Search

The species of Purpureocillium are cosmopolitan and multitrophic fungi that can infect a wide range of invertebrate hosts. This study reports the mitogenome of P. atypicola, a specialized spider pathogenic fungus. The 112,465 bp mitogenome encoded genes typically found in fungal mitogenomes, and a total of 52 introns inserted into seven genes. A comparison with three other Purpureocillium species revealed significant differences in length and intron number, primarily due to intron variation; however, there was no dynamic variation in the introns of the cox1 gene within the same species of the Purpureocillium genus. Different mitochondrial protein-coding genes showed variable degrees of genetic differentiation among these species, but they were all under purifying selection. Additionally, frequent intron loss or gain events were detected to have occurred during the evolution of the Ophiocordycipitaceae mitogenomes, yet the gene arrangement remains conserved. A phylogenetic analysis of the combined mitochondrial gene set gave identical and well-supported tree topologies. The estimated age of the crown of Ophiocordycipitaceae and Purpureocillium were around the Early Cretaceous period (127 Mya) and Late Cretaceous period (83 Mya), respectively. The results of this study advance our understanding of the genomics, evolution, and taxonomy of this important fungal group. [ABSTRACT FROM AUTHOR]

Cordyceps chanhua is an important cordycipitoid mushroom widely used in Asia and beyond. Beauvericin (BEA), one of the bioactive compounds of C. chanhua, has attracted much attention because of its medicinal value and food safety risk. In order to clear up the relationship between oxidative stress and BEA synthesis, we investigated the impact of H2O2-induced oxidative stress on the secondary metabolism of C. chanhua using untargeted metabolomics and a transcript profiling approach. Metabolic profiling of C. chanhua mycelia found that in total, 73 differential metabolites were identified, including organic acids, phospholipids, and non-ribosomal peptides (NRPs), especially the content of BEA, increasing 13-fold under oxidative stress treatment. Combining transcriptomic and metabolomic analyses, we found that the genes and metabolites associated with the NRP metabolism, especially the BEA biosynthesis, were highly significantly enriched under H2O2-induced stress, which indicated that the BEA metabolism might be positive in the resistance of C. chanhua to oxidative stress. These results not only aid in better understanding of the resistance mechanisms of C. chanhua against oxidative stress but also might be helpful for molecular breeding of C. chanhua with low BEA content. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi are one of the key regulators of insect populations in nature. Some species such as Beauveria bassiana with a wide host range have been developed as promising alternatives to chemical insecticides for the biocontrol of insect pests. However, the long-term persistence of the released strains, the effect on non-target hosts and local fungal populations remains elusive, but they are considerable concerns with respect to environmental safety. Here we report the temporal features of the Beauveria population genomics and evolution over 20 years after releasing exotic strains to control pine caterpillar pests. We found that the isolates within the biocontrol site were mostly of clonal origins. The released strains could persist in the environment for a long time but with low recovery rates. Similar to the reoccurrence of host jumping by local isolates, the infection of non-target insects by the released strains was evident to endemically occur in association with host seasonality. No obvious dilution effect on local population structure was evident by the releases. However, the population was largely replaced by genetically divergent isolates once per decade but evolved with a pattern of balancing selection and towards expansion through adaptation, non-random outcrossing and isolate migration. This study not only unveils the real-time features of entomopathogenic fungal population genomics and evolution but also provides added values to alleviate the concerns of environmental safety regarding the biocontrol application of mycoinsecticides. [ABSTRACT FROM AUTHOR]

Background: Ascomycete Cordyceps species have been using as valued traditional Chinese medicines. Particularly, the fruiting bodies of Cordyceps cicadae (syn. Isaria cicadae) have long been utilized for the treatment of chronic kidney disease. However, the genetics and bioactive chemicals in this fungus have been largely unexplored. Results: In this study, we performed comprehensive omics analyses of C. cicadae, and found that, in contrast to other Cordyceps fungi, C. cicadae produces asexual fruiting bodies with the production of conidial spores instead of the meiotic ascospores. Genome sequencing and comparative genomic analysis indicate that the protein families encoded by C. cicadae are typical of entomopathogenic fungi, including the expansion of proteases and chitinases for targeting insect hosts. Interestingly, we found that the MAT1-2 mating-type locus of the sequenced strain contains an abnormally truncated MAT1-1-1 gene. Gene deletions revealed that asexual fruiting of C. cicadae is independent of the MAT locus control. RNA-seq transcriptome data also indicate that, compared to growth in a liquid culture, the putative genes involved in mating and meiosis processes were not up-regulated during fungal fruiting, further supporting asexual reproduction in this fungus. The genome of C. cicadae encodes an array of conservative and divergent gene clusters for secondary metabolisms. Based on our analysis, the production of known carcinogenic metabolites by this fungus could be potentially precluded. However, the confirmed production of oosporein raises health concerns about the frequent consumption of fungal fruiting bodies. Conclusions: The results of this study expand our knowledge of fungal genetics that asexual fruiting can occur independent of the MAT locus control. The obtained genomic and metabolomic data will benefit future investigations of this fungus for medicinal uses. [ABSTRACT FROM AUTHOR]

Beauveria bassianais a ubiquitous entomopathogenic fungus, which causes white muscardine in the silkworm,Bombyx mori, and is an important limiting factor in global silk production. Knowledge of the genetic structure ofB. bassianapopulations as the causal agents in China will aid in tracing the origins of muscardine and in developing effective control strategies. In the present study, a total of 489B. bassianaisolates were obtained from silkworm cadavers in 12 different provinces of China. An analysis of the genetic structure of the causal agent populations using the internal simple sequence repeat technique to trace their origins revealed a high level (100%) of DNA polymorphism. An unweighted pair group method with arithmetic mean dendrogram revealed that the 489B. bassianaisolates were heterogenic and polyphyletic and displayed typical regional distribution, although the genetic differentiations were not associated with geographic distance. The genetic differentiation (Gst) among populations reached 0.406, with the maximumGstbetween populations reaching 0.647. The general gene flow (Nm) was low at 0.366, with the lowest at only 0.137, suggesting that the low gene flow maintained a high degree of differentiation. These data indicated that the white muscardine in each local silkworm population was predominantly caused by a native group ofB. bassiana, rather than by any exotic strain as in the case of biological control based onB. bassianainsecticides. [ABSTRACT FROM AUTHOR]

The original Bacillus subtilis was isolated from the soil of an apple orchard, and B. subtilis strain BS80-6, selected from Bacillus subtilis by ion implantation , was used as an antagonist for postharvest biological control against apple anthracnose (colletotrichum gloeosporioides). The mechanisms of action and efficacy of Bacillus subtilis strain BS80-6 against apple anthracnose caused by colletotrichum gloeosporioides were studied in vitro and on apples in controlled and semi-commercial conditions. An application of cell suspension (108 cells per mL) of the antagonist in artificial wounds of apples reduced growth of C. gloeosporioides after storage at different temperatures. The inhibitory actions of cell culture to hyphal growth and to spores germination were 86.6% and 98.65% , respectively, and the control efficacy of cell culture against the disease was 60.34% at room temperature. The results showed that BS80-6 was more effective against apple anthracnose. The cell culture of BS80-6 received better control efficacy against apple anthracnose than culture filtrates and autoclaved cell. All treatments significantly inhibited the disease both in vitro and in vivo compared with control. Fruits treated with cell culture and stored at 10 °C had lower infection rate, more delayed formation of acervwlus and smaller lesion diameter than those stored at 20 °C. There was better control efficacy in fruits inoculated with spores after application of BS80-6. The mechanisms of BS80-6 activity appeared to involve production of an antifungal substance, deformation of hyphal cell and disintegration of cell wall. Besides, BS80-6 could improve the activity of major defense enzymes of apple, such as peroxidase (POD) and polyphenol oxidase (PPO). [ABSTRACT FROM AUTHOR]

ABSTRACT In order to resolve the problem that collusion attack on attribute-based encryption (ABE) with multi-authority, we firstly formulize user action of making request for key into legality and collusion by the relationship between user's attributes and decryption threshold. Furthermore, we propose an ABE scheme without presenting user's global ID (GID). In our first system, a trusted central authority assists each attribute authority (AA) to independently run a security check for users' requests, such that only legal users have power to decrypt a message. In order to prevent a malicious user from passing security check by submitting duplication request to AA, we improve the first system by our second system, where the same requests of different users are transformed into different ones associated with the subset of attributes indexes. Finally, in order to adapt this transformation to ABE, discrete Fourier transform and inverse discrete Fourier transform are used to share and recover secret key, respectively. As shown in the results of security and performance evaluation, our scheme not only improves user's privacy but also is more efficient than existing ABE schemes. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Based on the internal transcribed spacer and inter-simple sequence repeats (ISSR), the phylogenetic relationship and genetic diversity of Metarhizium spp., pathogens found in Chinese burrower bugs, Schiodtella formosana, were analyzed. The results showed that the causative agents of the epizootic green muscardine disease in populations of S. formosana were actually composed of M. anisopliae and its sister species, M. robertsii. The genetic structure of Metarhizium spp. populations were assessed using ten ISSR. A 3D principal component analysis of 51 isolates sampled on different occasions revealed that the Metarhizium spp. populations were temporally heterogeneous. They differentiated into two main clades including over 71 % of all strains causing epizootics, with a similarity of 83 %. The population differentiation was relatively low ( G, 0.2080), reflecting a large proportion of gene differentiation (79.2 %) within the populations. Further knowledge of the complex species and heterogeneous populations of Metarhizium spp. may be necessary for sustainable control methods of S. formosana. [ABSTRACT FROM AUTHOR]

Field survey of the entomopathogenic fungusBeauveria bassianain association with the red turpentine beetle,Dendroctonus valens, was undertaken in three pine plantations in Northern China. In total, 88 strains ofB. bassiana sensu latowere isolated from the soil, bark, beetle frass, living adult and cadaver samples and soil was proved to be an important inoculum reservoir for fungal entomopathogens. Of these, 77 isolates were included for genetic diversity analysis by PCR for inter-simple sequence repeats (ISSR). Genetic diversity and population structure analysis of the isolates from three sites and five niches demonstrated high genetic diversity and heterogeneity between and/or within populations. Wright's statistics revealed a high gene flow rate (4.529) among the three populations, especially among the soil-derived isolate subpopulations. Low variation was mainly caused (94.8%) by variation among different substrates, suggesting the importance of microhabitat substrates on genetic diversity ofB. bassiana. Phylogenetic variation was not associated with geographic distance. [ABSTRACT FROM AUTHOR]

The large-scale bucket foundation with 30 m in diameter and 6 m in height was used as the foundation of wind turbine. The wide-shallow foundation is different from the traditional bucket foundation with high ratio of height to diameter. The cover-load-bearing mode of the new type foundation can resist more external loadings. To achieve the bearing mode, the muddy soil inside the bucket should be reinforced, which will improve the soil strength and make the soil and foundation into a whole part to resist the external loadings. The vacuum and electro-osmotic soil reinforcing methods were used in the experiments. The results showed that the bearing behavior of the muddy soil were effectively improved by the negative pressure and electro-osmotic effect, and the improved muddy soil with better strength could work together with the bucket foundation, meaning that the top-cover bearing mode of the new bucket foundation was achieved. During the soil reinforcing process, the foundation moved downward, i.e., the settlement of foundation was almost finished during the pre-loading process caused by the vacuum and electro-osmotic method. [ABSTRACT FROM AUTHOR]

To improve the insecticidal efficacy of the entomopathogen Beauveria bassiana, the fungus was genetically modified with an insect-specific scorpion neurotoxin AAIT and an insect cuticle degrading protease PR1A from another insect pathogen ( Metarhizium anisopliae). The wild-type and the transformants were bioassayed against the larvae of Masson’s pine caterpillar Dendrolimus punctatus and the wax moth Galleria mellonella. In comparison to the wild-type strain, engineered isolates took fewer spores to kill 50% of pine caterpillars, 15-fold less for the aaIT single transformant Bb13T and eightfold less for the double transformant Bb13TPR1A, respectively. The median lethal times for Bb13T and Bb13TPR1A were reduced by 40% and 36.7%, respectively against D. punctatus and 24.4% and 20.9%, respectively against G. mellonella. Our data showed that the cotransformation of these two genes produced no synergistic effects on virulence improvement. It is evident from this study that AAIT could be degraded by the protease PR1A when they are expressed together, emphasizing that protein interactions need to be evaluated when working with multiple genes, particularly if they include proteases. [ABSTRACT FROM AUTHOR]

Three field experiments using cages were conducted in Anhui, China, to test the efficacy of entomopathogenic fungi against adult Asian longhorned beetles, Anoplophora glabripennis (Motschulsky). The use of two commercially available Beauveria spp. strains, Beauveria bassiana (Balsamo) Vuillemin and Beauveria brongniartii (Saccardo) Petch, applied as cultures in fiber bands fastened around tree trunks, was compared with trunk sprays in the first cage experiment. Longevity of A. glabripennis was decreased by both strains compared with controls, with females killed earlier by B. brongniartii than by B. bassiana. This decrease in longevity was independent of the application method used. In addition, oviposition scars per cage and daily oviposition rate per female were also reduced by both strains, showing a sublethal effect of the entomopathogens. After 10 d, conidial viability was still high on the bands but was drastically reduced when the strains were sprayed onto tree trunks. In the second cage experiment, four strains, proven to be highly pathogenic in the laboratory, were applied as bands alone. During the second cage experiment, daily temperatures were much higher and relative humidities were much lower than during the first cage experiment, and these conditions probably reduced fungal pathogenicity and decreased the sublethal oviposition reduction effect. It was demonstrated that one other B. bassiana strain and one Metarhizium anisopliae (Metchnikoff) Sorokin strain reduced male A. glabripennis longevity. None of the four strains tested had any significant effect on A. glabripennis when applied as 15-d-old bands in a third field experiment. [ABSTRACT FROM AUTHOR]

Summary Triplicate molecular methods, i.e. polymerase chain reaction-restriction fragment length polymorphism of the pr 1 gene, microsatellite markers and 28S rDNA haplotyping by detecting the presence or absence of group I introns, were used for population study of the entomopathogenic fungus, Beauveria bassiana . The findings showed that the average genetic diversity index of geographical populations was significantly smaller than that of populations derived from insect host orders, indicating that the genetic relatedness of B. bassiana strains was highly associated with geographical locality rather than insect host species. The reproductive style of all the B. bassiana populations was found to be non-clonal. Population structure analysis revealed that the average divergent coefficient among populations of B. bassiana was far below 1 (0.1112), which indicated that there was no significant genetic differentiation between populations, and that the overall genetic diversity mainly resulted from the genetic variations within geographical populations. Statistically, genetic distances between populations were positively correlated with geographical distances, suggesting that geographical separation poses an obstacle to the possibility and frequency of genetic exchanges between populations. On the other hand, gene flow was indirectly established to occur between B. bassiana populations. [ABSTRACT FROM AUTHOR]

The foundation of any network management systems is a database that contains information about the network resources relevant to the management tasks. A network information model is an abstraction of network resources, including both managed resources and managing resources. In the SNMP-based management framework, management information is defined almost exclusively from a “device” viewpoint, namely, managing a network is equivalent to managing a collection of individual nodes. Aiming at making use of recent advances in distributed computing and in object-oriented analysis and design, the Internet management architecture can also be based on the Open Distributed Processing Reference Model (RM-ODP). The purpose of this article is to provide an Internet Network Resource Information Model. First, a layered management information architecture will be discussed. Then the Internet network resource information model is presented. The information model is specified using Object-Z. [ABSTRACT FROM AUTHOR]

Describes the teleomorph of entomopathogenic fungus Beauveria bassiana. Discovery of the genus Beauveria; Physical characteristics; Type locality and host; Anatomic description.

An introduction is presented in which editor discusses various articles within issue on topics including distributions of soil entomopathogenic fungi Metarhizium, mycelia of Cordyceps species assessed by using fluorescence difference gel electrophoresis and mycelia of Ophiocordyceps formosana.

Isaria cicadae is one of the fungi used in traditional Chinese medicine with the longest tradition. It is used not only as a herbal medicine but also as a health food in Asia, together with cultured cordyceps and mycelia of the fungus used as substitute. However, the differences in their metabolite are unknown. Using a high‐performance liquid chromatography–mass spectrometry (HPLC–MS)‐based metabolomic method, we found that the fungus varies in its metabolism during growth on wild insects, artificially raised insects and artificial medium. There were 109 discriminatory metabolites detected in the samples by orthogonal projection to latent structure discriminant analysis and one‐way ANOVA. High level of nonribosomal peptides (NRPs) only existed in the insect portions of the wild cordyceps (WI) and cultured cordyceps (CI), revealing that immunostimulation of the host insects enhanced the synthesis of NRPs in the fungus. The finding of a significantly higher level of sphingolipids in both the insect portions (WI, CI) and the coremia of the wild cordyceps (WC) and cultured cordyceps (CC) but not in cultured mycelia (CM) of I. cicadae implies that the immunostimulation of the live insects can induce the fungus to produce more sphingolipids, and this enhanced ability is probably heritable. Apart from NRPs and sphingolipids, the insect portions also contained higher levels of bioactive compounds such as lateritin, anisomycin, streptimidone and ustiloxins. In contrast, the coremium groups (WC, CC) and CM contained 10‐fold less NRP but much higher levels of sanative metabolites such as tocotrienol, 3′‐deoxy‐hanasanagin, γ‐aminobutyric acid and phospholipids than the insect portions. The significantly higher content of antioxidants in WC, CC and CM than in WI and CI suggests that environmental oxygen has a significant effect on the metabolites. The temperature stress which the wild cordyceps encounters during growth is responsible for the relatively high content of trehalose. These findings indicate that the immunity of the host insect and growth environment have a strong impact on the metabolomic variation in Isaria cicadae. The variation in metabolites suggests differential utilization value for the insect portions, coremia and mycelia of the fungus. [ABSTRACT FROM AUTHOR]