36 research outputs found
Common, unsightly and until now undescribed : Fumiglobus pieridicola sp. nov., a sooty mold infesting Pieris japonica from western North America
Sooty molds (Capnodiaceae) are saprotrophs
on the surfaces of leaves, and they take their
nutrients from honeydew exuded by sap-sucking
insects. We describe and illustrate the sooty mold
Fumiglobus pieridicola sp. nov., which, to the dismay of
gardeners, forms a thick black mycelial coating on the
leaves and twigs of ornamental Japanese andromeda
(Pieris japonica) in western North America. As a
mitosporic species with a pycnidium that lacks an
elongated neck and has at most a rudimentary stalk,
the species belongs in the genus Fumiglobus. Although
locally common, we found no specimens
identified under Fumiglobus or its synonyms in
regional herbaria and no record of any similar fungus
in host indices. Our species differs from others in
Fumiglobus in having smaller pycnidia and conidia
and in having intercalary as well as apical pycnidia.
We determined partial 18S and 28S ribosomal gene
sequences for F. pieridicola, the first for any Fumiglobus
species. Sequence analysis provides strong bootstrap
support for including Fumiglobus within Capnodiaceae.
We also determined 18S and 28S sequences
for the type species of the mitosporic genus Conidiocarpus, also in Capnodiaceae. We confirm
that Conidiocarpus is the anamorph of Phragmocapnias.
Following the rules of nomenclatural priority, we
propose the new combinations Conidiocarpus asiaticus,
Conidiocarpus betle, Conidiocarpus callitris, Conidiocarpus
fuliginodes, Conidiocarpus heliconiae, Conidiocarpus
imperspicuus and Conidiocarpus siamensis. We hope that describing the mystery fungus from our
region and providing sequences for its molecular
identification will lead to new studies on its biology
and distribution.http://www.mycologia.org/am201
A phylum-level phylogenetic classification of zygomycete fungi based on genome-scale data
Zygomycete fungi were classified as a single phylum, Zygomycota, based on sexual reproduction by zygospores, frequent asexual reproduction by sporangia, absence of multicellular sporocarps, and production of coenocytic hyphae, all with some exceptions. Molecular phylogenies based on one or a few genes did not support the monophyly of the phylum, however, and the phylum was subsequently abandoned. Here we present phylogenetic analyses of a genome-scale data set for 46 taxa, including 25 zygomycetes and 192 proteins, and we demonstrate that zygomycetes comprise two major clades that form a paraphyletic grade. A formal phylogenetic classification is proposed herein and includes two phyla, six subphyla, four classes and 16 orders. On the basis of these results, the phyla Mucoromycota and Zoopagomycota are circumscribed. Zoopagomycota comprises Entomophtoromycotina, Kickxellomycotina and Zoopagomycotina; it constitutes the earliest diverging lineage of zygomycetes and contains species that are primarily parasites and pathogens of small animals (e.g. amoeba, insects, etc.) and other fungi, i.e. mycoparasites. Mucoromycota comprises Glomeromycotina, Mortierellomycotina, and Mucoromycotina and is sister to Dikarya. It is the more derived clade of zygomycetes and mainly consists of mycorrhizal fungi, root endophytes, and decomposers of plant material. Evolution of trophic modes, morphology, and analysis of genome-scale data are discussed
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Phylogenomic Analyses Indicate that Early Fungi Evolved Digesting Cell Walls of Algal Ancestors of Land Plants
As decomposers, fungi are key players in recycling plant material in global carbon cycles. We hypothesized that genomes of early diverging fungi may have inherited pectinases from an ancestral species that had been able to extract nutrients from pectin-containing land plants and their algal allies (Streptophytes). We aimed to infer, based on pectinase gene expansions and on the organismal phylogeny, the geological timing of the plant–fungus association. We analyzed 40 fungal genomes, three of which, including Gonapodya prolifera, were sequenced for this study. In the organismal phylogeny from 136 housekeeping loci, Rozella diverged first from all other fungi. Gonapodya prolifera was included among the flagellated, predominantly aquatic fungal species in Chytridiomycota. Sister to Chytridiomycota were the predominantly terrestrial fungi including zygomycota I and zygomycota II, along with the ascomycetes and basidiomycetes that comprise Dikarya. The Gonapodya genome has 27 genes representing five of the seven classes of pectin-specific enzymes known from fungi. Most of these share a common ancestry with pectinases from Dikarya. Indicating functional and sequence similarity, Gonapodya, like many Dikarya, can use pectin as a carbon source for growth in pure culture. Shared pectinases of Dikarya and Gonapodya provide evidence that even ancient aquatic fungi had adapted to extract nutrients from the plants in the green lineage. This implies that 750 million years, the estimated maximum age of origin of the pectin-containing streptophytes represents a maximum age for the divergence of Chytridiomycota from the lineage including Dikarya.Keywords: fungal phylogeny, carbohydrate active enzymes, streptophytes, geological time, Gonapodya, evolution, pectinasesKeywords: fungal phylogeny, carbohydrate active enzymes, streptophytes, geological time, Gonapodya, evolution, pectinase
Data from: Over the hills, but how far away? estimates of mushroom geographic range extents
Aim: Geographic distributions of mushroom species remain poorly understood despite their importance for advancing our understanding of the habitat requirements, species interactions and ecosystem functions of this key group of organisms. Here, we estimate geographic range extents (maximum within-species geographic distance) of genetically defined operational taxonomic units (OTUs).
Location: World-wide, with emphasis on the American Pacific Northwest
Taxa: Amanita, Agaricus, Cortinarius, Galerina, Hebeloma, Hydnum, Hygrocybe, Hygrophorus, Inocybe, Lepiota, Pholiota, and Russula+Lactarius; other genera in Agaricomycotina
Method: We used publicly available OTUs from ribosomal internal transcribed spacer (ITS) sequences (n=15,373) from 12 mushroom genera with worldwide distributions. For each of 2,324 ~species-level OTUs, we estimated the maximum within-species range extent based on sample locality records. In parallel, we estimated range extents for species in four tree genera. Contrasting estimates from well-studied trees allowed us to test for potential biases in our range estimates of less well inventoried mushrooms.
Results: The median range extents across the 2,324 mushroom OTUs varied from ~1,200 km to 4,039 km, depending on assumptions. These extents were significantly lower than estimates from permuted or randomized data. Mushroom ranges were comparable to the median natural range extent of tree species (1,613 km). In contrast, the tree median species range increased to 16,581 km when anthropogenic range extensions were included. At least ten mushroom species were similarly broadly distributed, eight of which have been associated with human activity.
Main conclusions: Overall, like tree species, mycorrhizal and saprotrophic fungi show evidence of biogeographic structure rather than global distributions. This reconstruction of geographic range extents drew upon investments into ITS barcoding of extensive herbarium collections. Large scale analyses such as ours can yield estimates of fungal geographic range extents that are a prerequisite to a deeper understanding of the diverse roles of fungi in ecosystems
Diversity of opisthokont septin proteins reveals structural constraints and conserved motifs
Background:
Septins are cytoskeletal proteins important in cell division and in establishing and maintaining cell polarity. Although septins are found in various eukaryotes, septin genes had the richest history of duplication and diversification in the animals, fungi and protists that comprise opisthokonts. Opisthokont septin paralogs encode modular proteins that assemble into heteropolymeric higher order structures. The heteropolymers can create physical barriers to diffusion or serve as scaffolds organizing other morphogenetic proteins. How the paralogous septin modules interact to form heteropolymers is still unclear. Through comparative analyses, we hoped to clarify the evolutionary origin of septin diversity and to suggest which amino acid residues were responsible for subunit binding specificity.
Results:
Here we take advantage of newly sequenced genomes to reconcile septin gene trees with a species phylogeny from 22 animals, fungi and protists. Our phylogenetic analysis divided 120 septins representing the 22 taxa into seven clades (Groups) of paralogs. Suggesting that septin genes duplicated early in opisthokont evolution, animal and fungal lineages share septin Groups 1A, 4 and possibly also 1B and 2. Group 5 septins were present in fungi but not in animals and whether they were present in the opisthokont ancestor was unclear. Protein homology folding showed that previously identified conserved septin motifs were all located near interface regions between the adjacent septin monomers. We found specific interface residues associated with each septin Group that are candidates for providing subunit binding specificity.
Conclusions:
This work reveals that duplication of septin genes began in an ancestral opisthokont more than a billion years ago and continued through the diversification of animals and fungi. Evidence for evolutionary conservation of ~ 49 interface residues will inform mutagenesis experiments and lead to improved understanding of the rules guiding septin heteropolymer formation and from there, to improved understanding of development of form in animals and fungi.Science, Faculty ofNon UBCBotany, Department ofReviewedFacult
Phylogenetic analysis of the distribution of deadly amatoxins among the little brown mushrooms of the genus Galerina.
Some but not all of the species of 'little brown mushrooms' in the genus Galerina contain deadly amatoxins at concentrations equaling those in the death cap, Amanita phalloides. However, Galerina's ~300 species are notoriously difficult to identify by morphology, and the identity of toxin-containing specimens has not been verified with DNA barcode sequencing. This left open the question of which Galerina species contain toxins and which do not. We selected specimens for toxin analysis using a preliminary phylogeny of the fungal DNA barcode region, the ribosomal internal transcribed spacer (ITS) region. Using liquid chromatography/mass spectrometry, we analyzed amatoxins from 70 samples of Galerina and close relatives, collected in western British Columbia, Canada. To put the presence of toxins into a phylogenetic context, we included the 70 samples in maximum likelihood analyses of 438 taxa, using ITS, RNA polymerase II second largest subunit gene (RPB2), and nuclear large subunit ribosomal RNA (LSU) gene sequences. We sequenced barcode DNA from types where possible to aid with applications of names. We detected amatoxins only in the 24 samples of the G. marginata s.l. complex in the Naucoriopsis clade. We delimited 56 putative Galerina species using Automatic Barcode Gap Detection software. Phylogenetic analysis showed moderate to strong support for Galerina infrageneric clades Naucoriopsis, Galerina, Tubariopsis, and Sideroides. Mycenopsis appeared paraphyletic and included Gymnopilus. Amatoxins were not detected in 46 samples from Galerina clades outside of Naucoriopsis or from outgroups. Our data show significant quantities of toxin in all mushrooms tested from the G. marginata s.l. complex. DNA barcoding revealed consistent accuracy in morphology-based identification of specimens to G. marginata s.l. complex. Prompt and careful morphological identification of ingested G. marginata s.l. has the potential to improve patient outcomes by leading to fast and appropriate treatment