant vph2Delta, lacking a vacuolar type H (+) ATPase (V-ATPase) assembly protein. Cell growth of tsa1Delta, a deletion mutant of S. cerevisiae lacking a thioredoxin peroxidase (cTPx I), was greatly reduced when grown on media containing eutypinol or eulatachromene and exposed to hydrogen peroxide (H(2)O(2)) as an oxidative stress. This reduction in growth establishes the toxic mode of action of these compounds through inhibition of mitochondrial respiration.

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.

The role of ecosystem-atmosphere interactions in simulated Amazonian precipitation decrease and forest dieback under global climate warming

NASA Astrophysics Data System (ADS)

Betts, R. A.; Cox, P. M.; Collins, M.; Harris, P. P.; Huntingford, C.; Jones, C. D.

A suite of simulations with the HadCM3LC coupled climate-carbon cycle model is used to examine the various forcings and feedbacks involved in the simulated precipitation decrease and forest dieback. Rising atmospheric CO2 is found to contribute 20% to the precipitation reduction through the physiological forcing of stomatal closure, with 80% of the reduction being seen when stomatal closure was excluded and only radiative forcing by CO2 was included. The forest dieback exerts two positive feedbacks on the precipitation reduction; a biogeophysical feedback through reduced forest cover suppressing local evaporative water recycling, and a biogeochemical feedback through the release of CO2 contributing to an accelerated global warming. The precipitation reduction is enhanced by 20% by the biogeophysical feedback, and 5% by the carbon cycle feedback from the forest dieback. This analysis helps to explain why the Amazonian precipitation reduction simulated by HadCM3LC is more extreme than that simulated in other GCMs; in the fully-coupled, climate-carbon cycle simulation, approximately half of the precipitation reduction in Amazonia is attributable to a combination of physiological forcing and biogeophysical and global carbon cycle feedbacks, which are generally not included in other GCM simulations of future climate change. The analysis also demonstrates the potential contribution of regional-scale climate and ecosystem change to uncertainties in global CO2 and climate change projections. Moreover, the importance of feedbacks suggests that a human-induced increase in forest vulnerability to climate change may have implications for regional and global scale climate sensitivity.

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.

Dispersion of marked Euwallacea nr. fornicatus in Florida avocado groves, and estimation of lure sampling range

USDA-ARS?s Scientific Manuscript database

The shot hole borer, Euwallacea nr. fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae), is a significant invasive pest of avocado. Females introduce pathogenic Fusarium fungus into galleries, resulting in a disease called Fusarium die-back. Lures containing either quercivorol or a-copaene a...

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 demonstrated

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.

Analysis of ecological thresholds in a temperate forest undergoing dieback

PubMed Central

Newton, Adrian C.; Cantarello, Elena; Evans, Paul M.

2017-01-01

Positive feedbacks in drivers of degradation can cause threshold responses in natural ecosystems. Though threshold responses have received much attention in studies of aquatic ecosystems, they have been neglected in terrestrial systems, such as forests, where the long time-scales required for monitoring have impeded research. In this study we explored the role of positive feedbacks in a temperate forest that has been monitored for 50 years and is undergoing dieback, largely as a result of death of the canopy dominant species (Fagus sylvatica, beech). Statistical analyses showed strong non-linear losses in basal area for some plots, while others showed relatively gradual change. Beech seedling density was positively related to canopy openness, but a similar relationship was not observed for saplings, suggesting a feedback whereby mortality in areas with high canopy openness was elevated. We combined this observation with empirical data on size- and growth-mediated mortality of trees to produce an individual-based model of forest dynamics. We used this model to simulate changes in the structure of the forest over 100 years under scenarios with different juvenile and mature mortality probabilities, as well as a positive feedback between seedling and mature tree mortality. This model produced declines in forest basal area when critical juvenile and mature mortality probabilities were exceeded. Feedbacks in juvenile mortality caused a greater reduction in basal area relative to scenarios with no feedback. Non-linear, concave declines of basal area occurred only when mature tree mortality was 3–5 times higher than rates observed in the field. Our results indicate that the longevity of trees may help to buffer forests against environmental change and that the maintenance of old, large trees may aid the resilience of forest stands. In addition, our work suggests that dieback of forests may be avoidable providing pressures on mature and juvenile trees do not pass critical

Estimating the risk of Amazonian forest dieback.

PubMed

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

2010-08-01

*Climate change will very likely affect most forests in Amazonia during the course of the 21st century, but the direction and intensity of the change are uncertain, in part because of differences in rainfall projections. In order to constrain this uncertainty, we estimate the probability for biomass change in Amazonia on the basis of rainfall projections that are weighted by climate model performance for current conditions. *We estimate the risk of forest dieback by using weighted rainfall projections from 24 general circulation models (GCMs) to create probability density functions (PDFs) for future forest biomass changes simulated by a dynamic vegetation model (LPJmL). *Our probabilistic assessment of biomass change suggests a likely shift towards increasing biomass compared with nonweighted results. Biomass estimates range between a gain of 6.2 and a loss of 2.7 kg carbon m(-2) for the Amazon region, depending on the strength of CO(2) fertilization. *The uncertainty associated with the long-term effect of CO(2) is much larger than that associated with precipitation change. This underlines the importance of reducing uncertainties in the direct effects of CO(2) on tropical ecosystems.

Condition-dependent co-regulation of genomic clusters of virulence factors in the grapevine trunk pathogen Neofusicoccum parvum

USDA-ARS?s Scientific Manuscript database

The ascomycete Neofusicoccum parvum, one of the causal agents of Botryosphaeria dieback, is a destructive wood-infecting fungus and a serious threat to grape production worldwide. The capability of colonizing woody tissue combined with the secretion of phytotoxic compounds is thought to underlie its...

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.

Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine

PubMed Central

Pouzoulet, Jérôme; Pivovaroff, Alexandria L.; Santiago, Louis S.; Rolshausen, Philippe E.

2014-01-01

This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance toward vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management. PMID:24971084

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.

Widespread Dieback of Forests in North America under Rapid Global Warming: Response to the VINCERA Future Climate Scenarios Simulated by the MC1 DGVM

NASA Astrophysics Data System (ADS)

Lenihan, J.; Neilson, R.; Bachelet, D.; Drapek, R.

2005-12-01

The VINCERA project is an intercomparison among three dynamic general vegetation models (DGVMs) simulating the response of North American ecosystems to six new future climate scenarios. The scenarios were produced by three general circulation models, each using two different future trace gas emissions scenarios. All of the scenarios are near the warmer end of the Intergovernmental Panel on Climate Change's projected future temperature range. Here we present results from the MC1 DGVM. All major forested ecosystems in North America exhibit carbon sequestration until the late 20th or early 21st century, followed by a drought induced decline and loss of carbon to levels below those at 1900 in the absence of fire suppression. By the end of the 21st century, the entire continent will have lost from 10 to 30 Pg of carbon, depending on the scenario. However, fire suppression can significantly mitigate carbon losses and ecosystem declines, producing a net change in carbon from a loss of about 5 Pg to a gain of about 8 Pg under the different scenarios. Most of the suppression benefits are obtained by forests in the western U.S. Suppression also mitigates carbon losses and conversions to savanna or grassland in the eastern U.S., but forest decline still occurs in the east under all scenarios. Dieback is triggered by two mechanisms. Reduced regional precipitation, variable among the scenarios, is one. The second more pervasive mechanism is the influence of rising temperatures on evapotranspiration. Even with the benefits of enhanced water use efficiency from elevated CO2 and slight increases in precipitation, dramatic increases in temperature can produce widespread forest dieback, and increases in fire severity. The eastern United States appear to be particularly vulnerable, as does the central Canadian boreal forest because of the relative flatness of climate gradients near ecotones. Under some scenarios, dieback is also driven by both increasing temperatures and decreasing

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.

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.

Amazonian forest dieback under climate-carbon cycle projections for the 21st century

NASA Astrophysics Data System (ADS)

Cox, P. M.; Betts, R. A.; Collins, M.; Harris, P. P.; Huntingford, C.; Jones, C. D.

The first GCM climate change projections to include dynamic vegetation and an interactive carbon cycle produced a very significant amplification of global warming over the 21st century. Under the IS92a ``business as usual'' emissions scenario CO2 concentrations reached about 980ppmv by 2100, which is about 280ppmv higher than when these feedbacks were ignored. The major contribution to the increased CO2 arose from reductions in soil carbon because global warming is assumed to accelerate respiration. However, there was also a lesser contribution from an alarming loss of the Amazonian rainforest. This paper describes the phenomenon of Amazonian forest dieback under elevated CO2 in the Hadley Centre climate-carbon cycle model.

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

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.

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.

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...

Effectiveness of several dosage formula of oil and nano emulsion of citronella against vascular streak dieback (VSD) disease on cocoa

NASA Astrophysics Data System (ADS)

Noveriza, R.; Trisno, J.; Rahma, H.; Yuliani, S.; Reflin; Martinius

2018-02-01

The disease of Vascular streak dieback (VSD) is a deadly disease of cocoa plants, because it attacks the vascular tissue of cocoa at growing point of the plant. In West Sumatra the disease was first reported in 2015 with an incidence of disease range 58.82% - 100% and an intensity of disease range 24.29% - 44.7%. The purpose of this study was to examine the effectiveness of dosage application of oil formula and nano emulsion of citronella formula against Vascular streak dieback (VSD) disease on cocoa plants in West Sumatra (in Padang Pariaman District and Limapuluh Kota District). The results showed that the percentage of VSD disease attacks in both testing sites was 100%. The oil and nano emulsion of citronella formulas can reduce the intensity of VSD disease on cocoa plants in West Sumatra, particularly in Padang Pariaman District and Limapuluh Kota District. The reduction of VSD intensity in Padang Pariaman district ranged from 8.32 to 21.13%; while in Limapuluh Kota district ranged from 4.33 to 11.80%. The nano emulsion of citronella formulation is effective to suppress the intensity of VSD disease on cocoa plants at doses 0.1% (≥ 30% of effectiveness level).

Ozone and Botrytis interactions in onion-leaf dieback: open-top chamber studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wukasch, R.T.; Hofstra, G.

1977-09-01

Paired open-top chambers were used to study interactions between Botrytis spp. and ozone in field-grown onions. Charcoal filters removed 35 to 65% of the ambient ozone, resulting in six-fold reduction of onion leaf dieback and a 28% increase in onion yield compared with unfiltered chambers. Symptoms of leaf injury appeared soon after ozone levels exceeded 294 ..mu..g/m/sup 3/ (0.15 ppm) for 4 hr. Lesions caused by Botrytis were few because no dew formed in the chambers. However, when leaves were wetted with foggers, inoculation with mycelial suspensions of B. sauamosa in late August produced significantly more lesions and leaf diebackmore » in the unfiltered chamber. Botrytis squamosa, B. cinerea, B. allii, and several genera of secondary fungi were isolated from these lesions. Botrytis squamosa was recovered from lesions only, whereas B. cinerea and B. allii were associated more generally with onion leaf tissue regardless of lesions. 25 references, 1 figure, 2 tables.« less

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.

Dentigerumycin: a bacterial mediator of an ant-fungus symbiosis

PubMed Central

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

2009-01-01

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. In the first system to be analyzed at the molecular level, the bacterium associated with the ant Apterostigma dentigerum produces dentigerumycin, a cyclic depsipeptide with highly modified amino acids, to selectively inhibit the parasitic fungus (Escovopsis sp.). PMID:19330011

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

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.

Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lasure, Linda L; Dai, Ziyu

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.

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

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...

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...

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…

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. © 2015 by The Mycological Society of America.

Genome sequence and genetic diversity of European ash trees.

PubMed

Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J; Sambles, Christine M; Ramirez-Gonzalez, Ricardo H; Swarbreck, David; Kaithakottil, Gemy; Cooper, Endymion D; Uauy, Cristobal; Havlickova, Lenka; Worswick, Gemma; Studholme, David J; Zohren, Jasmin; Salmon, Deborah L; Clavijo, Bernardo J; Li, Yi; He, Zhesi; Fellgett, Alison; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Douglas, Gerry C; Kjær, Erik Dahl; Downie, J Allan; Boshier, David; Lee, Steve; Clark, Jo; Grant, Murray; Bancroft, Ian; Caccamo, Mario; Buggs, Richard J A

2017-01-12

Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low-heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re-sequence 37 F. excelsior trees from Europe, finding evidence for apparent long-term decline in effective population size. Using our reference sequence, we re-analyse association transcriptomic data, yielding improved markers for reduced susceptibility to ash dieback. Surveys of these markers in British populations suggest that reduced susceptibility to ash dieback may be more widespread in Great Britain than in Denmark. We also present evidence that susceptibility of trees to H. fraxineus is associated with their iridoid glycoside levels. This rapid, integrated, multidisciplinary research response to an emerging health threat in a non-model organism opens the way for mitigation of the epidemic.

Mucormycosis (Mucor fungus ball) of the maxillary sinus.

PubMed

Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

2014-01-01

A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp.

THE ROLE OF PREDISPOSING FACTORS IN EXPERIMENTAL FUNGUS INFECTIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheldon, W.H.; Bauer, H.

Among other factors, the influence of ionizing radiations on susceptibility to fungus diseases is reviewed. X irradiation singly or in combination with cortisone administration has been employed in the study of experimental fungus diseases, and it has been shown that total-body radiation enhaaced infection with Candida albicans, Blastomyces dermatididis, and Cryptococcus neoformans in mice. Enhanced susceptibility to fungus infections following radiation therapy has also been reported, the mechanism resulting in lowered host resistance being presumably the same as in other infections. (BBB)

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

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.

Caecomyces sympodialis sp. nov., a new rumen fungus isolated from Bos indicus.

PubMed

Chen, Yo-Chia; Tsai, Sheng-Da; Cheng, Hsueh-Ling; Chien, Chiu-Yuan; Hu, Chun-Yi; Cheng, Tai-Yi

2007-01-01

A new anaerobic rumen fungus was isolated from the rumen fluid of a yellow cow (Bos indicus). This fungus appears to be a previously undescribed species of the genus Caecomyces, it possessing uniflagellate zoospores, a spherical holdfast, tubular sporangiophores and bulbous rhizoids. This new fungus also features distinctive multisporangiate thallus sympodially distributed on sporangiophores. The fungus resembles Caecomyces communis and C. equi in that it characterizes bulbous rhizoids and uniflagellate zoospores but differs from C. communis and C. equi in that it possesses multisporangiate and sympodial sporangia. This new fungus and Cyllamyces aberensis both reveal similar morphology during early thallus development in having a spherical holdfast, but they vary from unbranched sporangiophores and additional bulbous rhizoids. In addition, the molecular phylogenetic analyses ITS1 (internal transcribed spacer 1) also conform to the results of the morphological examinations of Caecomyces. For the mentioned reasons, this new species of fungus is described as Caecomyces sympodialis sp. nov. The genera of Neocallimasticaceae and species of Caecomyces are also keyed out.

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.

Lignocellulose pretreatment in a fungus-cultivating termite

DOE PAGES

Li, Hongjie; Yelle, Daniel J.; Li, Chang; ...

2017-04-19

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 termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid ofmore » various condensed units that are traditionally recognized to be the most recalcitrant. Subsequently, the fungus-comb microbiome preferentially uses xylose and cleaves polysaccharides, thus facilitating final utilization of easily digestible oligosaccharides by old worker termites. This complementary symbiotic pretreatment process in the fungus-growing termite symbiosis reveals a previously unappreciated natural system for efficient lignocellulose degradation.« less

Lignocellulose pretreatment in a fungus-cultivating termite

PubMed Central

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

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 termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid of various condensed units that are traditionally recognized to be the most recalcitrant. Subsequently, the fungus-comb microbiome preferentially uses xylose and cleaves polysaccharides, thus facilitating final utilization of easily digestible oligosaccharides by old worker termites. This complementary symbiotic pretreatment process in the fungus-growing termite symbiosis reveals a previously unappreciated natural system for efficient lignocellulose degradation. PMID:28424249

Lignocellulose pretreatment in a fungus-cultivating termite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hongjie; Yelle, Daniel J.; Li, Chang

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 termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid ofmore » various condensed units that are traditionally recognized to be the most recalcitrant. Subsequently, the fungus-comb microbiome preferentially uses xylose and cleaves polysaccharides, thus facilitating final utilization of easily digestible oligosaccharides by old worker termites. This complementary symbiotic pretreatment process in the fungus-growing termite symbiosis reveals a previously unappreciated natural system for efficient lignocellulose degradation.« less

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.

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

[Effects of fungus on the growth of Dendrobium candidum and D. nobile in vitro culture].

PubMed

Song, J Y; Guo, S X

2001-12-01

To examine effects of fungus AR-18 (Epulorhiza sp.) on the growth of Dendrobium candidum and D. nobile in vitro culture. Effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when agar was used as rest, and effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when vermiculite was used as rest. In agar medium, effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were not significant (P > 0.05). However, in vermiculite medium, the effect of fungus AR-18 on fresh weight of D. nobile was significant (P < 0.05). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 16% compared with the non-inoculated ones (control). The effect of fungus AR-18 on dry weight of D. nobile was very significant (P < 0.01). Dry weight of D. nobile inoculated with fungus AR-18 was increased by 21% compared with the control. In vermiculite medium, the effect of combination treatment (Fungus AR-18 + Distilled H2O) on fresh weight of D. nobile was very significant (P < 0.01). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 47% compared with the control, while the effect of combination treatment (Fungus AR-18 + Nutrients) on fresh weight of D. nobile was not significant (P > 0.05). In addition, the effect of combinations treatment (Fungus AR-18 + Nutrients) and (Fungus AR-18 + Distilled H2O) on dry weight of D. nobile was not significant (P > 0.05). So the combination treatment (Fungus AR-18 + Distilled H2O) was the best for the growth of D. nobile. In vermiculite medium, effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum were not significant (P > 0.05). It is important in vitro culture to select a proper rest for the control of the growth of fungus to establish a beneficial symbiotic relationship between plants and fungi. If the fungus AR-18 is utilized as

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

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.

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...

AFLP Approach Reveals Variability in Phragmites australis: Implications for Its Die-Back and Evidence for Genotoxic Effects

PubMed Central

Coppi, Andrea; Lastrucci, Lorenzo; Cappelletti, David; Cerri, Martina; Ferranti, Francesco; Ferri, Valentina; Foggi, Bruno; Gigante, Daniela; Venanzoni, Roberto; Viciani, Daniele; Selvaggi, Roberta; Reale, Lara

2018-01-01

Phragmites australis is a subcosmopolitan species typical of wetlands being studied in Europe for its disappearance from natural stands, a phenomenon called reed die-back syndrome (RDBS). Although it is conjectured that low genetic variability contributes to RDBS, this aspect remains neglected to this day. Using a molecular fingerprinting approach and a sequence analysis of the trnT-trnL/rbcL-psaI regions of cpDNA, this study aimed to compare the genetic structure of stable vs. RDBS-affected P. australis stands from five wetlands of central Italy. Beforehand, in order to characterize the health condition of reed populations, the occurrence of the main macromorphological descriptors for RDBS was considered on 40 reed stands. Soil samples were also collected to examine the total content of heavy metals. The current study analyzed cpDNA in 19 samples and AFLP profiles in 381 samples to investigate the genetic structure of Phragmites populations. Based on the multinomial-Dirichlet model, an analysis of candidate loci under selective pressure was also performed. The relationships among AFLP data, RDBS descriptors and chemicals were evaluated with the use of Linear Mixed Models. The analysis of the cpDNA shows the occurrence of the haplotypes M (the most widespread), and K here recorded for the first time in Italy. Three new haplotypes were also described. The DNA fingerprinting analysis has produced a total of 322 loci (98% polymorphic) and shows the medium-to-high amount of genetic diversity. The significant genetic differentiation among wetlands (Fst = 0.337) suggests either low gene flow or small effective population size. Moreover, the low amount of outlier loci (only 5; l.5% of the total), seems to indicate the scarce occurrence of selective pressure upon the reed’s genome. Genetic diversity increased in relationship to the decrease in diameter and of flowering buds of the reed, two of the trends associated with the die-back. The current study rejects the

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.

Biosynthesis of size-controlled gold nanoparticles using fungus, Penicillium sp.

PubMed

Zhang, Xiaorong; He, Xiaoxiao; Wang, Kemin; Wang, Yonghong; Li, Huimin; Tan, Weihong

2009-10-01

The unique optoelectronic and physicochemical properties of gold nanoparticles are significantly dependent on the particle size, shape and structure. In this paper, biosynthesis of size-controlled gold nanoparticles using fungus Penicillium sp. is reported. Fungus Penicillium sp. could successfully bioreduce and nucleate AuCl4(-) ions, and lead to the assembly and formation of intracellular Au nanoparticles with spherical morphology and good monodispersity after exposure to HAuCl4 solution. Reaction temperature, as an important physiological parameter for fungus Penicillium sp. growth, could significantly control the size of the biosynthesized Au nanoparticles. The biological compositions and FTIR spectra analysis of fungus Penicillium sp. exposed to HAuCl4 solution indicated the intracellular reducing sugar played an important role in the occurrence of intracellular reduction of AuCl4(-) ions and the growth of gold nanoparticles. Furthermore, the intracellular gold nanoparticles could be easily separated from the fungal cell lysate by ultrasonication and centrifugation.

Biochemical Characterization of Fungus Isolated during In vitro Propagation of Bambusa balcooa.

PubMed

Tyagi, Bhawna; Tewari, Salil; Dubey, Ashutosh

2018-01-01

Bambusa balcooa ( Poaceae: Bambusoideae ) is a multipurpose bamboo species, which is native of the Indian subcontinent. B. balcooa is regarded as one of the best species for scaffolding and building purposes because of its strong culm. Other uses include paper pulp, handicrafts, and products of the wood chip industry. Due to these various uses in industries, this species has been identified as one of the priority bamboos by the National Bamboo Mission. This study is designed to analyze the identification of fungus and develop the strategy to eliminate the contamination during in vitro establishment of B. balcooa through nodal part. Fungus contamination is a problem which is encountered during in vitro establishment of B. balcooa cultures. In the present study, fungus contamination from in vitro cultured plant has been isolated and subjected to partial sequence analysis of the 18S rRNA gene to identify the fungus strain. Experiments were designed to develop a strategy for removal of the fungus contamination with the help of antifungal compounds and commercial antimicrobial supplement supplied by HiMedia. Fusarium equiseti was identified as endophytic fungus. It was observed that antimicrobial supplement at concentration of 500 μl/l was more effective concentration to remove fungus contamination and not showed any detrimental effect on growth parameters of shoot. This experiment would help in identification and to get rid of fungal contamination and improve the in vitro establishment of B. balcooa cultures for large-scale propagation. Endogenous fungus was isolated from contaminated culture of B. balcooa , and it was identified as Fusarium equiseti and submitted to NCBI under accession no. KP274872. The endophytic fungus had shown substantial production of amylase, cellulase, and protease media. Gibberellic acid (GA 3 ) production by F. equiseti was maximum on the 7 th day on inoculation. Abbreviations used: B. balcooa : Bambusa balcooa , F. equiseti : Fusarium

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

Noninvasive medical management of fungus ball uropathy in a premature infant.

PubMed

Alkalay, A L; Srugo, I; Blifeld, C; Komaiko, M S; Pomerance, J J

1991-09-01

Unilateral renal obstruction secondary to fungus balls is described in a premature infant. Noninvasive medical management, which included amphotericin B and 5-flucytosine therapy and forced diuresis, resulted in disappearance of fungus balls and resolution of the obstruction.

Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants.

PubMed

Ruiz-González, Mario X; Malé, Pierre-Jean G; Leroy, Céline; Dejean, Alain; Gryta, Hervé; Jargeat, Patricia; Quilichini, Angélique; Orivel, Jérôme

2011-06-23

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.

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...

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.

Fire-mediated dieback and compositional cascade in an Amazonian forest.

PubMed

Barlow, Jos; Peres, Carlos A

2008-05-27

The only fully coupled land-atmosphere global climate model predicts a widespread dieback of Amazonian forest cover through reduced precipitation. Although these predictions are controversial, the structural and compositional resilience of Amazonian forests may also have been overestimated, as current vegetation models fail to consider the potential role of fire in the degradation of forest ecosystems. We examine forest structure and composition in the Arapiuns River basin in the central Brazilian Amazon, evaluating post-fire forest recovery and the consequences of recurrent fires for the patterns of dominance of tree species. We surveyed tree plots in unburned and once-burned forests examined 1, 3 and 9 years after an unprecedented fire event, in twice-burned forests examined 3 and 9 years after fire and in thrice-burned forests examined 5 years after the most recent fire event. The number of trees recorded in unburned primary forest control plots was stable over time. However, in both once- and twice-burned forest plots, there was a marked recruitment into the 10-20cm diameter at breast height tree size classes between 3 and 9 years post-fire. Considering tree assemblage composition 9 years after the first fire contact, we observed (i) a clear pattern of community turnover among small trees and the most abundant shrubs and saplings, and (ii) that species that were common in any of the four burn treatments (unburned, once-, twice- and thrice-burned) were often rare or entirely absent in other burn treatments. We conclude that episodic wildfires can lead to drastic changes in forest structure and composition, with cascading shifts in forest composition following each additional fire event. Finally, we use these results to evaluate the validity of the savannization paradigm.

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...

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.

Evolutionary patterns of proteinase activity in attine ant fungus gardens

PubMed Central

2011-01-01

Background Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing eight genera. We mapped these activity profiles on an independently obtained molecular phylogeny of the symbionts and show that total proteinase activity in lower attine symbionts peaks at ca. pH 6. The higher attine symbionts that have no known free-living relatives had much higher proteinase activities than the lower attine symbionts. Their total in vitro proteinase activity peaked at pH values around 5, which is close to the pH that the ants maintain in their fungus gardens, suggesting that the pH optimum of fungal proteinases may have changed after the irreversible domestication of evolutionary more derived fungal symbionts. This notion is also supported by buffering capacities of fungus gardens at pH 5.2 being remarkably high, and suggests that the fungal symbiont actively helps to maintain garden acidity at this specific level. Metalloproteinases dominated the activity profiles of lower attine gardens and may thus represent the ancestral type of proteinase production, whereas serine proteinase activity dominated the activity profiles of the higher attine gardens reared by Trachymyrmex and Sericomyrmex, suggesting that there may be trade-offs in the production of these enzyme classes. Remarkably, the single symbiont that is shared by species of the crown group of Atta and Acromyrmex leaf-cutting ants mostly showed metalloproteinase activity, suggesting that recurrent

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.…

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...

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.

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.

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.

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...

Chytrid fungus parasitizing the wild amphibian Leptodactylus ocellatus (Anura: Leptodactylidae) in Argentina.

PubMed

Herrera, Raúl A; Steciow, Mónica M; Natale, Guillermo S

2005-05-20

The present contribution is the first report of parasitosis by a chytrid fungus in wild anuran amphibians in Argentina, as well as the first case of amphibian mortality documented to date in Argentina. We report the presence of the chytrid fungus in dead adult Leptodactylus ocellatus. It has been suggested that chytridiomycosis is the main cause of death in several amphibian populations worldwide. Our study demonstrates that chytridiomycosis afflicts L. ocellatus, a common widespread amphibian species, and is the first report of chytridiomycosis in the Argentinian lowlands. The occurrence at this latitude would indicate an extended distribution of this fungus in wildlife populations. It is also the first report of amphibian mortality due to chytrid fungus in our country. It is noteworthy that the site of collection is situated very close to sea level in a temperate climate zone and that this represents the southern most record for South American wild amphibians.

Isocoumarin Derivatives from the Sea Squirt-derived Fungus Penicillium stoloniferum QY2-10 and the Halotolerant Fungus Penicillium notatum B-52.

PubMed

Xin, Zhi-Hong; Tian, Li; Zhu, Tian-Jiao; Wang, Wen-Liang; Du, Lin; Fang, Yu-Chun; Gu, Qian-Qun; Zhu, Wei-Ming

2007-07-01

Two isocoumarin derivatives, stoloniferol A (1) and B (2), a known 5alpha, 8alpha-epidioxy-23-methyl-(22E, 24R)-ergosta-6, 22-dien-3beta-ol (3), and a known dihydrocitrinone (4) were isolated from the ethyl acetate extract of the sea squirt-derived fungus, Penicillium stoloniferum QY2-10, and a halophilic fungus, Penicillium notatum B-52, respectively. Their structures were elucidated by spectroscopic methods and optical rotation. The stereochemistry of 2 was determined on the basis of different NOE experiments and chemical transformation. Compound 3 showed cytotoxicity against P388 cells, with an IC50 value of 4.07 microM.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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.

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

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

Yarsagumba Fungus: Health Problems in the Himalayan Gold Rush.

PubMed

Koirala, Pranawa; Pandit, Bidur; Phuyal, Pratibha; Zafren, Ken

2017-09-01

Seasonal migration of people in search of Yarsagumba fungus creates a population of collectors that faces hardship and health risks in austere high-altitude settings. In 2016, our 4-person team performed a 2-day health-needs survey of people collecting Yarsagumba fungus near the village of Yak Kharka (4020 m) in the Manang District of Nepal. There were approximately 800 people, both male and female, from age 10 to over 60, collecting Yarsagumba fungus. They had paid high prices for permits, hoping to recoup the cost and make a profit by selling specimens of Yarsagumba, but the fungus seemed scarce in 2016, resulting in a bleak economic forecast. Most collectors were living in austere conditions, walking long hours to the collection areas early in the morning and returning in the late afternoon. Most were subsisting on 1 daily meal. Health problems, including acute mountain sickness as well as respiratory and gastrointestinal illnesses, were common. Yarsagumba has become harder to find in recent years, increasing hardships and risk of injury. Medical care was almost nonexistent. As abundance decreases and demand increases, there is increasing pressure on collectors to find Yarsagumba. The collectors are an economically disadvantaged population who live in austere conditions at high altitude with poor shelter and sanitation, strenuous work, and limited availability of food. Health care resources are very limited. There are significant risks of illness, injury, and death. Targeted efforts by government entities and nongovernmental organizations might be beneficial in meeting the health needs. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

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.

Microsatellite variability in the entomopathogenic fungus Paeciolomyces fumosoroseus: genetic diversity and population structure

USDA-ARS?s Scientific Manuscript database

The hyphomycete Paecilomyces fumosoroseus (Pfr) is a geographically widespread fungus capable of infecting various insect hosts. The fungus has been used for the biological control of several important insect pests of agriculture. However knowledge of the fungus’ genetic diversity and population str...

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...

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

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...

Datasheet: Pseudogymnoascus destructans (white-nose syndrome fungus)

USGS Publications Warehouse

Blehert, David; Lankau, Emily W.

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.

Multifarious plant growth promotion by an entomopathogenic fungus Lecanicillium psalliotae.

PubMed

Senthil Kumar, C M; Jacob, T K; Devasahayam, S; Thomas, Stephy; Geethu, C

2018-03-01

An entomopathogenic fungus, Lecanicillium psalliotae strain IISR-EPF-02 previously found infectious to cardamom thrips, Sciothrips cardamomi promoted plant growth in cardamom, Elettaria cardamomum. The isolate exhibited direct plant growth promoting traits by production of indole-3-acetic acid and ammonia and by solubilizing inorganic phosphate and zinc. It also showed indirect plant growth promoting traits by producing siderophores and cell wall-degrading enzymes like, α-amylases, cellulases and proteases. In pot culture experiments, application of the fungus at the root zone of cardamom seedlings significantly increased shoot and root length, shoot and root biomass, number of secondary roots and leaves and leaf chlorophyll content compared to untreated plants. This is the first report on the plant growth promoting traits of this fungus. The entomopathogenic and multifarious growth promoting traits of L. psalliotae strain IISR-EPF-02 suggest that it has great potential for exploitation in sustainable agriculture. Copyright © 2017 Elsevier GmbH. All rights reserved.

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.

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.

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...

Ecology of coarse wood decomposition by the saprotrophic fungus Fomes fomentarius.

PubMed

Větrovský, Tomáš; Voříšková, Jana; Snajdr, Jaroslav; Gabriel, Jiří; Baldrian, Petr

2011-07-01

Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.

Fungus-Specific Sirtuin HstD Coordinates Secondary Metabolism and Development through Control of LaeA

PubMed Central

Kawauchi, Moriyuki; Nishiura, Mika

2013-01-01

The sirtuins are members of the NAD+-dependent histone deacetylase family that contribute to various cellular functions that affect aging, disease, and cancer development in metazoans. However, the physiological roles of the fungus-specific sirtuin family are still poorly understood. Here, we determined a novel function of the fungus-specific sirtuin HstD/Aspergillus oryzae Hst4 (AoHst4), which is a homolog of Hst4 in A. oryzae yeast. The deletion of all histone deacetylases in A. oryzae demonstrated that the fungus-specific sirtuin HstD/AoHst4 is required for the coordination of fungal development and secondary metabolite production. We also show that the expression of the laeA gene, which is the most studied fungus-specific coordinator for the regulation of secondary metabolism and fungal development, was induced in a ΔhstD strain. Genetic interaction analysis of hstD/Aohst4 and laeA clearly indicated that HstD/AoHst4 works upstream of LaeA to coordinate secondary metabolism and fungal development. The hstD/Aohst4 and laeA genes are fungus specific but conserved in the vast family of filamentous fungi. Thus, we conclude that the fungus-specific sirtuin HstD/AoHst4 coordinates fungal development and secondary metabolism via the regulation of LaeA in filamentous fungi. PMID:23729383

The fungus gardens of leaf-cutter ants undergo a distinct physiological transition during biomass degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Eric L.; Aylward, Frank O.; Kim, Young-Mo

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 easilymore » 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.« less

Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 formore » 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.« less

Biomimetics of silver nanoparticles by white rot fungus, Phaenerochaete chrysosporium.

PubMed

Vigneshwaran, Nadanathangam; Kathe, Arati A; Varadarajan, P V; Nachane, Rajan P; Balasubramanya, R H

2006-11-01

Extracellular synthesis of silver nanoparticles by a white rot fungus, Phaenerochaete chrysosporium is reported in this paper. Incubation of P. chrysosporium mycelium with silver nitrate solution produced silver nanoparticles in 24h. These silver nanoparticles were characterized by means of UV-vis spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The synthesized silver nanoparticles absorbed maximum at 470 nm in the visible region. XRD spectrum of the silver nanoparticles confirmed the formation of metallic silver. The SEM characterization of the fungus reacted on the Ag+ indicated that the protein might be responsible for the stabilization of silver nanoparticles. This result was further supported by the TEM examination. Though shape variation was noticed, majority of the nanoparticles were found to be of pyramidal shape as seen under TEM. Photoluminescence spectrum showed a broad emission peak of silver nanoparticles at 423 nm when excited at 350 nm. Apart from eco-friendliness, fungus as bio-manufacturing unit will give us an added advantage in ease of handling when compared to other classes of microorganisms.

Scanning electron microscopy of Ancylostoma spp. dog infective larvae captured and destroyed by the nematophagous fungus Duddingtonia flagrans.

PubMed

Maciel, A S; Araújo, J V; Campos, A K; Benjamin, L A; Freitas, L G

2009-06-01

The interaction between the nematode-trapping fungus Duddingtonia flagrans (isolate CG768) against Ancylostoma spp. dog infective larvae (L(3)) was evaluated by means of scanning electron microscopy. Adhesive network trap formation was observed 6h after the beginning of the interaction, and the capture of Ancylostoma spp. L(3) was observed 8h after the inoculation these larvae on the cellulose membranes colonized by the fungus. Scanning electron micrographs were taken at 0, 12, 24, 36 and 48 h, where 0 is the time when Ancylostoma spp. L(3) was first captured by the fungus. Details of the capture structure formed by the fungus were described. Nematophagous Fungus Helper Bacteria (NHB) were found at interactions points between the D. flagrans and Ancylostoma spp. L(3). The cuticle penetration by the differentiated fungal hyphae with the exit of nematode internal contents was observed 36 h after the capture. Ancylostoma spp. L(3) were completely destroyed after 48 h of interaction with the fungus. The scanning electron microscopy technique was efficient on the study of this interaction, showing that the nematode-trapping fungus D. flagrans (isolate CG768) is a potential exterminator of Ancylostoma spp. L(3).

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

Pseudocopulatory pollination in lepanthes (orchidaceae: pleurothallidinae) by fungus gnats.

PubMed

Blanco, Mario A; Barboza, Gabriel

2005-04-01

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. 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. 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. 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 consistent with patterns of male sciarid behaviour.

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

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...

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

PubMed

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

2017-12-01

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.

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.

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.

Identifying the core microbial community in the gut of fungus-growing termites.

PubMed

Otani, Saria; Mikaelyan, Aram; Nobre, Tânia; Hansen, Lars H; Koné, N'Golo A; Sørensen, Søren J; Aanen, Duur K; Boomsma, Jacobus J; Brune, Andreas; Poulsen, Michael

2014-09-01

Gut microbes play a crucial role in decomposing lignocellulose to fuel termite societies, with protists in the lower termites and prokaryotes in the higher termites providing these services. However, a single basal subfamily of the higher termites, the Macrotermitinae, also domesticated a plant biomass-degrading fungus (Termitomyces), and how this symbiont acquisition has affected the fungus-growing termite gut microbiota has remained unclear. The objective of our study was to compare the intestinal bacterial communities of five genera (nine species) of fungus-growing termites to establish whether or not an ancestral core microbiota has been maintained and characterizes extant lineages. Using 454-pyrosequencing of the 16S rRNA gene, we show that gut communities have representatives of 26 bacterial phyla and are dominated by Firmicutes, Bacteroidetes, Spirochaetes, Proteobacteria and Synergistetes. A set of 42 genus-level taxa was present in all termite species and accounted for 56-68% of the species-specific reads. Gut communities of termites from the same genus were more similar than distantly related species, suggesting that phylogenetic ancestry matters, possibly in connection with specific termite genus-level ecological niches. Finally, we show that gut communities of fungus-growing termites are similar to cockroaches, both at the bacterial phylum level and in a comparison of the core Macrotermitinae taxa abundances with representative cockroach, lower termite and higher nonfungus-growing termites. These results suggest that the obligate association with Termitomyces has forced the bacterial gut communities of the fungus-growing termites towards a relatively uniform composition with higher similarity to their omnivorous relatives than to more closely related termites. © 2014 John Wiley & Sons Ltd.

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.

[Scytalidium dimidiatum an opportunistic fungus for both man and Mangifera indica trees in Venezuela].

PubMed

Padin, Carmiña; Fernández-Zeppenfeldt, Guillermo; Yegres, Francisco; Richard-Yegres, Nicole

2005-09-01

The purpose of this study was to confirm the presence of Scytalidium dimidiatum on Mangifera indica (mango) trees, in a plantation managed by a diabetic patient with a white grain mycetoma of the foot caused by the same fungus. Samples from necrotic apices, roots, burned leaves and rotten stems from eight trees were processed by the Smith and Furcolow's mineral oil technique (modified). Several isolates from the apex material and clinical samples from the diabetic patient isolated in pure culture a fungus with the macroscopic and microscopic characteristics of that in S. dimidiatum. This fungus should be considered as an opportunistic microorganism for both humans and M. indica.

[Difference of water relationships of poplar trees in Zhangbei County, Hebei, China based on stable isotope and thermal dissipation method].

PubMed

Miao, Bo; Meng, Ping; Zhang, Jin Song; He, Fang Jie; Sun, Shou Jia

2017-07-18

The water sources and transpiration of poplar trees in Zhangbei County were measured using stable hydrogen isotope and thermal dissipation method. The differences in water relationships between dieback and non-dieback poplar trees were analyzed. The results showed that the dieback trees mainly used shallow water from 0-30 cm soil layer during growing season while the non-dieback trees mainly used water from 30-80 cm soil layer. There was a significant difference in water source between them. The non-dieback trees used more water from middle and deep soil layers than that of the dieback trees during the dry season. The percentage of poplar trees using water from 0-30 cm soil layer increased in wet season, and the increase of dieback trees was higher than that of non-dieback trees. The contributions of water from 30-180 cm soil layer of dieback and non-dieback trees both decreased in wet season. The sap flow rate of non-dieback trees was higher than that of dieback trees. There was a similar variation tend of sap flow rate between dieback and non-dieback trees in different weather conditions, but the start time of sap flow of non-dieback trees was earlier than that of dieback trees. Correlation analysis showed that the sap flow rate of either dieback or non-dieback poplar trees strongly related to soil temperature, wind speed, photosynthetically active radiation, relative humidity and air temperature. The sap flow rate of die-back poplar trees strongly negatively related to soil temperature and relative humidity, and strongly positively related to the other factors. The sap flow rate of non-dieback poplar trees only strongly negatively related to relative humidity but positively related to the other factors. The results revealed transpiration of both poplar trees was easily affected by environmental factors. The water consumption of dieback trees was less than non-dieback trees because the cumulative sap flow amount of dieback trees was lower. Reduced transpiration

Gene expression analysis of wood decay fungus Fibroporia Radiculosa grown In ACQ-treated wood

Treesearch

Ayfer Akgul; Ali Akgul; Juliet D. Diehl Tang

2018-01-01

Copper-tolerant brown-rot fungi are able todegrade wood treated with copper or copper-based wood preservatives. This research used quantitative reverse transcriptase polymerase chain reaction to explore what genes of the brown-rot fungus, Fibroporia radiculosa, were expressed when the fungus was overcoming the wood preservatives and decaying the...

Amphibians acquire resistance to live and dead fungus overcoming fungal immunosuppression.

PubMed

McMahon, Taegan A; Sears, Brittany F; Venesky, Matthew D; Bessler, Scott M; Brown, Jenise M; Deutsch, Kaitlin; Halstead, Neal T; Lentz, Garrett; Tenouri, Nadia; Young, Suzanne; Civitello, David J; Ortega, Nicole; Fites, J Scott; Reinert, Laura K; Rollins-Smith, Louise A; Raffel, Thomas R; Rohr, Jason R

2014-07-10

Emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group, causing declines of many taxa, including bats, corals, bees, snakes and amphibians. Currently, there is little evidence that wild animals can acquire resistance to these pathogens. Batrachochytrium dendrobatidis is a pathogenic fungus implicated in the recent global decline of amphibians. Here we demonstrate that three species of amphibians can acquire behavioural or immunological resistance to B. dendrobatidis. Frogs learned to avoid the fungus after just one B. dendrobatidis exposure and temperature-induced clearance. In subsequent experiments in which B. dendrobatidis avoidance was prevented, the number of previous exposures was a negative predictor of B. dendrobatidis burden on frogs and B. dendrobatidis-induced mortality, and was a positive predictor of lymphocyte abundance and proliferation. These results suggest that amphibians can acquire immunity to B. dendrobatidis that overcomes pathogen-induced immunosuppression and increases their survival. Importantly, exposure to dead fungus induced a similar magnitude of acquired resistance as exposure to live fungus. Exposure of frogs to B. dendrobatidis antigens might offer a practical way to protect pathogen-naive amphibians and facilitate the reintroduction of amphibians to locations in the wild where B. dendrobatidis persists. Moreover, given the conserved nature of vertebrate immune responses to fungi and the fact that many animals are capable of learning to avoid natural enemies, these results offer hope that other wild animal taxa threatened by invasive fungi might be rescued by management approaches based on herd immunity.

Entomopathogenicity and Biological Attributes of Himalayan Treasured Fungus Ophiocordyceps sinensis (Yarsagumba)

PubMed Central

Baral, Bikash

2017-01-01

Members of the entomophagous fungi are considered very crucial in the fungal domain relative to their natural phenomenon and economic perspectives; however, inadequate knowledge of their mechanisms of interaction keeps them lagging behind in parallel studies of fungi associated with agro-ecology, forest pathology and medical biology. Ophiocordyceps sinensis (syn. Cordyceps sinensis), an intricate fungus-caterpillar complex after it parasitizes the larva of the moth, is a highly prized medicinal fungus known widely for ages due to its peculiar biochemical assets. Recent technological innovations have significantly contributed a great deal to profiling the variable clinical importance of this fungus and other related fungi with similar medicinal potential. However, a detailed mechanism behind fungal pathogenicity and fungal-insect interactions seems rather ambiguous and is poorly justified, demanding special attention. The goal of the present review is to divulge an update on the published data and provides promising insights on different biological events that have remained underemphasized in previous reviews on fungal biology with relation to life-history trade-offs, host specialization and selection pressures. The infection of larvae by a fungus is not a unique event in Cordyceps; hence, other fungal species are also reviewed for effective comparison. Conceivably, the rationale and approaches behind the inheritance of pharmacological abilities acquired and stored within the insect framework at a time when they are completely hijacked and consumed by fungal parasites, and the molecular mechanisms involved therein, are clearly documented. PMID:29371523

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)

Polyketide-Terpene Hybrid Metabolites from an Endolichenic Fungus Pestalotiopsis sp.

PubMed Central

Ding, Gang; Wang, Hai-Ying; Guo, Yu-Hua; Shang, Hai

2017-01-01

Five new polyketide-terpene hybrid metabolites (1–5) with highly functionalized groups, together with six known derivatives (6–11), were isolated from the endolichenic fungus Pestalotiopsis sp. Their structures were elucidated by extensive NMR experiments including 1H, 13C, HMQC, COSY, and HMBC. The relative configurations of the new compounds were determined by analysis of coupling constants and ROESY correlations. The absolute configurations especially the secondary alcohol at C-15 in 1 and secondary alcohol at C-14 in 5 were established via the CD experiments of the in situ formed [Rh2(OCOCF3)4] complex with the acetonide derivatives. These compounds were tested for their inhibition activity against six plant pathogens. Compounds 1 and 5 exhibited pronounced efficiency against Fusarium oxysporum, and compounds 5 and 6 potently inhibited Fusarium gramineum with MIC value of 8 µg/mL, which revealed the plausible ecological role of endolichenic fungus in providing chemical protection for its host lichen in the fungus-plant relationship. The biosynthetic pathway of compounds 1–11 was postulated for the first time, which paved the way for its further biosynthesis research. PMID:28593175

Polyketide-Terpene Hybrid Metabolites from an Endolichenic Fungus Pestalotiopsis sp.

PubMed

Yuan, Chao; Ding, Gang; Wang, Hai-Ying; Guo, Yu-Hua; Shang, Hai; Ma, Xiao-Jun; Zou, Zhong-Mei

2017-01-01

Five new polyketide-terpene hybrid metabolites ( 1 - 5 ) with highly functionalized groups, together with six known derivatives ( 6 - 11 ), were isolated from the endolichenic fungus Pestalotiopsis sp. Their structures were elucidated by extensive NMR experiments including 1 H, 13 C, HMQC, COSY, and HMBC. The relative configurations of the new compounds were determined by analysis of coupling constants and ROESY correlations. The absolute configurations especially the secondary alcohol at C-15 in 1 and secondary alcohol at C-14 in 5 were established via the CD experiments of the in situ formed [Rh 2 (OCOCF 3 ) 4 ] complex with the acetonide derivatives. These compounds were tested for their inhibition activity against six plant pathogens. Compounds 1 and 5 exhibited pronounced efficiency against Fusarium oxysporum , and compounds 5 and 6 potently inhibited Fusarium gramineum with MIC value of 8  µ g/mL, which revealed the plausible ecological role of endolichenic fungus in providing chemical protection for its host lichen in the fungus-plant relationship. The biosynthetic pathway of compounds 1 - 11 was postulated for the first time, which paved the way for its further biosynthesis research.

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.

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...

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...

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.

Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.

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 andmore » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeda, Itaru; Tamano, Koichi; Yamane, Noriko

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.

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.

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.

The Blast Fungus Decoded: Genomes in Flux.

PubMed

Langner, Thorsten; Białas, Aleksandra; Kamoun, Sophien

2018-04-17

Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae ), which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name, M. oryzae is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018, https://doi.org/10.1128/mBio.01219-17) reports the most extensive population genomic analysis of the blast fungus thus far. M. oryzae consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining M. oryzae as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases. Copyright © 2018 Langner et al.

First unusual case of keratitis in Europe due to the rare fungus Metarhizium anisopliae.

PubMed

Dorin, Josephine; Debourgogne, Anne; Zaïdi, Mohamed; Bazard, Marie-Christine; Machouart, Marie

2015-05-01

Metarhizium anisopliae is a fungus utilized worldwide for insect-pest biocontrol. Few M. anisopliae infections have been reported previously. Here, M. anisopliae was isolated from a corneal ulcer in a healthy man. It is the first ocular case in France and Europe of this extremely rare fungus in humans. Copyright © 2015 Elsevier GmbH. All rights reserved.

Fungus mediated synthesis of biomedically important cerium oxide nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Shadab Ali; Ahmad, Absar, E-mail: a.ahmad@ncl.res.in

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 formore » 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

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.

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

Formation of Ramified Colony of Fungus Aspergillus Oryzae on Agar Media

NASA Astrophysics Data System (ADS)

Matsuura, Shu; Miyazima, Sasuke

Ramified colonies of fungus Aspergillus oryzae have been found to grow at a low growth rate on "liquid-like" agar media with low concentrations of agar and glucose. Box-counting fractal dimensions of the individual colony branches have been found to decrease with the time of incubation. Addition of glucose solution in the interior of branched colonies has brought about the production of the hyphal filaments almost only at the apical region of the colony branches. Active growth of the ramified colonies is localized in the peripheral zone, and this growth manner implies that the fungus is exhibiting a positive exploitation.

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...

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens.

PubMed

Willis, W L; Isikhuemhen, O S; Allen, J W; Byers, A; King, K; Thomas, C

2009-10-01

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

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.

Defending against parasites: fungus-growing ants combine specialized behaviours and microbial symbionts to protect their fungus gardens.

PubMed

Little, Ainslie E F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

2006-03-22

Parasites influence host biology and population structure, and thus shape the evolution of their hosts. Parasites often accelerate the evolution of host defences, including direct defences such as evasion and sanitation and indirect defences such as the management of beneficial microbes that aid in the suppression or removal of pathogens. Fungus-growing ants are doubly burdened by parasites, needing to protect their crops as well as themselves from infection. We show that parasite removal from fungus gardens is more complex than previously realized. In response to infection of their fungal gardens by a specialized virulent parasite, ants gather and compress parasitic spores and hyphae in their infrabuccal pockets, then deposit the resulting pellet in piles near their gardens. We reveal that the ants' infrabuccal pocket functions as a specialized sterilization device, killing spores of the garden parasite Escovopsis. This is apparently achieved through a symbiotic association with actinomycetous bacteria in the infrabuccal pocket that produce antibiotics which inhibit Escovopsis. The use of the infrabuccal pocket as a receptacle to sequester Escovopsis, and as a location for antibiotic administration by the ants' bacterial mutualist, illustrates how the combination of behaviour and microbial symbionts can be a successful defence strategy for hosts.

Defending against parasites: fungus-growing ants combine specialized behaviours and microbial symbionts to protect their fungus gardens

PubMed Central

Little, Ainslie E.F; Murakami, Takahiro; Mueller, Ulrich G; Currie, Cameron R

2005-01-01

Parasites influence host biology and population structure, and thus shape the evolution of their hosts. Parasites often accelerate the evolution of host defences, including direct defences such as evasion and sanitation and indirect defences such as the management of beneficial microbes that aid in the suppression or removal of pathogens. Fungus-growing ants are doubly burdened by parasites, needing to protect their crops as well as themselves from infection. We show that parasite removal from fungus gardens is more complex than previously realized. In response to infection of their fungal gardens by a specialized virulent parasite, ants gather and compress parasitic spores and hyphae in their infrabuccal pockets, then deposit the resulting pellet in piles near their gardens. We reveal that the ants' infrabuccal pocket functions as a specialized sterilization device, killing spores of the garden parasite Escovopsis. This is apparently achieved through a symbiotic association with actinomycetous bacteria in the infrabuccal pocket that produce antibiotics which inhibit Escovopsis. The use of the infrabuccal pocket as a receptacle to sequester Escovopsis, and as a location for antibiotic administration by the ants' bacterial mutualist, illustrates how the combination of behaviour and microbial symbionts can be a successful defence strategy for hosts. PMID:17148313

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

The relationship between an endangered North American tree and an endophytic fungus.

PubMed

Lee, J C; Yang, X; Schwartz, M; Strobel, G; Clardy, J

1995-11-01

The Florida torreya (Torreya taxifolia) began a catastrophic decline in the late 1950s and is now the rarest tree in North America for which a full species designation has been established. The trees have common plant disease symptoms, but the reason for the decline has never been identified. T. taxifolia's imminent extinction gains special poignancy through its close relationship to the Pacific yew (Taxus brevifolia), which produces the potent anticancer agent, taxol. An examination of the endophytic fungal communities of wild torreyas consistently found a filamentous fungus, Pestalotiopsis microspora, associated with diseased trees and also with most symptomless trees. P. microspora can be cultured in the laboratory, and when it is introduced into greenhouse-grown torreyas, it causes disease symptoms similar to those seen in the field. The fungus can then be reisolated from these deliberately infected trees. The phytotoxins pestalopyrone, hydroxypestalopyrone and pestaloside have been isolated and characterized from axenic fungal cultures, and both pestalopyrone and hydroxypestalopyrone can be isolated from artificially infected torreyas. In addition, pestaloside has antifungal activity against other fungal endophytes of T. taxifolia. The filamentous fungus, P. microspora, has an endophytic-pathologic relationship with T. taxifolia. The fungus resides in the inner bark of symptomless trees, and physiological or environmental factors could trigger its pathological activity. P. microspora produces the phytotoxins pestalopyrone, hydroxypestalopyrone, and pestaloside which give rise to the disease. Pestaloside, which also has antifungal activity, could reduce competition from other fungal endophytes within the host.

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...

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.

De novo biosynthesis of cytokinins in the biotrophic fungus Claviceps purpurea.

PubMed

Hinsch, Janine; Vrabka, Josef; Oeser, Birgitt; Novák, Ondřej; Galuszka, Petr; Tudzynski, Paul

2015-08-01

Disease symptoms of some phytopathogenic fungi are associated with changes in cytokinin (CK) levels. Here, we show that the CK profile of ergot-infected rye plants is also altered, although no pronounced changes occur in the expression of the host plant's CK biosynthesis genes. Instead, we demonstrate a clearly different mechanism: we report on the first fungal de novo CK biosynthesis genes, prove their functions and constitute a biosynthetic pathway. The ergot fungus Claviceps purpurea produces substantial quantities of CKs in culture and, like plants, expresses enzymes containing the isopentenyltransferase and lonely guy domains necessary for de novo isopentenyladenine production. Uniquely, two of these domains are combined in one bifunctional enzyme, CpIPT-LOG, depicting a novel and potent mechanism for CK production. The fungus also forms trans-zeatin, a reaction catalysed by a CK-specific cytochrome P450 monooxygenase, which is encoded by cpp450 forming a small cluster with cpipt-log. Deletion of cpipt-log and cpp450 did not affect virulence of the fungus, but Δcpp450 mutants exhibit a hyper-sporulating phenotype, implying that CKs are environmental factors influencing fungal development. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Geosmithia-Ophiostoma: a New Fungus-Fungus Association.

PubMed

Pepori, Alessia L; Bettini, Priscilla P; Comparini, Cecilia; Sarrocco, Sabrina; Bonini, Anna; Frascella, Arcangela; Ghelardini, Luisa; Scala, Aniello; Vannacci, Giovanni; Santini, Alberto

2018-04-01

In Europe as in North America, elms are devastated by Dutch elm disease (DED), caused by the alien ascomycete Ophiostoma novo-ulmi. Pathogen dispersal and transmission are ensured by local species of bark beetles, which established a novel association with the fungus. Elm bark beetles also transport the Geosmithia fungi genus that is found in scolytids' galleries colonized by O. novo-ulmi. Widespread horizontal gene transfer between O. novo-ulmi and Geosmithia was recently observed. In order to define the relation between these two fungi in the DED pathosystem, O. novo-ulmi and Geosmithia species from elm, including a GFP-tagged strain, were grown in dual culture and mycelial interactions were observed by light and fluorescence microscopy. Growth and sporulation of O. novo-ulmi in the absence or presence of Geosmithia were compared. The impact of Geosmithia on DED severity was tested in vivo by co-inoculating Geosmithia and O. novo-ulmi in elms. A close and stable relation was observed between the two fungi, which may be classified as mycoparasitism by Geosmithia on O. novo-ulmi. These results prove the existence of a new component in the complex of organisms involved in DED, which might be capable of reducing the disease impact.

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.

Changes in selected enzyme activities during growth of pure and mixed cultures of the white-rot decay fungus Trametes versicolor and the potential biocontrol fungus Trichoderma harzianum.

PubMed

Freitag, M; Morrell, J J

1992-04-01

Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organism Trichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase, and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum.

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.

Arbuscular mycorrhizal fungus inoculation reduces the drought-resistance advantage of endophyte-infected versus endophyte-free Leymus chinensis.

PubMed

Liu, Hui; Chen, Wei; Wu, Man; Wu, Rihan; Zhou, Yong; Gao, Yubao; Ren, Anzhi

2017-11-01

Grasses can be infected simultaneously by endophytic fungi and arbuscular mycorrhizal (AM) fungi. In this study, we tested the hypothesis that endophyte-associated drought resistance of a native grass was affected by an AM fungus. In a greenhouse experiment, we compared the performance of endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis, a dominant species native to the Inner Mongolia steppe, under altered water and AM fungus availability. The results showed that endophyte infection significantly increased drought resistance of the host grass, but the beneficial effects were reduced by AM fungus inoculation. In the mycorrhizal-non-inoculated (MF) treatment, EI plants accumulated significantly more biomass, had greater proline and total phenolic concentration, and lower malondialdehyde concentration than EF plants. In the mycorrhizal-inoculation (MI) treatment, however, no significant difference occurred in either growth or physiological characters measured between EI and EF plants. AM fungus inoculation enhanced drought resistance of EF plants but had no significant effect on drought resistance of EI plants, thus AM fungus inoculation reduced the difference between EI and EF plants. Our findings highlight the importance of interactions among multiple microorganisms for plant performance under drought stress.

Fungus-Farming Termites Selectively Bury Weedy Fungi that Smell Different from Crop Fungi.

PubMed

Katariya, Lakshya; Ramesh, Priya B; Gopalappa, Thejashwini; Desireddy, Sathish; Bessière, Jean-Marie; Borges, Renee M

2017-10-01

Mutualistic associations such as the fungal farms of insects are prone to parasitism and are consequently vulnerable to attack by weeds and pests. Therefore, efficient farm management requires quick detection of weeds for their elimination. Furthermore, if the available weedicides are non-specific, then the ability of insects to discriminate between crop and weeds becomes essential for targeted application of such compounds. Here, we demonstrate for the first time in fungus-farming insects, that worker castes of the fungus-growing termite Odontotermes obesus discriminate between their crop (Termitomyces) and the weedy (Pseudoxylaria) fungi, even if exposed to only fungal scents. Termites respond to the presence of fungal mycelium or scent alone, by burying the weed with the offered material such as soil or agar, possibly anointing the weed with chemicals in the process. The scent profiles of crop and weedy fungi are distinct and the differences are likely exploited by termites to selectively mount their defences. Sesquiterpene compounds such as aristolene and viridiflorol, which are absent from crop odours, may constitute the "weedy scent". Our results provide a general mechanism of how other fungus-farming insects could avoid indiscriminate application of non-specific fungicides which could lead to poisoning their crops, and have bearing on the stability of the mutualism between termites and their crop fungus in the face of parasitism by weedy fungi.

The Hidden Habit of the Entomopathogenic Fungus Beauveria bassiana: First Demonstration of Vertical Plant Transmission

PubMed Central

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. PMID:24551242

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.

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...

RNAi-mediated down-regulation of a melanin polyketide synthase (pks1) gene in the fungus Slafractonia leguminicola

USDA-ARS?s Scientific Manuscript database

The fungus Slafractonia leguminicola, the causal agent of blackpatch disease of legumes produces two mycotoxins slaframine and swainsonine, causing slobbers’ symptoms and locoism of grazing animals, respectively. The genetics of this important fungus is poorly understood. This work aimed to develop ...

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...

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.

Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

PubMed

Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

2016-03-01

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus

PubMed Central

Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk

2016-01-01

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously. PMID:27103854

Plant-driven weathering of apatite--the role of an ectomycorrhizal fungus.

PubMed

Smits, M M; Bonneville, S; Benning, L G; Banwart, S A; Leake, J R

2012-09-01

Ectomycorrhizal (EcM) fungi are increasingly recognized as important agents of mineral weathering and soil development, with far-reaching impacts on biogeochemical cycles. Because EcM fungi live in a symbiotic relationship with trees and in close contact with bacteria and archaea, it is difficult to distinguish between the weathering effects of the fungus, host tree and other micro-organisms. Here, we quantified mineral weathering by the fungus Paxillus involutus, growing in symbiosis with Pinus sylvestris under sterile conditions. The mycorrhizal trees were grown in specially designed sterile microcosms in which the supply of soluble phosphorus (P) in the bulk media was varied and grains of the calcium phosphate mineral apatite mixed with quartz, or quartz alone, were provided in plastic wells that were only accessed by their fungal partner. Under P limitation, pulse labelling of plants with (14)CO(2) revealed plant-to-fungus allocation of photosynthates, with 17 times more (14)C transferred into the apatite wells compared with wells with only quartz. Fungal colonization increased the release of P from apatite by almost a factor of three, from 7.5 (±1.1) × 10(-10) mol m(-2) s(-1) to 2.2 (±0.52) × 10(-9) mol m(-2) s(-1). On increasing the P supply in the microcosms from no added P, through apatite alone, to both apatite and orthophosphate, the proportion of biomass in roots progressively increased at the expense of the fungus. These three observations, (i) proportionately more plant energy investment in the fungal partner under P limitation, (ii) preferential fungal transport of photosynthate-derived carbon towards patches of apatite grains and (iii) fungal enhancement of weathering rate, reveal the tightly coupled plant-fungal interactions underpinning enhanced EcM weathering of apatite and its utilization as P source. © 2012 Blackwell Publishing Ltd.

Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens

PubMed Central

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

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. PMID:23469353

Comparison of radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa forel in two culture media

PubMed Central

Miyashira, C.H.; Tanigushi, D.G.; Gugliotta, A.M.; Santos, D.Y.A.C.

2010-01-01

In vitro culture of the mutualistic fungus of leaf-cutting ants is troublesome due to its low growth rate, which leads to storage problems and contaminants accumulation. This paper aims at comparing the radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa Forel in two different culture media (Pagnocca B and MEA LP). Although total MEA LP radial growth was greater all along the bioassay, no significant difference was detected between growth efficiencies of the two media. Previous evidences of low growth rate for this fungus were confirmed. Since these data cannot point greater efficiency of one culture medium over the other, MEA LP medium is indicated for in vitro studies with this mutualistic fungus due its simpler composition and translucent color, making the analysis easier. PMID:24031524

Laccase production by Monotospora sp., an endophytic fungus in Cynodon dactylon.

PubMed

Wang, J W; Wu, J H; Huang, W Y; Tan, R X

2006-03-01

The effects of the carbon and nitrogen sources, initial pH and incubation temperature on laccase production by the endophytic fungus Monotospora sp. were evaluated. The optimal temperature and initial pH for laccase production by Monotospora sp. in submerged culture were found to be 30 degrees C and 8.5, respectively. Maltose (2 g l(-1)) and ammonium tartrate (10 g l(-1)) were the most suitable carbon and nitrogen source for laccase production. Under optimal culture medium, the maximum laccase activity was determined to be 13.55 U ml(-1), which was approximately four times higher than that in basal medium. This is the first report on laccase production by an endophytic fungus.

Fungus mediated biosynthesis of WO3 nanoparticles using Fusarium solani extract

NASA Astrophysics Data System (ADS)

Kavitha, N. S.; Venkatesh, K. S.; Palani, N. S.; Ilangovan, R.

2017-05-01

Currently nanoparticles were synthesized by emphasis bioremediation process due to less hazardous, eco-friendly and imperative applications on biogenic process. Fungus mediated biosynthesis strategy has been developed to prepare tungsten oxide nanoflakes (WO3, NFs) using the plant pathogenic fungus F.solani. The powder XRD pattern revealed the monoclinic crystal structure with improved crystalline nature of the synthesized WO3 nanoparticles. FESEM images showed the flake-like morphology of WO3, with average thickness and length around 40 nm and 300 nm respectively. The Raman spectrum of WO3 NFs showed their characteristic vibration modes that revealed the defect free nature of the WO3 NFs. Further, the elemental analysis indicated the stoichiometric composition of WO3 phase.

Unintentional ingestion of Cordyceps fungus-infected cicada nymphs causing ibotenic acid poisoning in Southern Vietnam.

PubMed

Doan, Uyen Vy; Mendez Rojas, Bomar; Kirby, Ralph

2017-09-01

Cordyceps fungus found in infected cicada nymphs ("cicada flowers") is utilized in traditional Chinese medicine. Cordyceps fungus toxicity in humans has not been previously reported. We report 60 cases of apparent Cordyceps poisoning in Southern Vietnam. We retrospectively collected demographic and clinical data from the medical records (21 cases) and by telephone interview (39 cases) of patients admitted to seven hospitals in Southern Vietnam following ingestion of cicada flowers between 2008 and 2015. We also determined the species of Cordyceps present in the cicada flowers and performed a partial chemical analysis of the fungus. Sixty cases of toxic effects following ingestion of cicada flowers were documented. Symptom onset occurred within 60 minutes following ingestion. Symptoms included dizziness, vomiting, salivation, mydriasis, jaw stiffness, urinary retention, seizures, agitated delirium, hallucinations, somnolence and coma. None of the patients suffered liver or kidney injury. There was one fatality. The Cordyceps fungus involved in these poisoning was identified as Ophiocordyceps heteropoda. The presence of ibotenic acid was confirmed, but musimol and muscarine were absent. Cicada infected with Ophiocordyceps heteropoda in Vietnam contain ibotenic acid and are associated with a clinical syndrome consistent with its effects.

Complete Genome of Serratia sp. Strain FGI 94, a Strain Associated with Leaf-Cutter Ant Fungus Gardens

PubMed Central

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

2013-01-01

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. PMID:23516234

Volatiles from the xylarialean fungus Hypoxylon invadens.

PubMed

Dickschat, Jeroen S; Wang, Tao; Stadler, Marc

2018-01-01

The volatiles emitted by agar plate cultures of the xylarialean fungus Hypoxylon invadens were investigated by use of a closed loop stripping apparatus in combination with GC-MS. Several aromatic compounds were found that could only be identified by comparison to all possible constitutional isomers with different ring substitution patterns. For the set of identified compounds a plausible biosynthetic scheme was suggested that gives further support for the assigned structures.

Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

PubMed Central

Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

2015-01-01

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490

Leaf-cutter ant fungus gardens are biphasic mixed microbial bioreactors that convert plant biomass to polyols with biotechnological applications.

PubMed

Somera, Alexandre F; Lima, Adriel M; Dos Santos-Neto, Álvaro J; Lanças, Fernando M; Bacci, Maurício

2015-07-01

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Biological control of trichostrongyles in beef cattle by the nematophagous fungus Duddingtonia flagrans in tropical southeastern Brazil.

PubMed

Assis, R C L; Luns, F D; Araújo, J V; Braga, F R

2012-11-01

The efficacy of a fungal formulation based on the nematophagous fungus Duddingtonia flagrans was assessed in the control of cattle trichostrongyles. Twenty male Nellore calves, six-month-old, divided in two groups (fungus-treated and control without fungus) were fed on a pasture of Brachiaria decumbens naturally infected with larvae of bovine trichostrongyles. Animals of the treated group received doses of sodium alginate mycelial pellets orally (1 g/10 kg live weight, twice a week), for 12 months. Feces samples were collected for egg count (eggs per gram of feces-EPG) and coprocultures during 12 months. There was a significant reduction in EPG (56.7%) and infective larvae (L3) in coprocultures (60.5%) for animals of the treated group in relation to the control group at the end of the study. There was a significant reduction of L3 (64.5%) in herbage samples collected up to 0-20 cm from fecal pats and 73.2% in distant samples (20-40 cm) between the fungus-treated group and the control group. The treatment with sodium alginate pellets containing the nematode trapping fungus D. flagrans reduced trichostrongylid in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode in beef cattle. Copyright © 2012 Elsevier Inc. All rights reserved.

Synergistic interaction between the fungus Beauveria bassiana and desiccant dusts applied against poultry red mites (Dermanyssus gallinae).

PubMed

Steenberg, Tove; Kilpinen, Ole

2014-04-01

The poultry red mite, Dermanyssus gallinae, is a major pest in egg production, feeding on laying hens. Widely used non-chemical control methods include desiccant dusts, although their persistence under field conditions is often short. Entomopathogenic fungi may also hold potential for mite control, but these fungi often take several days to kill mites. Laboratory experiments were carried out to study the efficacy of 3 types of desiccant dusts, the fungus Beauveria bassiana and combinations of the two control agents against D. gallinae. There was significant synergistic interaction between each of the desiccant dusts and the fungus, with observed levels of mite mortality significantly higher than those expected for an additive effect (up to 38 % higher). Synergistic interaction between desiccant dust and fungus was found also when different application methods were used for the fungus and at different levels of relative humidity. Although increased levels of mortality were reached due to the synergistic interaction, the speed of lethal action was not influenced by combining the two components. The persistence of the control agents applied separately or in combination did not change over a period of 4 weeks. Overall, combinations of desiccant dusts and fungus conidia seem to hold considerable promise for future non-chemical control of poultry red mites.

A new polyoxygenated farnesylcyclohexenone from Fungus Penicillium sp.

PubMed

Yang, Yabin; Yang, Fangfang; Zhao, Lixing; Duang, Rongting; Chen, Guangyi; Li, Xiaozhan; Li, Qiling; Qin, Shaohuan; Ding, Zhongtao

2016-01-01

A new polyoxygenated farnesylcyclohexenone, peniginsengin A (1), was isolated from the fermentation of Penicillium sp. YIM PH30003, an endophytic fungus associated with Panax notoginseng (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound 1 were investigated.

Enzyme Activities at Different Stages of Plant Biomass Decomposition in Three Species of Fungus-Growing Termites

PubMed Central

Pedersen, Kristine S. K.; Aanen, Duur K.

2017-01-01

ABSTRACT Fungus-growing termites rely on mutualistic fungi of the genus Termitomyces and gut microbes for plant biomass degradation. Due to a certain degree of symbiont complementarity, this tripartite symbiosis has evolved as a complex bioreactor, enabling decomposition of nearly any plant polymer, likely contributing to the success of the termites as one of the main plant decomposers in the Old World. In this study, we evaluated which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We found a diversity of active enzymes at different stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant substrate. However, preliminary fungal RNA sequencing (RNA-seq) analyses suggest that this likely transport is supplemented with enzymes produced in situ. Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mixture of plant material, fungal spores, and enzymes, is likely the key to the extraordinarily efficient plant decomposition in fungus-growing termites. IMPORTANCE Fungus-growing termites have a substantial ecological footprint in the Old World (sub)tropics due to their ability to decompose dead plant material. Through the establishment of an elaborate plant biomass inoculation strategy and through fungal and bacterial enzyme contributions, this farming symbiosis has become an efficient and versatile aerobic bioreactor for plant substrate conversion. Since little is known about what enzymes are expressed and where they are active at different stages of the decomposition process, we used enzyme assays, transcriptomics, and plant content measurements to shed light on how this decomposition of plant

Enzyme Activities at Different Stages of Plant Biomass Decomposition in Three Species of Fungus-Growing Termites.

PubMed

da Costa, Rafael R; Hu, Haofu; Pilgaard, Bo; Vreeburg, Sabine M E; Schückel, Julia; Pedersen, Kristine S K; Kračun, Stjepan K; Busk, Peter K; Harholt, Jesper; Sapountzis, Panagiotis; Lange, Lene; Aanen, Duur K; Poulsen, Michael

2018-03-01

Fungus-growing termites rely on mutualistic fungi of the genus Termitomyces and gut microbes for plant biomass degradation. Due to a certain degree of symbiont complementarity, this tripartite symbiosis has evolved as a complex bioreactor, enabling decomposition of nearly any plant polymer, likely contributing to the success of the termites as one of the main plant decomposers in the Old World. In this study, we evaluated which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We found a diversity of active enzymes at different stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant substrate. However, preliminary fungal RNA sequencing (RNA-seq) analyses suggest that this likely transport is supplemented with enzymes produced in situ Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mixture of plant material, fungal spores, and enzymes, is likely the key to the extraordinarily efficient plant decomposition in fungus-growing termites. IMPORTANCE Fungus-growing termites have a substantial ecological footprint in the Old World (sub)tropics due to their ability to decompose dead plant material. Through the establishment of an elaborate plant biomass inoculation strategy and through fungal and bacterial enzyme contributions, this farming symbiosis has become an efficient and versatile aerobic bioreactor for plant substrate conversion. Since little is known about what enzymes are expressed and where they are active at different stages of the decomposition process, we used enzyme assays, transcriptomics, and plant content measurements to shed light on how this decomposition of plant substrate is so

Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

PubMed Central

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

2012-01-01

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. PMID:22378535

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...

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...

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

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.

Bioactive Constituents from an Endophytic Fungus, Penicillium polonicum NFW9, Associated with Taxus fauna.

PubMed

Fatima, Nighat; Sripisut, Tawanun; Youn, Ui J; Ahmed, Safia; Ul-Haq, Ihsan; Munoz-Acuna, Ulyana; Simmons, Charles J; Qazi, Muneer A; Jadoon, Muniba; Tan, Ghee T; de Blanco, Esperanza J C; Chang, Leng C

2017-01-01

Endophytic fungi are being recognized as vital and untapped sources of a variety of structurally novel and unique bioactive secondary metabolites in the field of natural products drug discovery. Herein, this study reports the isolation and characterization of secondary metabolites from an endophytic fungus Penicillium polonicum (NFW9) associated with Taxus fuana. The extracts of the endophytic fungus cultured on potato dextrose agar were purified using several chromatographic techniques. Biological evaluation was performed based on their abilities to inhibit tumor necrosis factor-alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB) and cytotoxicity assays. Bioactivity-directed fractionation of the ethyl acetate extract of a fermentation culture of an endophytic fungus, Penicillium polonicum led to the isolation of a dimeric anthraquinone, (R)- 1,1',3,3',5,5'-hexahydroxy-7,7'-dimethyl[2,2'-bianthracene]-9,9',10,10'-tetraone (1), a steroidal furanoid (-)-wortmannolone (2), along with three other compounds (3-4). Moreover, this is the first report on the isolation of compound 1 from an endophytic fungus. All purified metabolites were characterized by NMR and MS data analyses. The stereo structure of compound 1 was determined by the measurement of specific optical rotation and CD spectrum. The relative stereochemistry of 2 was confirmed by single-crystal X-ray diffraction. Compounds 2-3 showed inhibitory activities in the TNF-α-induced NF-κB assay with IC50 values in the range of 0.47-2.11 µM. Compounds 1, 4 and 5 showed moderate inhibition against NF-κB and cancer cell lines. The endophytic fungus Penicillium polonicum of Taxus fuana is capable of producing biologically active natural compounds. Our results provide a scientific rationale for further chemical investigations into endophyte-producing natural products, drug discovery and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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...

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. Copyright © 2011 Elsevier Inc. All rights reserved.

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

The fungus Ustilago maydis, from the aztec cuisine to the research laboratory.

PubMed

Ruiz-Herrera, J; Martínez-Espinoza, A D

1998-06-01

Ustilago maydis is a plant pathogen fungus responsible for corn smut. It has a complex life cycle. In its saprophitic stage, it grows as haploid yeast cells, while in the invasive stage it grows as a mycelium formed by diploid cells. Thus, a correlation exists between genetic ploidy, pathogenicity and morphogenesis. Dimorphism can be modulated in vitro by changing environmental parameters such as pH. Studies with auxotrophic mutants have shown that polyamines play a central role in regulating dimorphism. Molecular biology approaches are being employed for the analysis of fundamental aspects of the biology of this fungus, such as mating type regulation, dimorphism or cell wall biogenesis.

Meroterpenoids and isoberkedienolactone from endophytic fungus Penicillium sp. associated with Dysosma versipellis.

PubMed

Li, Jun-Wei; Duan, Rui-Gang; Zou, Jian-Hua; Chen, Ri-Dao; Chen, Xiao-Guang; Dai, Jun-Gui

2014-06-01

Seven meroterpenoids and five small-molecular precursors were isolated from Penicillium sp., an endophytic fungus from Dysosma versipellis. The structures of new compounds, 11beta-acetoxyisoaustinone (1) and isoberkedienolactone (2) were elucidated based on analysis of the spectral data, and the absolute configuration of 2 was established by TDDFT ECD calculation with satisfactory match to its experimental ECD data. Meroterpenoids originated tetraketide and pentaketide precursors, resepectively, were found to be simultaneously produced in specific fungus of Penicillium species. These compounds showed weak cytotoxicity in vitro against HCT-116, HepG2, BGC-823, NCI-H1650, and A2780 cell lines with IC 50 > 10 micromol x L(-1).

Muscodor kashayum sp. nov. – a new volatile anti-microbial producing endophytic fungus

PubMed Central

Meshram, Vineet; Kapoor, Neha; Saxena, Sanjai

2014-01-01

Muscodor kashayum (MycoBank no.: MB 803800; GenBank no.: KC481680) is a newly described endophytic fungus of a medicinal plant Aegle marmelos (Bael tree), growing in the tropical conserved rainforest in the Western Ghats of India. Muscodor kashayum possesses distinct morphological, molecular and physiological features from the earlier reported Muscodor species. The fungus forms characteristic rings of the ropy mycelium on potato dextrose agar medium. This sterile fungus is characterised by the presence of a pungent smell which is attributable to a blend of more than 23 volatile organic constituents, predominantly 3-cyclohexen-1-ol,1-(1,5-dimethyl-4-hexenyl)-4-methyl; 1,6-dioxacyclododecane-7,12-dione; 2,6-bis(1,1-dimethylethyl)-4-(1-oxopropyl) phenol; 2,4-di-tert-butylthiophenol and 4-octadecylmorpholine. In the in vitro anti-microbial assay using M. kashayum, growth of 75% of test fungi/yeasts and 72% of the test bacteria were completely inhibited. Therefore, M. Kashayum holds potential for future application to be used as a myco-fumigation agent. PMID:24587960

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...

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...

Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.

Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass ismore » degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.« less

Oligocene Termite Nests with In Situ Fungus Gardens from the Rukwa Rift Basin, Tanzania, Support a Paleogene African Origin for Insect Agriculture

PubMed Central

Roberts, Eric M.; Todd, Christopher N.; Aanen, Duur K.; Nobre, Tânia; Hilbert-Wolf, Hannah L.; O’Connor, Patrick M.; Tapanila, Leif; Mtelela, Cassy; Stevens, Nancy J.

2016-01-01

Based on molecular dating, the origin of insect agriculture is hypothesized to have taken place independently in three clades of fungus-farming insects: the termites, ants or ambrosia beetles during the Paleogene (66–24 Ma). Yet, definitive fossil evidence of fungus-growing behavior has been elusive, with no unequivocal records prior to the late Miocene (7–10 Ma). Here we report fossil evidence of insect agriculture in the form of fossil fungus gardens, preserved within 25 Ma termite nests from southwestern Tanzania. Using these well-dated fossil fungus gardens, we have recalibrated molecular divergence estimates for the origins of termite agriculture to around 31 Ma, lending support to hypotheses suggesting an African Paleogene origin for termite-fungus symbiosis; perhaps coinciding with rift initiation and changes in the African landscape. PMID:27333288

Chemical study of the fungus Psilocybe merdaria.

PubMed

Yang, Ning-Ning; Ma, Qing-Yun; Huang, Sheng-Zhuo; Kong, Fan-Dong; Dai, Hao-Fu; Yu, Zhi-Fang; Zhao, You-Xing

2017-04-01

Chemical investigation on the cultures of the fungus Psilocybe merdaria resulted in the first isolation of 10 compounds including two new ones 11,14-dihydroxylneoechinulin E (1) and (S)-4-(4-methylpent-3-en-1-yl)-butyrolactone (2). Their structures were elucidated from the analysis of 1D and 2D NMR and MS data. Among them, compound 7 showed inhibitory activity against AChE with 20% percentage at a concentration of 50 μg/ml.

New Cytochalasin from Rosellinia sanctae-cruciana, an Endophytic Fungus of Albizia lebbeck.

PubMed

Sharma, Nisha; Kushwaha, Manoj; Arora, Divya; Jain, Shreyans; Singamaneni, Venugopal; Sharma, Sonia; Shankar, Ravi; Bhushan, Shashi; Gupta, Prasoon; Jaglan, Sundeep

2018-03-24

To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds. One novel cytochalasin, named Jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus Rosellinia sanctae-cruciana, harbored from the leaves of medicinal plant Albizia lebbeck. Their structures were elucidated by extensive spectroscopic analyses including 1D and 2D NMR data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for the cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa -2 and MDA-MB-231), was found to be active against MOLT-4 with IC 50 value of 10 μg/mL. Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukemia cancer cell line (MOLT-4) with IC 50 values of 20.0, 10.0, 8.0 and 6.0 μM, respectively, while compound 3 showed IC 50 value of 25 μM. This is the first report of existence of this class of secondary metabolites in Rosellinia sanctae-cruciana fungus. This study discovered a novel compound, named Jammosporin A, isolated for the first time from Rosellinia sanctae-cruciana, an endophytic fungus of Albizia lebbeck with anticancer activity against MOLT-4 cell line. Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against human leukemia cancer cell line (MOLT-4). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Microbial community structure of leaf-cutter ant fungus gardens and refuse dumps.

PubMed

Scott, Jarrod J; Budsberg, Kevin J; Suen, Garret; Wixon, Devin L; Balser, Teri C; Currie, Cameron R

2010-03-29

Leaf-cutter ants use fresh plant material to grow a mutualistic fungus that serves as the ants' primary food source. Within fungus gardens, various plant compounds are metabolized and transformed into nutrients suitable for ant consumption. This symbiotic association produces a large amount of refuse consisting primarily of partly degraded plant material. A leaf-cutter ant colony is thus divided into two spatially and chemically distinct environments that together represent a plant biomass degradation gradient. Little is known about the microbial community structure in gardens and dumps or variation between lab and field colonies. Using microbial membrane lipid analysis and a variety of community metrics, we assessed and compared the microbiota of fungus gardens and refuse dumps from both laboratory-maintained and field-collected colonies. We found that gardens contained a diverse and consistent community of microbes, dominated by Gram-negative bacteria, particularly gamma-Proteobacteria and Bacteroidetes. These findings were consistent across lab and field gardens, as well as host ant taxa. In contrast, dumps were enriched for Gram-positive and anaerobic bacteria. Broad-scale clustering analyses revealed that community relatedness between samples reflected system component (gardens/dumps) rather than colony source (lab/field). At finer scales samples clustered according to colony source. Here we report the first comparative analysis of the microbiota from leaf-cutter ant colonies. Our work reveals the presence of two distinct communities: one in the fungus garden and the other in the refuse dump. Though we find some effect of colony source on community structure, our data indicate the presence of consistently associated microbes within gardens and dumps. Substrate composition and system component appear to be the most important factor in structuring the microbial communities. These results thus suggest that resident communities are shaped by the plant degradation

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)

The effector candidate repertoire of the arbuscular mycorrhizal fungus Rhizophagus clarus.

PubMed

Sędzielewska Toro, Kinga; Brachmann, Andreas

2016-02-09

Arbuscular mycorrhizal fungi (AMF) form an ecologically important symbiosis with more than two thirds of studied land plants. Recent studies of plant-pathogen interactions showed that effector proteins play a key role in host colonization by controlling the plant immune system. We hypothesise that also for symbiotic-plant interactions the secreted effectome of the fungus is a major component of communication and the conservation level of effector proteins between AMF species may be indicative whether they play a fundamental role. In this study, we used a bioinformatics pipeline to predict and compare the effector candidate repertoire of the two AMF species, Rhizophagus irregularis and Rhizophagus clarus. Our in silico pipeline revealed a list of 220 R. irregularis candidate effector genes that create a valuable information source to elucidate the mechanism of plant infection and colonization by fungi during AMF symbiotic interaction. While most of the candidate effectors show no homologies to known domains or proteins, the candidates with homologies point to potential roles in signal transduction, cell wall modification or transcription regulation. A remarkable aspect of our work is presence of a large portion of the effector proteins involved in symbiosis, which are not unique to each fungi or plant species, but shared along the Glomeromycota phylum. For 95% of R. irregularis candidates we found homologs in a R. clarus genome draft generated by Illumina high-throughput sequencing. Interestingly, 9% of the predicted effectors are at least as conserved between the two Rhizophagus species as proteins with housekeeping functions (similarity > 90%). Therefore, we state that this group of highly conserved effector proteins between AMF species may play a fundamental role during fungus-plant interaction. We hypothesise that in symbiotic interactions the secreted effectome of the fungus might be an important component of communication. Identification and functional

Ethanol effect on metabolic activity of the ethalogenic fungus Fusarium oxysporum.

PubMed

Paschos, Thomas; Xiros, Charilaos; Christakopoulos, Paul

2015-03-12

Fusarium oxysporum is a filamentous fungus which has attracted a lot of scientific interest not only due to its ability to produce a variety of lignocellulolytic enzymes, but also because it is able to ferment both hexoses and pentoses to ethanol. Although this fungus has been studied a lot as a cell factory, regarding applications for the production of bioethanol and other high added value products, no systematic study has been performed concerning its ethanol tolerance levels. In aerobic conditions it was shown that both the biomass production and the specific growth rate were affected by the presence of ethanol. The maximum allowable ethanol concentration, above which cells could not grow, was predicted to be 72 g/L. Under limited aeration conditions the ethanol-producing capability of the cells was completely inhibited at 50 g/L ethanol. The lignocellulolytic enzymatic activities were affected to a lesser extent by the presence of ethanol, while the ethanol inhibitory effect appears to be more severe at elevated temperatures. Moreover, when the produced ethanol was partially removed from the broth, it led to an increase in fermenting ability of the fungus up to 22.5%. The addition of F. oxysporum's system was shown to increase the fermentation of pretreated wheat straw by 11%, in co-fermentation with Saccharomyces cerevisiae. The assessment of ethanol tolerance levels of F. oxysporum on aerobic growth, on lignocellulolytic activities and on fermentative performance confirmed its biotechnological potential for the production of bioethanol. The cellulolytic and xylanolytic enzymes of this fungus could be exploited within the biorefinery concept as their ethanol resistance is similar to that of the commercial enzymes broadly used in large scale fermentations and therefore, may substantially contribute to a rational design of a bioconversion process involving F. oxysporum. The SSCF experiments on liquefied wheat straw rich in hemicellulose indicated that the

Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basavaraja, S.; Balaji, S.D.; Department of Chemistry, Gulbarga University, Gulbarga 585106, Karnataka

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 particlesmore » 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.« less

Genome characteristics reveal the impact of lichenization on lichen-forming fungus Endocarpon pusillum Hedwig (Verrucariales, Ascomycota)

PubMed Central

2014-01-01

Background Lichen is a classic mutualistic organism and the lichenization is one of the fungal symbioses. The lichen-forming fungus Endocarpon pusillum is living in symbiosis with the green alga Diplosphaera chodatii Bialsuknia as a lichen in the arid regions. Results 454 and Illumina technologies were used to sequence the genome of E. pusillum. A total of 9,285 genes were annotated in the 37.5 Mb genome of E. pusillum. Analyses of the genes provided direct molecular evidence for certain natural characteristics, such as homothallic reproduction and drought-tolerance. Comparative genomics analysis indicated that the expansion and contraction of some protein families in the E. pusillum genome reflect the specific relationship with its photosynthetic partner (D. chodatii). Co-culture experiments using the lichen-forming fungus E. pusillum and its algal partner allowed the functional identification of genes involved in the nitrogen and carbon transfer between both symbionts, and three lectins without signal peptide domains were found to be essential for the symbiotic recognition in the lichen; interestingly, the ratio of the biomass of both lichen-forming fungus and its photosynthetic partner and their contact time were found to be important for the interaction between these two symbionts. Conclusions The present study lays a genomic analysis of the lichen-forming fungus E. pusillum for demonstrating its general biological features and the traits of the interaction between this fungus and its photosynthetic partner D. chodatii, and will provide research basis for investigating the nature of its drought resistance and symbiosis. PMID:24438332

Impact of Climate Change on Potential Distribution of Chinese Caterpillar Fungus (Ophiocordyceps sinensis) in Nepal Himalaya

PubMed Central

Shrestha, Uttam Babu; Bawa, Kamaljit S.

2014-01-01

Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11–4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species. PMID:25180515

Impact of climate change on potential distribution of Chinese caterpillar fungus (Ophiocordyceps sinensis) in Nepal Himalaya.

PubMed

Shrestha, Uttam Babu; Bawa, Kamaljit S

2014-01-01

Climate change has already impacted ecosystems and species and substantial impacts of climate change in the future are expected. Species distribution modeling is widely used to map the current potential distribution of species as well as to model the impact of future climate change on distribution of species. Mapping current distribution is useful for conservation planning and understanding the change in distribution impacted by climate change is important for mitigation of future biodiversity losses. However, the current distribution of Chinese caterpillar fungus, a flagship species of the Himalaya with very high economic value, is unknown. Nor do we know the potential changes in suitable habitat of Chinese caterpillar fungus caused by future climate change. We used MaxEnt modeling to predict current distribution and changes in the future distributions of Chinese caterpillar fungus in three future climate change trajectories based on representative concentration pathways (RCPs: RCP 2.6, RCP 4.5, and RCP 6.0) in three different time periods (2030, 2050, and 2070) using species occurrence points, bioclimatic variables, and altitude. About 6.02% (8,989 km2) area of the Nepal Himalaya is suitable for Chinese caterpillar fungus habitat. Our model showed that across all future climate change trajectories over three different time periods, the area of predicted suitable habitat of Chinese caterpillar fungus would expand, with 0.11-4.87% expansion over current suitable habitat. Depending upon the representative concentration pathways, we observed both increase and decrease in average elevation of the suitable habitat range of the species.

Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

PubMed Central

Arroyo-Figueroa, Gabriela; Ruiz-Aguilar, Graciela M. L.; López-Martínez, Leticia; González-Sánchez, Guillermo; Cuevas-Rodríguez, Germán; Rodríguez-Vázquez, Refugio

2011-01-01

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. PMID:21552764

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.

Characteristics of a newly isolated fungus Geotrichum candidum Dec 1 with broad degradation spectrum of xenobiotic compounds.

PubMed

Shoda, M

2003-01-01

A newly isolated fungus, Geotrichum candidum Dec 1 (abbreviated as Dec 1), was found to have the ability to degrade many xenobiotic compounds such as synthetic dyes, food coloring agents, molasses, organic halogens, lignin and kraft pulp effluents. The broad spectrum of the degradation of these compounds are associated mainly with peroxidases produced by the fungus.

Intercontinental divergence in the Populus-associated ectomycorrhizal fungus, Tricholoma populinum

Treesearch

L.C. Grubisha; N. Levsen; M.S. Olson; D.L. Taylor

2012-01-01

The ectomycorrhizal fungus Tricholoma populinum is host-specific with Populus species. T. populinum has wind-dispersed progagules and may be capable of long-distance dispersal. In this study, we tested the hypothesis of a panmictic population between Scandinavia and North America. DNA sequences from five...

Cyclodepsipeptides, sesquiterpenoids, and other cytotoxic metabolites from the filamentous fungus Trichothecium sp. (MSX 51320).

PubMed

Sy-Cordero, Arlene A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Shen, Qi; Swanson, Steven M; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2011-10-28

Two new cyclodepsipeptides (1 and 2), two new sesquiterpenoids (3 and 4), and the known compounds guangomide A (5), roseotoxin S, and three simple trichothecenes were isolated from the cytotoxic organic extract of a terrestrial filamentous fungus, Trichothecium sp. The structures were determined using NMR spectroscopy and mass spectrometry. Absolute configurations of the cyclodepsipeptides were established by employing chiral HPLC, while the relative configurations of 3 and 4 were determined via NOESY data. The isolation of guangomide A was of particular interest, since it was reported previously from a marine-derived fungus.

The effects of the fungus Metarhizium anisopliae var. acridum on different stages of Lutzomyia longipalpis (Diptera: Psychodidae).

PubMed

Amóra, Sthenia Santos Albano; Bevilaqua, Claudia Maria Leal; Feijó, Francisco Marlon Carneiro; Pereira, Romeika Hermínia de Macedo Assunção; Alves, Nilza Dutra; Freire, Fúlvio Aurélio de Morais; Kamimura, Michel Toth; de Oliveira, Diana Magalhães; Luna-Alves Lima, Elza Aurea; Rocha, Marcos Fábio Gadelha

2010-03-01

The control of Visceral Leishmaniasis (VL) vector is often based on the application of chemical residual insecticide. However, this strategy has not been effective. The continuing search for an appropriate vector control may include the use of biological control. This study evaluates the effects of the fungus Metarhizium anisopliae var. acridum on Lutzomyia longipalpis. Five concentrations of the fungus were utilized, 1 x 10(4) to 1 x 10(8) conidia/ml, accompanied by controls. The unhatched eggs, larvae and dead adults previously exposed to fungi were sown to reisolate the fungi and analysis of parameters of growth. The fungus was subsequently identified by PCR and DNA sequencing. M. anisopliae var. acridum reduced egg hatching by 40%. The mortality of infected larvae was significant. The longevity of infected adults was lower than that of negative controls. The effects of fungal infection on the hatching of eggs laid by infected females were also significant. With respect to fungal growth parameters post-infection, only vegetative growth was not significantly higher than that of the fungi before infection. The revalidation of the identification of the reisolated fungus was confirmed post-passage only from adult insects. In terms of larvae mortality and the fecundity of infected females, the results were significant, proving that the main vector species of VL is susceptible to infection by this entomopathogenic fungus in the adult stage. Copyright 2009 Elsevier B.V. All rights reserved.

Copper sulfate controls fungus on mat-spawned largemouth bass eggs

USDA-ARS?s Scientific Manuscript database

Copper sulfate (CuSO4) is widely used by the catfish and hybrid striped bass industries as an economical treatment to control fungus (Saprolegnia spp.) on eggs; these industries use hatching troughs and McDonald jars, respectively, in moderate alkalinity waters. This study determined the effectivene...

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...

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.

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.

Monitoring persistence of the entomopathogenic fungus Metarhizium anisopliae under simulated field conditions with the aim of controlling adult Aedes aegypti (Diptera: Culicidae).

PubMed

Carolino, Aline T; Paula, Adriano R; Silva, Carlos P; Butt, Tariq M; Samuels, Richard I

2014-04-25

Entomopathogenic fungi are potential candidates for use in integrated vector management, with recent emphasis aimed at developing adult mosquito control methods. Here we investigated the persistence of the fungus Metarhizium anisopliae when tested against female A. aegypti under field conditions. Black cotton cloths impregnated with M. anisopliae conidia, formulated in vegetable oil + isoparaffin, were maintained on a covered veranda for up to 30 days. At specific times, pieces of the cloths were removed, placed in Tween 80 and the resuspended conidia were sprayed directly onto mosquitoes. The persistence of conidia impregnated on black cloths using three different carriers was evaluated in test rooms. Fifty mosquitoes were released into each room and after a 5 day period, the surviving insects were captured. Another 50 insects were then released into each room. The capacity of the fungus at reducing mosquito survival was evaluated over a total of 35 days. Conidia extracted from cloths maintained on the veranda for 2 to 18 days remained virulent, with 28 to 60% mosquito survival observed. Mosquito survival following exposure to fungus impregnated cloths showed that fungus + Tween caused similar reductions to that of fungus + vegetable oil. Mosquitoes exposed to the formulation fungus + vegetable oil had survival rates of 36% over the first 5 days of the experiment. Following the release of the second cohort of mosquitoes (6-11days), survival increased to 50%. The survival of the 12-17 day cohort (78%) was statistically equal to that of the controls (84%). Formulation of the fungus in vegetable oil + isoparaffin increased the persistence of the fungus, with the 18-23 day cohort (64% survival) still showing statistical differences to that of the controls (87% survival). The potential of entomopathogenic fungi for the control of adult A. aegypti was confirmed under field conditions. Vegetable oil + isoparaffin formulations of M. anisopliae significantly increased the

Mathematical modeling on obligate mutualism: Interactions between leaf-cutter ants and their fungus garden.

PubMed

Kang, Yun; Clark, Rebecca; Makiyama, Michael; Fewell, Jennifer

2011-11-21

We propose a simple mathematical model by applying Michaelis-Menton equations of enzyme kinetics to study the mutualistic interaction between the leaf cutter ant and its fungus garden at the early stage of colony expansion. We derive sufficient conditions on the extinction and coexistence of these two species. In addition, we give a region of initial condition that leads to the extinction of two species when the model has an interior attractor. Our global analysis indicates that the division of labor by worker ants and initial conditions are two important factors that determine whether leaf cutter ants' colonies and their fungus garden can survive and grow or not. We validate the model by comparing model simulations and data on fungal and ant colony growth rates under laboratory conditions. We perform sensitive analysis of the model based on the experimental data to gain more biological insights on ecological interactions between leaf-cutter ants and their fungus garden. Finally, we give conclusions and discuss potential future work. Published by Elsevier Ltd.

Cuticle hydrolysis in four medically important fly species by enzymes of the entomopathogenic fungus Conidiobolus coronatus.

PubMed

Boguś, M I; Włóka, E; Wrońska, A; Kaczmarek, A; Kazek, M; Zalewska, K; Ligęza-Żuber, M; Gołębiowski, M

2017-03-01

Entomopathogenic fungi infect insects via penetration through the cuticle, which varies remarkably in chemical composition across species and life stages. Fungal infection involves the production of enzymes that hydrolyse cuticular proteins, chitin and lipids. Host specificity is associated with fungus-cuticle interactions related to substrate utilization and resistance to host-specific inhibitors. The soil fungus Conidiobolus coronatus (Constantin) (Entomophthorales: Ancylistaceae) shows virulence against susceptible species. The larvae and pupae of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae), Calliphora vomitoria (Linnaeus), Lucilia sericata (Meigen) (Diptera: Calliphoridae) and Musca domestica (Linnaeus) (Diptera: Muscidae) are resistant, but adults exposed to C. coronatus quickly perish. Fungus was cultivated for 3 weeks in a minimal medium. Cell-free filtrate, for which activity of elastase, N-acetylglucosaminidase, chitobiosidase and lipase was determined, was used for in vitro hydrolysis of the cuticle from larvae, puparia and adults. Amounts of amino acids, N-glucosamine and fatty acids released were measured after 8 h of incubation. The effectiveness of fungal enzymes was correlated with concentrations of compounds detected in the cuticles of tested insects. Positive correlations suggest compounds used by the fungus as nutrients, whereas negative correlations may indicate compounds responsible for insect resistance. Adult deaths result from the ingestion of conidia or fungal excretions. © 2016 The Royal Entomological Society.

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...

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...

[Biochemical basis of tolerance to osmotic stress in phytopathogenic fungus: The case of Macrophomina phaseolina (Tassi) Goid.

PubMed

Martínez-Villarreal, Rodolfo; Garza-Romero, Tamar S; Moreno-Medina, Víctor R; Hernández-Delgado, Sanjuana; Mayek-Pérez, Netzahualcoyotl

Fungus Macrophomina phaseolina (Tassi) Goid. is the causative agent of charcoal rot disease which causes significant yield losses in major crops such as maize, sorghum, soybean and common beans in Mexico. This fungus is a facultative parasite which shows broad ability to adapt itself to stressed environments where water deficits and/or high temperature stresses commonly occur. These environmental conditions are common for most cultivable lands throughout Mexico. Here we describe some basic facts related to the etiology and epidemiology of the fungus as well as to the importance of responses to stressed environments, particularly to water deficits, based on morphology and growth traits, as well as on physiology, biochemistry and pathogenicity of fungus M. phaseolina. To conclude, we show some perspectives related to future research into the genus, which emphasize the increasing need to improve the knowledge based on the application of both traditional and biotechnological tools in order to elucidate the mechanisms of resistance to environmental stress which can be extrapolated to other useful organisms to man. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

BIODEGRADATION OF CRYSTAL VIOLET BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM

EPA Science Inventory

Biodegradation of crystal violet (N,N,N',N',N",N"-hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,...

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...

A Laboratory Maintenance Regime for a Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

PubMed

Lee, Ching-Chen; Lee, Chow-Yang

2015-06-01

The optimum maintenance conditions of the fungus-growing termite, Macrotermes gilvus (Hagen) (Blattodea: Termitidae), in the laboratory were studied. Termites were kept on a matrix of moist sand and with fungus comb as food. The survival of groups of termites was measured when maintained at different population densities by changing group size and container volume. Larger groups (≥0.6 g) were more vigorous and had significant higher survival rates than smaller groups (≤0.3 g). The population density for optimal survival of M. gilvus is 0.0025 g per container volume (ml) or 0.0169 g per matrix volume (cm(3)), i.e., 1.2 g of termites kept in a 480-ml container filled with 71 cm3 of sand. In termite groups of smaller size (i.e., 0.3 g) or groups maintained in smaller container (i.e., 100 ml) the fungus comb was overgrown with Xylaria spp., and subsequently all termites died within the study period. The insufficient number of workers for regulating the growth of unwanted fungi other than Termitomyces spp. in the fungus comb is the most likely reason. Unlike some other mound-building termite species, M. gilvus showed satisfactory survival when maintained in non-nutritious matrix (i.e., sand). There was no significant difference in the survival rate between different colonies of M. gilvus (n=5), with survival in the range of 78.5-84.4% after 4 wk. Advances in the maintenance of Macrotermes will enable researchers to study with more biological relevance many aspects of the biology, behavior, and management of this species. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The degradation of three-ringed polycyclic aromatic hydrocarbons by wood-inhabiting fungus Pleurotus ostreatus and soil-inhabiting fungus Agaricus bisporus.

PubMed

Pozdnyakova, Natalia; Dubrovskaya, Ekaterina; Chernyshova, Marina; Makarov, Oleg; Golubev, Sergey; Balandina, Svetlana; Turkovskaya, Olga

2018-05-01

The degradation of two isomeric three-ringed polycyclic aromatic hydrocarbons by the white rot fungus Pleurotus ostreatus D1 and the litter-decomposing fungus Agaricus bisporus F-8 was studied. Despite some differences, the degradation of phenanthrene and anthracene followed the same scheme, forming quinone metabolites at the first stage. The further fate of these metabolites was determined by the composition of the ligninolytic enzyme complexes of the fungi. The quinone metabolites of phenanthrene and anthracene produced in the presence of only laccase were observed to accumulate, whereas those formed in presence of laccase and versatile peroxidase were metabolized further to form products that were further included in basal metabolism (e.g. phthalic acid). Laccase can catalyze the initial attack on the PAH molecule, which leads to the formation of quinones, and that peroxidase ensures their further oxidation, which eventually leads to PAH mineralization. A. bisporus, which produced only laccase, metabolized phenanthrene and anthracene to give the corresponding quinones as the dominant metabolites. No products of further utilization of these compounds were detected. Thus, the fungi's affiliation with different ecophysiological groups and their cultivation conditions affect the composition and dynamics of production of the ligninolytic enzyme complex and the completeness of PAH utilization. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Decolorization and degradation of xanthene dyes by a white rot fungus, Coriolus versicolor.

PubMed

Itoh, Kiyoharu; Yatome, Chizuko

2004-01-01

The decolorization of six xanthene dyes (conc. 100 microM) by a white rot fungus, Coriolus versicolor (C. versicolor), was investigated in liquid culture. The decolorization of Fluorescein, 4-Aminofluorescein, and 5-Aminofluorescein by the fungus was 85.0, 95.0, and 91.9% after 14 days incubation, respectively. However, no decolorization of Rhodamine B, Rhodamine 123 hydrate, and Rhodamine 6G was observed. The first three dyes also were decolorized with cell-free extracts from C. versicolor. The decolorization activity was 10.2, 6.7, and 7.2 microM min(-1)mg(-1), respectively. Thin layer chromatography (TLC) analyses indicated that degradation of Fluorescein was occurring with the detection of three degradation products.

Pestalotiopamide E, a new amide from the endophytic fungus Pestalotiopsis sp.

PubMed

Xu, Jing; Lin, Qiang; Wang, Bin; Wray, Victor; Lin, Wen-Han; Proksch, Peter

2011-04-01

Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded a new amide called pestalotiopamide E (1). The structure of the new compound was unambiguously elucidated on the basis of extensive spectroscopic data analysis.

An in vivo transcriptome for entomopathogenic fungus Metarhizium robertsii ARSEF 2575

USDA-ARS?s Scientific Manuscript database

Molecular mechanisms underlying the pathogenic process of the insect pathogen Metarhizium robertsii ARSEF 2575 in its host are only partially understood. To probe the transcriptional responses of the fungus during the interaction with insects, we have developed a method to specifically recover patho...

The chestnut blight fungus for studies on virus/host and virus/virus interactions: from a natural to a model host.

PubMed

Eusebio-Cope, Ana; Sun, Liying; Tanaka, Toru; Chiba, Sotaro; Kasahara, Shin; Suzuki, Nobuhiro

2015-03-01

The chestnut blight fungus, Cryphonectria parasitica, is an important plant pathogenic ascomycete. The fungus hosts a wide range of viruses and now has been established as a model filamentous fungus for studying virus/host and virus/virus interactions. This is based on the development of methods for artificial virus introduction and elimination, host genome manipulability, available host genome sequence with annotations, host mutant strains, and molecular tools. Molecular tools include sub-cellular distribution markers, gene expression reporters, and vectors with regulatable promoters that have been long available for unicellular organisms, cultured cells, individuals of animals and plants, and certain filamentous fungi. A comparison with other filamentous fungi such as Neurospora crassa has been made to establish clear advantages and disadvantages of C. parasitica as a virus host. In addition, a few recent studies on RNA silencing vs. viruses in this fungus are introduced. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Lead immobilization by geological fluorapatite and fungus Aspergillus niger.

PubMed

Li, Zhen; Wang, Fuwei; Bai, Tongshuo; Tao, Jinjin; Guo, Jieyun; Yang, Mengying; Wang, Shimei; Hu, Shuijin

2016-12-15

Phosphate solubilizing fungi have high ability to secrete organic acids. In this study, fungus Aspergillus niger and geological fluorapatite were applied in lead remediation in aqueous solution. Formation and morphology of the lead minerals, e.g., pyromorphite and lead oxalate, were investigated by SEM, XRD, and ATR-IR. The total quantity of organic acids reached the maximum at the sixth day, which improved the concentration of soluble P up to ∼370mg/L from ∼0.4mg/L. The organic acids, especially the oxalic acid, enhance the solubility of fluorapatite significantly. The stable fluoropyromorphite [Pb 5 (PO 4 ) 3 F] is precipitated with the elevated solubility of fluorapatite in the acidic environment. Furthermore, A. niger grows normally with the presence of lead cations. It is shown that >99% lead cations can be removed from the solution. However, immobilization caused by the precipitation of lead oxalate cannot be ignored if the fungus A. niger was cultured in the Pb solution. This study elucidates the mechanisms of lead immobilization by FAp and A. niger, and sheds its perspective in lead remediation, especially for high Pb concentration solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Stachybotrys, a mycotoxin-producing fungus of increasing toxicologic importance.

PubMed

Fung, F; Clark, R; Williams, S

1998-01-01

Stachybotrys as a fungus has been implicated as a source of mycotoxins. While the toxicity of several well-known mycotoxins (aflatoxins) is well documented, recent studies on Stachybotrys have raised the question that mycotoxins produced by this fungus may be responsible for the health effects of occupants in water-damaged buildings. Published articles regarding Stachybotrys-related mycotoxins were reviewed with particular focus on human toxicity. A critical review of papers, reports, and studies on Stachybotrys mycotoxins revealed only descriptive reports of suspected animal and human poisoning secondary to consumption of mold-contaminated food products. No studies of good toxicologic and epidemiologic designs answer whether airborne mycotoxins produced by Stachybotrys could produce specific human toxicity. Current data on the toxicology of mycotoxins produced by Stachybotrys demonstrate that this group of mycotoxins is capable of producing immunosuppression and inflammatory insults to gastrointestinal and pulmonary systems. Case control study and case reports have suggested a possible association with environmental exposure to Stachybotrys mycotoxins, although a firm causal relationship has not been firmly established. Additional studies are needed to document that humans with sufficient exposure to these mycotoxins develop compatible clinical and pathologic pictures as demonstrated in animal models.

Efficient Transmission of an Introduced Pathogen Via an Ancient Insect-Fungus Association

NASA Astrophysics Data System (ADS)

Battisti, A.; Roques, A.; Colombari, F.; Frigimelica, G.; Guido, M.

In Cupressus sempervirens the association between seed insects and tree pathogens has resulted in optimal exploitation of the cones. A fungus-infected cone can be inhabited by the nymphs of a true seed bug (Orsillus maculatus), the adults of which may carry a heavy spore load at emergence. Cones are infected when eggs are laid within the cone, most frequently via the emergence holes of a seed wasp (Megastigmus wachtli). This symbiotic association evolved with the nonaggressive fungus Pestalotiopsis funerea within the natural range of the cypress. When the aggressive cypress canker disease (Seiridium cardinale) was introduced into Europe, it was transmitted by O. maculatus to cones usually colonized by Pestalotiopsis funerea, with disastrous consequences for the regeneration and survival of C. sempervirens in the entire Mediterranean area.

Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

PubMed

Srinivasan, S V; Murthy, D V S; Swaminathan, T

2012-07-01

The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies.

Preliminary data on growth and enzymatic abilities of soil fungus Humicolopsis cephalosporioides at different incubation temperatures.

PubMed

Elíades, Lorena Alejandra; Cabello, Marta N; Pancotto, Verónica; Moretto, Alicia; Rago, María Melisa; Saparrat, Mario C N

2015-01-01

Nothofagus pumilio (Poepp & Endl.) Krasser, known as "lenga" is the most important timber wood species in southernmost Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand is a soil fungus associated with Nothofagus pumilio forests, which has outstanding cellulolytic activity. However, there is no information about the ability of this fungus to use organic substrates other than cellulose, and its ability to produce different enzyme systems, as well as its response to temperature. The aim of this study was to examine the role of H. cephalosporioides in degradation processes in N. pumilio forests in detail by evaluating the in vitro ability of four isolates of this fungus to grow and produce different lytic enzyme systems, and their response to incubation temperature. The ability of the fungi to grow and produce enzyme systems was estimated by inoculating them on agar media with specific substrates, and the cultures were incubated at three temperatures. A differential behavior of each strain in levels of growth and enzyme activity was found according to the medium type and/or incubation temperature. A intra-specific variability was found in H. cephalosporioides. Likewise a possible link between the saprotrophic role of this fungus in N. pumilio forests and the degradation of organic matter under stress conditions, such as those from frosty environments, was also discussed. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Monitoring persistence of the entomopathogenic fungus Metarhizium anisopliae under simulated field conditions with the aim of controlling adult Aedes aegypti (Diptera: Culicidae)

PubMed Central

2014-01-01

Background Entomopathogenic fungi are potential candidates for use in integrated vector management, with recent emphasis aimed at developing adult mosquito control methods. Here we investigated the persistence of the fungus Metarhizium anisopliae when tested against female A. aegypti under field conditions. Methods Black cotton cloths impregnated with M. anisopliae conidia, formulated in vegetable oil + isoparaffin, were maintained on a covered veranda for up to 30 days. At specific times, pieces of the cloths were removed, placed in Tween 80 and the resuspended conidia were sprayed directly onto mosquitoes. The persistence of conidia impregnated on black cloths using three different carriers was evaluated in test rooms. Fifty mosquitoes were released into each room and after a 5 day period, the surviving insects were captured. Another 50 insects were then released into each room. The capacity of the fungus at reducing mosquito survival was evaluated over a total of 35 days. Results Conidia extracted from cloths maintained on the veranda for 2 to 18 days remained virulent, with 28 to 60% mosquito survival observed. Mosquito survival following exposure to fungus impregnated cloths showed that fungus + Tween caused similar reductions to that of fungus + vegetable oil. Mosquitoes exposed to the formulation fungus + vegetable oil had survival rates of 36% over the first 5 days of the experiment. Following the release of the second cohort of mosquitoes (6-11days), survival increased to 50%. The survival of the 12–17 day cohort (78%) was statistically equal to that of the controls (84%). Formulation of the fungus in vegetable oil + isoparaffin increased the persistence of the fungus, with the 18–23 day cohort (64% survival) still showing statistical differences to that of the controls (87% survival). Conclusions The potential of entomopathogenic fungi for the control of adult A. aegypti was confirmed under field conditions. Vegetable oil + isoparaffin formulations of

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

A fibronectin receptor on Candida albicans mediates adherence of the fungus to extracellular matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klotz, S.A.; Smith, R.L.

1991-03-01

Binding of fibronectin, an extracellular matrix (ECM) protein, to Candida albicans was measured, and adherence of the fungus to immobilized ECM proteins, fibronectin, laminin, types I and IV collagen, and subendothelial ECM was studied. 125I-labeled fibronectin was inhibited from binding to the fungus by unlabeled human plasma fibronectin and by Arg-Gly-Asp (RGD), Gly-Arg-Gly-Glu-Ser-Pro (GRGESP), and Gly-Arg-Gly-Asp-Thr-Pro (GRGDTP), but binding was not inhibited by Gly-Arg-Gly-Asp-Ser-Pro. Soluble fibronectin, RGD, GRGESP, and GRGDTP also inhibited fungal adherence to the individual immobilized ECM proteins in a complex pattern, but only soluble fibronectin (10(-7) M) inhibited fungal adherence to subendothelial ECM. Thus, C. albicans possessesmore » at least one type of cell surface receptor for binding soluble fibronectin that can be inhibited with peptides. This receptor apparently is used to bind the fungus to immobilized ECM proteins and to subendothelial ECM and may play a role in the initiation of disseminated disease by bloodborne fungi by providing for adherence of the microorganisms to ECM proteins.« less

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. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Scenes of Devastation: Chasing Hawaii's Deadly Ohia Fungus | Hawaii Public

Science.gov Websites

Scenes of Devastation: Chasing Hawaii's Deadly Ohia Fungus By Molly Solomon * Mar 25, 2016 TweetShareGoogle+Email Molly Solomon Rapid Ohia Death has devastated native forests on Hawaii Island, especially in Lower Puna subdivisions like Leilani Estates. Credit Molly Solomon One of Hawai'i's oldest and most

Identification and sequence determination of a new chrysovirus infecting the entomopathogenic fungus Isaria javanica.

PubMed

Herrero, Noemi

2017-04-01

A new double-stranded RNA (dsRNA) mycovirus has been identified in the isolate NB IFR-19 of the entomopathogenic fungus Isaria javanica. Isaria javanica chrysovirus-1 (IjCV-1) constitutes a new member of the Chrysoviridae family, and its genome is made up of four dsRNA elements designated dsRNA1, 2, 3 and 4 from largest to smallest. dsRNA1 and dsRNA2 encode an RNA-dependent RNA polymerase (RdRp) and a coat protein (CP), respectively. dsRNA3 and 4 encode hypothetical proteins of unknown function. IjCV-1 constitutes the first report of a chrysovirus infecting the entomopathogenic fungus Isaria javanica.

Mode of Infection of Metarhizium spp. Fungus and Their Potential as Biological Control Agents

PubMed Central

Aw, Kimberly Moon San; Hue, Seow Mun

2017-01-01

Chemical insecticides have been commonly used to control agricultural pests, termites, and biological vectors such as mosquitoes and ticks. However, the harmful impacts of toxic chemical insecticides on the environment, the development of resistance in pests and vectors towards chemical insecticides, and public concern have driven extensive research for alternatives, especially biological control agents such as fungus and bacteria. In this review, the mode of infection of Metarhizium fungus on both terrestrial and aquatic insect larvae and how these interactions have been widely employed will be outlined. The potential uses of Metarhizium anisopliae and Metarhizium acridum biological control agents and molecular approaches to increase their virulence will be discussed. PMID:29371548

Draft genome sequence of the fungus associated with oak-wilt mortality in South Korea, Raffaelea quercus-mongolicae KACC44405

Treesearch

Jongbum Jeon; Ki-Tae Kim; Hyeunjeong Song; Gir-Won Lee; Kyeongchae Cheong; Hyunbin Kim; Gobong Choi; Yong-Hwan Lee; Jane E. Stewart; Ned B. Klopfenstein; Mee-Sook Kim

2017-01-01

The fungus Raffaelea quercus-mongolicae is the causal agent of Korean oak wilt, a disease associated with mass mortality of oak trees (e.g., Quercus spp.). The fungus is vectored and dispersed by the ambrosia beetle, Platypus koryoensis. Here, we present the 27.0-Mb draft genome sequence of R. quercus-mongolicae strain KACC44405.

Fabrication of a superhydrophobic surface with fungus-cleaning properties on brazed aluminum for industrial application in heat exchangers

NASA Astrophysics Data System (ADS)

Lee, Jeong-Won; Hwang, Woonbong

2018-06-01

Extensive research has been carried out concerning the application of superhydrophobic coating in heat exchangers, but little is known about the application of this technique to brazed aluminum heat exchangers (BAHEs). In this work, we describe a new superhydrophobic coating method, which is suitable for BAHE use on an industrial scale. We first render the BAHE superhydrophobic by fabricating micro/nanostructures using solution dipping followed by fluorination. After the complete removal of the silicon residue, we verify using surface analysis that the BAHE surface is perfectly superhydrophobic. We also studied the fungus-cleaning properties of the superhydrophobic surface by growing fungus for 4 weeks in a moist environment on BAHE fins with and without superhydrophobic coating. We observed that, whereas the fungus grown on the untreated fins is extremely difficult to remove, the fungus on the fins with the superhydrophobic coating can be removed easily with only a modest amount of water. We also found that the coated BAHE fins exhibit excellent resistance to moisture. The superhydrophobic coating method that we propose is therefore expected to have a major impact in the heating, ventilating and air conditioning industry market.

Abscisic acid negatively regulates post-penetration resistance of Arabidopsis to the biotrophic powdery mildew fungus.

PubMed

Xiao, Xiang; Cheng, Xi; Yin, Kangquan; Li, Huali; Qiu, Jin-Long

2017-08-01

Pytohormone abscisic acid (ABA) plays important roles in defense responses. Nonetheless, how ABA regulates plant resistance to biotrophic fungi remains largely unknown. Arabidopsis ABA-deficient mutants, aba2-1 and aba3-1, displayed enhanced resistance to the biotrophic powdery mildew fungus Golovinomyces cichoracearum. Moreover, exogenously administered ABA increased the susceptibility of Arabidopsis to G. cichoracearum. Arabidopsis ABA perception components mutants, abi1-1 and abi2-1, also displayed similar phenotypes to ABA-deficient mutants in resistance to G. cichoracearum. However, the resistance to G. cichoracearum is not changed in downstream ABA signaling transduction mutants, abi3-1, abi4-1, and abi5-1. Microscopic examination revealed that hyphal growth and conidiophore production of G. cichoracearum were compromised in the ABA deficient mutants, even though pre-penetration and penetration growth of the fungus were not affected. In addition, salicylic acid (SA) and MPK3 are found to be involved in ABA-regulated resistance to G. cichoracearum. Our work demonstrates that ABA negatively regulates post-penetration resistance of Arabidopsis to powdery mildew fungus G. cichoracearum, probably through antagonizing the function of SA.

Pycnoscelus surinamensis cockroach gut microbiota respond consistently to a fungal diet without mirroring those of fungus-farming termites.

PubMed

Richards, Callum; Otani, Saria; Mikaelyan, Aram; Poulsen, Michael

2017-01-01

The gut microbiotas of cockroaches and termites play important roles in the symbiotic digestion of dietary components, such as lignocellulose. Diet has been proposed as a primary determinant of community structure within the gut, acting as a selection force to shape the diversity observed within this "bioreactor", and as a key factor for the divergence of the termite gut microbiota from the omnivorous cockroach ancestor. The gut microbiota in most termites supports primarily the breakdown of lignocellulose, but the fungus-farming sub-family of higher termites has become similar in gut microbiota to the ancestral omnivorous cockroaches. To assess the importance of a fungus diet as a driver of community structure, we compare community compositions in the guts of experimentally manipulated Pycnoscelus surinamensis cockroaches fed on fungus cultivated by fungus-farming termites. MiSeq amplicon analysis of gut microbiotas from 49 gut samples showed a step-wise gradient pattern in community similarity that correlated with an increase in the proportion of fungal material provided to the cockroaches. Comparison of the taxonomic composition of manipulated communities to that of gut communities of a fungus-feeding termite species showed that although some bacteria OTUs shared by P. surinamensis and the farming termites increased in the guts of cockroaches on a fungal diet, cockroach communities remained distinct from those of termites. These results demonstrate that a fungal diet can play a role in structuring gut community composition, but at the same time exemplifies how original community compositions constrain the magnitude of such change.

Report membrane transport of lactic acid in the filamentous 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...

Ethidium bromide stimulated hyper laccase production from bird's nest fungus Cyathus bulleri.

PubMed

Dhawan, S; Lal, R; Kuhad, R C

2003-01-01

Effect of ethidium bromide, a DNA intercalating agent, on laccase production from Cyathus bulleri was studied. The bird's nest fungus, Cyathus bulleri was grown on 2% (w/v) malt extract agar (MEA) supplemented with 1.5 microg ml(-1) of the phenanthridine dye ethidium bromide (EtBr) for 7 d and when grown subsequently in malt extract broth (MEB), produced a 4.2-fold increase in laccase production as compared to the untreated fungus. The fungal cultures following a single EtBr treatment, when regrown on MEA devoid of EtBr, produced a sixfold increase in laccase in MEB. However, on subsequent culturing on MEA in the absence of EtBr, only a 2.5-fold increase in laccase production could be maintained. In another attempt, the initial EtBr-treated cultures, when subjected to a second EtBr treatment (1.5 microg ml(-1)) on MEA for 7 d, produced a 1.4-fold increase in laccase production in MEB. The white-rot fungus Cyathus bulleri, when treated with EtBr at a concentration of 1.5 microg ml(-1) and regrown on MEA devoid of EtBr, produced a sixfold increase in laccase production in MEB. The variable form of C. bulleri capable of hyper laccase production can improve the economic feasibility of environmentally benign processes involving use of fungal laccases in cosmetics (including hair dyes), food and beverages, clinical diagnostics, pulp and paper industry, industrial effluent treatment, animal biotechnology and biotransformations.

Nickel oxide nanoparticles film produced by dead biomass of filamentous fungus

PubMed Central

Salvadori, Marcia Regina; Nascimento, Cláudio Augusto Oller; Corrêa, Benedito

2014-01-01

The synthesis of nickel oxide nanoparticles in film form using dead biomass of the filamentous fungus Aspergillus aculeatus as reducing agent represents an environmentally friendly nanotechnological innovation. The optimal conditions and the capacity of dead biomass to uptake and produce nanoparticles were evaluated by analyzing the biosorption of nickel by the fungus. The structural characteristics of the film-forming nickel oxide nanoparticles were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). These techniques showed that the nickel oxide nanoparticles had a size of about 5.89 nm and were involved in a protein matrix which probably permitted their organization in film form. The production and uptake of nickel oxide nanoparticles organized in film form by dead fungal biomass bring us closer to sustainable strategies for the biosynthesis of metal oxide nanoparticles. PMID:25228324

An endophytic fungus from Azadirachta indica A. Juss. that produces azadirachtin.

PubMed

Kusari, Souvik; Verma, Vijay C; Lamshoeft, Marc; Spiteller, Michael

2012-03-01

Azadirachtin A and its structural analogues are a well-known class of natural insecticides having antifeedant and insect growth-regulating properties. These compounds are exclusive to the neem tree, Azadirachta indica A. Juss, from where they are currently sourced. Here we report for the first time, the isolation and characterization of a novel endophytic fungus from A. indica, which produces azadirachtin A and B in rich mycological medium (Sabouraud dextrose broth), under shake-flask fermentation conditions. The fungus was identified as Eupenicillium parvum by ITS analysis (ITS1 and ITS2 regions and the intervening 5.8S rDNA region). Azadirachtin A and B were identified and quantified by LC-HRMS and LC-HRMS(2), and by comparison with the authentic reference standards. The biosynthesis of azadirachtin A and B by the cultured endophyte, which is also produced by the host neem plant, provides an exciting platform for further scientific exploration within both the ecological and biochemical contexts.

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...

Chemical constituents of the mangrove-associated fungus Capnodium sp. SZ-F22. A new eremophilane sesquiterpene.

PubMed

He, Haibing; Ma, Zhongjun; Wang, Qianqian; Liu, Yu; Xu, Hualin

2016-07-01

A new eremophilane sesquiterpene, capnodiumone (1), along with five known eremophilane sesquiterpenes (2-6) and eight other compounds (7-14), have been isolated from a mangrove-associated fungus Capnodium sp. SZ-F22. The chemical structures were elucidated on the basis of extensive spectroscopic analysis. The broth extract of the fungus exhibited a good inhibitory effect on the mycelium growth against Fusarium graminearum at 100 μg/mL, however, all the 14 compounds showed no expected antifungal activity. The probable reasons were discussed.

Degradation of Lignin in Agricultural Residues by locally Isolated Fungus Neurospora discreta.

PubMed

Pamidipati, Sirisha; Ahmed, Asma

2017-04-01

Locally isolated fungus, Neurospora discreta, was evaluated for its ability to degrade lignin in two agricultural residues: cocopeat and sugarcane bagasse with varying lignin concentrations and structures. Using Klason's lignin estimation, high-performance liquid chromatography, and UV-visible spectroscopy, we found that N. discreta was able to degrade up to twice as much lignin in sugarcane bagasse as the well-known white rot fungus Phanerochaete chrysosporium and produced nearly 1.5 times the amount of lignin degradation products in submerged culture. Based on this data, N. discreta is a promising alternative to white rot fungi for faster microbial pre-treatment of agricultural residues. This paper presents the lignin degrading capability of N. discreta for the first time and also discusses the difference in biodegradability of cocopeat and sugarcane bagasse as seen from the analysis carried out using Fourier transform infrared spectroscopy.

Allelopathic Polyketides from an Endolichenic Fungus Myxotrichum SP. by Using OSMAC Strategy.

PubMed

Yuan, Chao; Guo, Yu-Hua; Wang, Hai-Ying; Ma, Xiao-Jun; Jiang, Tao; Zhao, Jun-Ling; Zou, Zhong-Mei; Ding, Gang

2016-02-03

Three new polyketides myxotritones A-C (2-4), together with a new natural product 7,8-dihydro-7R,8S-dihydroxy-3,7-dimethyl-2-benzopyran-6-one (1) were obtained from the endolichenic fungus Myxotrichum sp. by using OMSAC (One Strain, Many Compounds) method. The planar structures of these new compounds were determined by NMR experiment and HRESIMS data, and the absolute configuration of 1 was established by X-ray diffraction, and the stereochemistry of the new compounds 2-4 were determined by same biosynthesis origin, and similar CD spectra with 1. Allelopathic test showed that compound 4 significantly retarded root elongation of Arabidopsis thaliana seed, indicating that this fungus might contribute to the defense of its host lichen. From the view of biosynthetic pathway, all four compounds 1-4 might be originated from Non-Reduced Polyketide synthase (NR-PKS).

Parasitic fungus Claviceps as a source for biotechnological production of ergot alkaloids.

PubMed

Hulvová, Helena; Galuszka, Petr; Frébortová, Jitka; Frébort, Ivo

2013-01-01

Ergot alkaloids produced by the fungus Claviceps parasitizing on cereals, include three major groups: clavine alkaloids, d-lysergic acid and its derivatives and ergopeptines. These alkaloids are important substances for the pharmatech industry, where they are used for production of anti-migraine drugs, uterotonics, prolactin inhibitors, anti-Parkinson agents, etc. Production of ergot alkaloids is based either on traditional field cultivation of ergot-infected rye or on submerged cultures of the fungus in industrial fermentation plants. In 2010, the total production of these alkaloids in the world was about 20,000 kg, of which field cultivation contributed about 50%. This review covers the recent advances in understanding of the genetics and regulation of biosynthesis of ergot alkaloids, focusing on possible applications of the new knowledge to improve the production yield. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

Temperature determines symbiont abundance in a multipartite bark beetle-fungus ectosymbiosis

Treesearch

D. L. Six; B. J. Bentz

2007-01-01

In this study, we report evidence that temperature plays a key role in determining the relative abundance of two mutualistic fungi associated with an economically and ecologically important bark beetle, Dendroctonus ponderosae. The symbiotic fungi possess different optimal temperature ranges. These differences determine which fungus is vectored by...

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...

Multiple mycotic aneurysms with a rare fungus, Aspergillus niger: a complex case report.

PubMed

Parameswaran, Vatsala

2008-03-01

The term "mycotic aneurysm" was first used by William Osler in 1885 to describe a nonsyphilitic bacterial infection of the arterial wall. It is now known that mycotic aneurysm, a rare infectious condition, can arise from a wide variety of clinical causes. The aorta is most often affected; however, such aneurysms may arise in any artery. Mycotic aneurysms are classified as primary (direct extension from surrounding area of infection), secondary (septic embolization that lodges in peripheral arteries), and cryptogenic (unknown cause). A mycotic aneurysm is a threat to life, organs, and limbs. Mycotic aneurysms of the aorta caused by fungi are rare. William Osler used the term "mycotic," referring to all infected aneurysms excluding fungal infections. Yet, the term "mycotic" by definition is a disease caused by a fungus. Only seven cases of aneurysms caused by a fungus were reported from 1966 to 1999. This article will focus on the care of a young female patient with end-stage renal disease receiving peritoneal dialysis who developed a mycotic aneurysm. She was treated with high doses of antifungal medications for the fungus Aspergillus niger. She was switched to hemodialysis from peritoneal dialysis and was later diagnosed with a primary multiple mycotic aneurysms. This article will describe the complex medical, surgical, and nursing care provided to this patient.

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

No sex in fungus-farming ants or their crops.

PubMed

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

2009-07-22

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.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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...

Testing fungus impregnated cloths for the control of adult Aedes aegypti under natural conditions.

PubMed

Paula, Adriano R; Carolino, Aline T; Silva, Carlos P; Pereira, César R; Samuels, Richard I

2013-09-08

Entomopathogenic fungi could be useful tools for reducing populations of the dengue mosquito Aedes aegypti. Here the efficiency of fungus (Metarhizium anisopliae) impregnated cloths (with and without imidacloprid [IMI]) was evaluated against adult A. aegypti in simulated human dwellings. Behaviour of mosquitoes in the presence of black cloths was also investigated. When mosquitoes were released into the test rooms, the lowest survival rates (38%) were seen when five black cloths impregnated with conidia of ESALQ 818 + 10 ppm IMI were fixed under tables and chairs. This result was significantly lower than the survival rate recorded when cloths were impregnated with ESALQ 818 alone (44%) or ESALQ 818 + 0.1 ppm IMI (43%). Blood fed A. aegypti had lower landing frequencies on black cloths than sucrose fed insects during the first 24 h following feeding, which may have been due to reduced flight activity. Few mosquitoes (4-5%) were observed to land on the cloths during the hours of darkness. The landing pattern of sucrose-fed mosquitoes on non-treated and fungus-treated cloths was similar. The synergism between M. anisopliae and IMI significantly reduced Aedes survival in simulated field conditions. The use of fungus impregnated cloths is a promising point source application method for the control of adult A. aegypti.

Which Fungus Originally was Trichophyton mentagrophytes? Historical Review and Illustration by a Clinical Case.

PubMed

Chollet, Annemay; Cattin, Vincent; Fratti, Marina; Mignon, Bernard; Monod, Michel

2015-08-01

Several dermatophytes producing numerous pyriform or round microconidia were called Trichophyton mentagrophytes. Among these dermatophytes are the teleomorph species Arthroderma benhamiae, Arthroderma vanbreuseghemii and Arthroderma simii, and other species such as Trichophyton interdigitale, Trichophyton erinacei and Trichophyton quinckeanum for which only the anamorph is known. Confusion exists about which fungus should be really called T. mentagrophytes and about the rational use of this name in practice. We report a case of beard ringworm (tinea barbae) with A. vanbreuseghemii. According to both clinical signs and the type of hair parasitism, this case was exactly compatible to the first description of a non-favic dermatophytosis by Gruby under the name of "mentagrophyte" from which was derived the dermatophyte epithet mentagrophytes. In addition, the phenotypic characters of the isolated fungus in cultures perfectly matched with those of the first description of a dermatophyte under T. mentagrophytes by Blanchard (Parasites animaux et parasites végétaux à l'exclusion des Bactéries, Masson, Paris, 1896). In conclusion, T. mentagrophytes corresponds to the fungus later named A. vanbreuseghemii. However, because the neotype of T. mentagrophytes was not adequately designated in regard to the ancient literature, we would privilege the use of A. vanbreuseghemii and abandon the name of T. mentagrophytes.

Strategies for durable resistance to the grapevine powdery mildew fungus, Erysiphe necator

USDA-ARS?s Scientific Manuscript database

Nearly all cultivars of Vitis vinifera are highly susceptible to the grapevine powdery mildew fungus, Erysiphe necator. Grape breeders around the world are working to introgress resistance from wild Vitis. Of the widely-used introgressions, most involve dominant, race-specific resistance phenotype...

Liquefaction/solubilization of low-rank Turkish coals by white-rot fungus (Phanerochaete chrysosporium)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elbeyli, I.Y.; Palantoken, A.; Piskin, S.

2006-08-15

Microbial coal liquefaction/solubilization of three low-rank Turkish coals (Bursa-Kestelek, Kutahya-Seyitomer and Mugla-Yatagan lignite) was attempted by using a white-rot fungus (Phanerochaete chrysosporium DSM No. 6909); chemical compositions of the products were investigated. The lignite samples were oxidized by nitric acid under moderate conditions and then oxidized samples were placed on the agar medium of Phanerochaete chrysosporium. FTIR spectra of raw lignites, oxidized lignites and liquid products were recorded, and the acetone-soluble fractions of these samples were identified by GC-MS technique. Results show that the fungus affects the nitro and carboxyl/carbonyl groups in oxidized lignite sample, the liquid products obtained bymore » microbial effects are the mixture of water-soluble compounds, and show limited organic solubility.« less

Antibacterial polyketides from the jellyfish-derived fungus Paecilomyces variotii.

PubMed

Liu, Juan; Li, Famei; Kim, Eun La; Li, Jian Lin; Hong, Jongki; Bae, Kyung Sook; Chung, Hae Young; Kim, Hyung Sik; Jung, Jee H

2011-08-26

Four new polyketides (1-4) were isolated from the fungus Paecilomyces variotii, which was derived from the jellyfish Nemopilema nomurai. The planar structures and relative configurations of these polyketides were elucidated on the basis of spectroscopic analyses, including 2D NMR experiments. The compounds showed inhibitory activity against pathogenic bacteria including methicillin-resistant Staphylococcus aureus 3089 and multi-drug-resistant Vibrio parahemolyticus 7001 with MIC values in the range 5-40 μg/mL.

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

Isolation and characterization of a chitinase gene from entomopathogenic fungus Verticillium lecanii

PubMed Central

Zhu, Yanping; Pan, Jieru; Qiu, Junzhi; Guan, Xiong

2008-01-01

Entomopathogenic fungus Verticillium lecanii is a promising whitefly and aphid control agent. Chitinases secreted by this insect pathogen have considerable importance in the biological control of some insect pests. An endochitinase gene Vlchit1 from the fungus was cloned and overexpressed in Escherichia coli. The Vlchit1 gene not only contains an open reading frame (ORF) which encodes a protein of 423 amino acids (aa), but also is interrupted by three short introns. Vlchit1 protein showed that the chitinase Vlchit1 has a (a/b)8 TIM barrel structure. Overexpression test and Enzymatic activity assay indicated that the Vlchit1 is a functional enzyme that can hydrolyze the chitin substrate, so the Vlchit1 gene can service as a useful gene source for genetic manipulation leading to strain improvement of entomopathogenic fungi or constructing new transgenic plants with resistance to various fungal and insects pests. PMID:24031223

Potential Fungus surface resistance of the silica/acrylic coated leaves waste composite

NASA Astrophysics Data System (ADS)

Masturi; Jannah, WN; Maulana, RM; Darsono, T.; Sunarno; Rustad, S.

2018-04-01

The composite coated by some materials coaters have been made. This coating was done to isolate the fungus possibly growing on the composite. The composite was made from a mixture of teak leaves waste and polyurethane polymer using a simple mixing method; then the mixture was pressed at a pressure of 3 metric-tons for 15 minutes. The composite produced then was coated with acrylic only and acrylic-silica using spray method. The coated samples then were characterized using scanning electron microscopy (SEM) to determine the surface pores. Further, it was obtained the average surface pore size of acrylic coater is 1.24 µm, while the acrylic-silica pore forms an oval shape with a length and a width of 0.75 µm and 0.38 µm, respectively. In comparison with the fungus size of 2-7 µm, it can be concluded that the composite is proper as home appliance application.

Potential of endophytic fungus Phomopsis liquidambari for transformation and degradation of recalcitrant pollutant sinapic acid.

PubMed

Xie, Xing-Guang; Huang, Chun-Yan; Fu, Wan-Qiu; Dai, Chuan-Chao

2016-03-01

The biodegradation potential of sinapic acid, one of the most representative methoxy phenolic pollutants presented in industrial wastewater, was first studied using an endophytic fungus called Phomopsis liquidambari. This strain can effectively degrade sinapic acid in flasks and in soil and the possible biodegradation pathway was first systematically proposed on the basis of the metabolite production patterns and the identification of the metabolites by GC-MS and HPLC-MS. Sinapic acid was first transformed to 2,6-dimethoxy-4-vinylphenol that was further degraded via 4-hydroxy-3,5-dimethoxybenzaldehyde, syringic acid, gallic acid, and citric acid which involved in the continuous catalysis by phenolic acid decarboxylase, laccase, and gallic acid dioxygenase. Moreover, their activities and gene expression levels exhibited a 'cascade induction' response with the changes in metabolic product concentrations and the generation of fungal laccase significantly improved the degradation process. This study is the first report of an endophytic fungus that has great potential to degrade xenobiotic sinapic acid, and also provide a basis for practical application of endophytic fungus in the bioremediation of sinapic acid-contaminated industrial wastewater and soils. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

The fungus that came in from the cold: dry rot's pre-adapted ability to invade buildings.

PubMed

Balasundaram, S V; Hess, J; Durling, M B; Moody, S C; Thorbek, L; Progida, C; LaButti, K; Aerts, A; Barry, K; Grigoriev, I V; Boddy, L; Högberg, N; Kauserud, H; Eastwood, D C; Skrede, I

2018-03-01

Many organisms benefit from being pre-adapted to niches shaped by human activity, and have successfully invaded man-made habitats. One such species is the dry rot fungus Serpula lacrymans, which has a wide distribution in buildings in temperate and boreal regions, where it decomposes coniferous construction wood. Comparative genomic analyses and growth experiments using this species and its wild relatives revealed that S. lacrymans evolved a very effective brown rot decay compared to its wild relatives, enabling an extremely rapid decay in buildings under suitable conditions. Adaptations in intracellular transport machineries promoting hyphal growth, and nutrient and water transport may explain why it is has become a successful invader of timber in houses. Further, we demonstrate that S. lacrymans has poor combative ability in our experimental setup, compared to other brown rot fungi. In sheltered indoor conditions, the dry rot fungus may have limited encounters with other wood decay fungi compared to its wild relatives. Overall, our analyses indicate that the dry rot fungus is an ecological specialist with poor combative ability against other fungi.

Comparative vesicle proteomics reveals selective regulation of protein expression in chestnut blight fungus by a hypovirus.

PubMed

Wang, Jinzi; Wang, Fangzhen; Feng, Youjun; Mi, Ke; Chen, Qi; Shang, Jinjie; Chen, Baoshan

2013-01-14

The chestnut blight fungus (Cryphonectria parasitica) and hypovirus constitute a model system to study fungal pathogenesis and mycovirus-host interaction. Knowledge in this field has been gained largely from investigations at gene transcription level so far. Here we report a systematic analysis of the vesicle proteins of the host fungus with/without hypovirus infection. Thirty-three differentially expressed protein spots were identified in the purified vesicle protein samples by two-dimensional electrophoresis and mass spectrometry. Down-regulated proteins were mostly cargo proteins involved in primary metabolism and energy generation and up-regulated proteins were mostly vesicle associated proteins and ABC transporter. A virus-encoded protein p48 was found to have four forms with different molecular mass in vesicles from the virus-infected strain. While a few of the randomly selected differentially expressed proteins were in accordance with their transcription profiles, majority were not in agreement with their mRNA accumulation patterns, suggesting that an extensive post-transcriptional regulation may have occurred in the host fungus upon a hypovirus infection. Copyright © 2012 Elsevier B.V. All rights reserved.

Mosquitocidal activity of a naturally occurring isochroman and synthetic analogs from the plant pathogenic fungus, Diaporthe eres against Aedes aegypti ( Diptera: Culicidae)

USDA-ARS?s Scientific Manuscript database

The culture filtrate of a plant pathogenic fungus that infects English ivy (Hegera helix) was investigated for mosquitocidal constituents by bioassay guided isolation. The fungus responsible for pathogenic effects on the plant Hegera helix has been identified as Diaporthe eres by molecular technique...

Trichopeptides A and B, trichocyclodipeptides A-C, new peptides from the ascomycete fungus Stagonospora trichophoricola.

PubMed

Chen, Zhengkun; Xu, Xiuli; Ren, Jinwei; Wang, Wenzhao; Liu, Xingzhong; Li, Erwei

2017-08-01

Trichopeptides A (1) and B (2), new linear tetrapeptide and tripeptide, respectively, and three new diketopiperazines trichocyclodipeptides A-C (3-5) were isolated from the fermentation of the ascomycete fungus Stagonospora trichophoricola, a fungus isolated from the soil sample surrounding the fruiting body of Ophiocordyceps sinensis in Maqin Country, Qinghai Province, People's Republic of China. Their structures were primarily elucidated by interpretation of NMR and MS experiments. The absolute configurations of 1-5 were assigned through Marfey's method on their acid hydrolyzates. Compound 3 showed antifungal activity against Candida albicans with the IC 50 and MIC values of 22 and 90 μg ml -1 , respectively.

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.

Isolation and identification of nematode-antagonistic compounds from the fungus Aspergillus candidus

USDA-ARS?s Scientific Manuscript database

An isolate of the fungus Aspergillus candidus was tested for production of nematicidal compounds. Adults of the nematode Ditylenchus destructor were completely inactive after 24 hr exposure to soy medium in which A. candidus was cultured. Column, thin layer and preparative chromatographies, and spec...

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

Efficacy of the nematode-trapping fungus Duddingtonia flagrans against three species of gastro-intestinal nematodes in laboratory faecal cultures from sheep and goats.

PubMed

Waghorn, T S; Leathwick, D M; Chen, L-Y; Skipp, R A

2003-12-30

The ability of the nematode-killing fungus Duddingtonia flagrans to reduce number of infective larvae of three species of gastro-intestinal parasitic nematodes developing in dung was investigated in both goats and sheep. Groups of lambs and kids (12-20 weeks old) were given mono-specific infections of Haemonchus contortus, Ostertagia (Teladorsagia) circumcincta or Trichostrongylus colubriformis. Following patency of the infections (t1) faecal samples were collected for determination of faecal nematode egg count (FEC) and culture of parasite larvae. Groups of animals were then dosed on 2 consecutive days with one of the two dose rates of the fungus (250,000 or 500,000 spores/kg liveweight). One (t2) and 5 (t3) days after the second dose of fungus samples were again collected for FEC and culture. The number of larvae recovered from the faecal cultures at t1 and t3 were used as controls to assess the efficacy of the experimental treatment at t2. Average efficacy was 78% with group means ranging from 40 to 93%. Dose rate of fungus appeared to influence efficacy against O. circumcincta but not against H. contortus or T. colubriformis. Overall, there were no differences in the efficacy of the fungus against any of the parasite species or in either host animal. The results of this trial indicate the potential use of this fungus as a broad spectrum anti-parasite agent for use in both goats and sheep.

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...

Enhancement of β-xylosidase productivity in cellulase producing fungus Acremonium cellulolyticus

PubMed Central

2011-01-01

Enzymatic hydrolysis is one of the most important processes in bioethanol production from lignocellulosic biomass. Acremonium cellulolyticus is a filamentous fungus with high cellulase production but productivity of hemicellulase, especially β-xylosidase, is lower than other filamentous fungi. We identified 2.4 Kb β-xylosidase gene in the A. cellulolyticus genome sequence information and it encoded 798 amino acids without introns. To enhance hemicellulase productivity in A. cellulolyticus, we transformed this fungus with the identified β-xylosidase gene driven by the cellobiohydrolase Ι (cbh1) promoter, using the protoplast-polyethyleneglycol (PEG) method, and obtained a transformant, YKX1. Hydrolysis rate of xylooligosaccharides was more than 50-fold higher using culture supernatant from YKX1 than that from the parental strain, Y-94. Total cellulase activity (measured by filter paper assay) in YKX1 was not affected by the cbh1 promoter used for expression of β-xylosidase, and induced by cellulose. Since YKX1 can produce larger amount of β-xylosidase without affecting cellulase productivity, it is considered to be beneficial for practical monosaccharide recoveries from lignocellulosic biomass. PMID:21906369

Enhancement of β-xylosidase productivity in cellulase producing fungus Acremonium cellulolyticus.

PubMed

Kanna, Machi; Yano, Shinichi; Inoue, Hiroyuki; Fujii, Tatsuya; Sawayama, Shigeki

2011-06-30

Enzymatic hydrolysis is one of the most important processes in bioethanol production from lignocellulosic biomass. Acremonium cellulolyticus is a filamentous fungus with high cellulase production but productivity of hemicellulase, especially β-xylosidase, is lower than other filamentous fungi. We identified 2.4 Kb β-xylosidase gene in the A. cellulolyticus genome sequence information and it encoded 798 amino acids without introns. To enhance hemicellulase productivity in A. cellulolyticus, we transformed this fungus with the identified β-xylosidase gene driven by the cellobiohydrolase Ι (cbh1) promoter, using the protoplast-polyethyleneglycol (PEG) method, and obtained a transformant, YKX1. Hydrolysis rate of xylooligosaccharides was more than 50-fold higher using culture supernatant from YKX1 than that from the parental strain, Y-94. Total cellulase activity (measured by filter paper assay) in YKX1 was not affected by the cbh1 promoter used for expression of β-xylosidase, and induced by cellulose. Since YKX1 can produce larger amount of β-xylosidase without affecting cellulase productivity, it is considered to be beneficial for practical monosaccharide recoveries from lignocellulosic biomass.

Analysis of compositional monosaccharides in fungus polysaccharides by capillary zone electrophoresis.

PubMed

Hu, Yuanyuan; Wang, Tong; Yang, Xingbin; Zhao, Yan

2014-02-15

A rapid analytical method of capillary zone electrophoresis (CZE) was established for the simultaneous separation and determination of 10 monosaccharides (aldoses and uronic acids). The monosaccharides were labeled with 1-phenyl-3-methyl-5-pyrazolone (PMP), and subsequently separated using an uncoated capillary (50 μm i.d. × 58.5 cm) and detected by UV at 245 nm with pH 11.0, 175 mM borate buffer at voltage 20 kV and capillary temperature 25 °C by CZE. The 10 PMP-labeled monosaccharides were rapidly baseline separated within 20 min. The optimized CZE method was successfully applied to the simultaneous separation and identification of the monosaccharide composition in Termitomyces albuminosus polysaccharides (TAPs) and Panus giganteus polysaccharides (PGPs). The quantitative recovery of the component monosaccharides in the fungus polysaccharides was in the range of 92.0-101.0% and the CV value was lower than 3.5%. The results demonstrate that the proposed CZE method is precise and practical for the monosaccharide analysis of fungus polysaccharides. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales) from Tierra del Fuego, Argentina.

PubMed

Scorsetti, Ana C; Elíades, Lorena A; Stenglein, Sebastián A; Cabello, Marta N; Pelizza, Sebastián A; Saparrat, Mario C N

2012-06-01

Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4 degreeC, 12 degreeC and 24 degreeC), on different agar media supplemented with the following specific substrates: chitin azure, Tween 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4 degree C, 12 degree C and 24 degree C). The suspension was adjusted to a concentration of 1x10(7) conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24 degreeC), the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween 20 at the lower two incubation

Colony Size Affects the Efficacy of Bait Containing Chlorfluazuron Against the Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

PubMed

Lee, Ching-Chen; Neoh, Kok-Boon; Lee, Chow-Yang

2014-12-01

The efficacy of chitin synthesis inhibitors (CSIs) against fungus-growing termites is known to vary. In this study, 0.1% chlorfluazuron (CFZ) cellulose bait was tested against medium and large field colonies of Macrotermes gilvus (Hagen). The termite mounds were dissected to determine the health of the colony. Individual termites (i.e., workers and larvae) and fungus combs were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to detect the presence of CFZ. In this study, 540.0 ± 25.8 g (or equivalent to 540.0 ± 25.8 mg active ingredient) and 680.0 ± 49.0 g (680.0 ± 49.0 mg active ingredient) of bait matrix were removed by the medium- and large-sized colonies, respectively, after baiting. All treated medium-sized colonies were moribund. The dead termites were scattered in the mound, larvae were absent, population size had decreased by 90%, and the queens appeared unhealthy. In contrast, no or limited effects were found in large-sized colonies. Only trace amounts of CFZ were detected in workers, larvae, and fungus combs, and the population of large-sized colonies had declined by only up to 40%. This might be owing to the presence of large amount of basidiomycete fungus and a drastic decrease of CFZ content per unit fungus comb (a main food source of larvae) in the large-sized colonies, and hence reduced the toxic effect and longer time is required to accumulate the lethal dose in larvae. Nevertheless, we do not deny the possibility of CSI bait eliminating or suppressing the higher termite if the test colonies could pick up adequate lethal dose by installing more bait stations and prolonging the baiting period. © 2014 Entomological Society of America.

Identification of Immunity-Related Genes in Dialeurodes citri against Entomopathogenic Fungus Lecanicillium attenuatum by RNA-Seq Analysis.

PubMed

Yu, Shijiang; Ding, Lili; Luo, Ren; Li, Xiaojiao; Yang, Juan; Liu, Haoqiang; Cong, Lin; Ran, Chun

2016-01-01

Dialeurodes citri is a major pest in citrus producing areas, and large-scale outbreaks have occurred increasingly often in recent years. Lecanicillium attenuatum is an important entomopathogenic fungus that can parasitize and kill D. citri. We separated the fungus from corpses of D. citri larvae. However, the sound immune defense system of pests makes infection by an entomopathogenic fungus difficult. Here we used RNA sequencing technology (RNA-Seq) to build a transcriptome database for D. citri and performed digital gene expression profiling to screen genes that act in the immune defense of D. citri larvae infected with a pathogenic fungus. De novo assembly generated 84,733 unigenes with mean length of 772 nt. All unigenes were searched against GO, Nr, Swiss-Prot, COG, and KEGG databases and a total of 28,190 (33.3%) unigenes were annotated. We identified 129 immunity-related unigenes in transcriptome database that were related to pattern recognition receptors, information transduction factors and response factors. From the digital gene expression profile, we identified 441 unigenes that were differentially expressed in D. citri infected with L. attenuatum. Through calculated Log2Ratio values, we identified genes for which fold changes in expression were obvious, including cuticle protein, vitellogenin, cathepsin, prophenoloxidase, clip-domain serine protease, lysozyme, and others. Subsequent quantitative real-time polymerase chain reaction analysis verified the results. The identified genes may serve as target genes for microbial control of D. citri.

Identification of Immunity-Related Genes in Dialeurodes citri against Entomopathogenic Fungus Lecanicillium attenuatum by RNA-Seq Analysis

PubMed Central

Yu, Shijiang; Ding, Lili; Luo, Ren; Li, Xiaojiao; Yang, Juan; Liu, Haoqiang; Cong, Lin; Ran, Chun

2016-01-01

Dialeurodes citri is a major pest in citrus producing areas, and large-scale outbreaks have occurred increasingly often in recent years. Lecanicillium attenuatum is an important entomopathogenic fungus that can parasitize and kill D. citri. We separated the fungus from corpses of D. citri larvae. However, the sound immune defense system of pests makes infection by an entomopathogenic fungus difficult. Here we used RNA sequencing technology (RNA-Seq) to build a transcriptome database for D. citri and performed digital gene expression profiling to screen genes that act in the immune defense of D. citri larvae infected with a pathogenic fungus. De novo assembly generated 84,733 unigenes with mean length of 772 nt. All unigenes were searched against GO, Nr, Swiss-Prot, COG, and KEGG databases and a total of 28,190 (33.3%) unigenes were annotated. We identified 129 immunity-related unigenes in transcriptome database that were related to pattern recognition receptors, information transduction factors and response factors. From the digital gene expression profile, we identified 441 unigenes that were differentially expressed in D. citri infected with L. attenuatum. Through calculated Log2Ratio values, we identified genes for which fold changes in expression were obvious, including cuticle protein, vitellogenin, cathepsin, prophenoloxidase, clip-domain serine protease, lysozyme, and others. Subsequent quantitative real-time polymerase chain reaction analysis verified the results. The identified genes may serve as target genes for microbial control of D. citri. PMID:27644092

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...

Quantitative evaluation of protocorm growth and fungal colonization in Bletilla striata (Orchidaceae) reveals less-productive symbiosis with a non-native symbiotic fungus.

PubMed

Yamamoto, Tatsuki; Miura, Chihiro; Fuji, Masako; Nagata, Shotaro; Otani, Yuria; Yagame, Takahiro; Yamato, Masahide; Kaminaka, Hironori

2017-02-21

In nature, orchid plants depend completely on symbiotic fungi for their nutrition at the germination and the subsequent seedling (protocorm) stages. However, only limited quantitative methods for evaluating the orchid-fungus interactions at the protocorm stage are currently available, which greatly constrains our understanding of the symbiosis. Here, we aimed to improve and integrate quantitative evaluations of the growth and fungal colonization in the protocorms of a terrestrial orchid, Blettila striata, growing on a plate medium. We achieved both symbiotic and asymbiotic germinations for the terrestrial orchid B. striata. The protocorms produced by the two germination methods grew almost synchronously for the first three weeks. At week four, however, the length was significantly lower in the symbiotic protocorms. Interestingly, the dry weight of symbiotic protocorms did not significantly change during the growth period, which implies that there was only limited transfer of carbon compounds from the fungus to the protocorms in this relationship. Next, to evaluate the orchid-fungus interactions, we developed an ink-staining method to observe the hyphal coils in protocorms without preparing thin sections. Crushing the protocorm under the coverglass enables us to observe all hyphal coils in the protocorms with high resolution. For this observation, we established a criterion to categorize the stages of hyphal coils, depending on development and degradation. By counting the symbiotic cells within each stage, it was possible to quantitatively evaluate the orchid-fungus symbiosis. We describe a method for quantitative evaluation of orchid-fungus symbiosis by integrating the measurements of plant growth and fungal colonization. The current study revealed that although fungal colonization was observed in the symbiotic protocorms, the weight of the protocorm did not significantly increase, which is probably due to the incompatibility of the fungus in this symbiosis. These

Cutinase in Cryphonectria parasitica, the chestnut blight fungus: suppression of cutinase gene expression in isogenic hypovirulent strains containing double-stranded RNAs

Treesearch

D.A. ​Varley; G.K. Podila; S.T. Hiremath

1992-01-01

Plant-pathogenic fungi produce cutinase, an enzyme required to degrade plant cuticles and facilitate penetration into the host. The absence of cutinase or a decrease in its production has been associated with a decrease in pathogenicity of the fungus. A set of isogenic strains of Cryphonectria parasitica, the chestnut blight fungus, was tested for...

An arbuscular mycorrhizal fungus and Epichloë festucae var. lolii reduce Bipolaris sorokiniana disease incidence and improve perennial ryegrass growth.

PubMed

Li, Fang; Guo, Yan'e; Christensen, Michael J; Gao, Ping; Li, Yanzhong; Duan, Tingyu

2018-02-01

Leaf spot of perennial ryegrass (Lolium perenne) caused by Bipolaris sorokiniana is an important disease in temperate regions of the world. We designed this experiment to test for the combined effects of the arbuscular mycorrhizal (AM) fungus Claroideoglomus etunicatum and the grass endophyte fungus Epichloë festucae var. lolii on growth and disease occurrence in perennial ryegrass. The results show that C. etunicatum increased plant P uptake and total dry weight and that this beneficial effect was slightly enhanced when in association with the grass endophyte. The presence in plants of both the endophyte and B. sorokiniana decreased AM fungal colonization. Plants inoculated with B. sorokiniana showed the typical leaf spot symptoms 2 weeks after inoculation and the lowest disease incidence was with plants that were host to both C. etunicatum and E. festucae var. lolii. Plants with these two fungi had much higher activity of peroxidases (POD), superoxide dismutase (SOD) and catalase (CAT) and lower values of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ). The AM fungus C. etunicatum and the grass endophyte fungus E. festucae var. lolii have the potential to promote perennial ryegrass growth and resistance to B. sorokiniana leaf spot.

Genome sequencing and analysis of the paclitaxel-producing endophytic fungus Penicillium aurantiogriseum NRRL 62431

PubMed Central

2014-01-01

Background Paclitaxel (Taxol™) is an important anticancer drug with a unique mode of action. The biosynthesis of paclitaxel had been considered restricted to the Taxus species until it was discovered in Taxomyces andreanae, an endophytic fungus of T. brevifolia. Subsequently, paclitaxel was found in hazel (Corylus avellana L.) and in several other endophytic fungi. The distribution of paclitaxel in plants and endophytic fungi and the reported sequence homology of key genes in paclitaxel biosynthesis between plant and fungi species raises the question about whether the origin of this pathway in these two physically associated groups could have been facilitated by horizontal gene transfer. Results The ability of the endophytic fungus of hazel Penicillium aurantiogriseum NRRL 62431 to independently synthesize paclitaxel was established by liquid chromatography-mass spectrometry and proton nuclear magnetic resonance. The genome of Penicillium aurantiogriseum NRRL 62431 was sequenced and gene candidates that may be involved in paclitaxel biosynthesis were identified by comparison with the 13 known paclitaxel biosynthetic genes in Taxus. We found that paclitaxel biosynthetic gene candidates in P. aurantiogriseum NRRL 62431 have evolved independently and that horizontal gene transfer between this endophytic fungus and its plant host is unlikely. Conclusions Our findings shed new light on how paclitaxel-producing endophytic fungi synthesize paclitaxel, and will facilitate metabolic engineering for the industrial production of paclitaxel from fungi. PMID:24460898

Comparative Transcriptome Analysis of the Cosmopolitan Marine Fungus Corollospora maritima Under Two Physiological Conditions

PubMed Central

Velez, Patricia; Alejandri-Ramírez, Naholi D.; González, María C.; Estrada, Karel J.; Sanchez-Flores, Alejandro; Dinkova, Tzvetanka D.

2015-01-01

Marine sandy beaches represent dynamic environments often subject to harsh conditions and climate fluctuations, where natural and anthropogenic inputs of freshwater from fluvial and pluvial sources alter salinity, which has been recognized as a key variable affecting the distribution of aquatic organisms and influencing critical physiological processes. The marine arenicolous fungus Corollospora maritima is a worldwide-distributed saprobe that has been reported to present tolerance to freshwater. Here, we present a transcriptome analysis that will provide the first insight of the genomic content for this fungus and a gene expression comparison between two different salinity conditions. We also identified genes that are candidates for being differentially expressed in response to environmental variations on salinity during the fungal growth. The de novo reconstruction of C. maritima transcriptome Illumina sequencing provided a total of 14,530 transcripts (16 megabases). The comparison between the two growth conditions rendered 103 genes specifically overexpressed in seawater, and 132 genes specifically up-regulated under freshwater. Using fungal isolates collected from different beaches, the specific environmental regulation of particular transcript differential expression was confirmed by RT-qPCR. To our knowledge, this is the first analysis that explores the marine fungus C. maritima molecular responses to overcome freshwater stress, and these data could shed light to understand the fungal adaptation and plasticity mechanisms to the marine habitat. PMID:26116293

Investigating the effects of laser beams (532 and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis

NASA Astrophysics Data System (ADS)

Saghafi, S.; Penjweini, R.; Becker, K.; Kratky, K. W.; Dodt, H.-U.

2010-09-01

When moulds are illuminated by visible electromagnetic-EM radiations, several effects on nucleus materials and nucleotides can be detected. These effects have a significant influence on mould generation or destruction. This paper presents the effects and implications of a red diode laser beam (660 nm), a second-harmonics of a Nd:YAG laser emitting green beam (532 nm), or the combination of both, on the eradication of Pistachio mould fungus. Incident doses (ID) of both beams are kept identical throughout the experiment. The absorption spectrums of irradiated mouldy samples and the bright-greenish-yellow-fluorescence (BGYF) of fungus occurring in mould texture due to electronic excitation are investigated. We found that a combination of a green and a red laser beam with an ID of 0.5 J/cm2 provides the optimal effects on Pistachio mould fungus eradication.

Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S

Treesearch

Blake R. Hossack; Michael J. Adams; Evan H. Campbell Grant; Christopher A. Pearl; James B. Bettaso; William J. Barichivich; Winsor H. Lowe; Kimberly True; Joy L. Ware; Paul Stephen Corn

2010-01-01

Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To...

Dissolved oxygen levels affect dimorphic growth by the entomopathogenic fungus Isaria fumosorosea

USDA-ARS?s Scientific Manuscript database

The entomopathogenic fungus Isaria fumosorosea is capable of dimorphic growth (hyphal or yeast-like) in submerged culture. In shake flask studies, we evaluated the impact of aeration on the mode of growth of I. fumosorosea. Using 250 mL baffled Erlenmeyer flasks, culture volumes of 50, 100, 150, a...

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...

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

USGS Publications Warehouse

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

2017-01-01

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

Interactions and consequences of silicon, nitrogen, and Fusarium palustre on herbivory and DMSP levels of Spartina alterniflora

NASA Astrophysics Data System (ADS)

Bazzano, Magalí; Elmer, Wade

2017-11-01

Sudden Vegetation Dieback (SVD) has been associated with multiple factors affecting the health of Spartina alterniflora. These include altered nutrition (N, Si and various metals), herbivory from the purple marsh crab, and the association with a fungal pathogen (Fusarium palustre). A metabolite produced by Spartina alterniflora that has been associated with plant health is dimethylsulfoniopropionate (DMSP), but little information exist on how these biotic stressors and nutrition interact to affect DMSP levels. Understanding how these factors might be interrelated might provide insight into the etiology of SVD. Surveys of a marsh affected by SVD confirmed lower levels of DMSP and higher concentrations of Si and other metals were present in Sp. alterniflora when compared to plants from marsh that exhibited no signs of SVD. In repeated greenhouse experiments, the application of Si to Sp. alterniflora had no effect on DMSP concentrations. However, when plants were inoculated with the pathogenic fungus, Fusarium palustre, and then treated with Si, DMSP levels were elevated 27%. Inoculation alone had no effect on DMSP levels. Si application neither favor growth nor suppress the stunting effect of disease by F. palustre. Furthermore, grazing by Sesarma reticulatum, a herbivorous crab, was not affected by Si nutrition. Grazing was increased by nitrogen fertilization and inoculation with F. palustre. Deciphering the role of Si nutrition in Sp. alterniflora and dieback remains unresolved, but no evidence suggests enhancing Si nutrition would directly favor marsh health.

Probiotics for Plants? Growth Promotion by the Entomopathogenic Fungus Beauveria bassiana Depends on Nutrient Availability.

PubMed

Tall, Susanna; Meyling, Nicolai V

2018-03-28

Cultivation of crops requires nutrient supplements which are costly and impact the environment. Furthermore, global demands for increased crop production call for sustainable solutions to increase yield and utilize resources such as nutrients more effectively. Some entomopathogenic fungi are able to promote plant growth, but studies over such effects have been conducted under optimal conditions where nutrients are abundantly available. We studied the effects of Beauveria bassiana (strain GHA) seed treatment on the growth of maize (Zea mays) at high and low nutrient conditions during 6 weeks in greenhouse. As expected, B. bassiana seed treatment increased plant growth, but only at high nutrient conditions. In contrast, the seed treatment did not benefit plant growth at low nutrient conditions where the fungus potentially constituted a sink and tended to reduce plant growth. The occurrence of endophytic B. bassiana in experimental plant tissues was evaluated by PCR after 6 weeks, but B. bassiana was not documented in any of the above-ground plant tissues indicating that the fungus-plant interaction was independent of endophytic establishment. Our results suggest that B. bassiana seed treatment could be used as a growth promoter of maize when nutrients are abundantly available, while the fungus does not provide any growth benefits when nutrients are scarce.

Neem oil increases the efficiency of the entomopathogenic fungus Metarhizium anisopliae for the control of Aedes aegypti (Diptera: Culicidae) larvae.

PubMed

Gomes, Simone A; Paula, Adriano R; Ribeiro, Anderson; Moraes, Catia O P; Santos, Jonathan W A B; Silva, Carlos P; Samuels, Richard I

2015-12-30

Entomopathogenic fungi are potential candidates for use in integrated vector management and many isolates are compatible with synthetic and natural insecticides. Neem oil was tested separately and in combination with the entomopathogenic fungus Metarhizium anisopliae against larvae of the dengue vector Aedes aegypti. Our aim was to increase the effectiveness of the fungus for the control of larval mosquito populations. Commercially available neem oil was used at concentrations ranging from 0.0001 to 1%. Larval survival rates were monitored over a 7 day period following exposure to neem. The virulence of the fungus M. anisopliae was confirmed using five conidial concentrations (1 × 10(5) to 1 × 10(9) conidia mL(-1)) and survival monitored over 7 days. Two concentrations of fungal conidia were then tested together with neem (0.001%). Survival curve comparisons were carried out using the Log-rank test and end-point survival rates were compared using one-way ANOVA. 1% neem was toxic to A. aegypti larvae reducing survival to 18% with S50 of 2 days. Neem had no effect on conidial germination or fungal vegetative growth in vitro. Larval survival rates were reduced to 24% (S50 = 3 days) when using 1 × 10(9) conidia mL(-1). Using 1 × 10(8) conidia mL(-1), 30% survival (S50 = 3 days) was observed. We tested a "sub-lethal" neem concentration (0.001%) together with these concentrations of conidia. For combinations of neem + fungus, the survival rates were significantly lower than the survival rates seen for fungus alone or for neem alone. Using a combination of 1 × 10(7) conidia mL(-1) + neem (0.001%), the survival rates were 36%, whereas exposure to the fungus alone resulted in 74% survival and exposure to neem alone resulted in 78% survival. When using 1 × 10(8) conidia mL(-1), the survival curves were modified, with a combination of the fungus + neem resulting in 12% survival, whilst the fungus alone at this concentration also

Overexpression of the wasabi defensin gene confers enhanced resistance to blast fungus ( Magnaporthe grisea) in transgenic rice.

PubMed

Kanzaki, H.; Nirasawa, S.; Saitoh, H.; Ito, M.; Nishihara, M.; Terauchi, R.; Nakamura, I.

2002-11-01

Transgenic rice ( Oryza sativa cv. Sasanishiki) overexpressing the wasabi defensin gene, a plant defensin effective against the rice blast fungus, was generated by Agrobacterium tumefaciens-mediated transformation. Twenty-two T2 homozygous lines harboring the wasabi defensin gene were challenged by the blast fungus. Transformants exhibited resistance to rice blast at various levels. The inheritance of the resistance over generations was investigated. T3 plants derived from two highly blast-resistant T2 lines (WT14-5 and WT43-5) were challenged with the blast fungus using the press-injured spots method. The average size of disease lesions of the transgenic line WT43-5 was reduced to about half of that of non-transgenic plants. The 5-kDa peptide, corresponding to the processed form of the wasabi defensin, was detected in the total protein fraction extracted from the T3 progeny. Transgenic rice plants overproducing wasabi defensin are expected to possess a durable and wide-spectrum resistance (i.e. field resistance) against various rice blast races.

Effect of salinity medium on antioxidant and antidiabetic activity marine endophytic fungus of asperegillus elegans ptf 9

NASA Astrophysics Data System (ADS)

Mulyani, Hani; Artanti, Nina; Fitria, Irni; Filailla, Euis; Kandace, Yoice Sri; Udin, Linar Zalinar

2017-11-01

Our previous studies on screening of antioxidant activities from various endophytic fungi isolated from marine bioata showed that A. elegans PTF9 isolated from sea weed is one of the fungus that has good antioxidant activity. In current study we reported the effect of medium salinity (0, 3 and 10% salt in PDB medium) on antioxidant and antidiabetes activity of mycelium and filtrate ethyl acetate extracts of A. elegans Ptf 9. The antioxidant assay was conducted using DPPH free radical scavenging activity method. The antidiabetes assay was conducted using a-glucosidase inhibitory activity method. The results showed that the best antioxidant activity was obtained from filtrate extract of fungus cultures with 0% salt (IC50=1.56 ppm), whereas the best antidiabetes activity was obtained from filtrate extract of fungus culture with 10% salt (IC50= 3.64 ppm). Addition of salt reduced the antioxidant activity, but not the antidiabetes activity. The results suggest that A. elegans PTF9 showed potential for further studies on isolation of antioxidant and antidiabetes lead compounds that could be use for further development of new drugs.

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.

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

Dynamic changes of rice blast fungus in the USA through six decades

USDA-ARS?s Scientific Manuscript database

Rice blast disease caused by the fungus Magnaporthe oryzae is a serious rice disease in the USA and worldwide. M. oryzae is highly adaptive and changeable due to the instability of its genome and resistance genes which are effective only when M. oryzae isolates contain the cognate avirulence (AVR) g...

Cellular development associated with induced secondary metabolism in the filamentous fungus Fusarium graminearum

USDA-ARS?s Scientific Manuscript database

Several species of the filamentous fungus Fusarium colonize plants and produce toxic small molecules that contaminate agricultural products, rendering them unsuitable for consumption. Among the most destructive of these species is F. graminearum, which causes disease in wheat and barley and often in...

Biological pretreatment of corn stover with white-rot fungus for improved enzymatic hydrolysis

USDA-ARS?s Scientific Manuscript database

Biological pretreatment of lignocellulosic biomass by white-rot fungus can represent a low-cost and eco-friendly alternative to harsh physical, chemical or physico-chemical pretreatment methods to facilitate enzymatic hydrolysis. However, fungal pretreatment can cause carbohydrate loss and it is, th...

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...

Characterization of salt-adapted secreted lignocellulolytic enzymes from the mangrove fungus Pestalotiopsis sp.

PubMed

Arfi, Yonathan; Chevret, Didier; Henrissat, Bernard; Berrin, Jean-Guy; Levasseur, Anthony; Record, Eric

2013-01-01

Fungi are important for biomass degradation processes in mangrove forests. Given the presence of sea water in these ecosystems, mangrove fungi are adapted to high salinity. Here we isolate Pestalotiopsis sp. NCi6, a halotolerant and lignocellulolytic mangrove fungus of the order Xylariales. We study its lignocellulolytic enzymes and analyse the effects of salinity on its secretomes. De novo transcriptome sequencing and assembly indicate that this fungus possesses of over 400 putative lignocellulolytic enzymes, including a large fraction involved in lignin degradation. Proteomic analyses of the secretomes suggest that the presence of salt modifies lignocellulolytic enzyme composition, with an increase in the secretion of xylanases and cellulases and a decrease in the production of oxidases. As a result, cellulose and hemicellulose hydrolysis is enhanced but lignin breakdown is reduced. This study highlights the adaptation to salt of mangrove fungi and their potential for biotechnological applications.

Susceptibility of adult female Aedes aegypti (Diptera: Culicidae) to the entomopathogenic fungus Metarhizium anisopliae is modified following blood feeding.

PubMed

Paula, Adriano R; Carolino, Aline T; Silva, Carlos P; Samuels, Richard I

2011-05-26

The mosquito Aedes aegypti, vector of dengue fever, is a target for control by entomopathogenic fungi. Recent studies by our group have shown the susceptibility of adult A. aegypti to fungal infection by Metarhizium anisopliae. This fungus is currently being tested under field conditions. However, it is unknown whether blood-fed A. aegypti females are equally susceptible to infection by entomopathogenic fungi as sucrose fed females. Insect populations will be composed of females in a range of nutritional states. The fungus should be equally efficient at reducing survival of insects that rest on fungus impregnated surfaces following a blood meal as those coming into contact with fungi before host feeding. This could be an important factor when considering the behavior of A. aegypti females that can blood feed on multiple hosts over a short time period. Female A. aegypti of the Rockefeller strain and a wild strain were infected with two isolates of the entomopathogenic fungus M. anisopliae (LPP 133 and ESALQ 818) using an indirect contact bioassay at different times following blood feeding. Survival rates were monitored on a daily basis and one-way analysis of variance combined with Duncan's post-hoc test or Log-rank survival curve analysis were used for statistical comparisons of susceptibility to infection. Blood feeding rapidly reduced susceptibility to infection, determined by the difference in survival rates and survival curves, when females were exposed to either of the two M. anisopliae isolates. Following a time lag which probably coincided with digestion of the blood meal (96-120 h post-feeding), host susceptibility to infection returned to pre-blood fed (sucrose fed) levels. Reduced susceptibility of A. aegypti to fungi following a blood meal is of concern. Furthermore, engorged females seeking out intra-domicile resting places post-blood feeding, would be predicted to rest for prolonged periods on fungus impregnated black cloths, thus optimizing infection

Secondary metabolites from the mangrove endophytic fungus Penicillium sp. (SBE-8).

PubMed

Guo, Zhiyong; Cheng, Fan; Zou, Kun; Wang, Junzhi; She, Zhigang; Lin, Yongcheng

2009-11-01

A new metabolite, 7-hydroxyjanthinone (1), was isolated from the mangrove endophytic fungus Penicillium sp. (SBE-8), together with two known compounds, janthinone (2) and citrinin (3). The structures of these compounds were identified by spectroscopic methods. Compounds 1 and 2 showed no cytotoxicity against KB and KBv cell lines when tested by the MTT method, but compound 3 was weakly active.

Intercontinental divergence in the Populus-associated ectomycorrhizal fungus, Tricholoma populinum.

PubMed

Grubisha, Lisa C; Levsen, Nicholas; Olson, Matthew S; Taylor, D Lee

2012-04-01

The ectomycorrhizal fungus Tricholoma populinum is host-specific with Populus species. T. populinum has wind-dispersed progagules and may be capable of long-distance dispersal. In this study, we tested the hypothesis of a panmictic population between Scandinavia and North America. DNA sequences from five nuclear loci were used to assess phylogeographic structure and nucleotide divergence between continents. Tricholoma populinum was composed of Scandinavian and North American lineages with complete absence of shared haplotypes and only one shared nucleotide mutation. Divergence of these lineages was estimated at approx. 1.7-1.0 million yr ago (Ma), which occurred after the estimated divergence of host species Populus tremula and Populus balsamifera/Populus trichocarpa at 5 Ma. Phylogeographic structure was not observed within Scandinavian or North American lineages of T. populinum. Intercontinental divergence appears to have resulted from either allopatric isolation; a recent, rare long-distance dispersal founding event followed by genetic drift; or the response in an obligate mycorrhizal fungus with a narrow host range to contractions and expansion of host distribution during glacial and interglacial episodes within continents. Understanding present genetic variation in populations is important for predicting how obligate symbiotic fungi will adapt to present and future changing climatic conditions. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

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

The carbon starvation response of the ectomycorrhizal fungus Paxillus involutus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellstrom, Magnus; Shah, Firoz; Johansson, Tomas

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

Non-targeted Colonization by the Endomycorrhizal Fungus, Serendipita vermifera, in Three Weeds Typically Co-occurring with Switchgrass

PubMed Central

Ray, Prasun; Guo, Yingqing; Kolape, Jaydeep; Craven, Kelly D.

2018-01-01

Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted to study movement of vegetative mycelia of S. vermifera between intentionally inoculated switchgrass (Panicum virgatum L.) and nearby weeds. We constructed size-exclusion microcosms to test three different common weeds, large crabgrass (Digitaria sanguinalis L.), Texas panicum (Panicum texanum L.), and Broadleaf signalgrass (Brachiaria platyphylla L.), all species that typically co-occur in Southern Oklahoma and potentially compete with switchgrass. We report that such colonization of non-target plants by S. vermifera can indeed occur, seemingly via co-mingled root systems. As a consequence of colonization, significant enhancement of growth was noted in signalgrass, while a mild increase (albeit not significant) was evident in crabgrass. Migration of the fungus seems unlikely in root-free bulk soil, as we failed to see transmission when the roots were kept separate. This research is the first documentation of non-targeted colonization of this unique root symbiotic fungus and highlights the need for such assessments prior to deployment of biological organisms in the field. PMID:29375607

A disseminated infection with the antifungal-multiresistant teleomorphic fungus Neocosmospora vasinfecta in a patient with acute B-lymphoblastic leukemia.

PubMed

Gabriel, Frédéric; D'Almeida, Mahussi; Albert, Olivier; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

2013-02-09

We report on a fatal invasive infection due to the ascomycetous fungus Neocosmospora vasinfecta, in a 20-year-old European patient suffering from an acute lymphoblastic leukemia. The infection could not be controlled by a bitherapy combining liposomal amphotericin B and voriconazole. This is the second case of disseminated infection reported with this unusual fungus, which develops under its teleomorphic state, is fully resistant to all systemic antifungals, and which is known to live in tropical countries.

A disseminated infection with the antifungal-multiresistant teleomorphic fungus Neocosmospora vasinfecta in a patient with acute B-lymphoblastic leukemia

PubMed Central

Gabriel, Frédéric; D’Almeida, Mahussi; Albert, Olivier; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

2013-01-01

We report on a fatal invasive infection due to the ascomycetous fungus Neocosmospora vasinfecta, in a 20-year-old European patient suffering from an acute lymphoblastic leukemia. The infection could not be controlled by a bitherapy combining liposomal amphotericin B and voriconazole. This is the second case of disseminated infection reported with this unusual fungus, which develops under its teleomorphic state, is fully resistant to all systemic antifungals, and which is known to live in tropical countries. PMID:24432214

Phylogenetic placement of an unusual coral mushroom challenges the classic hypothesis of strict coevolution in the Apterostigma pilosum group ant-fungus mutualism

Treesearch

Bryn T.M. Dentinger; D.Jean Lodge; Andrew B. Munkacsi; Dennis E. Desjardin; David J. McLaughlin

2009-01-01

The ~50 million-year-old fungus-farming ant mutualism is a classic example of coevolution, involving ants that subsist on asexual, fungal biomass, in turn propagating the fungus clonally through nest-to-nest transmission. Most mutualistic ants cultivate two closely related groups of gilled mushrooms, whereas one small group of ants in the genus ...

Immune-physiological aspects of synergy between avermectins and the entomopathogenic fungus Metarhizium robertsii in Colorado potato beetle larvae.

PubMed

Tomilova, Oksana G; Kryukov, Vadim Yu; Duisembekov, Bahytzhan A; Yaroslavtseva, Olga N; Tyurin, Maksim V; Kryukova, Natalia A; Skorokhod, Valery; Dubovskiy, Ivan M; Glupov, Viktor V

2016-10-01

The interaction between the entomopathogenic fungus Metarhizium robertsii and natural avermectin metabolites of the actinomycete Streptomyces avermitilis were investigated on Colorado potato beetle larvae. A synergy in the mortality of larvae was detected after simultaneous treatment with half-lethal doses of avermectins (commercial name actarophit) 0.005% and fungus (5×10 5 conidia/ml). The treatment with avermectins led to rapid fungal colonization of the hemolymph. The defense strategies of insects infected by fungus and treated with avermectins and untreated insects were compared to investigate the mechanisms of this synergy. We have shown an increase in hemocytes, especially immunocompetent cells - plasmatocytes and granular cells in the initial stages of mycosis (third day post inoculation). In contrast, avermectins suppressed cellular immunity in hemolymph. Specifically, avermectins dramatically decreased the count of granular cells in larvae infected and uninfected with fungus. Apoptosis inducement and hemocyte necrosis under the influence of avermectins has been shown in vitro as one of the possible reasons for hemocyte mortality. In addition, avermectins enhanced the activity of phenoloxidases in integuments and hemolymph and increased the activity of glutathione-S-transferases activity in the fat body and hemolymph of infected and uninfected larvae, thereby intensifying the development of fungal infection by M. robertsii in Colorado potato beetle larvae. The combination of fungal infection and avermectins constitutes a new perspective for developing multicomponent bioinsecticides. Copyright © 2016 Elsevier Inc. All rights reserved.

Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.; Teiling, Clotilde; Tremmel, Daniel M.; Moeller, Joseph A.; Scott, Jarrod J.; Barry, Kerrie W.; Piehowski, Paul D.; Nicora, Carrie D.; Malfatti, Stephanie A.; Monroe, Matthew E.; Purvine, Samuel O.; Goodwin, Lynne A.; Smith, Richard D.; Weinstock, George M.; Gerardo, Nicole M.; Suen, Garret; Lipton, Mary S.

2013-01-01

Plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and, using genomic and metaproteomic tools, we investigate its role in lignocellulose degradation in the gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in ant gardens and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that likely play an important role in lignocellulose degradation. Our study provides a detailed analysis of plant biomass degradation in leaf-cutter ant fungus gardens and insight into the enzymes underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar. PMID:23584789

Two new compounds from the plant endophytic fungus Pestalotiopsis versicolor.

PubMed

Yang, Xiao-Long; Huang, Le; Li, Hai-Ying; Yang, Deng-Feng; Li, Zhuang-Zhuang

2015-01-01

A new coumarin, 4,6-dihydroxy-7-formyl-3-methylcoumarin (1), and an α-pyrone derivative, 6-[(7S,8R)-8-propyloxiran-1-yl]-4-methoxy-pyran-2-one (2), together with four known α-pyrone derivatives (3-6), were isolated from the broth extract of the plant endophytic fungus Pestalotiopsis versicolor. Their structures were elucidated by extensive spectroscopic analysis and by comparison of the chemical shift values with those of related known compounds.

Two new compounds from an endophytic fungus Pestalotiopsis heterocornis.

PubMed

Xing, Jian-Guang; Deng, Hui-Ying; Luo, Du-Qiang

2011-12-01

Two new compounds, 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-α-L-rhamnosyl-phthalide and 7-hydroxy-5-methoxy-4,6-dimethyl-7-O-β-D-glucopyranosyl-phthalide, along with one known and related metabolite 7-hydroxy-5-methoxy-4,6-dimethylphthalide were isolated from the EtOAc extract of fermentation broth of an endophytic fungus Pestalotiopsis heterocornis. The structures of these compounds were elucidated on the basis of spectroscopic methods (UV, IR, HR-ESI-MS, 1D NMR, and 2D NMR).

Intersporal Genetic Variation of Gigaspora margarita, a Vesicular Arbuscular Mycorrhizal Fungus, Revealed by M13 Minisatellite-Primed PCR.

PubMed

Zeze, A; Sulistyowati, E; Ophel-Keller, K; Barker, S; Smith, S

1997-02-01

Spores of vesicular arbuscular mycorrhizal (VAM) fungi contain thousands of nuclei. In order to understand the karyotic structure of a VAM fungus spore, the genetic variation of the first generation of spores from a VAM fungus (Gigaspora margarita) was examined. Spores originating from both single- and multispore inoculations of the species G. margarita were analyzed by M13 minisatellite-primed PCR. In both cases, different fingerprints were obtained from individual spores with few spores exhibiting similar fingerprints. These results can be explained only by a heterokaryotic status of the nuclear population within a spore.

Climate-induced forest dieback as an emergent global phenomenon: Organized oral session at the Ecological Society of America/Society of Ecological Restoration Joint Meeting; San Jose, California, 5-10 August 2007

USGS Publications Warehouse

Allen, Craig D.; Breshears, David D.

2007-01-01

An organized oral session at the annual meeting of the Ecological Society of America in San Jose, Calif., posed this question: Is climate-induced drought stress triggering increasing rates and unusual patterns of forest die-off at a global scale? Twenty-nine researchers representing five continents reported on patterns, mechanisms, and projections of forest mortality.Observations include widespread forest dieback or reductions in tree cover and biodiversity in response to drought and warmer temperatures in the African Sahel (Patrick Gonzalez, The Nature Conservancy), Mediterranean and alpine Europe (Jorge Castro, Universidad de Granada), and Argentinean Patagonia (Thomas Kitzberger, Universidad Nacional del Comahue). In contrast, although much Eucalyptus mortality has resulted from recent droughts in Australia, warming trends have been less pronounced in the Southern Hemisphere and it is unclear if contemporary climate-induced tree mortality differs from previous historical drought impacts (Rod Fensham, Queensland Herbarium).

New brefeldins and penialidins from marine fungus Penicillium janthinellum DT-F29.

PubMed

Cheng, Xiangwei; Yu, Liyan; Wang, Qianqian; Ding, Wanjing; Chen, Zhe; Ma, Zhongjun

2018-02-01

A fermentation of marine fungus Penicillium janthinellum DT-F29 on solid rice medium led to the isolation of three new compounds, brefeldin D (1) and penialidins D-E (5-6), along with other five known brefeldins and penialidins. The structures of above compounds were determined on the basis of MS and NMR analysis.

Real-Time PCR Detection of Dogwood Anthracnose Fungus in Historical Herbarium Specimens from Asia.

PubMed

Miller, Stephen; Masuya, Hayato; Zhang, Jian; Walsh, Emily; Zhang, Ning

2016-01-01

Cornus species (dogwoods) are popular ornamental trees and important understory plants in natural forests of northern hemisphere. Dogwood anthracnose, one of the major diseases affecting the native North American Cornus species, such as C. florida, is caused by the fungal pathogen Discula destructiva. The origin of this fungus is not known, but it is hypothesized that it was imported to North America with its host plants from Asia. In this study, a TaqMan real-time PCR assay was used to detect D. destructiva in dried herbarium and fresh Cornus samples. Several herbarium specimens from Japan and China were detected positive for D. destructiva, some of which were collected before the first report of the dogwood anthracnose in North America. Our findings further support that D. destructiva was introduced to North America from Asia where the fungus likely does not cause severe disease.

Effect of biochar soil-amendments on Allium porrum growth, arbuscular mycorrhizal fungus colonization

USDA-ARS?s Scientific Manuscript database

Aims: Examine the interaction of biochar addition and arbuscular mycorrhizal [AM] fungus inoculation upon growth and Zn and Cu uptake by Allium porrum L. in heavy metal amended soil mix, and relate these responses to physicochemical properties of the biochars. Methods: The experiment was a complete ...

A Hair & a Fungus: Showing Kids the Size of a Microbe

ERIC Educational Resources Information Center

Richter, Dana L.

2013-01-01

A simple method is presented to show kids the size of a microbe--a fungus hypha--compared to a human hair. Common household items are used to make sterile medium on a stove or hotplate, which is dispensed in the cells of a weekly plastic pill box. Mold fungi can be easily and safely grown on the medium from the classroom environment. A microscope…

[Fungus microbiota in air conditioners in intensive care units in Teresina, Piauí].

PubMed

Mobin, Mitra; do Amparo Salmito, Maria

2006-01-01

With the aim of identifying the fungus microbiota in air conditioners in intensive care units (ICUs) within public and private hospitals in Teresina, Piauí, solid material was collected from ten different ICUs. Thirty-three species of Moniliaceae and Dematiaceae were isolated, which was the first report of these in Piauí. High frequencies of Aspergillus niger Van Tieghem (60%), Aspergillus fumigatus Fres (50%), Trichoderma koningii Oudem (50%) and Aspergillus flavus Link: Fr. (40%) were recorded. The air conditioner cleanliness validity had expired in all the ICUs, and the quantity of colony-forming units exceeded the levels permitted by Law 176/00 from the Ministry of Health. It is important to provide individual protection equipment for professionals, adopt hospital infection control measures, raise the awareness of the presence of fungus infection, improve air circulation around the environment, periodically clean the air conditioners, and make health professionals alert to the importance of these fungi in the hospital environment.

Degradation of a model pollutant ferulic acid by the endophytic fungus Phomopsis liquidambari.

PubMed

Xie, Xing-Guang; Dai, Chuan-Chao

2015-03-01

Biodegradation of ferulic acid, by an endophytic fungus called Phomopsis liquidambari was investigated in this study. This strain can use ferulic acid as the sole carbon for growth. Both in mineral salt medium and in soil, more than 97% of added ferulic acid was degraded within 48 h. The metabolites were identified and quantified using GC-MS and HPLC-MS. Ferulic acid was first decarboxylated to 4-vinyl guaiacol and then oxidized to vanillin and vanillic acid, followed by demethylation to protocatechuic acid, which was further degraded through the β-ketoadipate pathway. During degradation, ferulic acid decarboxylase, laccase and protocatechuate 3,4-dioxygenase activities and their gene transcription levels were significantly affected by the variation of substrate and product concentrations. Moreover, ferulic acid degradation was determined to some extent by P. liquidambari laccase. This study is the first report of an endophytic fungus that has a great potential for practical application in ferulic acid-contaminated environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Complement and innate immune evasion strategies of the human pathogenic fungus Candida albicans.

PubMed

Luo, Shanshan; Skerka, Christine; Kurzai, Oliver; Zipfel, Peter F

2013-12-15

Candida albicans is a medically important fungus that can cause a wide range of diseases ranging from superficial infections to disseminated disease, which manifests primarily in immuno-compromised individuals. Despite the currently applied anti-fungal therapies, both mortality and morbidity caused by this human pathogenic fungus are still unacceptably high. Therefore new prophylactic and therapeutic strategies are urgently needed to prevent fungal infection. In order to define new targets for combating fungal disease, there is a need to understand the immune evasion strategies of C. albicans in detail. In this review, we summarize different sophisticated immune evasion strategies that are utilized by C. albicans. The description of the molecular mechanisms used for immune evasion does on one hand help to understand the infection process, and on the other hand provides valuable information to define new strategies and diagnostic approaches to fight and interfere with Candida infections. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of the fungus Pochonia chlamydosporia on Echinostoma paraensei (Trematoda: Echinostomatidae).

PubMed

Lelis, Rosane Teixeira; Braga, Fabio Ribeiro; de Carvalho, Lorendane Millena; de Paula, Alessandra Teixeira; Araujo, Juliana Milani; Fausto, Mariana Costa; Junior, Arnaldo Maldonado; Rodrigues, João Victor Facchini; de Freitas Soares, Filippe Elias; Garcia, Juberlan Silva; de Araújo, Jackson Victor

2014-11-01

Echinostoma paraensei is a trematode of the genus Echinostoma that causes echinostomiasis in humans. The objectives of this study were to: evaluate the ovicidal activity of the nematophagous fungus Pochonia chlamydosporia (VC1 and VC4) on a solid medium 2% water-agar (2% WA) against E. paraensei eggs (assay A); evaluate ovicidal effect (destruction of eggs) of the isolate VC4 in supplemented culture media (assay B); and evaluate the ovicidal ability of the crude extract (VC4) on E. paraensei eggs (assay C). Eggs of E. paraensei (assay A) were placed in Petri dishes containing 2% WA with an isolate of the fungus P. chlamydosporia (VC1 and VC4) grown for 10 days, and without fungus as a control and evaluated regarding their destruction. In assay B, eggs of E. paraensei were placed in Petri dishes with different supplemented culture media and with VC4 isolate and the destruction of eggs was examined at the end of 25 days of interaction. In assay C, effects of the crude extract of P. chlamydosporia (VC4) on eggs were evaluated at the end of 7 days. In assay A, there was no difference (p>0.05) in ovicidal activity among the tested isolates (VC1 and VC4); however, the highest percentage for ovicidal activity (type 3 effect) was demonstrated by the isolate VC4. In assay B, the culture medium starch-agar showed the best results for the destruction of the eggs, with a percentage of 46.6% at the end of the assay. In assay C, the crude extract of VC4 was effective in the destruction of E. paraensei eggs, with a percentage reduction of 53%. The results of this study demonstrate that a rich culture medium with a greater availability of carbon and nitrogen may interfere directly in the predatory characteristics of ovicidal fungi. Copyright © 2014 Elsevier B.V. All rights reserved.

Three new compounds from the marine fungus Penicillium sp.

PubMed

Wu, Hong-Hua; Tian, Li; Feng, Bao-Min; Li, Zhi-Feng; Zhang, Qi-Hui; Pei, Yue-Hu

2010-01-01

Continuous research on the ethyl acetate extract of the fermentation broth of the marine fungus Y26-02 (Penicillium sp.) led to the purification of one known and three new compounds. Their structures were elucidated, respectively, as butyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (1), 4-hydroxyphenethyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (2), 3-hydroxybenzyl 2-(4-oxo-5,6-dihydro-2H-pyran-3-yl) acetate (3), and desoxypatulinic acid (4) on the basis of their spectroscopic and physico-chemical properties.

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.

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....

Thermostable Acid Protease Produced by Penicillium duponti K1014, a True Thermophilic Fungus Newly Isolated from Compost

PubMed Central

Hashimoto, Hikotaka; Iwaasa, Takashi; Yokotsuka, Tamotsu

1972-01-01

A thermophilic fungus, K1014, newly derived from a compost was selected on the basis of protease productivity as the only one of 81 isolates to produce high levels of acid protease. The fungus was named Penicillium duponti K1014 based on taxonomical studies. It grew in the temperature range of 28 to 58 C, and the optimum was 45 to 50 C. These temperature characteristics showed that the fungus was the most strongly thermophilic of all the fungi next to Humicola lanuginosa. When P. duponti K1014 was grown on moistened wheat bran, maximal accumulation of acid protease occurred after 2 days at 45 to 50 C. The addition of ammonium salts, but not nitrate, was effective for the production of the acid protease. The acid protease of P. duponti K1014 was stable at 60 C for 1 hr and retained more than 65% of original activity after the treatment for 1 hr at 70 C at pH 4.7. This thermal property was different from those of the ordinary acid proteases, indicating that the enzyme is a thermostable protein. Images PMID:4650601

Direct ethanol production from starch, wheat bran and rice straw by the white rot fungus Trametes hirsuta.

PubMed

Okamoto, Kenji; Nitta, Yasuyuki; Maekawa, Nitaro; Yanase, Hideshi

2011-03-07

The white rot fungus Trametes hirsuta produced ethanol from a variety of hexoses: glucose, mannose, cellobiose and maltose, with yields of 0.49, 0.48, 0.47 and 0.47 g/g of ethanol per sugar utilized, respectively. In addition, this fungus showed relatively favorable xylose consumption and ethanol production with a yield of 0.44 g/g. T. hirsuta was capable of directly fermenting starch, wheat bran and rice straw to ethanol without acid or enzymatic hydrolysis. Maximum ethanol concentrations of 9.1, 4.3 and 3.0 g/l, corresponding to 89.2%, 78.8% and 57.4% of the theoretical yield, were obtained when the fungus was grown in a medium containing 20 g/l starch, wheat bran or rice straw, respectively. The fermentation of rice straw pretreated with ball milling led to a small improvement in the ethanol yield: 3.4 g ethanol/20 g ball-milled rice straw. As T. hirsuta is an efficient microorganism capable of hydrolyzing biomass to fermentable sugars and directly converting them to ethanol, it may represent a suitable microorganism in consolidated bioprocessing applications. Copyright © 2010 Elsevier Inc. All rights reserved.

Draft Genome Sequence of the Patulin-Producing Fungus Paecilomyces niveus Strain CO7.

PubMed

Biango-Daniels, Megan N; Wang, Tristan W; Hodge, Kathie T

2018-06-21

Paecilomyces niveus is an extremotolerant fungus with surprising powers to survive high temperatures and infect apples and aphids. These abilities make it a formidable enemy in food and agricultural environments. In addition, it produces patulin, the most significant mycotoxin in apples. Copyright © 2018 Biango-Daniels et al.

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

Isocoumarin derivatives from the endophytic fungus, Pestalotiopsis sp.

PubMed

Song, Ren-Yu; Wang, Xiao-Bing; Yin, Guo-Ping; Liu, Rui-Huan; Kong, Ling-Yi; Yang, Ming-Hua

2017-10-01

Five new isocoumarin derivatives, pestalactone A-C (1-3) and pestapyrone D-E (4-5), together with two known compounds (6-7) were isolated from the solid cultures of the endophytic fungus Pestalotiopsis sp. obtained from Photinia frasery. Their structures were mainly determined by extensive spectroscopic analysis, Mo 2 (OCOCH 3 ) 4 -induced electronic circular dichroism (ECD), and ECD calculation. Compounds 1 and 2 were rare isocoumarin derivatives and derived from distinctive polyketide pathways. Compound 3 exhibited potent antifungal activity against Candida glabrata (ATCC 90030) with an MIC 50 value of 3.49±0.21μg/mL. Copyright © 2017. Published by Elsevier B.V.

Caryophyllene sesquiterpenoids from the endophytic fungus, Pestalotiopsis sp.

PubMed

Liu, Yi; Yang, Ming-Hua; Wang, Xiao-Bing; Li, Tian-Xiao; Kong, Ling-Yi

2016-03-01

Eight new caryophyllene sesquiterpenoids named pestaloporinates A-G (1-7) and 14-acetylhumulane (8) have been isolated from the solid cultures of an endophytic fungus Pestalotiopsis sp., which was obtained from the fresh stem bark of Melia azedarach Linn. Their structures as well as absolute configurations were determined by spectroscopic data, ECD experimentation, and single-crystal X-ray diffraction. Among all the isolates, compound 2 displayed potent inhibitory activity with IC50 value of 19.0 μM during the evaluation of nitric oxide (NO) inhibition in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells. Copyright © 2015 Elsevier B.V. All rights reserved.

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%.

Phenylquinolinones with antitumor activity from the Indian Ocean-derived fungus Aspergillus versicolor Y31-2

NASA Astrophysics Data System (ADS)

Li, Peihai; Fan, Yaqin; Chen, Hao; Chao, Yaxi; Du, Ning; Chen, Junhui

2016-09-01

Two phenylquinolinones, including one new compound ( 1) and a previously isolated compound ( 2), were isolated from the ethyl acetate extracts of the fungus Aspergillus versicolor Y31-2, which was obtained from seawater samples collected from the Indian Ocean. The structures of these compounds were established by spectroscopic analyses. 4-(3-Hydroxyphenyl)-3-methoxyquinolin-2(1H)-one ( 1) exhibited moderate cytotoxicity against MCF-7 (human breast carcinoma cell line) and SMMC-7721 (human liver cancer cell line) cells with IC50 values of 16.6 and 18.2 μmol/L, respectively. To the best of our knowledge, this study represents the first reported account of the isolation of compounds 1 and 2 as the secondary metabolites of the seawater derived fungus Aspergillus versicolor from the Indian Ocean.

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.

Agrobacterium tumefaciens-mediated transformation of the entomopathogenic fungus Nomuraea rileyi.

PubMed

Shao, Changwen; Yin, Youping; Qi, Zhaoran; Li, Ren; Song, Zhangyong; Li, Yan; Wang, Zhongkang

2015-10-01

An Agrobacterium-mediated genetic transformation system for the entomopathogenic fungus Nomuraea rileyi was established. Three binary T-DNA vectors, pPZP-Hph, pPZP-Hph-RNAi and pPZP-Hph-DsRed2, were constructed. The trpc promoter from Aspergillus nidulans was used as the cis-regulatory element to drive the expression of hygromycin phosphotransferase (hph) gene and DsRed2, which conferred the hygromycin B (Hyg B) resistance and red fluorescence visualization, respectively. The blastospores and conidia were used as the recipients. The blastospores' transformation efficiency reached ∼20-40 transformants per 10(6) blastospores, whereas the conidia were not transformed. Based on an analysis of five generations of subcultures, PCR and Southern blotting assays, the Ptrpc-hph cassette had integrated into the genomes of all transformants, which contained single copy of the hph gene and showed mitotic stability. Abundant altered morphologic phenotypes in colonies, blastospores and hyphae formations were observed in the arbitrary insertional mutants of N. rileyi, which made it possible to study the relationships between the functions and the interrupted genes over the whole genome. The transformation protocol will promote the functional characterization of genes, and the construction of genetically engineered strains of this important entomopathogenic fungus, and potentially of other similar fungal pathogens. Copyright © 2015 Elsevier Inc. All rights reserved.

Bacterium induces cryptic meroterpenoid pathway in the pathogenic fungus Aspergillus fumigatus.

PubMed

König, Claudia C; Scherlach, Kirstin; Schroeckh, Volker; Horn, Fabian; Nietzsche, Sandor; Brakhage, Axel A; Hertweck, Christian

2013-05-27

Stimulating encounter: The intimate, physical interaction between the soil-derived bacterium Streptomyces rapamycinicus and the human pathogenic fungus Aspergillus fumigatus led to the activation of an otherwise silent polyketide synthase (PKS) gene cluster coding for an unusual prenylated polyphenol (fumicycline A). The meroterpenoid pathway is regulated by a pathway-specific activator gene as well as by epigenetic factors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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-...

Avoidance of plants unsuitable for the symbiotic fungus in leaf-cutting ants: Learning can take place entirely at the colony dump.

PubMed

Arenas, Andrés; Roces, Flavio

2017-01-01

Plants initially accepted by foraging leaf-cutting ants are later avoided if they prove unsuitable for their symbiotic fungus. Plant avoidance is mediated by the waste produced in the fungus garden soon after the incorporation of the unsuitable leaves, as foragers can learn plant odors and cues from the damaged fungus that are both present in the recently produced waste particles. We asked whether avoidance learning of plants unsuitable for the symbiotic fungus can take place entirely at the colony dump. In order to investigate whether cues available in the waste chamber induce plant avoidance in naïve subcolonies, we exchanged the waste produced by subcolonies fed either fungicide-treated privet leaves or untreated leaves and measured the acceptance of untreated privet leaves before and after the exchange of waste. Second, we evaluated whether foragers could perceive the avoidance cues directly at the dump by quantifying the visits of labeled foragers to the waste chamber. Finally, we asked whether foragers learn to specifically avoid untreated leaves of a plant after a confinement over 3 hours in the dump of subcolonies that were previously fed fungicide-treated leaves of that species. After the exchange of the waste chambers, workers from subcolonies that had access to waste from fungicide-treated privet leaves learned to avoid that plant. One-third of the labeled foragers visited the dump. Furthermore, naïve foragers learned to avoid a specific, previously unsuitable plant if exposed solely to cues of the dump during confinement. We suggest that cues at the dump enable foragers to predict the unsuitable effects of plants even if they had never been experienced in the fungus garden.

Avoidance of plants unsuitable for the symbiotic fungus in leaf-cutting ants: Learning can take place entirely at the colony dump

PubMed Central

Roces, Flavio

2017-01-01

Plants initially accepted by foraging leaf-cutting ants are later avoided if they prove unsuitable for their symbiotic fungus. Plant avoidance is mediated by the waste produced in the fungus garden soon after the incorporation of the unsuitable leaves, as foragers can learn plant odors and cues from the damaged fungus that are both present in the recently produced waste particles. We asked whether avoidance learning of plants unsuitable for the symbiotic fungus can take place entirely at the colony dump. In order to investigate whether cues available in the waste chamber induce plant avoidance in naïve subcolonies, we exchanged the waste produced by subcolonies fed either fungicide-treated privet leaves or untreated leaves and measured the acceptance of untreated privet leaves before and after the exchange of waste. Second, we evaluated whether foragers could perceive the avoidance cues directly at the dump by quantifying the visits of labeled foragers to the waste chamber. Finally, we asked whether foragers learn to specifically avoid untreated leaves of a plant after a confinement over 3 hours in the dump of subcolonies that were previously fed fungicide-treated leaves of that species. After the exchange of the waste chambers, workers from subcolonies that had access to waste from fungicide-treated privet leaves learned to avoid that plant. One-third of the labeled foragers visited the dump. Furthermore, naïve foragers learned to avoid a specific, previously unsuitable plant if exposed solely to cues of the dump during confinement. We suggest that cues at the dump enable foragers to predict the unsuitable effects of plants even if they had never been experienced in the fungus garden. PMID:28273083

Metacridamides A and B, bioactive macrocycles from conidia of the entomopathogenic 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. Its conidia produce two novel 17-membered macrocycles, metacridamides A (1) and B (2), which consist of a Phe unit condensed with a nonaketide....

TESTING OF THE INSECT PEST CONTROL FUNGUS BEAUVERIA BASSIANA IN GRASS SHRIMP PALAEMONETES PUGIO

EPA Science Inventory

Embryos, larvae and adult grass shrimp Palaemonetes pugio were exposed to spores of the insect-control fungus Beauveria bassiana. onidiospores attached to embryos held by gravid females and remained with the egg mass for at least 6 d. In the first experiment where individual deve...

Colonization of Corn, Zea mays, by the Entomopathogenic Fungus Beauveria bassiana†

PubMed Central

Wagner, Bruce L.; Lewis, Leslie C.

2000-01-01

Light and electron microscopy were used to describe the mode of penetration by the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin into corn, Zea mays L. After inoculation with a foliar spray of conidia, germinating hyphae grew randomly across the leaf surface. Often a germ tube formed from a conidium and elongated only a short distance before terminating its growth. Not all developing hyphae on the leaf surface penetrated the cuticle. However, when penetration did occur, the penetration site(s) was randomly located, indicating that B. bassiana does not require specific topographic signals at an appropriate entry site as do some phytopathogenic fungi. Long hyphal structures were observed to follow the leaf apoplast in any direction from the point of penetration. A few hyphae were observed within xylem elements. Because vascular bundles are interconnected throughout the corn plant, this may explain how B. bassiana travels within the plant and ultimately provides overall insecticidal protection. Virulency bioassays demonstrate that B. bassiana does not lose virulence toward the European corn borer, Ostrinia nubilalis (Hübner), once it colonizes corn. This endophytic relationship between an entomopathogenic fungus and a plant suggests possibilities for biological control, including the use of indigenous fungal inocula as insecticides. PMID:10919808

Ultrastructural characterization of melanosomes of the human pathogenic fungus Fonsecaea pedrosoi.

PubMed

Franzen, Anderson J; Cunha, Marcel M L; Miranda, Kildare; Hentschel, Joachim; Plattner, Helmut; da Silva, Moises B; Salgado, Claudio G; de Souza, Wanderley; Rozental, Sonia

2008-04-01

Melanin is a complex polymer widely distributed in nature and has been described as an important virulence factor in pathogenic fungi. In the majority of fungi, the mechanism of melanin formation remains unclear. In Fonsecaea pedrosoi, the major etiologic agent of chromoblastomycosis, melanin is stored in intracellular vesicles, named melanosomes. This paper details the ultrastructural aspects of melanin formation, its storage and transportation to the cell wall in the human pathogenic fungus F. pedrosoi. In this fungus, melanin synthesis within melanosomes also begins with a fibrillar matrix formation, displaying morphological and structural features similar to melanosomes from amphibian and mammalian cells. Silver precipitation based on Fontana-Masson technique for melanin detection and immunocytochemistry showed that melanosome fuses with fungal cell membrane where the melanin is released and reaches the cell wall. Melanin deposition in the fungal cell wall occurs in concentric layers. Antibodies raised against F. pedrosoi melanin revealed the sites of melanin production and storage in the melanosomes. In addition, a preliminary description of the elemental composition of this organelle by X-ray microanalysis and elemental mapping revealed the presence of calcium, phosphorus and iron concentrated in its matrix, suggesting a new functional role for these organelles as iron storage compartments.

Draft genome sequence of the white-rot fungus Obba rivulosa 3A-2

Treesearch

Otto Miettinen; Robert Riley; Kerrie Barry; Daniel Cullen; Ronald P. de Vries; Matthieu Hainaut; Annele Hatakka; Bernard Henrissat; Kristiina Hilden; Rita Kuo; Kurt LaButti; Anna Lipzen; Miia R. Makela; Laura Sandor; Joseph W. Spatafora; Igor V. Grigoriev; David S. Hibbett

2016-01-01

We report here the first genome sequence of the white-rot fungus Obba rivulsa (Polyporales, Basidiomycota), a polypore known for its lignin-decomposing ability. The genome is based on the homokaryon 3A-2 originating in Finland. The genome is typical in size and carbohydrate active enzyme (CAZy) content for wood-decomposing basidiomycetes.

Sequential saccharification of corn fiber and ethanol production by the brown rot fungus Gloeophyllum trabeum.

PubMed

Rasmussen, M L; Shrestha, P; Khanal, S K; Pometto, A L; Hans van Leeuwen, J

2010-05-01

Degradation of lignocellulosic biomass to sugars through a purely biological process is a key to sustainable biofuel production. Hydrolysis of the corn wet-milling co-product-corn fiber-to simple sugars by the brown rot fungus Gloeophyllum trabeum was studied in suspended-culture and solid-state fermentations. Suspended-culture experiments were not effective in producing harvestable sugars from the corn fiber. The fungus consumed sugars released by fungal extracellular enzymes. Solid-state fermentation demonstrated up to 40% fiber degradation within 9days. Enzyme activity assays on solid-state fermentation filtrates confirmed the involvement of starch- and cellulose-degrading enzymes. To reduce fungal consumption of sugars and to accelerate enzyme activity, 2- and 3-d solid-state fermentation biomasses (fiber and fungus) were submerged in buffer and incubated at 37 degrees C without shaking. This anaerobic incubation converted up to almost 11% of the corn fiber into harvestable reducing sugars. Sugars released by G. trabeum were fermented to a maximum yield of 3.3g ethanol/100g fiber. This is the first report, to our knowledge, of G. trabeum fermenting sugar to ethanol. The addition of Saccharomyces cerevisiae as a co-culture led to more rapid fermentation to a maximum yield of 4.0g ethanol/100g fiber. The findings demonstrate the potential for this simple fungal process, requiring no pretreatment of the corn fiber, to produce more ethanol by hydrolyzing and fermenting carbohydrates in this lignocellulosic co-product. Copyright 2010 Elsevier Ltd. All rights reserved.

A novel endophytic Huperzine A-producing fungus, Shiraia sp. Slf14, isolated from Huperzia serrata.

PubMed

Zhu, D; Wang, J; Zeng, Q; Zhang, Z; Yan, R

2010-10-01

To characterize and identify a novel Huperzine A (HupA)-producing fungal strain Slf14 isolated from Huperzia serrata (Thunb. ex Murray) Trev. in China. The isolation, identification and characterization of a novel endophytic fungus producing HupA specifically and consistently from the leaves of H. serrata were investigated. The fungus was identified as Shiraia sp. Slf14 by molecular and morphological methods. The HupA produced by this endophytic fungus was shown to be identical to authentic HupA analysed by thin layer chromatographic, High-performance liquid chromatography (HPLC), LC-MS, (1) H NMR and acetylcholinesterase (AChE) inhibition activity in vitro. The amount of HupA produced by Shiraia sp. Slf14 was quantified to be 327.8 μg l(-1) by HPLC, which was far higher than that of the reported endophytic fungi, Acremonium sp., Blastomyces sp. and Botrytis sp. The production of HupA by endophyte Shiraia sp. Slf14 is an enigmatic observation. It would be interesting to further study the HupA production and regulation by the cultured endophyte in H. serrata and in axenic cultures. Although the current accumulation of HupA by the endophyte is not very high, it could provide a promising alterative approach for large-scale production of HupA. However, further strain improvement and the fermentation process optimization are required to result in the consistent and dependable production. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Three new drimane sesquiterpenoids from cultures of the fungus Penicillium sp.

PubMed

Ding, Jian-Hai; Ding, Zhang-Gui; Chunyu, Wei-Xun; Zhao, Jiang-Yuan; Wang, Hai-Bin; Liu, Shi-Wei; Wang, Fei

2017-08-01

Three new drimane sesquiterpenoids, 12-hydroxyalbrassitriol (1), drim-8(12)-en-6β,7α, 9α,11-tetraol (2), and drim-68(12)-dien-9α,11-diol (3), along with one known analog albrassitriol (4), were isolated from cultures of the tin mine tailings-associated fungus Penicillium sp. The new structures were determined on the basis of extensive spectroscopic analyses. All compounds were tested for their cytotoxicities against five human cancer cell lines.

The genome of an industrial workhorse : sequencing of the filamentous fungus Aspergillus niger offers new opportunities for the production of specialty chemicals and enzymes

Treesearch

Dan Cullen

2007-01-01

Few microbes compare with the filamentous fungus Aspergillus niger in its ability to produce prodigious amounts of useful chemicals and enzymes. This fungus is the principal source of citric acid for food, beverages and pharmaceuticals and of several important commercial enzymes, including glucoamylase, which is widely used for the conversion of starch to food syrups...

The sirodesmin biosynthetic gene cluster of the plant pathogenic fungus Leptosphaeria maculans.

PubMed

Gardiner, Donald M; Cozijnsen, Anton J; Wilson, Leanne M; Pedras, M Soledade C; Howlett, Barbara J

2004-09-01

Sirodesmin PL is a phytotoxin produced by the fungus Leptosphaeria maculans, which causes blackleg disease of canola (Brassica napus). This phytotoxin belongs to the epipolythiodioxopiperazine (ETP) class of toxins produced by fungi including mammalian and plant pathogens. We report the cloning of a cluster of genes with predicted roles in the biosynthesis of sirodesmin PL and show via gene disruption that one of these genes (encoding a two-module non-ribosomal peptide synthetase) is essential for sirodesmin PL biosynthesis. Of the nine genes in the cluster tested, all are co-regulated with the production of sirodesmin PL in culture. A similar cluster is present in the genome of the opportunistic human pathogen Aspergillus fumigatus and is most likely responsible for the production of gliotoxin, which is also an ETP. Homologues of the genes in the cluster were also identified in expressed sequence tags of the ETP producing fungus Chaetomium globosum. Two other fungi with publicly available genome sequences, Magnaporthe grisea and Fusarium graminearum, had similar gene clusters. A comparative analysis of all four clusters is presented. This is the first report of the genes responsible for the biosynthesis of an ETP. Copyright 2004 Blackwell Publishing Ltd

Microsporols A-C from the Plant Endophytic Fungus Pestalotiopsis microspore.

PubMed

Wu, Xianfu; Wang, Yadan; Liu, Shuchun; Liu, Xinzhong; Guo, Liangdong

2015-10-01

Three new ambuic acid derivatives, microsporols A-C (1-3) and the known compound ambuic acid (4), were isolated from the solid-substrate fermentation cultures of the plant endophytic fungus Pestalotiopsis microspora. Their structures were elucidated primarily by NMR experiments. The absolute configurations of the 6,7-diol moiety in 1 and 2 were assigned using the Snatzke's method, whereas that of 3 was deduced by circular dichroism (CD) exciton chirality method. Compounds 1, 3, and 4 showed moderate 5-lipoxygenase (5-LOX) inhibitory effects.

Antifouling and antibacterial polyketides from marine gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023.

PubMed

Bao, Jie; Sun, Yu-Lin; Zhang, Xiao-Yong; Han, Zhuang; Gao, Hai-Chun; He, Fei; Qian, Pei-Yuan; Qi, Shu-Hua

2013-04-01

Two new polyketides, 6,8,5'6'-tetrahydroxy-3'-methylflavone (1) and paecilin C (2), together with six known analogs secalonic acid D (3), secalonic acid B (4) penicillixanthone A (5), emodin (6), citreorosein (7) and isorhodoptilometrin (8) were obtained from a broth of gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023. Compounds 1 and 6-8 had significant antifouling activity against Balanus amphitrite larvae settlement with EC50 values of 6.7, 6.1, 17.9 and 13.7 μg ml(-1), respectively, and 3-5 showed medium antibacterial activity against four tested bacterial strains. This was the first report of antibacterial activity of 3-5 against marine bacteria and antifouling activity of 6-8 against marine biofouling organism's larvae. The results indicated that gorgonian coral-associated fungus Penicillium sp. SCSGAF 0023 strain could produce antifouling and antibacterial compounds that might aid the host gorgonian coral in protection against marine pathogen bacteria, biofouling organisms and other intruders.

Temperature-dependent growth of Geomyces destructans, the fungus that causes bat white-nose syndrome

USGS Publications Warehouse

Verant, Michelle L.; Boyles, Justin G.; Waldrep, William; Wibbelt, Gudrun; Blehert, David S.

2012-01-01

White-nose syndrome (WNS) is an emergent disease estimated to have killed over five million North American bats. Caused by the psychrophilic fungus Geomyces destructans, WNS specifically affects bats during hibernation. We describe temperature-dependent growth performance and morphology for six independent isolates of G. destructans from North America and Europe. Thermal performance curves for all isolates displayed an intermediate peak with rapid decline in performance above the peak. Optimal temperatures for growth were between 12.5 and 15.8°C, and the upper critical temperature for growth was between 19.0 and 19.8°C. Growth rates varied across isolates, irrespective of geographic origin, and above 12°C all isolates displayed atypical morphology that may have implications for proliferation of the fungus. This study demonstrates that small variations in temperature, consistent with those inherent of bat hibernacula, affect growth performance and physiology of G. destructans, which may influence temperature-dependent progression and severity of WNS in wild bats.

Two distinct secretion systems facilitate tissue invasion by the rice blast fungus Magnaporthe oryzae

PubMed Central

Giraldo, Martha C.; Dagdas, Yasin F.; Gupta, Yogesh K.; Mentlak, Thomas A.; Yi, Mihwa; Martinez-Rocha, Ana Lilia; Saitoh, Hiromasa; Terauchi, Ryohei; Talbot, Nicholas J.; Valent, Barbara

2013-01-01

To cause plant diseases, pathogenic micro-organisms secrete effector proteins into host tissue to suppress immunity and support pathogen growth. Bacterial pathogens have evolved several distinct secretion systems to target effector proteins, but whether fungi, which cause the major diseases of most crop species, also require different secretory mechanisms is not known. Here we report that the rice blast fungus Magnaporthe oryzae possesses two distinct secretion systems to target effectors during plant infection. Cytoplasmic effectors, which are delivered into host cells, preferentially accumulate in the biotrophic interfacial complex, a novel plant membrane-rich structure associated with invasive hyphae. We show that the biotrophic interfacial complex is associated with a novel form of secretion involving exocyst components and the Sso1 t-SNARE. By contrast, effectors that are secreted from invasive hyphae into the extracellular compartment follow the conventional secretory pathway. We conclude that the blast fungus has evolved distinct secretion systems to facilitate tissue invasion. PMID:23774898

Biotransformation of ginsenoside Rb1 to ginsenoside C-K by endophytic fungus Arthrinium sp. GE 17-18 isolated from Panax ginseng.

PubMed

Fu, Y; Yin, Z-H; Wu, L-P; Yin, C-R

2016-09-01

This research aimed to isolate β-glycosidase-producing endophytic fungus in Panax ginseng to achieve biotransformation of ginsenoside Rb1 to ginsenoside C-K. Of these 15 β-glucosidase-producing endophytic fungus isolated from ginseng roots, a β-glucosidase-producing endophytic fungi GE 17-18 could hydrolyse major ginsenosides Rb1 to minor ginsenoside C-K with metabolic pathways: ginsenoside Rb1→ginsenoside Rd→ginsenoside F2→ginsenoside C-K. Phylogenetic analysis of ITS gene sequences indicated that the strain GE 17-18 belongs to the genus Arthrinium and is most closely related to Arthrinium sp. HQ832803.1. This is the first study to provide information of cultivable β-glycosidase-producing Endophytic fungus in Panax ginseng. The strain GE 17-18 has potential to be applied on the preparation for minor ginsenoside C-K in pharmaceutical industry. © 2016 The Society for Applied Microbiology.

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

2017-09-01

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

Draft genome sequence of a monokaryotic model brown-rot fungus Postia (Rhodonia) placenta SB12

Treesearch

Jill Gaskell; Phil Kersten; Luis F. Larrondo; Paulo Canessa; Diego Martinez; David Hibbett; Monika Schmoll; Christian P. Kubicek; Angel T. Martinez; Jagjit Yadav; Emma Master; Jon Karl Magnuson; Debbie Yaver; Randy Berka; Kathleen Lail; Cindy Chen; Kurt LaButti; Matt Nolan; Anna Lipzen; Andrea Aerts; Robert Riley; Kerrie Barry; Bernard Henrissat; Robert Blanchette; Igor V. Grigoriev; Dan Cullen

2017-01-01

We report the genome of Postia (Rhodonia) placenta MAD-SB12, a homokaryotic wood decay fungus (Basidiomycota, Polyporales). Intensively studied as a representative brown rot decayer, the gene complement is consistent with the rapid depolymerization of cellulose but not lignin.

Virgatolides A-C, benzannulated spiroketals from the plant endophytic fungus Pestalotiopsis virgatula.

PubMed

Li, Jian; Li, Li; Si, Yikang; Jiang, Xuejun; Guo, Liangdong; Che, Yongsheng

2011-05-20

Virgatolides A-C (1-3), unique metabolites with a 3',4',5',6'-tetrahydrospiro[chroman-2,2'-pyran] core, were isolated from cultures of the plant endophytic fungus Pestalotiopsis virgatula. Compounds 1-3 possess two previously undescribed skeletons originating from a benzannulated 6,6-spiroketal and one (2 and 3) and two (1) γ-lactone units, respectively. The structure of 1 was secured by X-ray crystallography.

Penicillipyrones A and B, meroterpenoids from a marine-derived Penicillium sp. fungus.

PubMed

Liao, Lijuan; Lee, Jung-Ho; You, Minjung; Choi, Tae Joon; Park, Wanki; Lee, Sang Kook; Oh, Dong-Chan; Oh, Ki-Bong; Shin, Jongheon

2014-02-28

Penicillipyrones A (1) and B (2), two novel meroterpenoids, were isolated from the marine-derived fungus Penicillium sp. On the basis of the results of combined spectroscopic analyses, these compounds were structurally elucidated to be sesquiterpene γ-pyrones from a new skeletal class derived from a unique linkage pattern between the drimane sesquiterpene and pyrone moieties. Compound 2 elicited significant induction of quinone reductase.

Influence of Populus Genotype on Gene Expression by the Wood Decay Fungus Phanerochaete chrysosporium

Treesearch

Jill Gaskell; Amber Marty; Michael Mozuch; Philip J. Kersten; Sandra Splinter Bondurant; Grzegorz Sabat; Ali Azarpira; John Ralph; Oleksandr Skyba; Shawn D. Mansfield; Robert A. Blanchette; Dan Cullen

2014-01-01

We examined gene expression patterns in the lignin-degrading fungus Phanerochaete chrysosporium when it colonizes hybrid poplar (Populus alba tremula) and syringyl (S)-rich transgenic derivatives. Acombination ofmicroarrays and liquid chromatography- tandem mass spectrometry (LC-MS/MS) allowed detection of a total of 9,959 transcripts and 793...

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...

Short-Read Sequencing for Genomic Analysis of the Brown Rot Fungus Fibroporia radiculosa

Treesearch

J. D. Tang; A. D. Perkins; T. S. Sonstegard; S. G. Schroeder; S. C. Burgess; S. V. Diehl

2012-01-01

The feasibility of short-read sequencing for genomic analysis was demonstrated for Fibroporia radiculosa, a copper-tolerant fungus that causes brown rot decay of wood. The effect of read quality on genomic assembly was assessed by filtering Illumina GAIIx reads from a single run of a paired-end library (75-nucleotide read length and 300-bp fragment...

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.

The development of a spatially-explicit, individual-based, disease model for frogs and the chytrid fungus

EPA Science Inventory

Background / Question / Methods The fungal pathogen, Batrachochytrium dendrobatidis (BD), has been associated with amphibian population declines and even extinctions worldwide. Transmission of the fungus between amphibian hosts occurs via motile zoospores, which are produced on...

Genetic Transformation of the Biocontrol Fungus Gliocladium virens to Benomyl Resistance

PubMed Central

Ossanna, Nina; Mischke, Sue

1990-01-01

Methodology was developed to isolate and regenerate protoplasts from the biocontrol fungus Gliocladium virens and to transform them to benomyl resistance with a Neurospora crassa β-tubulin gene. Southern blots demonstrated that multiple copies of the vector integrated into the chromosomal DNA of stable biotypes but not of abortive transformants. Analysis of nuclear condition in vegetative and asexual structures demonstrated that no structure of G. virens is dependably uninucleate and thus preferentially suitable for transformation. Images PMID:16348312

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...

Secondary metabolites produced by solid fermentation of the marine-derived fungus Penicillium commune QSD-17.

PubMed

Gao, Shu-Shan; Shang, Zhuo; Li, Xiao-Ming; Li, Chun-Shun; Cui, Chuan-Ming; Wang, Bin-Gui

2012-01-01

The marine sediment-derived fungus Penicillium commune QSD-17 was re-investigated and cultured on rice solid medium. Two new compounds, isophomenone (1) and 3-deacetylcitreohybridonol (2), together with seven known derivatives (3-9), were identified. Their structures were determined by spectroscopic analysis.

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.

BIOTRANSFORMATION OF 2,4,6-TRINITROTOLUENE (TNT) BY A PLANT-ASSOCIATED FUNGUS FUSARIUM OXYSPORUM

EPA Science Inventory

The capability of a plant-associated fungus, Fusarium oxyvorum, to transform TNT in liquid cultures was investigated. TNT was transformed into 2-amino-4, 6-dinitrotoluene (2-A-DNT), 4-amino-2, 6-dinitrotoluene (4-A- DNT), and 2, 4-diamino-6-nitrotoluene (2, 4-DAT) via 2- and 4-hy...

Pathogenicity of entomopathogenic fungus Metarhizium anisopliae (Deuteromycetes) to Ixodes scapularis (Acari: Ixodidae)

USGS Publications Warehouse

Zhioua, E.; Browning, M.; Johnson, P.W.; Ginsberg, H.S.; LeBrun, R.A.

1997-01-01

The entomopathogenic fungus Metarhizium anisopliae is highly pathogenic to the black-legged tick, Ixodes scapularis. Spore concentrations of 108/ml for engorged larvae and 107/ml for engorged females resulted in 100% tick mortality, 2 wk post-infection. The LC50 value for engorged larvae (concentration to kill 50% of ticks) was 107 spores/ml. Metarhizium anisopliae shows considerable potential as a microbial control agent for the management of Ixodes scapularis.

Characterization of sakA gene from pathogenic dimorphic fungus Penicillium marneffei.

PubMed

Nimmanee, Panjaphorn; Woo, Patrick C Y; Kummasook, Aksarakorn; Vanittanakom, Nongnuch

2015-01-01

Eukaryotes utilize stress activated protein kinase (SAPK) pathways to adapt to environmental stress, including heat, osmotic, oxidative or nutrient stresses. Penicillium marneffei (Talaromyces marneffei), the dimorphic pathogenic fungus that can cause disseminated mycosis in HIV-infected patients, has to encounter various types of stresses both outside and inside host cells. However, the strategies used by this fungus in response to these stresses are still unclear. In this report, the stress-activated kinase (sakA) gene of P. marneffei was characterized and the roles of this gene on various stress conditions were studied. The sakA gene deletion mutant was constructed using the split marker method. The phenotypes and sensitivities to varieties of stresses, including osmotic, oxidative, heat and cell wall stresses of the deletion mutant were compared with the wild type and the sakA complemented strains. Results demonstrated that the P. marneffei sakA gene encoded a putative protein containing TXY phosphorylation lip found in the stress high osmolarity glycerol 1 (Hog1)/Spc1/p38 MAPK family, and that this gene was involved not only in tolerance against oxidative and heat stresses, but also played a role in asexual development, chitin deposition, yeast cell generation in vitro and survival inside mouse and human macrophages. Copyright © 2014 Elsevier GmbH. All rights reserved.

The evolution of fungus-growing termites and their mutualistic fungal symbionts

PubMed Central

Aanen, Duur K.; Eggleton, Paul; Rouland-Lefèvre, Corinne; Guldberg-Frøslev, Tobias; Rosendahl, Søren; Boomsma, Jacobus J.

2002-01-01

We have estimated phylogenies of fungus-growing termites and their associated mutualistic fungi of the genus Termitomyces using Bayesian analyses of DNA sequences. Our study shows that the symbiosis has a single African origin and that secondary domestication of other fungi or reversal of mutualistic fungi to a free-living state has not occurred. Host switching has been frequent, especially at the lower taxonomic levels, and nests of single termite species can have different symbionts. Data are consistent with horizontal transmission of fungal symbionts in both the ancestral state of the mutualism and most of the extant taxa. Clonal vertical transmission of fungi, previously shown to be common in the genus Microtermes (via females) and in the species Macrotermes bellicosus (via males) [Johnson, R. A., Thomas, R. J., Wood, T. G. & Swift, M. J. (1981) J. Nat. Hist. 15, 751–756], is derived with two independent origins. Despite repeated host switching, statistical tests taking phylogenetic uncertainty into account show a significant congruence between the termite and fungal phylogenies, because mutualistic interactions at higher taxonomic levels show considerable specificity. We identify common characteristics of fungus-farming evolution in termites and ants, which apply despite the major differences between these two insect agricultural systems. We hypothesize that biparental colony founding may have constrained the evolution of vertical symbiont transmission in termites but not in ants where males die after mating. PMID:12386341

Meroterpenoids with antiproliferative activity from a Hawaiian-plant associated fungus Peyronellaea coffeae-arabicae FT238

USDA-ARS?s Scientific Manuscript database

Three unusual polyketide-sesquiterpene metabolites peyronellins A-C (1-3), along with the new epoxyphomalin analog 11-dehydroxy epoxyphomalin A (4), have been isolated from the endophytic fungus Peyronellaea cof feae-arabicae FT238, which was isolated from the native Hawaiian plant Pritchardia lowre...

Carbohydrate-active enzymes from the zygomycete fungus Rhizopus oryzae: a highly specialized approach to carbohydrate degradation depicted at genome level

PubMed Central

2011-01-01

Background Rhizopus oryzae is a zygomycete filamentous fungus, well-known as a saprobe ubiquitous in soil and as a pathogenic/spoilage fungus, causing Rhizopus rot and mucomycoses. Results Carbohydrate Active enzyme (CAZy) annotation of the R. oryzae identified, in contrast to other filamentous fungi, a low number of glycoside hydrolases (GHs) and a high number of glycosyl transferases (GTs) and carbohydrate esterases (CEs). A detailed analysis of CAZy families, supported by growth data, demonstrates highly specialized plant and fungal cell wall degrading abilities distinct from ascomycetes and basidiomycetes. The specific genomic and growth features for degradation of easily digestible plant cell wall mono- and polysaccharides (starch, galactomannan, unbranched pectin, hexose sugars), chitin, chitosan, β-1,3-glucan and fungal cell wall fractions suggest specific adaptations of R. oryzae to its environment. Conclusions CAZy analyses of the genome of the zygomycete fungus R. oryzae and comparison to ascomycetes and basidiomycete species revealed how evolution has shaped its genetic content with respect to carbohydrate degradation, after divergence from the Ascomycota and Basidiomycota. PMID:21241472

Analysis of Volatile Organic Compounds Emitted by Plant Growth-Promoting Fungus Phoma sp. GS8-3 for Growth Promotion Effects on Tobacco

PubMed Central

Naznin, Hushna Ara; Kimura, Minako; Miyazawa, Mitsuo; Hyakumachi, Mitsuro

2013-01-01

We extracted volatile organic compounds (VOCs) emitted by a plant growth-promoting fungus (PGPF) Phoma sp. GS8-3 by gas chromatography and identified them by mass spectrometry. All of the identified compounds belonged to C4-C8 hydrocarbons. Volatiles varied in number and quantity by the culture period of the fungus (in days). 2-Methyl-propanol and 3-methyl-butanol formed the main components of the volatile blends for all the culture periods of fungus. Growth-promoting effects of the identified synthetic compounds were analyzed individually and in blends using tobacco plants. We found that the mixture of volatiles extracted from 3-day-old culture showed significant growth promotion in tobacco in vitro. The volatile blend showed better growth promotion at lower than higher concentrations. Our results confirm the potential role of volatile organic compounds in the mechanism of growth enhancement by GS8-3. PMID:23080408

Serine proteases activity is important for the interaction of nematophagous fungus Duddingtonia flagrans with infective larvae of trichostrongylides and free-living nematodes Panagrellus spp.

PubMed

Cruz, Daniela G; Costa, Luana M; Rocha, Letícia O; Retamal, Claudio A; Vieira, Ricardo A M; Seabra, Sergio H; Silva, Carlos P; DaMatta, Renato A; Santos, Clóvis P

2015-08-01

The nematode-trapping fungus Duddingtonia flagrans has been studied as a possible control method for gastrointestinal nematodes of livestock animals. These fungi capture and infect the nematode by cuticle penetration, immobilization, and digestion of the internal contents. It has been suggested that this sequence of events occurs by a combination of physical and enzymatical activities. The aim of this study was to investigate the participation of proteolytic enzymatic activity during the interaction of the nematophagous fungus D. flagrans with infective larvae of trichostrongylides and the free-living nematode Panagrellus spp. Protease inhibitors used interfered in the predatory activity of D. flagrans. However, only PMSF significantly reduced the mean number of Panagrellus spp. captured by D. flagrans in comparison with the control. The experiment with fluorogenic substrate showed that maximum urokinase activity during the interaction of the fungus with the infective larvae of trichostrongylides or Panagrellus spp. occurred within 7 or 1 h of incubation, respectively. The protease activity, especially of the serine class, may be important during the interaction between the fungus and nematodes. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Rice Blast Fungus (Magnaporthe oryzae) Infects Arabidopsis via a Mechanism Distinct from That Required for the Infection of Rice1[W][OA

PubMed Central

Park, Ju-Young; Jin, Jianming; Lee, Yin-Won; Kang, Seogchan; Lee, Yong-Hwan

2009-01-01

Magnaporthe oryzae is a hemibiotrophic fungal pathogen that causes rice (Oryza sativa) blast. Although M. oryzae as a whole infects a wide variety of monocotyledonous hosts, no dicotyledonous plant has been reported as a host. We found that two rice pathogenic strains of M. oryzae, KJ201 and 70-15, interacted differentially with 16 ecotypes of Arabidopsis (Arabidopsis thaliana). Strain KJ201 infected all ecotypes with varying degrees of virulence, whereas strain 70-15 caused no symptoms in certain ecotypes. In highly susceptible ecotypes, small chlorotic lesions appeared on infected leaves within 3 d after inoculation and subsequently expanded across the affected leaves. The fungus produced spores in susceptible ecotypes but not in resistant ecotypes. Fungal cultures recovered from necrotic lesions caused the same symptoms in healthy plants, satisfying Koch's postulates. Histochemical analyses showed that infection by the fungus caused an accumulation of reactive oxygen species and eventual cell death. Similar to the infection process in rice, the fungus differentiated to form appressorium and directly penetrated the leaf surface in Arabidopsis. However, the pathogenic mechanism in Arabidopsis appears distinct from that in rice; three fungal genes essential for pathogenicity in rice played only limited roles in causing disease symptoms in Arabidopsis, and the fungus seems to colonize Arabidopsis as a necrotroph through the secretion of phytotoxic compounds, including 9,12-octadecadienoic acid. Expression of PR-1 and PDF1.2 was induced in response to infection by the fungus, suggesting the activation of salicylic acid- and jasmonic acid/ethylene-dependent signaling pathways. However, the roles of these signaling pathways in defense against M. oryzae remain unclear. In combination with the wealth of genetic and genomic resources available for M. oryzae, this newly established pathosystem allows comparison of the molecular and cellular mechanisms underlying

First draft genome sequencing of indole acetic acid producing and plant growth promoting fungus Preussia sp. BSL10.

PubMed

Khan, Abdul Latif; Asaf, Sajjad; Khan, Abdur Rahim; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

2016-05-10

Preussia sp. BSL10, family Sporormiaceae, was actively producing phytohormone (indole-3-acetic acid) and extra-cellular enzymes (phosphatases and glucosidases). The fungus was also promoting the growth of arid-land tree-Boswellia sacra. Looking at such prospects of this fungus, we sequenced its draft genome for the first time. The Illumina based sequence analysis reveals an approximate genome size of 31.4Mbp for Preussia sp. BSL10. Based on ab initio gene prediction, total 32,312 coding sequences were annotated consisting of 11,967 coding genes, pseudogenes, and 221 tRNA genes. Furthermore, 321 carbohydrate-active enzymes were predicted and classified into many functional families. Copyright © 2016 Elsevier B.V. All rights reserved.

Wood decay fungus Flavodon ambrosius (Basidiomycota: Polyporales) is widely farmed by two genera of ambrosia beetles

Treesearch

You Li; Craig Christopher Bateman; James Skelton; Michelle Alice Jusino; Zachary John Nolen; David Rabern Simmons; Jiri Hulcr

2017-01-01

The ambrosia fungus Flavodon ambrosius is the primary nutritional mutualist of ambrosia beetles Ambrosiodmus and Ambrosiophilus in North America. F. ambrosius is the only known ambrosial basidiomycete, unique in its efficient lignocellulose degradation. F. ambrosius is associated with...

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...

Rebuilding after collapse: evidence for long-term cohort dynamics in the native Hawaiian rain forest

USGS Publications Warehouse

Boehmer, Hans Juergen; Wagner, Helene H.; Jacobi, James D.; Gerrish, Grant C.; Mueller-Dombois, Dieter

2013-01-01

Questions: Do long-term observations in permanent plots confirm the conceptual model of Metrosideros polymorpha cohort dynamics as postulated in 1987? Do regeneration patterns occur independently of substrate age, i.e. of direct volcanic disturbance impact? Location: The windward mountain slopes of the younger Mauna Loa and the older Mauna Kea volcanoes (island of Hawaii, USA). Methods: After widespread forest decline (dieback), permanent plots were established in 1976 in 13 dieback and 13 non-dieback patches to monitor the population structure of M. polymorpha at ca. 5-yr intervals. Within each plot of 20 × 20 m, all trees with DBH >2.5 cm were individually tagged, measured and tree vigour assessed; regeneration was quantified in 16 systematically placed subplots of 3 × 5 m. Data collected in the subplots included the total number of M. polymorpha seedlings and saplings (five stem height classes). Here we analyse monitoring data from six time steps from 1976 to 2003 using repeated measures ANOVA to test specific predictions derived from the 1987 conceptual model. Results: Regeneration was significantly different between dieback and non-dieback plots. In dieback plots, the collapse in the 1970s was followed by a ‘sapling wave’ that by 2003 led to new cohort stands of M. polymorpha. In non-dieback stands, seedling emergence did not result in sapling waves over the same period. Instead, a ‘sapling gap’ (i.e. very few or no M. polymorpha saplings) prevailed as typical for mature stands. Canopy dieback in 1976, degree of recovery by 2003 and the number of living trees in 2003 were unrelated to substrate age. Conclusions: Population development of M. polymorpha supports the cohort dynamics model, which predicts rebuilding of the forest with the same canopy species after dieback. The lack of association with substrate age suggests that the long-term maintenance of cohort structure in M. polymorpha does not depend on volcanic disturbance but may be related to

An anti-HBV anthraquinone from aciduric fungus Penicillium sp. OUCMDZ-4736 under low pH stress.

PubMed

Jin, Yanzheng; Qin, Shidong; Gao, Hai; Zhu, Guoliang; Wang, Wei; Zhu, Weiming; Wang, Yi

2018-01-01

To obtain new bioactive natural products, the effect of acidic stress on the metabolites of an aciduric fungus was investigated. This fungus, Penicillium sp. OUCMDZ-4736, which was isolated from the sediment around roots of mangrove (Acanthus ilicifolius), produced different compounds and higher yields under pH 2.5 than under neutral conditions. Using spectroscopic analyses and calculations, three new anthraquinone derivatives (1-3) were isolated and identified from the acidic fermentation broth (pH 2.5) of OUCMDZ-4736. Compound 1 showed much stronger anti-hepatitis B virus activity than that of the positive control, lamivudine, strongly inhibiting HBsAg and HBeAg secretion from HepG2.2.15 cells. These results show that extremophiles are a valuable resource of bioactive compounds, and that pH regulation is an effective strategy to induce metabolite production in aciduric fungi.

A Fungus-Inducible Pepper Carboxylesterase Exhibits Antifungal Activity by Decomposing the Outer Layer of Fungal Cell Walls.

PubMed

Seo, Hyo-Hyoun; Park, Ae Ran; Lee, Hyun-Hwa; Park, Sangkyu; Han, Yun-Jeong; Hoang, Quyen T N; Choi, Gyung Ja; Kim, Jin-Cheol; Kim, Young Soon; Kim, Jeong-Il

2018-05-01

Colletotrichum species are major fungal pathogens that cause devastating anthracnose diseases in many economically important crops. In this study, we observed the hydrolyzing activity of a fungus-inducible pepper carboxylesterase (PepEST) on cell walls of C. gloeosporioides, causing growth retardation of the fungus by blocking appressorium formation. To determine the cellular basis for the growth inhibition, we observed the localization of PepEST on the fungus and found the attachment of the protein on surfaces of conidia and germination tubes. Moreover, we examined the decomposition of cell-wall materials from the fungal surface after reaction with PepEST, which led to the identification of 1,2-dithiane-4,5-diol (DTD) by gas chromatography mass spectrometry analysis. Exogenous DTD treatment did not elicit expression of defense-related genes in the host plant but did trigger the necrosis of C. gloeosporioides. Furthermore, the DTD compound displayed protective effects on pepper fruits and plants against C. gloeosporioides and C. coccodes, respectively. In addition, DTD was also effective in preventing other diseases, such as rice blast, tomato late blight, and wheat leaf rust. Therefore, our results provide evidence that PepEST is involved in hydrolysis of the outmost layer of the fungal cell walls and that DTD has antifungal activity, suggesting an alternative strategy to control agronomically important phytopathogens.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus.

PubMed

Wolfe, Benjamin E; Pringle, Anne

2012-04-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus

PubMed Central

Wolfe, Benjamin E; Pringle, Anne

2012-01-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world. PMID:22134645

Specific and sensitive detection of the conifer pathogen Gremmeniella abietina by nested PCR

PubMed Central

Zeng, Qing-Yin; Hansson, Per; Wang, Xiao-Ru

2005-01-01

Background Gremmeniella abietina (Lagerb.) Morelet is an ascomycete fungus that causes stem canker and shoot dieback in many conifer species. The fungus is widespread and causes severe damage to forest plantations in Europe, North America and Asia. To facilitate early diagnosis and improve measures to control the spread of the disease, rapid, specific and sensitive detection methods for G. abietina in conifer hosts are needed. Results We designed two pairs of specific primers for G. abietina based on the 18S rDNA sequence variation pattern. These primers were validated against a wide range of fungi and 14 potential conifer hosts. Based on these specific primers, two nested PCR systems were developed. The first system employed universal fungal primers to enrich the fungal DNA targets in the first round, followed by a second round selective amplification of the pathogen. The other system employed G. abietina-specific primers in both PCR steps. Both approaches can detect the presence of G. abietina in composite samples with high sensitivity, as little as 7.5 fg G. abietina DNA in the host genomic background. Conclusion The methods described here are rapid and can be applied directly to a wide range of conifer species, without the need for fungal isolation and cultivation. Therefore, it represents a promising alternative to disease inspection in forest nurseries, plantations and quarantine control facilities. PMID:16280082

A New Chytridiomycete Fungus Intermixed with Crustacean Resting Eggs in a 407-Million-Year-Old Continental Freshwater Environment

PubMed Central

Goral, Tomasz; Longcore, Joyce E.; Olesen, Jørgen; Kenrick, Paul; Edgecombe, Gregory D.

2016-01-01

The 407-million-year-old Rhynie Chert (Scotland) contains the most intact fossilised remains of an early land-based ecosystem including plants, arthropods, fungi and other microorganisms. Although most studies have focused on the terrestrial component, fossilised freshwater environments provide critical insights into fungal-algal interactions and the earliest continental branchiopod crustaceans. Here we report interactions between an enigmatic organism and an exquisitely preserved fungus. The fungal reproductive structures are intermixed with exceptionally well-preserved globular spiny structures interpreted as branchiopod resting eggs. Confocal laser scanning microscopy enabled us to reconstruct the fungus and its possible mode of nutrition, the affinity of the resting eggs, and their spatial associations. The new fungus (Cultoraquaticus trewini gen. et sp. nov) is attributed to Chytridiomycota based on its size, consistent formation of papillae, and the presence of an internal rhizoidal system. It is the most pristine fossil Chytridiomycota known, especially in terms of rhizoidal development and closely resembles living species in the Rhizophydiales. The spiny resting eggs are attributed to the crustacean Lepidocaris rhyniensis, dating branchiopod adaptation to life in ephemeral pools to the Early Devonian. The new fungal interaction suggests that, as in modern freshwater environments, chytrids were important to the mobilisation of nutrients in early aquatic foodwebs. PMID:27973602

Interactions of Trametes versicolor, Coriolopsis rigida and the arbuscular mycorrhizal fungus Glomus deserticola on the copper tolerance of Eucalyptus globulus.

PubMed

Arriagada, C; Aranda, E; Sampedro, I; Garcia-Romera, I; Ocampo, J A

2009-09-01

The presence of high levels of Cu in soil decreases the shoot and root dry weights of Eucalyptus globulus. However, higher plant tolerance of Cu has been observed in the presence of the arbuscular mycorrhizal (AM) fungus Glomus deserticola. The hyphal length of G. deserticola was sensitive to low Cu concentrations, and the percentage of AM root colonisation and the metabolic activity of the AM fungus were also decreased by Cu. Therefore, a direct effect of Cu on the development of the AM fungus inside and outside the root cannot be ruled out. E. globulus colonised by G. deserticola had higher metal concentrations in the roots and shoots than do non-mycorrhizal plants; however, the absence of a higher root to shoot metal ratio in the mycorrhizal plants (1.70+/-0.11) indicated that G. deserticola did not play a filtering/sequestering role against Cu. The saprobe fungi Coriolopsis rigida and Trametes versicolor were able to remove Cu ions from the asparagine-glucose growth media. However, plants inoculated with C. rigida and T. versicolor did not accumulate more Cu than non-inoculated controls, and the growth of the plant was not increased in the presence of these fungi. However, C. rigida increased the shoot dry weight, AM root length colonisation, and metabolic mycelial activity of plants colonised with G. deserticola in the presence of Cu; only this saprobe-AM fungus combination increased the tolerance of E. globulus to Cu. Inoculation with G. deserticola and C. rigida increased the E. globulus Cu uptake to levels reached by hyperaccumulative plants.

Role of malate transporter in lipid accumulation of oleaginous fungus Mucor circinelloides.

PubMed

Zhao, Lina; Cánovas-Márquez, José T; Tang, Xin; Chen, Haiqin; Chen, Yong Q; Chen, Wei; Garre, Victoriano; Song, Yuanda; Ratledge, Colin

2016-02-01

Fatty acid biosynthesis in oleaginous fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in oleaginous fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in oleaginous fungus M. circinelloides.

Remediation of lead-contaminated water by geological fluorapatite and fungus Penicillium oxalicum.

PubMed

Tian, Da; Wang, Wenchao; Su, Mu; Zheng, Junyi; Wu, Yuanyi; Wang, Shimei; Li, Zhen; Hu, Shuijin

2018-05-16

Phosphate-solubilizing fungi (PSF) can secrete large amounts of organic acids. In this study, the application of the fungus Penicillium oxalicum and geological fluorapatite (FAp) to lead immobilization was investigated. The formation and morphology of the lead-related minerals were analyzed by ATR-IR, XRD, Raman, and SEM. The quantity of organic acids secreted by P. oxalicum reached the maximum on the fourth day, which elevated soluble P concentrations from 0.4 to 108 mg/L in water. The secreted oxalic acid dominates the acidity in solution. P. oxalicum can survive in the solution with Pb concentration of ~ 1700 mg/L. In addition, it was shown that ~ 98% lead cations were removed while the fungus was cultured with Pb (~ 1700 mg/L) and FAp. The mechanism is that the released P from FAp (enhanced by organic acids) can react with Pb 2+ to form the stable pyromorphite mineral [Pb 5 (PO 4 ) 3 F]. The precipitation of lead oxalate also contributes to Pb immobilization. However, lead oxalate is more soluble due to its relatively high solubility. P. oxalicum has a higher rate of organic acid secretion compared with other typical PSF, e.g., Aspergillus niger. This study sheds light on bright future of applying P. oxalicum in Pb remediation.

Occurrence of fungi in combs of fungus-growing termites (Isoptera: Termitidae, Macrotermitinae).

PubMed

Guedegbe, Herbert J; Miambi, Edouard; Pando, Anne; Roman, Jocelyne; Houngnandan, Pascal; Rouland-Lefevre, Corinne

2009-10-01

Fungus-growing termites cultivate their mutualistic basidiomycete Termitomyces species on a substrate called a fungal comb. Here, the Suicide Polymerase Endonuclease Restriction (SuPER) method was adapted for the first time to a fungal study to determine the entire fungal community of fungal combs and to test whether fungi other than the symbiotic cultivar interact with termite hosts. Our molecular analyses show that although active combs are dominated by Termitomyces fungi isolated with direct Polymerase Endonuclease Restriction - Denaturing Gradient Gel Electrophoresis (PCR-DGGE), they can also harbor some filamentous fungi and yeasts only revealed by SuPER PCR-DGGE. This is the first molecular evidence of the presence of non-Termitomyces species in active combs. However, because there is no evidence for a species-specific relationship between these fungi and termites, they are mere transient guests with no specialization in the symbiosis. It is however surprising to notice that termite-associated Xylaria strains were not isolated from active combs even though they are frequently retrieved when nests are abandoned by termites. This finding highlights the implication of fungus-growing termites in the regulation of fungi occurring within the combs and also suggests that they might not have any particular evolutionary-based association with Xylaria species.

Characterization of molecular identity and pathogenicity of rice blast fungus in Hunan province of China

USDA-ARS?s Scientific Manuscript database

Characterization of molecular identity and pathogenicity of the rice blast fungus benefits the deployment of effective blast resistance (R) genes. In order to identify blast resistance genes in rice producing areas where most of the hybrid rice is grown in Hunan province, 182 M. oryzae strains were ...

Microsatellite DNA suggests regional structure in the fusiform rust fungus Cronartium quercuum f. sp fusiforme

Treesearch

T.L Kubisiak; J.H. Roberds; P.C. Spaine; R.L. Doudrick

2004-01-01

This paper reports results obtained from microsatellite DNA analysis of genetic structure for populations of the native fungus Cronartium quercuum f. sp fusiforme infecting loblolly pine (Pinus taeda L.) over much of this host's natural range. Mostly all fusiform rust galls formed under field conditions are...

Aerial application of the insect-killing fungus Lecanicillium muscarium in a microfactory formulation for hemlock woolly adelgid suppression

Treesearch

Scott Costa; Karen Felton; Bradley Onken; Richard Reardon; Rusty. Rhea

2011-01-01

Forest populations of hemlock woolly adelgid (HWA) were reduced using an operational formulation of the insect-killing fungus Lecanicillium muscarium when it was supported by microfactory formulation technology.

Epigenetic genome mining of an endophytic fungus leads to the pleiotropic biosynthesis of natural products.

PubMed

Mao, Xu-Ming; Xu, Wei; Li, Dehai; Yin, Wen-Bing; Chooi, Yit-Heng; Li, Yong-Quan; Tang, Yi; Hu, Youcai

2015-06-22

The small-molecule biosynthetic potential of most filamentous fungi has remained largely unexplored and represents an attractive source for the discovery of new compounds. Genome sequencing of Calcarisporium arbuscula, a mushroom-endophytic fungus, revealed 68 core genes that are involved in natural product biosynthesis. This is in sharp contrast to the predominant production of the ATPase inhibitors aurovertin B and D in the wild-type fungus. Inactivation of a histone H3 deacetylase led to pleiotropic activation and overexpression of more than 75 % of the biosynthetic genes. Sampling of the overproduced compounds led to the isolation of ten compounds of which four contained new structures, including the cyclic peptides arbumycin and arbumelin, the diterpenoid arbuscullic acid A, and the meroterpenoid arbuscullic acid B. Such epigenetic modifications therefore provide a rapid and global approach to mine the chemical diversity of endophytic fungi. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rhizovarins A-F, Indole-Diterpenes from the Mangrove-Derived Endophytic Fungus Mucor irregularis QEN-189.

PubMed

Gao, Shu-Shan; Li, Xiao-Ming; Williams, Katherine; Proksch, Peter; Ji, Nai-Yun; Wang, Bin-Gui

2016-08-26

Genome mining of the fungus Mucor irregularis (formerly known as Rhizomucor variabilis) revealed the presence of various gene clusters for secondary metabolite biosynthesis, including several terpene-based clusters. Investigation into the chemical diversity of M. irregularis QEN-189, an endophytic fungus isolated from the fresh inner tissue of the marine mangrove plant Rhizophora stylosa, resulted in the discovery of 20 structurally diverse indole-diterpenes including six new compounds, namely, rhizovarins A-F (1-6). Among them, compounds 1-3 represent the most complex members of the reported indole-diterpenes. The presence of an unusual acetal linked to a hemiketal (1) or a ketal (2 and 3) in an unprecedented 4,6,6,8,5,6,6,6,6-fused indole-diterpene ring system makes them chemically unique. Their structures and absolute configurations were elucidated by spectroscopic analysis, modified Mosher's method, and chemical calculations. Each of the isolated compounds was evaluated for antitumor activity against HL-60 and A-549 cell lines.

Growth in rice cells requires de novo purine biosynthesis by the blast fungus Magnaporthe oryzae

PubMed Central

Fernandez, Jessie; Yang, Kuan Ting; Cornwell, Kathryn M.; Wright, Janet D.; Wilson, Richard A.

2013-01-01

Increasing incidences of human disease, crop destruction and ecosystem perturbations are attributable to fungi and threaten socioeconomic progress and food security on a global scale. The blast fungus Magnaporthe oryzae is the most devastating pathogen of cultivated rice, but its metabolic requirements in the host are unclear. Here we report that a purine-requiring mutant of M. oryzae could develop functional appressoria, penetrate host cells and undergo the morphogenetic transition to elaborate bulbous invasive hyphae from primary hyphae, but further in planta growth was aborted. Invasive hyphal growth following rice cell ingress is thus dependent on de novo purine biosynthesis by the pathogen and, moreover, plant sources of purines are neither available to the mutant nor required by the wild type during the early biotrophic phase of infection. This work provides new knowledge about the metabolic interface between fungus and host that might be applicable to other important intracellular fungal pathogens. PMID:23928947

Resistance of an Antarctic cryptoendolithic black fungus to radiation gives new insights of astrobiological relevance.

PubMed

Selbmann, Laura; Pacelli, Claudia; Zucconi, Laura; Dadachova, Ekaterina; Moeller, Ralf; de Vera, Jean-Pierre; Onofri, Silvano

2018-06-01

The Antarctic black meristematic fungus Cryomyces antarcticus CCFEE 515 occurs endolithically in the McMurdo Dry Valleys of Antarctica, one of the best analogue for Mars environment on Earth. To date, this fungus is considered one of the best eukaryotic models for astrobiological studies and has been repeatedly selected for space experiments in the last decade. The obtained results are reviewed here, with special focus on responses to space relevant irradiation, UV radiation, and both sparsely and densely ionizing radiation, which represent the major injuries for a putative space-traveller. The remarkable resistance of this model organism to space stress, its radioresistance in particular, and mechanisms involved, significantly contributed to expanding our concept of limits for life and provided new insights on the origin and evolution of life in planetary systems, habitability, and biosignatures for life detection as well as on human protection during space missions. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Isolation, identification, and culture optimization of a novel glycinonitrile-hydrolyzing fungus-Fusarium oxysporum H3.

PubMed

Gong, Jin-Song; Lu, Zhen-Ming; Shi, Jing-Song; Dou, Wen-Fang; Xu, Hong-Yu; Zhou, Zhe-Min; Xu, Zheng-Hong

2011-10-01

Microbial transformation of glycinonitrile into glycine by nitrile hydrolase is of considerable interest to green chemistry. A novel fungus with high nitrile hydrolase was newly isolated from soil samples and identified as Fusarium oxysporum H3 through 18S ribosomal DNA, 28S ribosomal DNA, and the internal transcribed spacer sequence analysis, together with morphology characteristics. After primary optimization of culture conditions including pH, temperature, carbon/nitrogen sources, inducers, and metal ions, the enzyme activity was greatly increased from 326 to 4,313 U/L. The preferred carbon/nitrogen sources, inducer, and metal ions were glucose and yeast extract, caprolactam, and Cu(2+), Mn(2+), and Fe(2+), respectively. The maximum enzyme formation was obtained when F. oxysporum H3 was cultivated at 30 °C for 54 h with the initial pH of 7.2. There is scanty report about the optimization of nitrile hydrolase production from nitrile-converting fungus.

Gibberellins Producing Endophytic Fungus Porostereum spadiceum AGH786 Rescues Growth of Salt Affected Soybean

PubMed Central

Hamayun, Muhammad; Hussain, Anwar; Khan, Sumera A.; Kim, Ho-Youn; Khan, Abdul L.; Waqas, Muhammad; Irshad, Muhammad; Iqbal, Amjad; Rehman, Gauhar; Jan, Samin; Lee, In-Jung

2017-01-01

In the pursuit of sustainable agriculture through environment and human health friendly practices, we evaluated the potential of a novel gibberellins (GAs) producing basidiomycetous endophytic fungus Porostereum spadiceum AGH786, for alleviating salt stress and promoting health benefits of soybean. Soybean seedlings exposed to different levels of NaCl stress (70 and 140 mM) under greenhouse conditions, were inoculated with the AGH786 strain. Levels of phytohormones including GAs, JA and ABA, and isoflavones were compared in control and the inoculated seedlings to understand the mechanism through which the stress is alleviated. Gibberellins producing endophytic fungi have been vital for promoting plant growth under normal and stress conditions. We report P. spadiceum AGH786 as the ever first GAs producing basidiomycetous fungus capable of producing six types of GAs. In comparison to the so for most efficient GAs producing Gibberella fujikuroi, AGH786 produced significantly higher amount of the bioactive GA3. Salt-stressed phenotype of soybean seedlings was characterized by low content of GAs and high amount of ABA and JA with reduced shoot length, biomass, leaf area, chlorophyll contents, and rate of photosynthesis. Mitigation of salt stress by AGH786 was always accompanied by high GAs, and low ABA and JA, suggesting that this endophytic fungus reduces the effect of salinity by modulating endogenous phytohormones of the seedlings. Additionally, this strain also enhanced the endogenous level of two isoflavones including daidzen and genistein in soybean seedlings under normal as well as salt stress conditions as compared to their respective controls. P. spadiceum AGH786 boosted the NaCl stress tolerance and growth in soybean, by modulating seedlings endogenous phytohormones and isoflavones suggesting a valuable contribution of this potent fungal biofertilizer in sustainable agriculture in salt affected soils. PMID:28473818

Comparative genomic and transcriptomic analyses of the Fuzhuan brick tea-fermentation fungus Aspergillus cristatus.

PubMed

Ge, Yongyi; Wang, Yuchen; Liu, YongXiang; Tan, Yumei; Ren, Xiuxiu; Zhang, Xinyu; Hyde, Kevin D; Liu, Yongfeng; Liu, Zuoyi

2016-06-07

Aspergillus cristatus is the dominant fungus involved in the fermentation of Chinese Fuzhuan brick tea. Aspergillus cristatus is a homothallic fungus that undergoes a sexual stage without asexual conidiation when cultured in hypotonic medium. The asexual stage is induced by a high salt concentration, which completely inhibits sexual development. The taxon is therefore appropriate for investigating the mechanisms of asexual and sexual reproduction in fungi. In this study, de novo genome sequencing and analysis of transcriptomes during culture under high- and low-osmolarity conditions were performed. These analyses facilitated investigation of the evolution of mating-type genes, which determine the mode of sexual reproduction, in A. cristatus, the response of the high-osmolarity glycerol (HOG) pathway to osmotic stimulation, and the detection of mycotoxins and evaluation of the relationship with the location of the encoding genes. The A. cristatus genome comprised 27.9 Mb and included 68 scaffolds, from which 10,136 protein-coding gene models were predicted. A phylogenetic analysis suggested a considerable phylogenetic distance between A. cristatus and A. nidulans. Comparison of the mating-type gene loci among Aspergillus species indicated that the mode in A. cristatus differs from those in other Aspergillus species. The components of the HOG pathway were conserved in the genome of A. cristatus. Differential gene expression analysis in A. cristatus using RNA-Seq demonstrated that the expression of most genes in the HOG pathway was unaffected by osmotic pressure. No gene clusters associated with the production of carcinogens were detected. A model of the mating-type locus in A. cristatus is reported for the first time. Aspergillus cristatus has evolved various mechanisms to cope with high osmotic stress. As a fungus associated with Fuzhuan tea, it is considered to be safe under low- and high-osmolarity conditions.

Seasonal dynamics of ectomycorrhizal fungus assemblages on oak seedlings in the southeastern Appalachian Mountains

Treesearch

John F. Walker; Orson K. Jr. Miller; Jonathan L. Horton

2008-01-01

The potential for seasonal dynamics in ectomycorrhizal (EM) fungal assemblages has important implications for the ecology of both the host trees and the fungal associates. We compared EM fungus distributions on root systems of out-planted oak seedlings at two sites in mixed southeastern Appalachian Mountain forests at the Coweeta Hydrologic Laboratory in North Carolina...

Comparative genomic analysis in the fungus Fusarium for production of toxins of concern to food safety

USDA-ARS?s Scientific Manuscript database

SUMMARY Comparative analysis of 207 genomes representing 159 species of the fungus Fusarium detected 9403 known and putative secondary metabolite (SM) biosynthetic gene clusters. The clusters included those responsible for synthesis of mycotoxins, plant hormones and pigments, and varied in distribut...

Transcriptional Basis of Drought-Induced Susceptibility to the Rice Blast Fungus Magnaporthe oryzae

PubMed Central

Bidzinski, Przemyslaw; Ballini, Elsa; Ducasse, Aurélie; Michel, Corinne; Zuluaga, Paola; Genga, Annamaria; Chiozzotto, Remo; Morel, Jean-Benoit

2016-01-01

Plants are often facing several stresses simultaneously. Understanding how they react and the way pathogens adapt to such combinational stresses is poorly documented. Here, we developed an experimental system mimicking field intermittent drought on rice followed by inoculation by the pathogenic fungus Magnaporthe oryzae. This experimental system triggers an enhancement of susceptibility that could be correlated with the dampening of several aspects of plant immunity, namely the oxidative burst and the transcription of several pathogenesis-related genes. Quite strikingly, the analysis of fungal transcription by RNASeq analysis under drought reveals that the fungus is greatly modifying its virulence program: genes coding for small secreted proteins were massively repressed in droughted plants compared to unstressed ones whereas genes coding for enzymes involved in degradation of cell-wall were induced. We also show that drought can lead to the partial breakdown of several major resistance genes by affecting R plant gene and/or pathogen effector expression. We propose a model where a yet unknown plant signal can trigger a change in the virulence program of the pathogen to adapt to a plant host that was affected by drought prior to infection. PMID:27833621

Pandora formicae, a specialist ant pathogenic fungus: New insights into biology and taxonomy.

PubMed

Małagocka, Joanna; Jensen, Annette Bruun; Eilenberg, Jørgen

2017-02-01

Among fungi from the order Entomophthorales (Entomophthoromycota), there are many specialized, obligatory insect-killing pathogens. Pandora formicae (Humber & Bałazy) Humber is a rare example of an entomophthoralean fungus adapted to exclusively infect social insects: wood ants from the genus Formica. There is limited information available on P. formicae; many important aspects of this host-pathogen system remain hitherto unknown, and the taxonomical status of the fungus is unclear. Our study fills out some main gaps in the life history of P. formicae, such as seasonal prevalence and overwintering strategy. Field studies of infection prevalence show a disease peak in late summer and early autumn. Typical thick-walled entomophthoralean resting spores of P. formicae are documented and described for the first time. The proportion of cadavers with resting spores increased from late summer throughout autumn, suggesting that these spores are the main overwintering fungal structures. In addition, the phylogenetic status of Pandora formicae is outlined. Finally, we review the available taxonomical literature and conclude that the name P. formicae should be used rather than the name P. myrmecophaga for ant-infecting fungi displaying described morphological features. Copyright © 2016 Elsevier Inc. All rights reserved.

[Enzymatic degradation of organophosphorus insecticide chlorpyrifos by fungus WZ-I].

PubMed

Xie, Hui; Zhu, Lu-sheng; Wang, Jun; Wang, Xiu-guo; Liu, Wei; Qian, Bo; Wang, Qian

2005-11-01

Degradation characteristics of chlorpyrifos insecticides was determined by the crude enzyme extracted from the isolated strain WZ-I ( Fusarium LK. ex Fx). The best separating condition and the degrading characteristic of chlorpyrifos were studied. Rate of degradation for chlorpyrifos by its intracellular enzyme, extracellular enzyme and cell fragment was 60.8%, 11.3% and 48%, respectively. The degrading enzyme was extracted after this fungus was incubated for 8 generations in the condition of noninducement, and its enzymic activity lost less, the results show that this enzyme is an intracellular and connatural enzyme. The solubility protein of the crude enzyme was determined with Albumin (bovine serum) as standard protein and the solubility protein of the crude enzyme was 3.36 mg x mL(-1). The pH optimum for crude enzyme was 6.8 for enzymatic degradation of chlorpyrifos, and it had comparatively high activity in the range of pH 6.0 - 9.0. The optimum temperature for enzymatic activity was at 40 degrees C, it still had comparatively high activity in the range of temperature 20-50 degrees C, the activity of enzyme rapidly reduced at 55 degrees C, its activity was 41% of the maximal activity. The crude enzyme showed Km value for chlorpyrifos of 1.049 26 mmol x L(-1), and the maximal enzymatic degradation rate was 0.253 5 micromol x (mg x min)(-1). Additional experimental evidence suggests that the enzyme had the stability of endure for temperature and pH, the crude enzyme of fungus WZ-I could effectively degrade chlorpyrifos.

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

Trait Differentiation within the Fungus-Feeding (Mycophagous) Bacterial Genus Collimonas

PubMed Central

Ballhausen, Max-Bernhard; Vandamme, Peter; de Boer, Wietse

2016-01-01

The genus Collimonas consists of facultative, fungus-feeding (mycophagous) bacteria. To date, 3 species (C. fungivorans, C. pratensis and C. arenae) have been described and over 100 strains have been isolated from different habitats. Functional traits of Collimonas bacteria that are potentially involved in interactions with soil fungi mostly negatively (fungal inhibition e.g.), but also positively (mineral weathering e.g.), affect fungal fitness. We hypothesized that variation in such traits between Collimonas strains leads to different mycophagous bacterial feeding patterns. We investigated a) whether phylogenetically closely related Collimonas strains possess similar traits, b) how far phylogenetic resolution influences the detection of phylogenetic signal (possession of similar traits by related strains) and c) if there is a pattern of co-occurrence among the studied traits. We measured genetically encoded (nifH genes, antifungal collimomycin gene cluster e.g.) as well as phenotypically expressed traits (chitinase- and siderophore production, fungal inhibition and others) and related those to a high-resolution phylogeny (MLSA), constructed by sequencing the housekeeping genes gyrB and rpoB and concatenating those with partial 16S rDNA sequences. Additionally, high-resolution and 16S rDNA derived phylogenies were compared. We show that MLSA is superior to 16SrDNA phylogeny when analyzing trait distribution and relating it to phylogeny at fine taxonomic resolution (a single bacterial genus). We observe that several traits involved in the interaction of collimonads and their host fungus (fungal inhibition e.g.) carry phylogenetic signal. Furthermore, we compare Collimonas trait possession with sister genera like Herbaspirillum and Janthinobacterium. PMID:27309848

Symbiont selection via alcohol benefits fungus farming by ambrosia beetles

PubMed Central

Ranger, Christopher M.; Phuntumart, Vipaporn; Beligala, Gayathri U.; Ghosh, Satyaki; Palmquist, Debra E.; Mueller, Robert; Barnett, Jenny; Schultz, Peter B.; Reding, Michael E.; Benz, J. Philipp

2018-01-01

Animal–microbe mutualisms are typically maintained by vertical symbiont transmission or partner choice. A third mechanism, screening of high-quality symbionts, has been predicted in theory, but empirical examples are rare. Here we demonstrate that ambrosia beetles rely on ethanol within host trees for promoting gardens of their fungal symbiont and producing offspring. Ethanol has long been known as the main attractant for many of these fungus-farming beetles as they select host trees in which they excavate tunnels and cultivate fungal gardens. More than 300 attacks by Xylosandrus germanus and other species were triggered by baiting trees with ethanol lures, but none of the foundresses established fungal gardens or produced broods unless tree tissues contained in vivo ethanol resulting from irrigation with ethanol solutions. More X. germanus brood were also produced in a rearing substrate containing ethanol. These benefits are a result of increased food supply via the positive effects of ethanol on food-fungus biomass. Selected Ambrosiella and Raffaelea fungal isolates from ethanol-responsive ambrosia beetles profited directly and indirectly by (i) a higher biomass on medium containing ethanol, (ii) strong alcohol dehydrogenase enzymatic activity, and (iii) a competitive advantage over weedy fungal garden competitors (Aspergillus, Penicillium) that are inhibited by ethanol. As ambrosia fungi both detoxify and produce ethanol, they may maintain the selectivity of their alcohol-rich habitat for their own purpose and that of other ethanol-resistant/producing microbes. This resembles biological screening of beneficial symbionts and a potentially widespread, unstudied benefit of alcohol-producing symbionts (e.g., yeasts) in other microbial symbioses. PMID:29632193

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

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

PubMed

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

2016-09-01

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.

Carbon availability for the fungus triggers nitrogen uptake and transport in the arbuscular mycorrhizal symbiosis

USDA-ARS?s Scientific Manuscript database

The arbuscular mycorrhizal (AM) symbiosis is characterized by a transfer of nutrients in exchange for carbon. We tested the effect of the carbon availability for the AM fungus Glomus intraradices on nitrogen (N) uptake and transport in the symbiosis. We followed the uptake and transport of 15N and ...

Cell Biology: Control of Partner Lifetime in a Plant-Fungus Relationship.

PubMed

Gutjahr, Caroline; Parniske, Martin

2017-06-05

Arbuscules are tree-shaped fungal structures inside plant root cells that facilitate the exchange of nutrients delivered by the fungus with carbon sources from the host. To maintain symbiotic efficiency, plant cells can trigger degeneration of underperforming arbuscules. A recent study reveals the first transcription factor, which induces genes encoding hydrolytic enzymes, to mediate arbuscule degeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficacy of the entomopathogenic fungus Metarhizium brunneum in controlling the tick Rhipicephalus annulatus under field conditions.

PubMed

Samish, M; Rot, A; Ment, D; Barel, S; Glazer, I; Gindin, G

2014-12-15

High infectivity of entomopathogenic fungi to ticks under laboratory conditions has been demonstrated in many studies. However, the few reports on their use under field conditions demonstrate large variations in their success, often with no clear explanation. The present study evaluated the factors affecting the efficacy of the fungus Metarhizium brunneum against the tick Rhipicephalus (Boophilus) annulatus. It demonstrates how environmental conditions and ground cover affect the efficiency of the fungus under field conditions. During the summer, 93% of tick females exposed to fungus-contaminated ground died within 1 week, whereas during the winter, only 62.2% died within 6 weeks. Nevertheless, the hatchability of their eggs was only 6.1% during the summer and 0.0% during winter. Covering the ground with grass, leaves or gravel improved fungal performance. Aside from killing female ticks, the fungus had a substantial effect on tick fecundity. Fungal infection reduced the proportion of female ticks laying full-size egg masses by up to 91%, and reduced egg hatchability by up to 100%. To reduce the negative effect of outdoor factors on fungal activity, its conidia were mixed with different oils (olive, canola, mineral or paraffin at 10% v/v) and evaluated in both laboratory and field tests for efficacy. All tested oils without conidia sprayed on the sand did not influence tick survival or weight of the laid eggs but significantly reduced egghatchability. Conidia in water with canola or mineral oil spread on agarose and incubated for 18 h showed 57% and 0% germination, respectively. Comparing, under laboratory conditions, the effects of adding each of the four oils to conidia in water on ticks demonstrated no effect on female mortality or weight of the laid egg mass, but the percentage of hatched eggs was reduced. In outdoor trials, female ticks placed on the ground sprayed with conidia in water yielded an average of 175 larvae per female and there was no hatching of

New Eudesmane-Type Sesquiterpenoids from the Mangrove-Derived Endophytic Fungus Penicillium sp. J-54.

PubMed

Qiu, Liuming; Wang, Pei; Liao, Ge; Zeng, Yanbo; Cai, Caihong; Kong, Fandong; Guo, Zhikai; Proksch, Peter; Dai, Haofu; Mei, Wenli

2018-03-28

Four new eudesmane-type sesquiterpenoids, penicieudesmol A-D ( 1 - 4 ), were isolated from the fermentation broth of the mangrove-derived endophytic fungus Penicillium sp. J-54. Their structures were determined by spectroscopic methods, the in situ dimolybdenum CD method, and modified Mosher's method. The bioassays results showed that 2 exhibited weak cytotoxicity against K-562 cells.

Differential Selection by Nematodes on an Introduced Biocontrol Fungus vs. Indigenous Fungi in Nonsterile Soil.

PubMed

Kim, Tae Gwan; Knudsen, Guy R

2018-03-15

Trophic interactions of introduced biocontrol fungi with soil animals can bea key determinant in the fungal proliferation and activity.This study investigated trophic interaction of an introduced biocontrol fungus with soil nematodes. The biocontrol fungus Trichoderma harzianum ThzID1-M3 and the fungivorous nematode Aphelenchoides sp. (10 per gram of soil) were added to nonsterile soil, and microbial populations were monitored for 40 days. Similar results were obtained when the experiment was duplicated. ThzID1-M3 stimulated the population growth of indigenous nematodes ( p <0.05), regardless of whether Aphelenchoides sp.was added.Without ThzID1-M3, indigenous nematodes did not increase in number and the added Aphelenchoides sp. nematodes almost disappeared by day 10. With ThzID1-M3, population growth of nematodes was rapid between 5 and 10 days after treatment. ThzID1-M3 biomass peaked on day 5, dropped at day 10, and then almost disappeared at day 20, which was not influenced by the addition of nematodes.In contrast, a large quantity of ThzID1-M3 hyphae were present in a heat-treated soil in which nematodes were eliminated.Total fungal biomass in all treatments peaked on day 5 and subsequently decreased.Addition of nematodes increased the total fungal biomass ( p <0.05), but ThzID1-M3 addition did not affect the fungal biomass.Hyphae oftotal fungi when homogenously distributed did not support the nematode population growth; however, hyphae of the introduced fungus when densely localized did.The results suggest that soil fungivorous nematodes are an important constraint onhyphal proliferation of fungal agents introduced into natural soils.

A small cysteine-rich protein from the Asian soybean rust fungus, Phakopsora pachyrhizi, suppresses plant immunity

USDA-ARS?s Scientific Manuscript database

The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate pathogen capable of causing explosive disease epidemics that drastically reduce the yield of soybean (Glycine max). Currently, the molecular mechanisms by which P. pachyrhizi and other rust fungi cause disease are poorly understood...

Four new steroids from the endophytic fungus Chaetomium sp. M453 derived of Chinese herbal medicine Huperzia serrata.

PubMed

Yu, Fei-Xue; Li, Zhe; Chen, Yao; Yang, Yin-He; Li, Guo-Hong; Zhao, Pei-Ji

2017-03-01

An endophytic fungus, Chaetomium sp. M453, was isolated from Huperzia serrata (Thunb. ex Murray) Trev. and subjected to phytochemical investigation. Three unusual C25 steroids, neocyclocitrinols E-G (1-3), and 3β-hydroxy-5,9-epoxy-(22E,24R)-ergosta-7,22-dien-6-one (4) together with three known steroids were isolated from solid fermentation products of the fungus, which were elucidated by extensive spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS experiments. The absolute configuration of 1 was determined by X-ray crystallographic analysis and CD analyses. The acetylcholinesterase inhibitory activities of compounds 1-4 were tested in vitro. Compound 4 showed weak acetylcholinesterase inhibitory activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial and immunomodulatory efficacy of extracellularly synthesized silver and gold nanoparticles by a novel phosphate solubilizing fungus Bipolaris tetramera.

PubMed

Fatima, Faria; Bajpai, Preeti; Pathak, Neelam; Singh, Sarika; Priya, Shivam; Verma, Smita Rastogi

2015-02-27

Particulates of nanometers size have occupied a significant area in the field of medicinal and agricultural purposes due to their large surface-to-volume ratio and exceptional physicochemical, electronic and mechanical properties. Myconanotechnology, an interface between mycology and nanotechnology is budding nowadays for nanoparticle-fabrication using fungus or its metabolites. In the present study, we have isolated and characterized a novel phosphate solubilizing fungus B. tetramera KF934408 from rhizospheric soil. This phosphatase releasing fungus was subjected to extracellular synthesis of metal nanoparticles by redox reaction. Silver (AgNPs) and gold nanoparticles (AuNPs) were characterized by dynamic light scattering and transmission electron microscopic analysis. The formulated AgNPs were irregular shaped with a size ranging between 54.78 nm to 73.49 nm whereas AuNPs were spherical or hexagonal, with a size of 58.4 and 261.73 nm, respectively. The nanoparticles were assessed for their antibacterial and antifungal efficacy. The results showed effective antimicrobial activity of AgNPs against Bacillus cereus, Staphylococcus aureus, Enterobacter aeroginosa and Trichoderma sp. at higher concentrations, however, AuNPs possessed only moderate antibacterial efficacy while they found no antifungal activity. Cytotoxicity analysis of nanoparticles on J774 and THP1 α cell lines revealed the dose dependence in case of AgNPs, while AuNPs were non-toxic at both low and high doses. Furthermore, significant elevation of intracellular ROS was observed after 4 h of incubation with both the nanoparticles. The capping of fungal proteins on the particulates might be involved in the activities demonstrated by these inert metal nanoparticles. In conclusion, the findings showed that the metal nanoparticles synthesized by fungus B. tetramera could be used as an antimicrobial agents as well as cost effective and nontoxic immunomodulatory delivery vehicle.

Occurrence of fungi and fungus-like organisms in the Horodnianka River in the vicinity of Białystok, Poland.

PubMed

Kiziewicz, Bozena; Zdrojkowska, Ewa; Gajo, Bernadetta; Godlewska, Anna; Muszyńska, Elzbieta; Mazalska, Bozenna

2011-01-01

Studies of fungi and fungus- like organisms in the northeastern Poland have mainly concentrated on running waters in the vicinity of Białystok, including the Horodnianka River. The main objective was to investigate biodiversity of fungi and fungus-like organisms which take part in decomposition of organic matter commonly found in inland waters. To obtain a complete picture of species composition of fungi and fungus-like organisms in running waters we decided to explore representative sites of the Horodnianka River such as Olmonty, Hryniewicze and Horodniany with close localization of landfill. Fungal species were isolated using baiting technique. Baits of onion skin (Alium cepa), hemp-seeds (Cannabis sativa), impregnated cellophane and snake skin (Natrix natrix) were applied to isolate fungi from water of the Horodnianka River. The fungal community consists of 26 species, 10 species of fungi belonging to class Chytridiomycetes (3), anamorphic fungi (6), and Zygomycetes (1). 16 species belong to fungus-like organisms from class Oomycetes. Most of the recognized species have already been found in other running waters. From all the examined habitats the fungi belonging to 26 species of 18 genera Achlya, Alternaria, Aphanomyces, Aspergillus, Catenophlyctis, Dictyuchus, Fusarium, Karlingia, Lagenidium, Leptomitus, Olpidiopsis, Penicillium, Phlyctochytrium, Pythium, Saprolegnia, Scoliognia, Thraustotheca and Zoophagus were obtained. Certain fungal species like Aphanomyces laevis, Fusarium aqueductum, F. moniliforme, F. oxysporum, Leptomitus lacteus, Saprolegnia feax and S. parasitica were found at all the study sites. Among fungi potentially pathogenic and allergogenic for humans the genera Alternaria, Aspergillus, Fusarium, Lagenidium and Penicillium have already been described. However, the species Lagenidium giganteum and Achlya androgyna are new in the fungal biota of Poland. The greatest number of fungal species occurred in Olmonty (24), the smallest in Horodniany

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...

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...

Response of ectomycorrhizal fungus sporocarp production to varying levels and patterns of green-tree retention.

Treesearch

Daniel L. Luoma; Joyce L. Eberhart; Randy Molina; Michael P. Amaranthus

2004-01-01

Forest management activities can reduce ectomycorrhizal fungus diversity and forest regeneration success. We examine contrasts in structural retention as they affect sporocarp production of ectomycorrhizal fungi (EMF)--functional guild of organisms well suited as indicators of disturbance effects on below-ground ecosystems. Our results are from an experiment that tests...

Compatibility of the insect pathogenic fungus Beauveria bassiana with neem against sweetpotato whitefly, Bemisia tabaci, on eggplant

USDA-ARS?s Scientific Manuscript database

A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (106, 1...

Growth inhibition of Microcystis aeruginosa by white-rot fungus Lopharia spadicea.

PubMed

Wang, Q; Su, M; Zhu, W; Li, X; Jia, Y; Guo, P; Chen, Z; Jiang, W; Tian, X

2010-01-01

Harmful cyanobacterial blooms cause water deterioration and threaten human health. It is necessary to remove harmful cyanobacteria with useful methods. A bio-treatment may be one of the best ways to do this. A strain of specific white-rot fungus, Lopharia spadicea, with algicidal ability was isolated. Its algicidal ability on algae under various conditions was determined using three main influence factors: initial chlorophyll-a content, initial pH, and algal cell mixture. The result showed that the chlorophyll-a content of Microcystis aeruginosa FACHB-912, Oocystis borgei FACHB-1108, and Microcystis flos-aquae FACHB-1028 decreased from 798+/-13, 756+/-40, and 773+/-24 microg/L to 0 within 39 h. L. spadicea could also remove more than 95% chlorophyll-a when initial chlorophyll-a content increased from 397+/-13 to 2,132+/-4 microg/L. Moreover, the strain has great removal ability under a broad initial pH range of 5.5 to 9.5. The chlorophyll-a content of the three algal strain mixtures decreased from about 672+/-23 microg/L to 0 within 45 h. After superoxide dismutase (SOD) and malondialdehyde (MAD) were assessed in a co-culture of L. spadicea, it was observed that an increase in MAD content was correlated with the decrease in chlorophyll-a content of M. aeruginosa FACHB-912. This result suggested that the algae was not only greatly inhibited but also severely damaged by the fungus.

Rapid evolution of avirulence genes in rice blast fungus Magnaporthe oryzae

PubMed Central

2014-01-01

Background Rice blast fungus Magnaporthe oryzae is one of the most devastating pathogens in rice. Avirulence genes in this fungus share a gene-for-gene relationship with the resistance genes in its host rice. Although numerous studies have shown that rice blast R-genes are extremely diverse and evolve rapidly in their host populations, little is known about the evolutionary patterns of the Avr-genes in the pathogens. Results Here, six well-characterized Avr-genes and seven randomly selected non-Avr control genes were used to investigate the genetic variations in 62 rice blast strains from different parts of China. Frequent presence/absence polymorphisms, high levels of nucleotide variation (~10-fold higher than non-Avr genes), high non-synonymous to synonymous substitution ratios, and frequent shared non-synonymous substitution were observed in the Avr-genes of these diversified blast strains. In addition, most Avr-genes are closely associated with diverse repeated sequences, which may partially explain the frequent presence/absence polymorphisms in Avr-genes. Conclusion The frequent deletion and gain of Avr-genes and rapid non-synonymous variations might be the primary mechanisms underlying rapid adaptive evolution of pathogens toward virulence to their host plants, and these features can be used as the indicators for identifying additional Avr-genes. The high number of nucleotide polymorphisms among Avr-gene alleles could also be used to distinguish genetic groups among different strains. PMID:24725999

Molecular Characterization and Antimicrobial Activity of an Endolichenic Fungus, Aspergillus sp. Isolated from Parmelia caperata of Similipal Biosphere Reserve, India.

PubMed

Padhi, Srichandan; Das, Devaranjan; Panja, Suraj; Tayung, Kumananda

2017-06-01

Endolichenic fungi are microbes that inhabit healthy inner lichen tissues without any disease symptoms. They have been reported to produce new and interesting bioactive metabolites. In the present study, an endolichenic fungus frequently isolated from surface-sterilized lichen thallus of Parmelia caperata has been described. The fungus was identified as Aspergillus tubingensis based on morphological traits and ITS rDNA sequence. Crude metabolites extracted from the culture broth exhibited considerable antimicrobial activity against a panel of clinically significant human pathogens. The fungus showed optimum antimicrobial activity in PDB medium in day 7 of incubation period. PDB medium amended with 1 % NaCl and at alkaline pH was found to be optimal for antimicrobial metabolites production. Enhanced activity was observed when the fungus was exposed briefly to a heat shock of 60 °C during incubation. The metabolites showed optimum λ-max at 214 nm with an absorbance value of 1.589. Molecular characterization of the isolate was carried out by ITS phylogeny and ITS2 secondary structure analyses. The phylogenetic trees based on both ITS rDNA and ITS2 sequences showed the isolate within the clade A. tubingensis. Considering the ubiquity and ambiguity in identifying Aspergillus species of different lifestyles, a method to differentiate pathogenic and endophytic Aspergillus at species level was developed using ITS2 secondary structure analysis. The results showed common folding pattern in the secondary structures with a helix and a 5' dangling end found to be highly conserved. Certain features in the secondary structure like multi-bulges and a symmetric interior loop were observed to be unique which distinguish our isolate from other A. tubingensis.

Five New Guanacastane-Type Diterpenes from Cultures of the Fungus Psathyrella candolleana.

PubMed

Yin, Xia; Feng, Tao; Li, Zheng-Hui; Leng, Ying; Liu, Ji-Kai

2014-06-01

Five new guanacastane-type diterpenes, named guanacastepenes P-T (1-5), were isolated from cultures of the fungus Psathyrella candolleana. Their structures were elucidated on the basis of extensive spectroscopic methods. All of the compounds were tested for their 11β-hydroxysteroid dehydrogenase (11β-HSD1) inhibitory activity. Compound 3 exhibited inhibitory activity against both human and mouse isozymes of 11β-HSD1 with IC50 values of 6.2 and 13.9 μM, respectively.

Metabolites of the endophytic fungus Penicillium sp. FJ-1 of Acanthus ilicifolius.

PubMed

Liu, Jian-Fang; Chen, Wei-Jie; Xin, Ben-Ru; Lu, Jie

2014-06-01

Two new compounds, named as (2R,3S)-pinobanksin-3-cinnamate (1), and 15alpha-hydroxy-(22E,24R)-ergosta-3,5,8(14),22-tetraen-7-one (2), were isolated from the endophytic fungus Penicillium sp. FJ-1 of Acanthus ilicifolius Linn. Their structures were elucidated on the basis of spectroscopic analysis. Additionally, compound 1 exhibited potent neuroprotective effects on corticosterone-damaged PC12 cells, and compound 2 showed potent cytotoxicity on glioma cell lines.

Polyketides with Immunosuppressive Activities from Mangrove Endophytic Fungus Penicillium sp. ZJ-SY₂.

PubMed

Liu, Hongju; Chen, Senhua; Liu, Weiyang; Liu, Yayue; Huang, Xishan; She, Zhigang

2016-11-25

Nine polyketides, including two new benzophenone derivatives, peniphenone ( 1 ) and methyl peniphenone ( 2 ), along with seven known xanthones ( 3 - 9 ) were obtained from mangrove endophytic fungus Penicillium sp. ZJ-SY₂ isolated from the leaves of Sonneratia apetala . Their structures were elucidated on the basis of MS, 1D, and 2D NMR data. Compounds 1 , 3 , 5 , and 7 showed potent immunosuppressive activity with IC 50 values ranging from 5.9 to 9.3 μg/mL.

Heterologous expression of VHb can improve the yield and quality of biocontrol fungus Paecilomyces lilacinus, during submerged fermentation.

PubMed

Zhang, Shumeng; Wang, Jieping; Wei, Yale; Tang, Qing; Ali, Maria Kanwal; He, Jin

2014-10-10

Paecilomyces lilacinus is an egg-parasitic fungus which is effective against plant-parasitic nematodes and it has been successfully commercialized for the control of many plant-parasitic nematodes. However, during the large-scale industrial fermentation process of the filamentous fungus, the dissolved oxygen supply is a limiting factor, which influences yield, product quality and production cost. To solve this problem, we intended to heterologously express VHb in P. lilacinus ACSS. After optimizing the vgb gene, we fused it with a selection marker gene nptII, a promoter PgpdA and a terminator TtrpC. The complete expression cassette PgpdA-nptII-vgb-TtrpC was transferred into P. lilacinus ACSS by Agrobacterium tumefaciens-mediated transformation. Consequently, we successfully screened an applicable fungus strain PNVT8 which efficiently expressed VHb. The submerged fermentation experiments demonstrated that the expression of VHb not only increased the production traits of P. lilacinus such as biomass and spore production, but also improved the beneficial product quality and application value, due to the secretion of more protease and chitinase. It can be speculated that the recombinant strain harboring vgb gene will have a growth advantage over the original strain under anaerobic conditions in soil and therefore will possess higher biocontrol efficiency against plant-parasitic nematodes. Copyright © 2014 Elsevier B.V. All rights reserved.

D-lysergic acid-activating enzyme from the ergot fungus Claviceps purpurea.

PubMed Central

Keller, U; Zocher, R; Krengel, U; Kleinkauf, H

1984-01-01

A D-lysergic acid-activating enzyme from the ergot fungus Claviceps purpurea was purified about 145-fold. The enzyme was able to catalyse both the D-lysergic acid-dependent ATP-pyrophosphate exchange and the formation of ATP from D-lysergic acid adenylate and pyrophosphate. Both reactions were also catalysed to a decreased but significant extent with respect to dihydrolysergic acid. The molecular mass of the enzyme was estimated to lie between 135 and 140 kDa. The involvement of the enzyme in the biosynthesis of ergot peptide alkaloids is discussed. Images Fig. 4. PMID:6326747

Melanoidin-containing wastewaters induce selective laccase gene expression in the white-rot fungus Trametes sp. I-62.

PubMed

González, Tania; Terrón, María Carmen; Yagüe, Susana; Junca, Howard; Carbajo, José María; Zapico, Ernesto Javier; Silva, Ricardo; Arana-Cuenca, Ainhoa; Téllez, Alejandro; González, Aldo Enrique

2008-03-01

Wastewaters generated from the production of ethanol from sugar cane molasses may have detrimental effects on the environment due to their high chemical oxygen demand and dark brown color. The color is mainly associated with the presence of melanoidins, which are highly recalcitrant to biodegradation. We report here the induction of laccases by molasses wastewaters and molasses melanoidins in the basidiomycetous fungus Trametes sp. I-62. The time course of effluent decolorization and laccase activity in the culture supernatant of the fungus were correlated. The expression of laccase genes lcc1 and lcc2 increased as a result of the addition of complete molasses wastewater and its high molecular weight fraction to fungal cultures. This is the first time differential laccase gene expression has been reported to occur upon exposure of fungal cultures to molasses wastewaters and their melanoidins.