4,952 research outputs found

    Molecular diversity of anthracnose pathogen populations associated with UK strawberry production suggests multiple introductions of three different Colletotrichum species.

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    Fragaria Ă— ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production

    Mind the gap: IR and the challenge of international politics

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    The discipline of International Relations (IR) for a long time of its history has developed in the form of Great Debates that involved competing paradigms and schools. More recently, it has been described as a cacophony of voices unable to communicate among themselves, but also incapable to provide keys to understand an ever more complex reality. This collection aims at evaluating the heuristic value of a selection of traditional paradigmsrealism and liberalism), schools (constructivism), and subdisciplines (security studies and international political economy) so as to assess the challenges before IR theory today and the ability of the discipline to provide tools to make the changed world still intelligible

    Insights on KP4 Killer Toxin-like Proteins of Fusarium Species in Interspecific Interactions

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    KP4 killer toxins are secreted proteins that inhibit cell growth and induce cell death in target organisms. In Fusarium graminearum, KP4-like (KP4L) proteins contribute to fungal virulence in wheat seedling rot and are expressed during Fusarium head blight development. However, fungal KP4L proteins are also hypothesized to support fungal antagonism by permeabilizing cell walls of competing fungi to enable penetration of toxic compounds. Here, we report the differential expression patterns of F. graminearum KP4L genes (Fgkp4l-1, -2, -3 and -4) in a competitive interaction, using Trichoderma gamsii as the antagonist. The results from dual cultures indicate that Fgkp4l-3 and Fgkp4l-4 could participate in the recognition at the distance of the antagonist, while all Fgkp4l genes were highly activated in the pathogen during the physical interaction of both fungi. Only Fgkp4l-4 was up-regulated during the interaction with T. gamsii in wheat spikes. This suggests the KP4L proteins could participate in supporting F. graminearum interspecific interactions, even in living plant tissues. The distribution of KP4L orthologous within the genus Fusarium revealed they are more represented in species with broad host-plant range than in host-specific species. Phylogeny inferred provides evidence that KP4L genes evolved through gene duplications, gene loss and sequence diversification in the genus Fusarium

    Electrophysiology of glioma: a Rho GTPase-activating protein reduces tumor growth and spares neuron structure and function

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    Background. Glioblastomas are the most aggressive type of brain tumor. A successful treatment should aim at halting tumor growth and protecting neuronal cells to prevent functional deficits and cognitive deterioration. Here, we exploited a Rho GTPase-activating bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), to interfere with glioma cell growth in vitro and vivo. We also investigated whether this toxin spares neuron structure and function in peritumoral areas. Methods. We performed a microarray transcriptomic and in-depth proteomic analysis to characterize the molecular changes triggered by CNF1 in glioma cells. We also examined tumor cell senescence and growth in vehicle-and CNF1-treated glioma-bearing mice. Electrophysiological and morphological techniques were used to investigate neuronal alterations in peritumoral cortical areas. Results. Administration of CNF1 triggered molecular and morphological hallmarks of senescence in mouse and human glioma cells in vitro. CNF1 treatment in vivo induced glioma cell senescence and potently reduced tumor volumes. In peritumoral areas of glioma-bearing mice, neurons showed a shrunken dendritic arbor and severe functional alterations such as increased spontaneous activity and reduced visual responsiveness. CNF1 treatment enhanced dendritic length and improved several physiological properties of pyramidal neurons, demonstrating functional preservation of the cortical network. Conclusions. Our findings demonstrate that CNF1 reduces glioma volume while at the same time maintaining the physiological and structural properties of peritumoral neurons. These data indicate a promising strategy for the development of more effective antiglioma therapies

    Alternaria species causing pomegranate and citrus fruit rots in Albania

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    The fungal genus Alternaria is a relevant pathogen for several commodities including citrus and pomegranate fruits. On citrus, it mainly causes brown spots on fruits and leaves, whereas on pomegranate, it mostly causes a fruit heart rot. In the present study the presence of Alternaria rots on citrus and pomegranate fruits cultivated in Albania was assessed. Representative fruits were collected from different regions. Nineteen and thirteen Alternaria spp. isolates were obtained from pomegranate and citrus samples, respectively. The isolates were identified at species and morphotype level. Micro and macroscopic features separated isolates into four morphotypes. BLAST and phylogenetic analysis using the SCAR Marker OPA1-3 confirmed the isolate identity. All 32 isolates proved to be Alternaria alternata and belonged mainly to morphotype alternata, followed by limoniasperae and tenuissima. All Alternaria strains proved to possess the pksI gene of alternariol biosynthesis. Citrus isolates were tested for the presence of genes of the biosynthesis of the phytotoxins ACT and ACR, but none of them proved to possess them. Concluding, Alternaria spp. might represent a treat to pomegranate and citrus production in Albania, and thus effective control means are needed

    How Water Interacts with the NOH Group: The Rotational Spectrum of the 1:1 N,N-diethylhydroxylamine·Water Complex

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    The rotational spectrum of the 1:1 N,N-diethylhydroxylamine-water complex has been investigated using pulsed jet Fourier transform microwave spectroscopy in the 6.5–18.5 GHz frequency region. The most stable conformer has been detected as well as the (Formula presented.) C monosubstituted isotopologues in natural abundance and the (Formula presented.) O enriched water species, allowing to determine the nitrogen nuclear quadrupole coupling constants and the molecular structure in the vibrational ground state. The molecule has a (Formula presented.) symmetry and the water lies in the (Formula presented.) symmetry plane forming two hydrogen bonds with the NOH frame with length: (Formula presented.) = 1.974 Å and (Formula presented.) = 2.096 Å. From symmetry-adapted perturbation theory calculations coupled to atoms in molecule approach, the corresponding interaction energy values are estimated to be 24 and 13 kJ·mol (Formula presented.), respectively. The great strength of the intermolecular interaction involving the nitrogen atom is in agreement with the high reactivity of hydroxylamine compounds at the nitrogen site

    Study of MDT calibration constants using H8 testbeam data of year 2004

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    In year 2004 Atlas performed a long campaign of test beam data taking at the H8 Cern beam. Two sectors of the barrel and endcap regions of the Muon Spectrometer were exposed to the beam and large amount of data were collected in well defined and controlled operating conditions. This allowed a careful study on MDT drift properties. A better understanding of the calibration constants, of their definition and determination and of the criteria for their acceptance has been obtained. Systematic effects and time stability of the constants have also been studied

    Service-Oriented Multigranular Optical Network Architecture for Clouds

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    This paper presents a novel service-oriented network architecture to bridge the informational gap between user applications and optical networks providing technology-agnostic multigranular optical network services for clouds. A mediation layer (service plane) between user applications and network control is proposed to facilitate a mapping process between user application requests and the network services. At the network level, a multigranular optical network (MGON) is proposed and implemented to support dynamic wavelength and subwavelength granularities with different transport formats [optical burst switched (OBS), optical burst transport (OBT)], reservation protocols (one-way, two-way), and different quality-of-service (QoS) levels per service type. The service-oriented multigranular optical network has been designed, implemented, and demonstrated on an experimental testbed. The testbed consists of service and network resource provisioning, service abstraction, and network resource virtualization. The service-to-network interoperation is provided by means of a gateway that maps service requests to technology-specific parameters and a common signaling channel for both service and network resource provisioning

    Genome sequence of the biocontrol agent coniothyrium minitans conio (IMI 134523)

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    Coniothyrium minitans (synonym, Paraphaeosphaeria minitans) is a highly specific mycoparasite of the wide host range crop pathogen Sclerotinia sclerotiorum. The capability of C. minitans to destroy the sclerotia of S. sclerotiorum has been well recognized and it is available as a widely used biocontrol product Contans WG. We present the draft genome sequence of C. minitans Conio (IMI 134523), which has previously been used in extensive studies that formed part of a registration package of the commercial product. This work provides a distinctive resource for further research into the molecular basis of mycoparasitism to harness the biocontrol potential of C. minitans

    Identification and Comparison of Colletotrichum Secreted Effector Candidates Reveal Two Independent Lineages Pathogenic to Soybean

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    Colletotrichum is one of the most important plant pathogenic genus of fungi due to its scientific and economic impact. A wide range of hosts can be infected by Colletotrichum spp., which causes losses in crops of major importance worldwide, such as soybean. Soybean anthracnose is mainly caused by C. truncatum, but other species have been identified at an increasing rate during the last decade, becoming one of the most important limiting factors to soybean production in several regions. To gain a better understanding of the evolutionary origin of soybean anthracnose, we compared the repertoire of effector candidates of four Colletotrichum species pathogenic to soybean and eight species not pathogenic. Our results show that the four species infecting soybean belong to two lineages and do not share any effector candidates. These results strongly suggest that two Colletotrichum lineages have acquired the capability to infect soybean independently. This study also provides, for each lineage, a set of candidate effectors encoding genes that may have important roles in pathogenicity towards soybean offering a new resource useful for further research on soybean anthracnose management
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