31 research outputs found
Phylogenetic classification of Cordyceps and the clavicipitaceous fungi
Cordyceps, comprising over 400 species, was historically
classified in the Clavicipitaceae, based on cylindrical asci,
thickened ascus apices and filiform ascospores, which often disarticulate into
part-spores. Cordyceps was characterized by the production of
well-developed often stipitate stromata and an ecology as a pathogen of
arthropods and Elaphomyces with infrageneric classifications
emphasizing arrangement of perithecia, ascospore morphology and host
affiliation. To refine the classification of Cordyceps and the
Clavicipitaceae, the phylogenetic relationships of 162 taxa were
estimated based on analyses consisting of five to seven loci, including the
nuclear ribosomal small and large subunits (nrSSU and
nrLSU), the elongation factor 1α (tef1), the largest
and the second largest subunits of RNA polymerase II (rpb1 and
rpb2), β-tubulin (tub), and mitochondrial ATP6
(atp6). Our results strongly support the existence of three
clavicipitaceous clades and reject the monophyly of both Cordyceps
and Clavicipitaceae. Most diagnostic characters used in current
classifications of Cordyceps (e.g., arrangement of perithecia,
ascospore fragmentation, etc.) were not supported as being phylogenetically
informative; the characters that were most consistent with the phylogeny were
texture, pigmentation and morphology of stromata. Therefore, we revise the
taxonomy of Cordyceps and the Clavicipitaceae to be
consistent with the multi-gene phylogeny. The family Cordycipitaceae
is validated based on the type of Cordyceps, C. militaris,
and includes most Cordyceps species that possess brightly coloured,
fleshy stromata. The new family Ophiocordycipitaceae is proposed
based on Ophiocordyceps Petch, which we emend. The majority of
species in this family produce darkly pigmented, tough to pliant stromata that
often possess aperithecial apices. The new genus Elaphocordyceps is
proposed for a subclade of the Ophiocordycipitaceae, which includes
all species of Cordyceps that parasitize the fungal genus
Elaphomyces and some closely related species that parasitize
arthropods. The family Clavicipitaceae s. s. is emended and
includes the core clade of grass symbionts (e.g., Balansia,
Claviceps, Epichloë, etc.), and the entomopathogenic
genus Hypocrella and relatives. In addition, the new genus
Metacordyceps is proposed for Cordyceps species that are
closely related to the grass symbionts in the Clavicipitaceae s.
s. Metacordyceps includes teleomorphs linked to
Metarhizium and other closely related anamorphs. Two new species are
described, and lists of accepted names for species in Cordyceps,
Elaphocordyceps, Metacordyceps and Ophiocordyceps
are provided
Finding needles in haystacks : linking scientific names, reference specimens and molecular data for Fungi
DNA phylogenetic comparisons have shown that morphology-based species recognition
often underestimates fungal diversity. Therefore, the need for accurate DNA sequence
data, tied to both correct taxonomic names and clearly annotated specimen data, has
never been greater. Furthermore, the growing number of molecular ecology and microbiome
projects using high-throughput sequencing require fast and effective methods for
en masse species assignments. In this article, we focus on selecting and re-annotating a
set of marker reference sequences that represent each currently accepted order of Fungi.
The particular focus is on sequences from the internal transcribed spacer region in the
nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Reannotated
and verified sequences were deposited in a curated public database at the
National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci
(RTL) database, and will be visible during routine sequence similarity searches with
NR_prefixed accession numbers. A set of standards and protocols is proposed to improve
the data quality of new sequences, and we suggest how type and other reference
sequences can be used to improve identification of Fungi.The Intramural Research Programs
of the National Center for Biotechnology Information, National
Library of Medicine and the National Human Genome Research
Institute, both at the National Institutes of Health.http://www.ncbi.nlm.nih.gov/bioproject/PRJNA177353am201
Viridistratins A−C, Antimicrobial and Cytotoxic Benzo[j]fluoranthenes from Stromata of Annulohypoxylon viridistratum (Hypoxylaceae, Ascomycota)
During the course of our search for novel biologically active metabolites from tropical fungi, we are using chemotaxonomic and taxonomic methodology for the preselection of interesting materials. Recently, three previously undescribed benzo[j]fluoranthenes (1−3) together with the known derivatives truncatones A and C (4, 5) were isolated from the stromata of the recently described species Annulohypoxylon viridistratum collected in Thailand. Their chemical structures were elucidated by means of spectral methods, including nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). The new compounds, for which we propose the trivial names viridistratins A−C, exhibited weak-to-moderate antimicrobial and cytotoxic activities in cell-based assays
Viridistratins A-C, Antimicrobial and Cytotoxic Benzo[]fluoranthenes from Stromata of (Hypoxylaceae, Ascomycota).
During the course of our search for novel biologically active metabolites from tropical fungi, we are using chemotaxonomic and taxonomic methodology for the preselection of interesting materials. Recently, three previously undescribed benzo[j]fluoranthenes (1-3) together with the known derivatives truncatones A and C (4, 5) were isolated from the stromata of the recently described species Annulohypoxylon viridistratum collected in Thailand. Their chemical structures were elucidated by means of spectral methods, including nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). The new compounds, for which we propose the trivial names viridistratins A-C, exhibited weak-to-moderate antimicrobial and cytotoxic activities in cell-based assays
Phylogeny- and morphology-based recognition of new species in the spider-parasitic genus (Hypocreales, Cordycipitaceae) from Thailand.
Thailand is known to be a part of what is called the Indo-Burma biodiversity hotspot, hosting a vast array of organisms across its diverse ecosystems. This is reflected by the increasing number of new species described over time, especially fungi. However, a very few fungal species from the specialized spider-parasitic genus Gibellula have ever been reported from this region. A survey of invertebrate-pathogenic fungi in Thailand over several decades has led to the discovery of a number of fungal specimens with affinities to this genus. Integration of morphological traits into multi-locus phylogenetic analysis uncovered four new species: G. cebrennini, G. fusiformispora, G. pigmentosinum, and G. scorpioides. All these appear to be exclusively linked with torrubiella-like sexual morphs with the presence of granulomanus-like asexual morph in G. pigmentosinum and G. cebrennini. A remarkably high host specificity of these new species towards their spider hosts was revealed, and for the first time, evidence is presented for manipulation of host behavior in G. scorpioides
Phylogenetic and chemotaxonomic studies confirm the affinities of Stromatoneurospora phoenix to the Coprophilous xylariaceae
The genus Stromatoneurospora was erected in 1973 by Jong and Davis to accommodate the pyrophilic pyrenomycete Sphaeria phoenix and has traditionally been placed in the family Xylariaceae based on morphological features. However, no living culture of this genus has so far been available in the public domain. Molecular data were restricted to an internal transcribed spacer (ITS) sequence that only confirmed the familial position, and was generated from a strain that is not deposited in a public culture collection. We have recently collected fresh material and were able to culture this fungus from Thailand. The secondary metabolites of this strains were analysed after fermentation in multiple media. The the prominent components of these fermentation were purified, using preparative chromatography. Aside from two new eremophilane sesquiterpenoids named phoenixilanes A-B (1-2), four other components that are known from species of the xylariaceous genera Xylaria and Poronia were identified by spectral methods (nuclear magnetic resonance spectroscopy and high resolution mass spectrometry). Notably, (-)-(R)-6-hydroxy-3-methyl-4-dihydroisocoumarin-5-carboxylic acid (6) has not been reported as a natural product before. Moreover, DNA sequences of Stromatoneurospora phoenix clustered with members of the genera Poronia and Podosordaria in a multi-locus molecular phylogeny. These results confirmed that the genus belongs to the same evolutionary lineage as the coprophilic Xylariaceae. The results also suggest that this lineage has evolved independently from the plant-inhabiting saprotrophs and endophytes that are closely related to the genus Xylaria. These findings are discussed in relation to some theories about the endophytic vs. the pyrophilic/coprophilic fungal life style.Horizon 202