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1.
J Basic Microbiol ; 59(6): 645-657, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30900744

RESUMO

This study aims to investigate the molecular phylogenetic analysis, morphological variability, nematode-capturing ability, and other biological properties of Chinese Duddingtonia flagrans isolates. We isolated 13 isolates of D. flagrans and found features that have never been reported before, such as two to three septa incluing club-shaped conidia. Meanwhile, we conducted molecular phylogenetic analysis of the seven isolates and tested the radical growth of the isolates under different pH values, temperatures, and media. The capturing ability against infective larvae (L3) of Cooperia spp. in yak was detected in vitro. Finally, one isolate was selected for scanning electron microscopy (SEM) to investigate the trap formation process. The fungal sequence was obtained and submitted to GenBank (Accession no. KY288614.1, KU881774.1, KP257593.1, KY419119.1, MF488979.1, MF488980.1, and MF488981.1), and the tested isolates were identified as D. flagrans. Except for three isolates, the radial growth of the other isolates on 2% corn meal agar and 2% water agar exhibited faster growth than on other media. The fungus could not grow at 10 and 40°C but grew within 11 to 30°C. Moreover, it did not grow at pH 1-3 and 13-14, but instead at pH 4-12. In the in vitro experimental, L3s were reduced by 94.36%, 88.15%, and 91.04% for SDH035, DH055, and F088, respectively. SEM results showed that at 8 hr post addition of nematodes, some of the latter were captured. In the later stages of the interaction of the fungus with nematodes, a large number of chlamydospores were produced, especially on the predation trap. Results of the present study provided information about the molecular phylogenetic analysis, morphological variability, nematode-capturing ability, and other biological properties of Chinese Arthrobotrys flagrans isolates before administering them for biocontrol.


Assuntos
Duddingtonia/classificação , Duddingtonia/fisiologia , Interações Hospedeiro-Patógeno , Filogenia , Trichostrongyloidea/microbiologia , Animais , Bovinos , DNA Fúngico/genética , DNA Ribossômico/genética , Duddingtonia/ultraestrutura , Fezes/parasitologia , Concentração de Íons de Hidrogênio , Larva/microbiologia , Microscopia Eletrônica de Varredura , Controle Biológico de Vetores , Análise de Sequência de DNA , Esporos Fúngicos/classificação , Esporos Fúngicos/fisiologia , Esporos Fúngicos/ultraestrutura , Temperatura
2.
Structure ; 27(4): 631-638.e8, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30773398

RESUMO

Histone methylation by histone methyltransferases (HMTases) has a key role in transcriptional regulation. Discrepancies between the known HMTases and the histone lysine methylome suggest that HMTases remain to be identified. Here we report the discovery, characterization, and crystal structure of Schizosaccharomyces pombe Set7, an HMTase methylating the uncharted histone H3 lysine 37 (H3K37) mark. Set7 forms a dimer with its substrate-binding site structurally specific to K37, not the neighboring well-studied K36 mark. We also discovered that H3K37 methylation levels dramatically increase during gametogenesis. Set7 deletion mutant cells show defects in gametogenesis and produce the abnormal number of spores with aberrant morphology. S. pombe gametogenesis shares similarities with mammalian spermatogenesis. These findings extend our understanding of epigenetic regulation during gametogenesis and support a link between Set7, the epigenetic H3K37 methyl mark, and proper gametogenesis.


Assuntos
Gametogênese/genética , Histona-Lisina N-Metiltransferase/genética , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Schizosaccharomyces pombe/genética , Schizosaccharomyces/genética , Sequência de Aminoácidos , Epigênese Genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/genética , Metilação , Modelos Moleculares , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Schizosaccharomyces/crescimento & desenvolvimento , Schizosaccharomyces/metabolismo , Schizosaccharomyces/ultraestrutura , Proteínas de Schizosaccharomyces pombe/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Esporos Fúngicos/ultraestrutura
3.
Fungal Biol ; 123(2): 109-116, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30709516

RESUMO

This study reconstructs early stages of Rozella allomycis endoparasitic infection of its host, Allomyces macrogynus. Young thalli of A. macrogynus were inoculated with suspensions of R. allomycis zoospores and allowed to develop for 120 h. Infected thalli at intervals were fixed for electron microscopy and observed. Zoospores were attracted to host thalli, encysted on their surfaces, and penetrated their walls with an infection tube. The parasite cyst discharged its protoplast through an infection tube, which invaginated the host plasma membrane. The host plasma membrane then surrounded the parasite protoplast and formed a compartment confining it inside host cytoplasm. The earliest host-parasite interface within host cytoplasm consisted of two membranes, the outer layer the host plasma membrane and the inner layer the parasite plasma membrane. At first a wide space separated the two membranes and no material was observed within this space. Later, as the endoparasite thallus expanded within the compartment, the two membranes became closely appressed. As the endoparasite thallus continued to enlarge, the interface developed into three membrane layers. Thus, host plasma membrane surrounded the parasite protoplast initially without the parasite having to pierce the host plasma membrane for entry. Significantly, host-derived membrane was at the interface throughout development.


Assuntos
Allomyces/ultraestrutura , Fungos/ultraestrutura , Interações Hospedeiro-Parasita/fisiologia , Microscopia Eletrônica/métodos , Esporos Fúngicos/ultraestrutura , Membrana Celular/ultraestrutura
4.
Proc Natl Acad Sci U S A ; 116(11): 4917-4922, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30804195

RESUMO

Raindrop impact on infected plants can disperse micron-sized propagules of plant pathogens (e.g., spores of fungi). Little is known about the mechanism of how plant pathogens are liberated and transported due to raindrop impact. We used high-speed photography to observe thousands of dry-dispersed spores of the rust fungus Puccinia triticina being liberated from infected wheat plants following the impact of a single raindrop. We revealed that an air vortex ring was formed during the raindrop impact and carried the dry-dispersed spores away from the surface of the host plant. The maximum height and travel distance of the airborne spores increased with the aid of the air vortex. This unique mechanism of vortex-induced dispersal dynamics was characterized to predict trajectories of spores. Finally, we found that the spores transported by the air vortex can reach beyond the laminar boundary layer of leaves, which would enable the long-distance transport of plant pathogens through the atmosphere.


Assuntos
Interações Hospedeiro-Patógeno/fisiologia , Chuva , Triticum/microbiologia , Ar , Basidiomycota/fisiologia , Microesferas , Modelos Teóricos , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Esporos Fúngicos/fisiologia , Esporos Fúngicos/ultraestrutura , Triticum/ultraestrutura
5.
PLoS One ; 14(1): e0210754, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30699153

RESUMO

Advanced air quality control requires real-time monitoring of particulate matter size and concentration, which can only be done using optical instruments. However, such techniques need regular calibration with reference samples. In this study, we suggest that puffball fungus (Lycoperdon pyriforme) spores can be utilized as a reference standard having a monodisperse size distribution. We compare the Lycoperdon pyriforme spores with the other commonly used reference samples, such as Al2O3 powder and polystyrene latex (PSL) microspheres. Here we demonstrate that the puffball spores do not coagulate and, thus, maintain the same particle size in the aerosol state for at least 15 minutes, which is enough for instrument calibration. Moreover, the puffball mushrooms can be stored for several years and no agglomeration of the spores occurs. They are also much cheaper than other calibration samples and no additional devices are needed for aerosol generation since the fungal fruiting body acts as an atomizer itself. The aforementioned features make the fungal spores a highly promising substance for calibration and validation of particle size analyzers, which outperforms the existing, artificially produced particles for aerosol sampling. Furthermore, the L. pyriforme spores are convenient for basic research and development of new optical measurement techniques, taking into account their uniform particle size and absent coagulation in the aerosol.


Assuntos
Agaricales/ultraestrutura , Dispositivos Ópticos/normas , Esporos Fúngicos/ultraestrutura , Aerossóis , Poluição do Ar/análise , Calibragem , Humanos , Microscopia Eletrônica de Varredura , Dispositivos Ópticos/estatística & dados numéricos , Tamanho da Partícula , Material Particulado/análise , Padrões de Referência
6.
Mycologia ; 110(6): 1205-1221, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30513277

RESUMO

Morphological and molecular phylogenetic studies of true morels (Morchella) in North America, the Dominican Republic, Venezuela, Ecuador, and Peru led to the discovery of four undescribed species of Morchella. Two new species in the Elata clade, one from the Dominican Republic, initially distinguished by the informal designation Mel-18, and a newly discovered sister species from northern Arizona, are now recognized. Mel-18 is described as a novel phylogenetically distinct species, M. hispaniolensis. Its sister species from Arizona is described as M. kaibabensis, also recovered as an endophyte of Rocky Mountain juniper. Two additional species in the Esculenta clade, M. peruviana discovered in Peru and M. gracilis (previously reported as Mes-14) from the Dominican Republic, Venezuela, and Ecuador, are described as new. We also demonstrate that scanning electron microscopy (SEM) imaging of ascospores using rehydration/dehydration/critical point drying preparation techniques provides for enhanced resolution of spore wall surfaces, thereby increasing the number of morphological traits available to assess differences among otherwise closely related species.


Assuntos
Ascomicetos/classificação , Filogenia , América , Arizona , Ascomicetos/isolamento & purificação , DNA Fúngico/genética , DNA Ribossômico/genética , Equador , Microscopia Eletrônica de Varredura , Técnicas de Tipagem Micológica , Peru , Fenótipo , Análise de Sequência de DNA , Esporos Fúngicos/ultraestrutura , Venezuela
7.
Sci Rep ; 8(1): 16278, 2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30390022

RESUMO

Efficient, fast and new micro-analytical methods for characterization of ultrastructures of fungal spores with electron microscopy are very much required and essential. SEM analysis of biological materials, especially fungi, requires optimal preparation of the specimen and often requires the usage of dried samples which demands a challenging sample preparation. In the present investigation, we described a fast and improved method for the preparation of fungal specimen for scanning electron microscopy (SEM). The fungus, Curvularia lunata was grown on the surface of sterile Whatman No.1 filter paper which was overlaid on Potato Dextrose Agar (PDA) medium, gold coated immediately after removal from the growth medium and subjected to imaging. Generally, SEM imaging is done with samples that were fixed with chemical fixatives, dehydrated and gold coated specimens, but here we describe an easy and more efficient sample preparation for SEM which enabled enhanced image quality and precision visualization of fungal cells, especially the spores. The developed method has enabled the analysis of even the robust samples like fungal spores that to eliminating special temperature requirement. The ultimate goal was to develop an improved protocol/method applied to analysis of fungal spores with greater coverage about fungal specimen preparation. This method permits the use of rapid sample preparation and will allow us to imaging of individual spore or conidia structures in the context of fungal cell architecture which clarifies our understanding in fungal taxonomy/biology.


Assuntos
Fungos/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Manejo de Espécimes/métodos , Esporos Fúngicos/ultraestrutura , Fungos/classificação , Fungos/citologia , Reprodutibilidade dos Testes
8.
Fungal Biol ; 122(12): 1171-1183, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30449355

RESUMO

The purpose of our research is to investigate the morphology, zoospore ultrastructure, and molecular phylogenetic placement of a chytrid from Australia. From a survey of chytrid fungi in New South Wales, Australia, we isolated strain PL AUS 026 and putatively identified it as Polyphlyctis unispina. Light microscopic evaluation determined strain PL AUS 026 to be similar to two other strains of P. unispina characterized in the literature but to have a more complex thallus than that of the type. Molecular phylogenetic analyses placed our strain as sister of or basal to Chytridiaceae, Chytridiales. Ultrastructural analysis of the zoospore of strain PL AUS 026 revealed unique features. On the basis of our analyses we designate strain PL AUS 026 as a new species, Polyphlyctis willoughbyi. This research extends our concept of Chytridiaceae systematics and ultrastructural variation in the Chytridiales zoospore.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/citologia , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Quitridiomicetos/genética , Quitridiomicetos/ultraestrutura , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Microscopia , Microscopia Eletrônica de Transmissão , New South Wales , RNA Fúngico/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Esporos Fúngicos/genética , Esporos Fúngicos/ultraestrutura
9.
Mem Inst Oswaldo Cruz ; 113(10): e180311, 2018 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-30304087

RESUMO

BACKGROUND: Scedosporium apiospermum is a ubiquitous, emerging and multidrug-resistant fungal pathogen with still rather unknown virulence mechanisms. OBJECTIVES/METHODS: The cellular basis of the in vitro interaction between fungi and host cells/tissues is the determinant factor for the development of a successful in vivo infection. Herein, we evaluated the interaction of S. apiospermum conidia with lung epithelial (A549), lung fibroblast (MRC-5) and RAW 264.7 macrophages by light and scanning/transmission electron microscopy. FINDINGS: After 4 h of fungi-host cell contact, the percentage of infected mammalian cells and the number of fungi per infected cell was measured by light microscopy, and the following association indexes were calculated for A549, MRC-5 and macrophage cells: 73.2 ± 25.9, 69.7 ± 22.5 and 59.7 ± 11.1, respectively. Both conidia and germinated conidia were regularly observed interacting with the evaluated cells, with a higher prevalence of non-germinated conidia. Interestingly, nests of germinated conidia were evidenced at the surface of lung cells by scanning electron microscopy. Some germination projections and hyphae were seen penetrating/evading the mammalian cells. Furthermore, internalised conidia were seen within vacuoles as visualised by transmission electron microscopy. MAIN CONCLUSIONS: The present study contributes to a better understanding of S. apiospermum pathogenesis by demonstrating the first steps of the infection process of this opportunistic fungus.


Assuntos
Células Epiteliais/microbiologia , Pulmão/microbiologia , Macrófagos/microbiologia , Scedosporium/ultraestrutura , Esporos Fúngicos/ultraestrutura , Células Epiteliais/ultraestrutura , Humanos , Pulmão/ultraestrutura , Macrófagos/ultraestrutura , Microscopia Eletrônica de Varredura , Scedosporium/fisiologia , Esporos Fúngicos/fisiologia
10.
Fungal Biol ; 122(11): 1041-1049, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30342620

RESUMO

While surveying chytrid diversity in lakes and streams, we found on cellulosic bait a chytrid that had both monocentric and polycentric thallus forms. We brought this chytrid into axenic culture from three sites in eastern North America, studied its thallus development and zoospore ultrastructure, and compared its 28S rDNA sequence with those of other members of the Chytridiomycota. Thallus morphology matched that described for the rare chytrid, Cladochytrium polystomum Zopf. Sporangia were spherical and produced numerous long discharge tubes. After discharge, zoospores remained in spherical clusters at the tips of the inoperculate openings of discharge tubes. After 10-30 min zoospores either swam away or encysted in place. Zoospore ultrastructural features included a cell coat, flagellar plug, and paracrystalline inclusion, features typical of members of the Chytridiales. However, the flagellar apparatus structure and organellar organization differed from that of zoospores previously described. Based on its molecular phylogeny and its zoospore ultrastructural features, we classify C. polystomum as a member of the Chytridiaceae in the Chytridiales. Because its thallus development and its ribosomal DNA sequences diverged decidedly from those of Cladochytrium tenue Nowak, the type species of Cladochytrium, we erected Zopfochytrium as a new genus for this chytrid.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/isolamento & purificação , Esporos Fúngicos/ultraestrutura , Quitridiomicetos/genética , Quitridiomicetos/ultraestrutura , Lagos/microbiologia , Microscopia Eletrônica de Transmissão , Filogenia , Rios/microbiologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
11.
Fungal Biol ; 122(11): 1109-1123, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30342626

RESUMO

The purpose of our research is to investigate morphology, zoospore ultrastructure, and molecular placement of six strains in the Asterophlyctis (Chytridiales) lineage. In previous molecular analyses strain JEL 186, putatively Asterophlyctis sarcoptoides, placed as basal in family Chytriomycetaceae. Recent sampling for chytrids resulted in isolation of five strains (WJD 209, MP 058, JEL 524, JEL 857, and JEL 885) molecularly related to strain JEL 186. Our morphological evaluations reveal that strains JEL 186 and WJD 209 are members of Asterophlyctis. Strain WJD 209 is considered representative of the type, A. sarcoptoides, and strain JEL 186 a new species, Asterophlyctis michiganensis. The four strains MP 058, JEL 524, JEL 857, and JEL 885 are distinct from Asterophlyctis, and we consider them as members of a new genus, Wheelerophlyctis, composed of two species, Wheelerophlyctis interior and Wheelerophlyctis interiexterior. Asterophlyctis and Wheelerophlyctis are sister taxa and we demarcate that lineage as Asterophlyctaceae. The two genera also have similar zoospore ultrastructure, which is unique among strains in Chytridiales. In consideration of their molecular position and zoospore ultrastructure, we hypothesize that Asterophlyctis and Wheelerophlyctis represent a bridge between Chytriomycetaceae and Chytridiaceae. This research expands our concepts of systematics and zoospore ultrastructural variation in Chytridiales.


Assuntos
Quitridiomicetos/crescimento & desenvolvimento , Quitridiomicetos/isolamento & purificação , Esporos Fúngicos/ultraestrutura , Quitridiomicetos/classificação , Quitridiomicetos/genética , DNA Fúngico/genética , DNA Ribossômico/genética , Água Doce/microbiologia , Microscopia Eletrônica de Transmissão , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
12.
Mycologia ; 110(4): 771-779, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30207872

RESUMO

Four new species, Tuber crassitunicatum, T. lishanense, T. piceatum, and T. wanglangense, are described and illustrated based on both morphological and molecular data. Morphologically, T. crassitunicatum is diagnosed by its brown ascomata and ellipsoidal ascospores ornamented by crowded spiny reticulum with more than 10 meshes across the spore width. Tuber lishanense can be recognized by its whitish to pale brown ascomata with a basal cavity, and very broadly ellipsoidal to subglobose ascospores ornamented by densely isolated spines. Tuber piceatum differs in its pale white ascomata and ellipsoidal ascospores with isolated spines, whereas T. wanglangense is characterized by its broad ellipsoidal ascospores with short spines that are connected by lower ridges when examined under scanning electron microscope (SEM). Phylogenetic analyses inferred the four new species in the Rufum group. Each species had less than 96% similarity in the internal transcribed spacer (ITS1-5.8S-ITS2) nuc rDNA ITS sequence to other Tuber species and represented a unique terminal clade in the phylogenetic tree. Our research did not confirm the occurrence in China of the European T. rufum and T. nitidum and the North American T. lyonii, although they are often reported in the literature on Chinese Tuber species.


Assuntos
Ascomicetos/classificação , Ascomicetos/genética , Filogenia , Ascomicetos/isolamento & purificação , Ascomicetos/ultraestrutura , China , DNA Fúngico/genética , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Análise de Sequência de DNA , Especificidade da Espécie , Esporos Fúngicos/classificação , Esporos Fúngicos/ultraestrutura
13.
Mycologia ; 110(5): 948-961, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30240340

RESUMO

Species of Laccaria (Hydnangiaceae, Basidiomycota) are important in forest ecosystems as ectomycorrhizal fungi. Nine of the 75 described Laccaria species worldwide been reported from Korea. Most of these have European and North American names, and their identities are based solely on morphological features. To evaluate the taxonomy of Korean Laccaria, we used 443 specimens collected between 1981 and 2016 in a phylogenetic analysis based on sequence data from nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 rDNA (ITS) region, nuc 28S rDNA (28S), RNA polymerase II subunit 2 (rpb2), and translation elongation factor 1-α (tef1). Ten Laccaria species were identified. Three of these were previously reported from Korea: L. bicolor, L. tortilis, and L. vinaceoavellanea. Laccaria alba, L. japonica, and L. murina are confirmed as new reports from Korea. Lastly, four new Laccaria species are described: L. araneosa, L. parva, L. torosa, and L. versiforma. This study supports the general contention that Asian species of ectomycorrhizal fungi may not be conspecific with morphologically similar species from Europe and North America. Furthermore, identification based on morphology alone is often unreliable in Laccaria due to considerable overlap of characters among species. Thus, use of molecular methods is necessary for effective identification. Illustrations of the four newly described species and a taxonomic key to species of Laccaria in Korea are provided.


Assuntos
Carpóforos/crescimento & desenvolvimento , Laccaria/classificação , Micorrizas/classificação , Filogenia , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Coreia (Geográfico) , Laccaria/citologia , Laccaria/genética , Laccaria/crescimento & desenvolvimento , Microscopia , Microscopia Eletrônica de Varredura , Micorrizas/citologia , Micorrizas/genética , Micorrizas/crescimento & desenvolvimento , Fator 1 de Elongação de Peptídeos/genética , RNA Polimerase II/genética , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA , Esporos Fúngicos/citologia , Esporos Fúngicos/ultraestrutura
14.
Mycologia ; 110(5): 822-834, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30240341

RESUMO

Sooty blotch and flyspeck (SBFS) fungi infect the cuticle of fruit, including apple fruit, and produce pigmented colonies. A new member of this fungal complex in the genus Peltaster is described on the basis of molecular and morphological evidence. The SBFS complex is a diverse group of ectophytic fungi that reside primarily within the order Capnodiales. Sooty blotch and flyspeck isolates from apple orchards in the central United States were subjected to parsimony and Bayesian analyses based on the internal transcribed spacer regions of nuc rDNA, the partial translation elongation factor 1-α gene, and the partial mitochondrial small subunit rRNA gene. Phylogenetic analysis delineated a new species, Peltaster gemmifer, from P. cerophilus and P. fructicola. Peltaster gemmifer conidiophores bear primary conidia that produce secondary conidia either through budding or through microcyclic conidiation; these were not seen in cultures of P. cerophilus and P. fructicola. On cellulose membrane that was placed on water agar amended with apple juice, P. gemmifer produced brown to black pycnothyria in a superficial brownish mycelial mat, similar to the colonies produced on apple fruit. Findings from the present study add to the >80 named and putative SBFS species so far described worldwide.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Malus/microbiologia , Filogenia , Ascomicetos/citologia , Ascomicetos/genética , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Microscopia , Microscopia Eletrônica de Varredura , Micélio/citologia , Micélio/crescimento & desenvolvimento , Micélio/ultraestrutura , Fator 1 de Elongação de Peptídeos/genética , Pigmentos Biológicos/análise , Reação em Cadeia da Polimerase , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Esporos Fúngicos/citologia , Esporos Fúngicos/ultraestrutura , Estados Unidos
15.
Mycologia ; 110(4): 677-691, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30081774

RESUMO

Three new species of Tomentella (Thelephorales) from Finland, T. globosa, T. lammiensis, and T. longisterigmata, are described and illustrated with morphological characteristics and nuc rDNA ITS1-5.8S-ITS2 sequences. T. globosa is characterized by mucedinoid, pale to dark brown basidiocarps adherent to the substrate, generative hyphae with clamps and rarely with simple septa, and echinulate, globose basidiospores (echinuli up to 1.5 µm long). T. lammiensis is characterized by mucedinoid, oxide yellow to golden brown basidiocarps adherent to the substrate, generative hyphae with clamps and rarely with simple septa, and echinulate, ellipsoid, triangular, or lobbed basidiospores (echinuli up to 2 µm long). T. longisterigmata is characterized by mucedinoid, dark brown to chestnut basidiocarps separable from the substrate, generative hyphae clamped and rarely with simple septa, the long basidial sterigmata (7-11 µm long), and echinulate, globose basidiospores (echinuli up to 2 µm long). An absence of rhizomorphs and cystidia is their common morphological feature. Molecular analyses by maximum likelihood, maximum parsimony, and Bayesian analyses confirm the phylogenetic position of these three new species. The discriminating characters of these new species and their closely related species are discussed in this study, and a key to the species from Finland is provided.


Assuntos
Basidiomycota/classificação , Basidiomycota/genética , DNA Fúngico/genética , Filogenia , Basidiomycota/isolamento & purificação , Teorema de Bayes , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Finlândia , Carpóforos/isolamento & purificação , Carpóforos/ultraestrutura , Hifas/ultraestrutura , Microscopia Eletrônica de Varredura , Esporos Fúngicos/isolamento & purificação , Esporos Fúngicos/ultraestrutura
16.
Mycologia ; 110(4): 692-709, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30067460

RESUMO

We present a taxonomic and phylogenetic study of Puccinia species (rust fungi) infecting tribe Lycieae (Solanaceae), with focus on the New World taxa. Phylogenetic analyses using nuclear (nuc) rDNA 5.8S-ITS2 (ITS2) and mitochondrial (mt) cytochrome oxidase subunit 3 (CO3) show that Puccinia species occurring on Lyciae are grouped in two major lineages, one New World and one Old World. We assessed the value of morphological traits and geographic range as important features for discriminating lineages. The morphology of teliospore pedicels and rust geographic ranges explained the relationships within this Puccinia species group. Four Puccinia species are recognized on Lycieae in the New World lineage and four in the Old World lineage. Puccinia tumidipes from North America is resurrected and P. dimidipes described as new from South America. In addition, P. spinulosa from Madagascar is reduced to a synonym of P. engleriana. Descriptions and a dichotomous key are presented for the accepted species.


Assuntos
Basidiomycota/classificação , Basidiomycota/genética , Doenças das Plantas/microbiologia , Solanaceae/microbiologia , Esporos Fúngicos/classificação , Basidiomycota/isolamento & purificação , Basidiomycota/ultraestrutura , DNA Fúngico/genética , DNA Ribossômico , DNA Espaçador Ribossômico/genética , Madagáscar , América do Norte , Filogenia , Análise de Sequência de DNA , América do Sul , Esporos Fúngicos/ultraestrutura
17.
PLoS One ; 13(8): e0201677, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30067835

RESUMO

Pseudozyma flocculosa is a fungus very useful and highly efficient as a biocontrol agent against powdery mildew. The reproduction of this fungus occurs exclusively by asexual production of conidia or sporidia that are the most suitable form for agricultural use and seems to be the most resistant to storage conditions. Despite the advantages offered by P. flocculosa in biological control, the use of this fungus use remains largely limited compared to that of chemical fungicides, at least partly due to the difficulty to obtain sporidia resistant to adverse environmental stresses in submerged culture conditions. Under solid-state and submerged-state cultivation, P. flocculosa strain CBS 16788 produced different types of sporidia. The submerged sporidia (SS) appeared relatively uniform in size, which was 15,4 ± 1,6 µm µm long, and 2,8 ± 0.8 µm wide. The aerial sporidia (AS) varied in shape and size, with a mean length of 8,2 ± 3 µm and width of 2,3 ± 0.6 µm. Under scanning and transmission electron microscopy, the cell wall of submerged sporidia was thinner than that of aerial spores, and the surface was smooth in contrast to the aerial sporidia that had a tendency to have verrucous, brittle surface characteristics. The thickness of the aerial sporidia wall is due to the presence of an outer layer rich in melanin. The sporidia germination was compared on YMPD (yeast extract, malt extract, soy peptone, dextrose and agar) coated coverslips. The aerial sporidia did not show germ tubes until 5 h of incubation, while the submerged sporidia showed many germ tubes after the same time. The resistance against the adverse environmental conditions in relation to the type of sporidia of P. flocculosa is discussed.


Assuntos
Ustilaginales/fisiologia , Parede Celular/ultraestrutura , Microscopia Acústica , Microscopia Eletrônica de Transmissão , Folhas de Planta/microbiologia , Esporos Fúngicos/ultraestrutura , Ustilaginales/isolamento & purificação , Ustilaginales/ultraestrutura
18.
Mol Plant Pathol ; 19(12): 2543-2560, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30027625

RESUMO

Spray-induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA (siRNA) amplification limits the application of SIGS. A myosin5 gene (Myo5) was chosen as the target of SIGS in an agronomically important pathogen-Fusarium asiaticum. Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5, resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5-8 (one of the Myo5 segments) induced sequence-specific RNA interference (RNAi) activity in F. asiaticum, F. graminearum, F. tricinctum and F. oxysporum, but not in other fungi, in vitro. Remarkably, the silencing of Myo5 lasted for only 9 h unless the double-stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.


Assuntos
Fusarium/metabolismo , Inativação Gênica , RNA Interferente Pequeno/metabolismo , Arabidopsis/microbiologia , Parede Celular/metabolismo , Quitina/metabolismo , Resistência à Doença/genética , Fusarium/genética , Fusarium/patogenicidade , Regulação Fúngica da Expressão Gênica , Técnicas de Silenciamento de Genes , Hifas/metabolismo , Hifas/ultraestrutura , Miosinas/genética , Células Vegetais/microbiologia , Doenças das Plantas/microbiologia , RNA de Cadeia Dupla/metabolismo , Reprodução , Esporos Fúngicos/metabolismo , Esporos Fúngicos/ultraestrutura , Transformação Genética , Triticum/microbiologia , Virulência
19.
Antonie Van Leeuwenhoek ; 111(12): 2323-2347, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29980901

RESUMO

Species of Leptographium are characterized by mononematous or synnematous conidiophores and are commonly associated with different arthropods. Some of them also produce a sexual state characterised by globose ascomata with elongated necks. Compared to investigations on coniferous trees, the occurrence of Leptographium species on hardwood trees has been poorly studied in Europe. During a survey of ophiostomatoid fungi on various hardwood tree species in Norway and Poland, three unusual species, which fit in the broader morphological description of Leptographium spp., were found in association with Trypodendron domesticum, Trypodendron signatum and Dryocoetes alni, and from wounds on a variety of hardwoods. Phylogenetic analyses of sequence data for six different loci (ITS1-5.8 S-ITS2, ITS2-LSU, ACT, ß-tubulin, CAL, and TEF-1α) showed that these Leptographium species are phylogenetically closely related to the species of the Grosmannia olivacea complex. The first species forms a well-supported lineage that includes Ophiostoma brevicolle, while the two other new taxa resided in a separate lineage; possibly affiliated with Grosmannia francke-grosmanniae. All the new species produce perithecia with necks terminating in ostiolar hyphae and orange-section shaped ascospores with cucullate, gelatinous sheaths. These species also produce dark olivaceous mononematous asexual states in culture. In addition, two of the newly described species have a second type of conidiophore with a short and non-pigmented stipe. The new Leptographium species can be easily distinguished from each other by their appearance and growth in culture. Based on novel morphological characters and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium tardum sp. nov., Leptographium vulnerum sp. nov., and Leptographium flavum sp. nov. are provided.


Assuntos
Alnus/microbiologia , DNA Fúngico/genética , Fagus/microbiologia , Ophiostomatales/classificação , Filogenia , Quercus/microbiologia , Alnus/parasitologia , Animais , Besouros/microbiologia , Código de Barras de DNA Taxonômico , Fagus/parasitologia , Hifas/classificação , Hifas/genética , Hifas/ultraestrutura , Noruega , Ophiostomatales/genética , Ophiostomatales/isolamento & purificação , Filogeografia , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Polônia , Quercus/parasitologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/ultraestrutura
20.
Mem Inst Oswaldo Cruz ; 113(6): e180102, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29924142

RESUMO

BACKGROUND Scedosporium/Lomentospora species are opportunistic mould pathogens, presenting notable antifungal resistance. OBJECTIVES/METHODS We analysed the conidia and germinated conidia of S. apiospermum (Sap), S. aurantiacum (Sau), S. minutisporum (Smi) and L. prolificans (Lpr) by scanning electron microscopy and exposition of surface molecules by fluorescence microscopy. FINDINGS Conidia of Sap, Smi and Sau had oval, ellipsoidal and cylindrical shape, respectively, with several irregularities surrounding all surface areas, whereas Lpr conidia were rounded with a smooth surface. The germination of Sap occurred at the conidial bottom, while Smi and Sau germination primarily occurred at the centre of the conidial cell, and Lpr germination initiated at any part of the conidial surface. The staining of N-acetylglucosamine-containing molecules by fluorescein-labelled WGA primarily occurred during the germination of all studied fungi and in the conidial scars, which is the primary location of germination. Calcofluor white, which recognises the polysaccharide chitin, strongly stained the conidial cells and, to a lesser extent, the germination. Both mannose-rich glycoconjugates (evidenced by fluoresceinated-ConA) and cell wall externally located polypeptides presented distinct surface locations and expression according to both morphotypes and fungal species. In contrast, sialic acid and galactose-containing structures were not detected at fungal surfaces. MAIN CONCLUSIONS The present study demonstrated the differential production/exposition of surface molecules on distinct morphotypes of Scedosporium/Lomentospora species.


Assuntos
Membrana Celular/ultraestrutura , Scedosporium/ultraestrutura , Esporos Fúngicos/ultraestrutura , Diferenciação Celular , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Scedosporium/crescimento & desenvolvimento , Esporos Fúngicos/fisiologia
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