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Drion G Boucias - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity of Hirsutella thompsonii isolates from Thailand based on AFLP analysis and partial -tubulin gene sequences
2015Co-Authors: Myrian S Tigano, S Maimala, Byron Adams, Drion G BouciasAbstract:Amplified fragment length polymorphism (AFLP) was used to investigate polymorphism among 43 Hirsutella thompsonii isolates (33 from Thailand) obtained from various mite species. The outgroups were an unidentified Hirsutella isolate along with Hirsutella nodulosa and Hirsutella kirchneri. Phylogenetic analyses of the AFLP data showed significant variation among isolates and the existence of three H. thompsonii clades. We also investigated the isolates using PCR with specific primers for the Hirsutella exotoxin gene Hirsutelin A (HtA) and 18 of these iso-lates were used for sequencing of the partial -tubulin gene. Phylogenetic analyses of -tubulin sequences showed two distinct H. thompsonii clades, one of which included AFLP clades I and II. For both markers grouping of the H. thompsonii isolates was not related to either host mite species or geographical origin, although for the HtA gene one clade contained only isolates with no detectable HtA band. These results confirm the high intraspecific polymorphism of H. thompsonii, and maximum likelihood analysis showed no monophyletic group within this species. To refine the taxonomy of this genus other studies should be undertaken using additional molecular markers and several other Hirsutella isolates
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morphological and molecular characterization of a Hirsutella species infecting the asian citrus psyllid diaphorina citri kuwayama hemiptera psyllidae in florida
Journal of Invertebrate Pathology, 2007Co-Authors: Jason M Meyer, Marjorie A Hoy, Drion G BouciasAbstract:The Asian citrus psyllid, Diaphorina citri Kuwayama, is an invasive pest that vectors citrus greening disease, which recently was detected in Florida. Mycosed adult D. citri were collected at four sites in central Florida between September 2005 and February 2006. Observation of the cadavers using scanning electron microscopy revealed that the pathogen had branched synnemata supporting monophiladic conidiogenous cells. A high-fidelity polymerase chain reaction (PCR) assay was used to amplify the 18S rRNA, 28S rRNA and β-tubulin genes of the pathogen for phylogenetic analysis. The morphological and genetic data indicated that the pathogen was a novel isolate related to Hirsutella citriformis Speare. PCR assays using isolate-specific primers designed from the unique putative intron region of the β-tubulin sequence distinguished the psyllid pathogen from five related Hirsutella species. The pathogen was maintained in vivo by exposing healthy D. citri to the synnemata borne on field-collected cadavers. Infected psyllids had an abundance of septate hyphal bodies in their hemolymph and exhibited behavioral symptoms of disease. In vitro cultures of the pathogen were slow-growing and produced synnemata similar to those found on mycosed D. citri. In laboratory bioassays, high levels of mortality were observed in D. citri that were exposed to the conidia-bearing synnemata produced in vivo and in vitro.
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genetic diversity of Hirsutella thompsonii isolates from thailand based on aflp analysis and partial beta tubulin gene sequences
Genetics and Molecular Biology, 2006Co-Authors: Myrian S Tigano, S Maimala, Byron J Adams, Drion G BouciasAbstract:Amplified fragment length polymorphism (AFLP) was used to investigate polymorphism among 43 Hirsutella thompsonii isolates (33 from Thailand) obtained from various mite species. The outgroups were an unidentified Hirsutella isolate along with Hirsutella nodulosa and Hirsutella kirchneri. Phylogenetic analyses of the AFLP data showed significant variation among isolates and the existence of three H. thompsonii clades. We also investigated the isolates using PCR with specific primers for the Hirsutella exotoxin gene Hirsutelin A (HtA) and 18 of these isolates were used for sequencing of the partial -tubulin gene. Phylogenetic analyses of -tubulin sequences showed two distinct H. thompsonii clades, one of which included AFLP clades I and II. For both markers grouping of the H. thompsonii isolates was not related to either host mite species or geographical origin, although for the HtA gene one clade contained only isolates with no detectable HtA band. These results confirm the high intraspecific polymorphism of H. thompsonii, and maximum likelihood analysis showed no monophyletic group within this species. To refine the taxonomy of this genus other studies should be undertaken using additional molecular markers and several other Hirsutella isolates.
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detection of the toxin hirsutellin a from Hirsutella thompsonii
Journal of Invertebrate Pathology, 2002Co-Authors: S Maimala, Drion G Boucias, Aurelien Tartar, Angsumarn ChandrapatyaAbstract:A total of 162 strains of Hirsutella thompsonii, isolated from infected mites collected worldwide, were examined for the production of Hirsutellin A (HtA). More than half of the broth filtrates exhibited mortality rates superior to 50% when assayed against Galleria mellonella. The presence of the gene coding for HtA, a previously characterized H. thompsonii protein exotoxin, was determined by PCR amplification using gene-specific primers. Most isolates (100 out of 162) were shown to possess the HtA gene. However, the presence of the gene could not be associated with enhanced insecticidal activity. Both isolate groups (with or without an amplifiable HtA gene) produced filtrates that caused the same average mortality rate (65%) when assayed against G. mellonella. The production and secretion of the HtA toxin were estimated by probing broth filtrates with an anti-HtA monoclonal antibody. Again, the detection of the HtA protein was poorly correlated with subsequent mortality rates induced by the broth filtrates of the various H. thompsonii strains. This study suggests that HtA is requisite for neither survival nor pathogenicity, and that H. thompsonii strains are likely to secrete other toxins that have yet to be characterized. Sequencing of a limited number of HtA genes showed that, when present, the gene is highly conserved, and it displays an interesting intronic polymorphism.
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Mycopathogens and their exotoxins infecting glassy-winged sharpshooter: survey, evaluation, and storage
2002Co-Authors: Russell F. Mizell, Drion G BouciasAbstract:A species of Hirsutella, the primary pathogen of glassy-winged sharpshooter (GWSS) in the southeastern US, has been the major focus of our research this past year. Due to the fastidious growth requirements of this fungus and the presence of numerous saprobic fungi associated with mycosed GWSS, a major effort has been made to design a series of gene-specific primers to be used to detect these diseases in field collected samples. Molecular-based diagnosis is being used to examine the hundreds of mycosed insects collected during the 2003 and 2004 regional surveys. A second effort has been directed at examining the seasonal incidence of this disease in an experimental crape myrtle plot. A number of parameters such as crape myrtle variety, host density, and mist irrigation (humidity) have been found to influence the onset of Hirsutella in GWSS populations. Current laboratory research is being directed at examining transmission of the lab culture to both GWSS and to alternate insect hosts. In addition, culture filtrates of all of the fungi collected from GWSS are being assessed for the presence of active metabolites
A E Muldoon - One of the best experts on this subject based on the ideXlab platform.
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sporulation of the nematophagous fungus Hirsutella rhossiliensis from hyphae produced in vitro and added to soil
Phytopathology, 1992Co-Authors: B A Lackey, B A Jaffee, A E MuldoonAbstract:After assimilating and killing host nematodes, Hirsutella rhossiliensis sporulates (i.e., produces external hyphae, phialides, and spores) from assimilative hyphae within the cadaver; the spores adhere to and infect nematodes. The ability of the fungus to sporulate from hyphae produced in vitro, rather than in host nematodes, was tested. Hyphae in the form of discrete vegetative colonies were grown in shake culture (potato-dextrose broth). In moist chambers, sporulation from vegetative colonies (rinsed free of broth) and from host nematodes was identical (...)
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effect of soil moisture and texture on transmission of the nematophagous fungus Hirsutella rhossiliensis to cyst and root knot nematodes
Phytopathology, 1992Co-Authors: E C Tedford, B A Jaffee, A E MuldoonAbstract:The nonmotile spores of Hirsutella rhossiliensis adhere to and initiate infection of vermiform nematodes in soil. Transmission of spores to second-state juveniles (J2) of Heterodera schachtii and Meloidogyne javanica was quantified in vials that contained 15-17 cm 3 of loam, loamy sand, or sand in the absence of a host plant. Fungal inoculum was added to the soil at day O as colonized nematodes from which the fungus sporulated, and healthy J2 of H. schachtii or M. javanica were added after 14 days at 20C and were extracted 66 h later (...)
Meichun Xiang - One of the best experts on this subject based on the ideXlab platform.
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Genome Studies on Nematophagous and Entomogenous Fungi in China
MDPI AG, 2016Co-Authors: Weiwei Zhang, Xingzhong Liu, Xiaoli Cheng, Meichun XiangAbstract:The nematophagous and entomogenous fungi are natural enemies of nematodes and insects and have been utilized by humans to control agricultural and forestry pests. Some of these fungi have been or are being developed as biological control agents in China and worldwide. Several important nematophagous and entomogenous fungi, including nematode-trapping fungi (Arthrobotrys oligospora and Drechslerella stenobrocha), nematode endoparasite (Hirsutella minnesotensis), insect pathogens (Beauveria bassiana and Metarhizium spp.) and Chinese medicinal fungi (Ophiocordyceps sinensis and Cordyceps militaris), have been genome sequenced and extensively analyzed in China. The biology, evolution, and pharmaceutical application of these fungi and their interacting with host nematodes and insects revealed by genomes, comparing genomes coupled with transcriptomes are summarized and reviewed in this paper
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development of a transformation system for Hirsutella spp and visualization of the mode of nematode infection by gfp labeled h minnesotensis
Scientific Reports, 2015Co-Authors: Jingzu Sun, Xingzhong Liu, Sook Young Park, Seogchan Kang, Junzhi Qiu, Meichun XiangAbstract:Hirsutella rhossiliensis and H. minnesotensis are endoparasitic fungi of the second-stage juvenile (J2) of the soybean cyst nematode (Heterodera glycines) in nature. They also parasitize both H. glycines J2 and Caenorhabditis elegans on agar plates. Agrobacterium tumefaciens-mediated transformation conditions were established for these Hirsutella spp. The resulting transformants were similar to the corresponding wild-type strains. The infection processes of H. glycines J2 and C. elegans second larval stage (L2) by H. minnesotensis expressing ZsGreen were microscopically analyzed. Conidia of H. minnesotensis adhered to passing nematodes within 8 h post-inoculation (hpi), formed an infection peg between 8 and 12 hpi, and penetrated the nematode cuticle between 12 and 24 hpi for C. elegans L2 and between 12 and 32 hpi for H. glycines J2. Hyphal proliferation inside of the nematode coelom was observed at approximately 32 hpi for C. elegans L2 and at approximately 40 hpi for H. glycines J2. The fungus consumed the whole body and grew out to produce conidia at approximately 156 and 204 hpi for C. elegans L2 and H. glycines J2, respectively. The efficient transformation protocol and a better understanding of infection process provide a solid foundation for studying the molecular and cellular mechanisms underlying fungal parasitism of nematodes.
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DOI 10.1007/s10267-008-0451-3 REVIEW
2013Co-Authors: Xingzhong Liu, Meichun Xiang, Yongsheng Che, -z. X. Liu, -c. M. Xiang, -s. Y. CheAbstract:Abstract The infection structures, trophism, and ecological character of nematophagous fungi are reviewed in this article on the basis of data extracted from the literature and the most recent experiments conducted in this area. Traditionally, nematophagous fungi are classified into four groups according to their modes of attacking nematodes: nematode-trapping fungi using adhesive or mechanical hyphal traps, endoparasitic fungi using their spores, eggparasitic fungi invading nematode eggs or females with their hyphal tips, and toxin-producing fungi immobilizing nematodes before invasion. In the present review, we focus on the first two groups. The living strategies of these nematophagous fungi depend on the diversity of their infection structures, such as different traps and spore types, which determine the modes of infecting nematodes. The diversity of trophic modes of nematophagous fungi is an important prerequisite for fungal survival and activity in soil. The abundance and activity of Hirsutella rhossiliensis and H. minnesotensis, representatives of endoparasites and potential biocontrol agents against nematodes, are highly dependent on environmental factors. Comprehensive understanding of the survival and activity of nematophagous fungi in soil is fundamental for the exploitation of these fungi as successful biocontrol agents. Key words Diversity · Hirsutella spp. · Infection structures · Nematophagous fungi · Trophis
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MICROBIOLOGY ECOLOGY
2009Co-Authors: Meichun Xiang, Xingzhong Liu, Limei Zhang, Correspondence Xingzhong Liu, Yongguan ZhuAbstract:of environment on the abundance and activity of the nematophagous fungus Hirsutella minnesotensis in soi
Xiao Zou - One of the best experts on this subject based on the ideXlab platform.
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two new species of Hirsutella ophiocordycipitaceae sordariomycetes that are parasitic on lepidopteran insects from china
MycoKeys, 2021Co-Authors: Xiao Zou, Wei Cao, Zongqi LiangAbstract:Hirsutella are globally distributed entomopathogenic fungi that offer important economic applications in biological control and biomedicine. Hirsutella was suppressed in favour of Ophiocordyceps affected by the ending of dual nomenclature for pleomorphic fungi in 2011. Currently, Hirsutella has been resurrected as a genus under Ophiocordycipitaceae. In this study, we introduce two new species of Hirsutella, based on morphological and phylogenetic analyses. Hirsutellaflava and H.kuankuoshuiensis are pathogenic on different species of larval Lepidoptera in China. Hirsutellaflava primarily differs from related species by its awl-shaped base; long and narrow neck, 24-40.8 × 2.2-2.5 μm; long and narrow cymbiform or fusoid conidia, 6.5-10 × 2.1-4.3 μm. Hirsutellakuankuoshuiensis has two types of phialides and distinctive 9.9-12.6 × 2.7-4.5 μm, clavate or botuliform conidia. The distinctions amongst the new species and phylogenetic relationships with other Hirsutella species are discussed.
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Additional file 1: of Estimated divergence times of Hirsutella (asexual morphs) in Ophiocordyceps provides insight into evolution of phialide structure
2018Co-Authors: Yeming Zhou, Jian Zhang, Yanfeng Han, Xiao ZouAbstract:Table S1. GenBank accession numbers for sequences used in the phylogenetic analysis of Hirsutella (asexual morph). Table S2. Morphological comparison among Ophiocordyceps retorta and its related species. (DOC 86 kb
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Estimated divergence times of Hirsutella (asexual morphs) in Ophiocordyceps provides insight into evolution of phialide structure
BMC, 2018Co-Authors: Yeming Zhou, Jian Zhang, Yanfeng Han, Xiao ZouAbstract:Abstract Background Hirsutella Pat genus, the asexual morphs of the Ophiocordyceps Sung, is globally distributed entomopathogenic fungi, which infect a variety of arthropods, mites and nematodes. The fungal species also have shown potential application in the field of biological control, bio-medicine and food development. Although these fungi are synonymized under Ophiocordyceps, formal taxonomic assignments remain necessary for classification of species in Hirsutella. However, due to the heterogeneity and complexity of Hirsutella genus, more detailed taxonomic and phylogenetic analyses are required to address the following subjects: (1) the relationships between the phialide morphological characteristics and phylogenetic information of Hirsutella with asexual morphs, (2) the origin and evolution of the phialide structure, and (3) host specificity and fungal pathogenicity. Results Five typical phialide structures are summarized, in which the variation in phialide characteristics overlaps well with phylogenetic information. A new member of the special twisted neck clade in the Hirsutella-like group, Ophiocordyceps retorta, was reported based on these analyses. The molecular clock calibration analysis based on one fossil record revealed that Hirsutella (asexual morph) species originated from a common ancestor approximately 102 million years ago (Mya) (Early Cretaceous, Lower Albian) and then resolved into two major lineages. One lineage was typically phialidic, which was a larger shape, including H. guyana, H. nodulosa and H. sinensis clades (86.9 Mya, 95% highest posterior density (HPD): 69.1–101.4 Mya). Another main lineage of the phialides was more diversified and smaller than the former, which included H. citriformis and H. thompsonii clades (71.9 Mya, 95% HPD: 41.8–99.6 Mya). Conclusions Our results showed that certain phialide characteristics of Hirsutella were phylogenetically informative for two groups of taxa. The differentiation of the phialides structures in the major clades demonstrated a clear evolutionary path of Hirsutella (asexual morph) species, which exhibited two trends depending on the host size. Fungi in one of the groups displayed elongated conidiogenous cells with increased complexity of auxiliary structures from the mycelia. The species in another group reduced the volume of phialides and spores, which might be due to an energy-efficient strategy. These results suggested that a common origin allowed for diversification of given clades into separate niches. The distinct parallel evolutionary path combined with the specific phialides structure might result in the host specificity of Hirsutella (asexual morphs). A direct relationship between Hirsutella (asexual morphs) and the Cretaceous–Tertiary extinction was not found, which suggested that the diversity of phialides is more likely to be caused by long-term environmental adaptation and evolution rather than dramatic extinction events. This evolutionary result might correspond to the background of important biological and geological events in the late Cretaceous occurring near the divergence times of Hirsutella (asexual morphs)
Zongqi Liang - One of the best experts on this subject based on the ideXlab platform.
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two new species of Hirsutella ophiocordycipitaceae sordariomycetes that are parasitic on lepidopteran insects from china
MycoKeys, 2021Co-Authors: Xiao Zou, Wei Cao, Zongqi LiangAbstract:Hirsutella are globally distributed entomopathogenic fungi that offer important economic applications in biological control and biomedicine. Hirsutella was suppressed in favour of Ophiocordyceps affected by the ending of dual nomenclature for pleomorphic fungi in 2011. Currently, Hirsutella has been resurrected as a genus under Ophiocordycipitaceae. In this study, we introduce two new species of Hirsutella, based on morphological and phylogenetic analyses. Hirsutellaflava and H.kuankuoshuiensis are pathogenic on different species of larval Lepidoptera in China. Hirsutellaflava primarily differs from related species by its awl-shaped base; long and narrow neck, 24-40.8 × 2.2-2.5 μm; long and narrow cymbiform or fusoid conidia, 6.5-10 × 2.1-4.3 μm. Hirsutellakuankuoshuiensis has two types of phialides and distinctive 9.9-12.6 × 2.7-4.5 μm, clavate or botuliform conidia. The distinctions amongst the new species and phylogenetic relationships with other Hirsutella species are discussed.