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1.
Pathogenicity of Candida albicans is associated with its capacity switch from yeast-like to hyphal growth. The hyphal form is capable to penetrate the epithelial surfaces and to damage the host tissues. Therefore, many investigations have focused on mechanisms that control the morphological transitions of C. albicans. Recently, certain studies have showed that non-albicans Candida species can reduce the capacity of C. albicans to form biofilms and to develop candidiasis in animal models. Then, the objective of this study was to evaluate the effects of Candida krusei and Candida glabrata on the morphogenesis of C. albicans. Firstly, the capacity of reference and clinical strains of C. albicans in forming hyphae was tested in vitro. After that, the expression of HWP1 (hyphal wall protein 1) gene was determined by quantitative real-time PCR (polymerase chain reaction) assay. For both reference and clinical strains, a significant inhibition of the hyphae formation was observed when C. albicans was incubated in the presence of C. krusei or C. glabrata compared to the control group composed only by C. albicans. In addition, the culture mixed of C. albicans-C. krusei or C. albicans-C. glabrata reduced significantly the expression of HWP1 gene of C. albicans in relation to single cultures of this specie. In both filamentation and gene expression assays, C. krusei showed the higher inhibitory activity on the morphogenesis of C. albicans compared to C. glabrata. C. krusei and C. glabrata are capable to reduce the filamentation of C. albicans and consequently decrease the expression of the HWP1 gene.  相似文献   

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In this contribution on the genus Cantharellus in Asia, C. subvaginatus is described from the Republic of Korea as a close relative to the Chinese C. vaginatus, which is here reported for the first time from India. Both species are here placed in Cantharellus subg. Cantharellus sect. Amethystini, together with the Indian C. pseudoformosus (syn.: C. umbonatus) and the Malayan C. subamethysteus. As such, Asia has suddenly become the continent with the highest diversity for Amethystini. Species delimitation in sect. Amethystini is molecularly supported by a combined phylogenetic analysis of rDNA sequences obtained for LSU and ITS and additionally suggests the existence of a still undescribed species in North America. Character variability is discussed for all known members of Amethystini, including atypical specimens of the North American C. lewisii that are morphologically more reminiscent of the South Korean C. subvaginatus.  相似文献   

5.
During a study on the biodiversity of yeasts and yeast-like ascomycetes from wild plants in Iran, four strains of yeast-like filamentous fungi were isolated from a healthy plant of Euphorbia polycaulis in the Qom Province, Iran (IR. of). All four strains formed small hyaline one-celled conidia from integrated conidiogenous cells directly on hyphae and sometimes on discrete phialides, as well as by microcyclic conidiation. Two strains additionally produced conidia in conidiomata that open by rupture. The internal transcribed spacer (ITS) sequences suggested the placement of these strains in the genera Collophorina (Leotiomycetes) and Coniochaeta (Sordariomycetes), respectively. Blast search results on NCBI GenBank and phylogenetic analyses of ITS, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the translation elongation factor 1α (EF-1α) sequences, and the nuclear large subunit ribosomal gene (LSU), partial actin (ACT), and β-tubulin (TUB) sequences, respectively, revealed the isolates to belong to three new species, that are described here as Collophorina euphorbiae, Coniochaeta iranica, and C. euphorbiae. All three species are characterised by morphological, physiological, and molecular data.  相似文献   

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Elaphoglossum mickeliorum, a new species from the eastern slopes of the Peruvian Andes, is here described and illustrated. It belongs to E. sect. Polytrichia, which is characterized by the presence of subulate scales and absence of hydathodes on the sterile leaves of adult sporophytes. Herbarium specimens of this new species were first collected by Alwyn H. Gentry ca. 40 years ago, but these got readily confused with E. erinaceum and went undescribed since then. The new species differs from members of the E. erinaceum complex by having a nearly continuous band of planar, nonsubulate scales along the laminar margins of sterile leaves. Based on this character, E. mickeliorum resembles species such as E. glaziovii, E. ornatum, and E. scolopendrifolium. It differs from these by the presence of minute glandular hairs on petioles and costae. A distribution map and a figure with line drawings are also provided. For comparative purposes, the line drawing includes E. blepharoglottis, which is here illustrated for the first time.  相似文献   

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Phylogenetic analyses based on protein-encoding gene exons and introns of ATP citrate lyase (ACL1), beta tubulin (TUB), the largest subunit of RNA polymerase II (RPB1), and translation elongation factor 1-α (TEF1) are used for inferring the existence of a new Clonostachys species from the Cerrado biome in Brazil, described here as C. chloroleuca. The species produces dimorphic, primary, and secondary conidiophores that form consistently greenish conidial masses on artificial media. It resembles therefore C. rosea f. catenulata although it differs from this species by less adpressed branches in the secondary conidiophores. The new species is also phylogenetically related to C. byssicola and C. rhizophaga. Our inventory suggests that C. byssicola, C. chloroleuca, C. pseudochroleuca, C. rhizophaga, C. rogersoniana, and C. rosea commonly occur in native and agriculturally used soils of the Cerrado and Amazon Forest. Using sequences available from two genome-sequenced strains employed as biological control agents, we confirm the identity of the European strain IK726 as C. rosea and identify strain 67-1 from China as C. chloroleuca.  相似文献   

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Heavy metal contamination represents an important environmental issue due to the toxic effects of metals on different organisms. Filamentous fungi play an important impact in the bioremediation of heavy metal-contaminated wastewater and soil. The purpose of this investigation was to observe fungal uptake behavior toward heavy metal. For this aim Trichoderma asperellum TS141 and T. harzianum TS103 at growth period were screened for their tolerance and uptake capability of cadmium (Cd), lead (Pb) and nickel (Ni) at different concentrations (0, 25, 50, 100, and 200 mg/L) in PDB media (potato dextrose broth as a complex medium). Results showed that both fungi were able to survive at the maximum concentration of 200 mg/L of the heavy metals, and remove them. T. asperellum had a better uptake capacity for Cd compared to Pb and Ni in the highest metal concentration in media. Maximum removal efficiency of Pb (68.4%) at 100 mg/L and Ni (78%) at 200 mg/L was performed by T. asperellum. For Cd, the highest removal efficiency (82.1%) was recorded by T. harzianum at 200 mg/L Cd in aqueous solution. The uptake of Cd was highly dependent on pH of solution than Pb and Ni so that the optimal pH of Cd uptake was 9 for T. asperellum and 4 for T. harzianum. Also, optimal temperature was 35°C for Cd and Pb uptake in both fungi, whereas for Ni uptake was 30 and 35°C in T. harzianum and T. asperellum, respectively. We propose that T. asperellum TS141 and T. harzianum TS103 can be used as a bioremediation agent for metal remediation from wastewater and heavy metal-contaminated soils.  相似文献   

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Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.  相似文献   

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Nucleotide and amino acid sequences of Corynebacterium glutamicum recA genes, from GenBank, were compared in silico. On the basis of the identity found between sequences, two degenerate primers were designed on the two sides of the deduced open reading frame (ORF) of the recA gene. PCR experiments, for amplifying the recA ORF region, were done. pGEM®-T Easy vector was selected to be used for cloning PCR products. Then recA ORF was placed under the control of Escherichia coli hybrid trc promoter, in pKK388-1 vector. pKK388-1 vector, containing recA ORF, was transformed to E. coli DH5α ΔrecA (recombinant deficient strain), in an attempt to phenotypically complement it. Ultraviolet (u.v.) exposure experiments of the transformed and non-transformed E. coli DH5α ΔrecA cells revealed tolerance of transformed cells up to dose 0.24 J/cm2, while non-transformed cells tolerated only up to dose 0.08 J/cm2. It is concluded that phenotypic complementation of E. coli DH5α ΔrecA with recA ORF of C. glutamicum, could be achieved and RecA activity could be restored.  相似文献   

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Here we evaluate the origins and relationships of Mexican and Central American Diplazium hybrids derived from crosses involving either D. plantaginifolium or D. ternatum. Based on study of live plants and herbarium specimens, we distinguish D. ×verapax from the similar D. riedelianum and present evidence that the former is a sterile hybrid derived from a cross between D. plantaginifolium and D. werckleanum. We also describe new hybrids, D. ×torresianum and D. ×subternatum from Mexico and northern Central America. Both involve D. ternatum as one parent. Diplazium. cristatum is the other putative parent of D. ×torresianum, and D. plantaginifolium is the second parent of D. ×subternatum. We also designate lectotypes for D. cordovense and D. dissimile.  相似文献   

14.
Boletus edulis Bull. is one of the most economically and gastronomically valuable fungi worldwide. Sporocarp production normally occurs when symbiotically associated with a number of tree species in stands over 40 years old, but it has also been reported in 3-year-old Cistus ladanifer L. shrubs. Efforts toward the domestication of B. edulis have thus focused on successfully generating C. ladanifer seedlings associated with B. edulis under controlled conditions. Microorganisms have an important role mediating mycorrhizal symbiosis, such as some bacteria species which enhance mycorrhiza formation (mycorrhiza helper bacteria). Thus, in this study, we explored the effect that mycorrhiza helper bacteria have on the efficiency and intensity of the ectomycorrhizal symbiosis between C. ladanifer and B. edulis. The aim of this work was to optimize an in vitro protocol for the mycorrhizal synthesis of B. edulis with C. ladanifer by testing the effects of fungal culture time and coinoculation with the helper bacteria Pseudomonas fluorescens Migula. The results confirmed successful mycorrhizal synthesis between C. ladanifer and B. edulis. Coinoculation of B. edulis with P. fluorescens doubled within-plant mycorrhization levels although it did not result in an increased number of seedlings colonized with B. edulis mycorrhizae. B. edulis mycelium culture time also increased mycorrhization levels but not the presence of mycorrhizae. These findings bring us closer to controlled B. edulis sporocarp production in plantations.  相似文献   

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TC1/Mariner transposons belong to class II transposable elements (TEs) that use DNA-mediated “cut and paste” mechanism to transpose, and they have been identified in almost all organisms. Although silkworm (Bombyx mori) has a large amount of TC1/Mariner elements, the genome wide information of this superfamily in the silkworm is unknown. In this study, we have identified 2670 TC1/Mariner (Bmmar) elements in the silkworm genome. All the TEs were classified into 22 families by means of fgclust, a tool of repetitive sequence classification, seven of which was first reported in this study. Phylogenetic and structure analyses based on the catalytic domain (DDxD/E) of transposase sequences indicated that all members of TC1/Mariner were grouped into five subgroups: Mariner, Tc1, maT, DD40D and DD41D/E. Of these five subgroups, maT rather than Mariner possessed most members of TC1/Mariner (51.23%) in the silkworm genome. In particular, phylogenetic analysis and structure analysis revealed that Bmmar15 (DD40D) formed a new basal subgroup of TC1/Mariner element in insects, which was referred to as bmori. Furthermore, we concluded that DD40D appeared to intermediate between mariner and Tc1. Finally, we estimated the insertion time for each copy of TC1/Mariner in the silkworm and found that most of members were dramatically amplified during a period from 0 to 1 mya. Moreover, the detailed functional data analysis showed that Bmmar1, Bmmar6 and Bmmar9 had EST evidence and intact transposases. These implied that TC1/Mariner might have potential transpositional activity. In conclusion, this study provides some new insights into the landscape, origin and evolution of TC1/Mariner in the insect genomes.  相似文献   

16.
Three species of cecidomyiid midges (Diptera: Cecidomyiidae), whose larvae overwinter in the soil, can cause significant yield losses on wheat in Europe: the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), the yellow wheat blossom midge, Contarinia tritici (Kirby), and the saddle gall midge, Haplodiplosis marginata (von Roser). The biological control of wheat midges by their parasitoids can contribute to reduce the midge populations. Soil samples were collected in several fields in Belgium in 2012–2014 in order to characterize the parasitism rates and parasitoid complexes in overwintering larvae. The parasitism rates varied greatly between the sampled fields: 3–100, 0–100 and 2% for S. mosellana, H. marginata and C. tritici, respectively. The parasitism rate was not related to the larval density of wheat midge. The three wheat midges have totally distinct parasitoid complexes in Belgium. Eight species (Hymenoptera: Pteromalidae and Platygastridae) were found as parasitoid of S. mosellana: Macroglenes penetrans (Kirby), Amblypasis tritici (Walker), Euxestonotus error (Fitch), Euxestonutus sp. Fouts, Leptacis sp. Foerster, Platygaster gracilipes (Huggert), Platygaster nisus Walker, and Platygaster tuberosula (Kieffer). According to their abundance, M. penetrans, E. error and P. tuberosula appeared as the main parasitoids of S. mosellana in Belgium. For the two other wheat midges, only one species of the family Platygastridae was found for each midge: Platygaster equestris (Spittler) for H. marginata and Synopeas myles (Walker) for C. tritici.  相似文献   

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In this article, we compared the resistance of two introduced populations of Elodea nuttallii and Elodea canadensis to two different herbivores. Samples were collected from the River Rhine and River Rhône in eastern France. The two populations of E. nuttallii differed in their introduction history, whereas E. canadensis was introduced at the same time in the two sites. The Daily Food Consumption (DFC) rates of the two macrophyte populations were evaluated in no-choice experiments using the scraper Lymnaea stagnalis and the shredder Gammarus roeseli. At the same time, we assessed four plant traits: dry matter content (DMC), total nitrogen content, carbon/nitrogen ratio and total phenolic content. The two populations of E. canadensis were consumed at low levels by both the herbivores. L. stagnalis showed a higher DFC on the Rhône population of E. nuttallii than on the Rhine population. No significant difference between the two populations was established with G. roeseli, but the level of DFC was high. This result demonstrates that the assessment of plant palatability should be carried out with several generalist herbivores belonging to various feeding groups (e.g. scrapers or shredders). Although the Rhône population of E. nuttallii had higher levels of phenols than the other populations, it was consistently consumed in greater quantities than E. canadensis. Neither the phenolic contents were not effective against these herbivores, nor the levels of phenolics too low to induce an efficient resistance. The higher DMC and the lower DFC of the two populations of E. canadensis suggest that this introduced plant has co-evolved with indigenous enemies in the introduced range.  相似文献   

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Seven non-basidiomycetic fungi, Aspergillus, Candida, Cladosporium, Fusarium, Monicillium, Trichoderma and Penicillium, and two basidiomycetic fungi, Pleurotus and Phanerochaete were isolated from a creosote-contaminated soil by using mineral salts medium and soil extract broth containing antibiotics. Soil contaminated with phenol, o-cresol, m-cresol and p-cresol was collected from the yard of a wood treatment plant in South Africa and inoculated with the strains of Aspergillus, Cladosporium, Fusarium, Monicillium, Penicillium and Phanerochaete, selected from the isolate. The soil in some of the treatment reactors was amended with nutrient supplements to give a C:N:P ratio of 25:5:1. A total of 18 duplicate treatments were established and incubated in the dark at 25°C for 70days. The soil in all the reactors was tilled weekly and moisture was maintained at 70% field capacity. Soil samples were collected every 2weeks for analysis of residual concentrations of the phenols tested, pH measurement and moisture content determination. The nutrient-supplemented treatments were more effective in degrading the phenols (between 84 and 100%) than those that were not supplemented. Barley, which was used as bulking agent enhanced the growth of the fungi and subsequently the degradation of the phenols. Inoculation with a mixture of the six fungal isolates promoted more phenol degradation than with single isolates.  相似文献   

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Using bioinformatics analysis, the homologs of genes Sr33 and Sr35 were identified in the genomes of Triticum aestivum, Hordeum vulgare, and Triticum urartu. It is known that these genes confer resistance to highly virulent wheat stem rust races (Ug99). To identify amino acid sites important for this resistance, the found homologs were compared with the Sr33 and Sr35 protein sequences. It was found that sequences S5DMA6 and E9P785 are the closest homologs of protein RGAle, a Sr33 gene product, and sequences M7YFA9 (CNL-C) and F2E9R2 are homologs of protein CNL9, a Sr35 gene product. It is assumed that the homologs of genes Sr33 and Sr35, which were obtained from the wild relatives of wheat and barley, can confer resistance to various forms of stem rust and can be used in the future breeding programs aimed at improvement of national wheat varieties.  相似文献   

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The yajC gene (Lbuc_0921) from Lactobacillus buchneri NRRL B-30929 was identified from previous proteomics analyses in response to ethanol treatment. The YajC protein expression was increased by 15-fold in response to 10 % ethanol vs 0 % ethanol. The yajC gene encodes the smaller subunit of the preprotein translocase complex, which interacts with membrane protein SecD and SecF to coordinate protein transport and secretion across cytoplasmic membrane in Escherichia coli. The YajC protein was linked to sensitivity to growth temperatures in E. coli, involved in translocation of virulence factors during Listeria infection, and stimulating a T cell-mediated response of Brucella abortus. In this study, the L. buchneri yajC gene was over-expressed in E. coli. The strain carrying pET28byajC that produces YajC after isopropyl β-d-1-thiogalactopyranoside induction showed tolerance to 4 % ethanol in growth media, compared to the control carrying pET28b. This is the first report linking YajC to ethanol stress and tolerance.  相似文献   

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