Neotropical Studies on Hymenochaetaceae: Unveiling the Diversity and Endemicity of Phellinotus.

Phellinotus, a neotropical genus of wood-decay fungi commonly found on living members of the Fabaceae family, was initially described as containing two species, P. neoaridus and P. piptadeniae. The members of this genus, along with six other well-established genera and some unresolved lineages, are the current representatives of the 'phellinotus clade'. On the other hand, based on a two-loci phylogenetic analysis, some entities/lineages of the 'phellinotus clade' have been found in Fomitiporella s.l. In this work, we performed four-loci phylogenetic analyses and based on our results the genera of the 'phellinotus clade' are shown to be monophyletic groups. In addition to the natural groups confirmed as different genera, morphological revisions, phylogenetic relationships, and host distribution of different specimens resembling P. neoaridus and P. piptadeniae revealed three new species in the Phellinotus genus, referred to here as P. magnoporatus, P. teixeirae and P. xerophyticus. Furthermore, for P. piptadeniae a narrower species concept was adopted with redefined morphological characters and a more limited distribution range. Both P. neoaridus and P. teixeirae have a distribution range restricted to seasonally dry tropical forests in South America. Additionally, based on detailed morphological revisions Phellinus badius, Phellinus resinaceus, and Phellinus scaber are transferred to the Phellinotus genus. The geographic distribution and host range of the genus are then discussed.

Community dynamics of soil-borne fungal communities along elevation gradients in neotropical and palaeotropical forests.

Because of their steep gradients in abiotic and biotic factors, mountains offer an ideal setting to illuminate the mechanisms that underlie patterns of species distributions and community assembly. We compared the composition of taxonomically and functionally diverse fungal communities in soils along five elevational gradients in mountains of the Neo- and Palaeotropics (northern Argentina, southern Brazil, Panama, Malaysian Borneo and Papua New Guinea). Both the richness and composition of soil fungal communities reflect environmental factors, particularly temperature and soil pH, with some shared patterns among neotropical and palaeotropical regions. Community dynamics are characterized by replacement of species along elevation gradients, implying a relatively narrow elevation range for most fungi, which appears to be driven by contrasting environmental preferences among both functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences in elevational patterns between neotropical and palaeotropical montane communities. The pronounced compositional and functional turnover along elevation gradients implies that tropical montane forest fungi will be sensitive to climate change, resulting in shifts in composition and functionality over time.

Comparative mitogenomics of Agaricomycetes: Diversity, abundance, impact and coding potential of putative open-reading frames.

The mitochondrion is an organelle found in eukaryote organisms, and it is vital for different cellular pathways. The mitochondrion has its own DNA molecule and, because its genetic content is relatively conserved, despite the variation of size and structure, mitogenome sequences have been widely used as a promising molecular biomarker for taxonomy and evolution in fungi. In this study, the mitogenomes of two fungal species of Agaricomycetes class, Phellinotus piptadeniae and Trametes villosa, were assembled and annotated for the first time. We used these newly sequenced mitogenomes for comparative analyses with other 55 mitogenomes of Agaricomycetes available in public databases. Mitochondrial DNA (mtDNA) size and content are highly variable and non-coding and intronic regions, homing endonucleases (HEGs), and unidentified ORFs (uORFs) significantly contribute to the total size of the mitogenome. Furthermore, accessory genes (most of them as HEGs) are shared between distantly related species, most likely as a consequence of horizontal gene transfer events. Conversely, uORFs are only shared between taxonomically related species, most probably as a result of vertical evolutionary inheritance. Additionally, codon usage varies among mitogenomes and the GC content of mitochondrial features may be used to distinguish coding from non-coding sequences. Our results also indicated that transposition events of mitochondrial genes to the nuclear genome are not common. Despite the variation of size and content of the mitogenomes, mitochondrial genes seemed to be reliable molecular markers in our time-divergence analysis, even though the nucleotide substitution rates of mitochondrial and nuclear genomes of fungi are quite different. We also showed that many events of mitochondrial gene shuffling probably happened amongst the Agaricomycetes during evolution, which created differences in the gene order among species, even those of the same genus. Altogether, our study revealed new information regarding evolutionary dynamics in Agaricomycetes.