No abstract

Respiratory syncytial virus (RSV) is a human respiratory pathogen which remains a leading viral cause of hospitalizations and mortality among infants in their first year of life. Here, we review the biology of RSV, the primary laboratory isolates or strains which have been used to best characterize the virus since its discovery in 1956, and discuss the implications for genetic and functional variations between the established laboratory strains and the recently identified clinical isolates.

Species delimitation is one of the most fundamental processes in biology. Biodiversity undertakings, for instance, require explicit species concepts and criteria for species delimitation in order to be relevant and translatable. However, a perfect species concept does not exist for Fungi. Here, we review the species concepts commonly used in Basidiomycota, the second largest phylum of Fungi that contains some of the best known species of mushrooms, rusts, smuts, and jelly fungi. In general, best practice is to delimitate species, publish new taxa, and conduct taxonomic revisions based on as many independent lines of evidence as possible, that is, by applying a so-called unifying (or integrative) conceptual framework. However, the types of data used vary considerably from group to group. For this reason we discuss the different classes of Basidiomycota, and for each provide: (i) a general introduction with difficulties faced in species recognition, (ii) species concepts and methods for species delimitation, and (iii) community recommendations and conclusions.

A smut fungus that hinders wiregrass restoration efforts in longleaf pine-grassland ecosystems was collected from Aristida stricta and A. beyrichiana (Poaceae) in three states in the southeastern USA. Morphological and phylogenetic characteristics of this fungus were examined. These data show that the specimens from both plant species were infected by the same fungus and represent a new species of Langdonia. The new species differs morphologically from other species of Langdonia by teliospores being solitary and not compacted into spore balls. Spore wall ornamentation and teliospore size also differ from other Langdonia species. Phylogenetic analyses of DNA sequences of the ITS, LSU, and EF-1α supported separation of the species from A. stricta and A. beyrichiana from other Langdonia species. Based on these results, a new species, Langdonia walkerae, is proposed.

Tilletia caries infection of wheat (Triticum aestivum) has become an increasing problem in organic wheat agriculture throughout the world. Little is known about how this pathogen alters host metabolism to ensure a successful infection. We investigated how T. caries allocates resources from wheat for its growth over the life cycle of the pathogen. An untargeted metabolomics approach that combined gas chromatography time-of-flight mass spectrometry and ultraperformance liquid chromatography tandem mass spectrometry platforms was used to determine which primary or specialized metabolite pathways are targeted and altered during T. caries infection. We found that T. caries does not dramatically alter the global metabolome of wheat but instead alters key metabolites for its own nutrient uptake and to antagonize host defenses by reducing wheat’s sweet immunity response and other related pathways. Our results highlight metabolic characteristics needed for selecting wheat varieties that are resistant to T. caries infection for organic agriculture. In addition, several wheat metabolites were identified that could be used in developing a diagnostic tool for early detection of T. caries infection.