Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ustilaginales”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The Ustilaginales as plant pests and model systems.

The Ustilaginales are a vast and diverse group of fungi, which includes the plant pathogenic smuts that cause significant losses to crops worldwide. Members of the Ustilaginales are also valuable models for the unraveling of fundamental mechanisms controlling important biological processes. Ustilago maydis is an important fungal model system and has been well studied with regard to mating, morphogenesis, pathogenicity, signal transduction, mycoviruses, DNA recombination, and, recently, genomics. In this review we discuss the life cycles of members of the Ustilaginales and provide background on their economic impact as agricultural pests. We then focus on providing a summary of the literature with special attention to topics not well covered in recent reviews such as the use of U. maydis in mycovirus research and as a model for understanding the molecular mechanisms of fungicide resistance and DNA recombination and repair.

Models, Biological↗

The genus Anthracoidea (Basidiomycota, Ustilaginales): a molecular phylogenetic approach using LSU rDNA sequences.

The phylogenetic relationship of 52 specimens representing 30 species of Anthracoidea (Ustilaginales) was investigated by molecular analyses using sequence data from the large subunit (LSU) of nuclear rDNA. Phylogenetic trees were inferred with neighbour-joining (NJ), maximum parsimony (MP), and Bayesian Markov chain Monte Carlo (MCMC) methods. The results are discussed with respect to the species concept and the subdivision of the genus into subgenera and sections. Collections from different hosts and localities were compared. Our analyses can neither support nor significantly reject the hypothesis of the bipartition of the genus Anthracoidea. Thus, the representatives of the subgenus Proceres appeared in the NJ analysis as a moderately supported monophylum, whereas MCMC analysis revealed a polyphyletic topology for this group. Paraphyly of the subgenus Anthracoidea was supported by all methods used. Sections Echinosporae and Leiosporae were each represented by two species in our analyses which grouped together with high support. Section Anthracoidea should be restricted to a highly supported group with extremely irregular to angular teliospore shape. However, these three sections do not cover the whole diversity of the subgenus Anthracoidea. Molecular data largely supported the traditional circumscription of species, and species delimitations are discussed.

Bayes Theorem↗

Utilization of tartaric acid and related compounds by yeasts: taxonomic implications.

A survey of yeasts capable of growing on L(+)-tartaric acid as the sole source of carbon and energy showed that this organic acid is assimilated by a significant number of species of basidiomycetous affinity and is seldom utilized by ascomycetous yeasts. This conclusion was further supported by the fact that among approximately 100 isolates from various natural substrates, using selective media with L(+)-tartaric acid, only one strain of ascomycetous affinity was obtained. In a more comprehensive survey 442 yeast strains belonging to 138 species, mostly of basidiomycetous affinity, were also screened for the assimilation of different aldaric acids: D(-)-tartaric acid, meso-tartaric acid, L(-)-malic acid, D(+)-glucaric acid (saccharic acid), and galactaric acid (mucic acid). L(+)-Tartrate was the most frequently utilized tartaric acid isomer (55% of the total number of strains of basidiomycetous affinity belonging to either the Tremellales/Filobasidiales or the Ustilaginales) when compared with the D(-) and meso forms, which were assimilated by 12 and 18% of the total number of strains, respectively (mainly of tremellaceous species). Saccharic acid was utilized by about 75% of the total number of species of Tremellales affinity and by less than 20% of the ustilaginaceous species. Assimilation of mucic acid occurred in more than 50% of the tremellaceous species and only in 5% of the species related to the Ustilaginales. These tests, not used in standard yeast identification sets, appear to contribute to distinguishing taxa at or above the species level.

Basidiomycota↗

Mycocin production in Pseudozyma tsukubaensis.

Killer activity expressed at pH values ranging from 3.5 to 6.0 was found in the ustilaginaceous yeast-like species, Pseudozyma tsukubaensis. Its killer phenotype was incurable, and extrachromosomal genetic elements were not detected. The toxin excreted with a molecular mass above 15 kDa is fungicidal, resistant to proteolytic cleavage, thermolabile and active only against fungi within the Ustilaginomycetes (the orders Microstromatales and Ustilaginales).

Mycotoxins↗

Molecular phylogeny of Ustilago, Sporisorium, and related taxa based on combined analyses of rDNA sequences.

Combined analyses of ITS and LSU rDNA sequences were utilized to resolve the phylogenetic relationships of 98 members of the smut genera Lundquistia, Melanopsichium, Moesziomyces, Macalpinomyces, Sporisorium, and Ustilago (Basidiomycota: Ustilaginales). Minimum Evolution and Bayesian inference of phylogeny resolve three major groups of almost identical composition: Sporisorium, Ustilago, and a basal assemblage of both Ustilago and Sporisorium species. Macalpinomyces deserves generic rank regarding its type species M. eriachnes; all other Macalpinomyces species of our study clearly turn out to be part of Ustilago or Sporisorium. Lundquistia evidently belongs to Sporisorium. Moesziomyces, probably paraphyletic, stands basal to all other genera. Interestingly, Melanopsichium belongs to the Ustilago clade, being the only member of the ingroup not parasitizing on Poaceae. The patchy distribution of commonly used morphological characters along our phylograms points to their variability and dependence on the host's morphological traits instead of being valuable for resolving parasite phylogeny. The new combination: Sporisorium fascicularis comb. nov. (syn. Lundquistia.fascicularis) is made.

DNA, Fungal↗

Molecular signaling in pathogenicity and host recognition in smut fungi taking Karnal bunt as a model system.

Karnal bunt of wheat, incited by a phytopathogen Tilletia indica (Syn. Neovossia indica) is a floret infecting disease. In the floral tissues fungus proliferates and produces massive amount of black spores. In smut fungi, belonging to order Ustilaginales, communication between cells is necessary to regulate growth, differentiation and monokaryotic to dikaryotic transition during pathogenic and sexual development. Neighbouring cells are able to communicate with each other by direct cell to cell contact through plasma membrane bound signaling molecules or through formation of gap junctions and alternatively through secretion of chemical signals if cells are some distance away. Current research efforts toward understanding of pathogenic and sexual development in phytopathogenic fungi, offer a number of opportunities. These include the analysis of molecular signal(s) for direct contribution of sexual interactions to ability of smut and bunt pathogens to cause disease. These efforts will provide not only to explore the mechanisms of pathogenesis, but also to enhance knowledge of basic cellular biology of an economically important group of fungi.

Cell Communication↗

[Pseudozyma fusiformata BKM Y-2821--a producer of antifungal glycolipid].

The yeast Pseudozyma fusiformata (the order Ustilaginales) produces an extracellular low-molecular-weight protease-resistant thermostable fungicide, which was active against more than 80% of the 280 yeast and yeastlike species tested. The fungicide, extracted with methanol and purified by column and thin-layer chromatography, was found to consist of glucose and saturated fatty acids.

Antifungal Agents↗

Host and parasite population structure in a natural plant-pathogen system

We investigated the genetic population structure in a metapopulation of the plant Silene latifolia (Caryophyllaceae) and its fungal pathogen Microbotryum violaceum (Ustilaginales), a pollinator-borne disease. Population structure of the host plant was estimated using allozyme markers and that of the fungus by microsatellites. Both host and parasite showed significant differentiation, but parasite populations were 12 times more strongly differentiated than those of the hosts. We found significant isolation by distance for host populations but not for parasite populations. Higher population differentiation for the parasite may result from small effective population size, high selfing rates, or low migration rate. In this system, hosts are obligate outcrossers and they migrate by seeds and pollen, whereas parasites can self-fertilize and migrate only on pollinating insects. We discuss the effect of limited gene flow in this parasite on its coevolutionary interaction with its host, and its potential for local adaptation on sympatric host populations.

Journal Article↗

Biodiversity and systematics of basidiomycetous yeasts as determined by large-subunit rDNA D1/D2 domain sequence analysis.

The molecular systematics of 337 strains of basidiomycetous yeasts and yeast-like fungi, representing 230 species in 18 anamorphic and 24 teleomorphic genera, was determined by sequence analysis of the D1/D2 region of the large-subunit rDNA. The data were compared with published sequences of other basidiomycetous fungi. The results demonstrated that the yeast species and genera are phylogenetically distributed among the Microbotryum, Sporidiobolus, Agaricostilbum and Erythrobasidium clades of the Urediniomycetes; the Tremellales, Trichosporonales ord. nov., Filobasidiales and Cystofilobasidiales clades of the Hymenomycetes; and the Ustilaginales, Microstromatales and Malasseziales clades of the Ustilaginomycetes. Genera such as Bensingtonia, Cryptococcus, Rhodotorula and Sporobolomyces are polyphyletic, i.e. they occur in two or more clades. In contrast, other genera, e.g. Bullera, Cystofilobasidium, Fellomyces, Filobasidiella, Filobasidium, Kondoa, Kurtzmanomyces, Leucosporidium, Rhodosporidium, Sporidiobolus and Udeniomyces, are monophyletic. The majority of the species can be identified using D1/D2 analyses, although the internal transcribed spacer region is required to distinguish closely related species. The intergenic spacer region is recommended for additional differentiation of species and strains.

Basidiomycota↗

Molecular phylogenetics of the genus Rhodotorula and related basidiomycetous yeasts inferred from the mitochondrial cytochrome b gene.

Phylogenetic relationships of basidiomycetous yeasts, especially of the genus Rhodotorula, were studied using partial sequences of the mitochondrial cytochrome b gene. The results demonstrated that the basidiomycetous yeasts under investigation distributed into two main clusters: one containing Tremellales, Filobasidiales and their anamorphs and the other containing Ustilaginales, Sporidiales and their anamorphs. This clustering in turn correlates with cell wall biochemistry, presence or absence of xylose, and septal ultrastructure, dolipore or simple pore. Bullera, Bulleromyces, Filobasidiella, Cryptococcus and Trichosporon, yeasts of the former cluster, contain xylose in the cell wall and have dolipore septa. In contrast yeasts of the latter cluster, which included Bensingtonia, Erythrobasidium, Leucosporidium, Malassezia, Rhodosporidium, Rhodotorula, Sporidiobolus, Sporobolomyces and Ustilago, have no xylose in the cell wall and have a simple pore septum. Yeasts of the latter group could be further divided into four clades (A-D). Species of Rhodotorula were distributed in all of these clades, indicating the polyphyletic nature of the genus. A limited number of Rhodotorula species demonstrated identical sequences, for example Rhodotorula bacarum and Rhodotorula foliorum, Rhodotorula fujisanensis and Rhodotorula futronensis, Rhodotorula glutinis var. dairenensis and Rhodotorula mucilaginosa. However, all the other test species of the genus Rhodotorula were well separated based on their 396 bp nucleotide sequences. These results demonstrate the effectiveness of the use of cytochrome b sequences for both species identification and the study of phylogenetic relationships among basidiomycetous yeasts.

Amino Acid Sequence↗