Showing papers by "Mohammad Bahram published in 2014"
American Museum of Natural History1, University of Tartu2, University of Colombo3, Royal Netherlands Academy of Arts and Sciences4, University of Florida5, University of Palermo6, Goethe University Frankfurt7, Hobart Corporation8, Nakhon Phanom University9, University of Bamenda10, University of Gothenburg11, Naturalis12, Swedish University of Agricultural Sciences13, Royal Botanic Gardens14, Universiti Malaysia Sabah15, United States Department of Agriculture16, Forest Research Institute Malaysia17, Humboldt State University18, Chinese Academy of Sciences19, Landcare Research20, University of Western Australia21, Estonian University of Life Sciences22, University of Southern Queensland23, Botanic Garden Meise24, Manchester Metropolitan University25, James Cook University26
TL;DR: Diversity of most fungal groups peaked in tropical ecosystems, but ectomycorrhizal fungi and several fungal classes were most diverse in temperate or boreal ecosystems, and manyfungal groups exhibited distinct preferences for specific edaphic conditions (such as pH, calcium, or phosphorus).
Abstract: Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.
2,346 citations
University of Gothenburg1, Mae Fah Luang University2, University of Warsaw3, Uppsala University4, University of Tartu5, University of Oslo6, University of Malaya7, University of Aveiro8, University of Arizona9, Swedish University of Agricultural Sciences10, University of California, Berkeley11, Estonian University of Life Sciences12, American Museum of Natural History13, Graz University of Technology14, Royal Horticultural Society15, Kansas State University16, University of Helsinki17, University of Warmia and Mazury in Olsztyn18, Universidade Federal de Santa Catarina19, Universidade Federal de Viçosa20, McMaster University21, ETH Zurich22, University of Tennessee23, Rutgers University24, Mie University25, Yale University26
TL;DR: A concerted effort was reported on to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages, to enrich the sequences with geographical and ecological metadata.
Abstract: Plant pathogenic fungi are a large and diverse assemblage of eukaryotes with substantial impacts on natural ecosystems and human endeavours. These taxa often have complex and poorly understood life cycles, lack observable, discriminatory morphological characters, and may not be amenable to in vitro culturing. As a result, species identification is frequently difficult. Molecular (DNA sequence) data have emerged as crucial information for the taxonomic identification of plant pathogenic fungi, with the nuclear ribosomal internal transcribed spacer (ITS) region being the most popular marker. However, international nucleotide sequence databases are accumulating numerous sequences of compromised or low-resolution taxonomic annotations and substandard technical quality, making their use in the molecular identification of plant pathogenic fungi problematic. Here we report on a concerted effort to identify high-quality reference sequences for various plant pathogenic fungi and to re-annotate incorrectly or insufficiently annotated public ITS sequences from these fungal lineages. A third objective was to enrich the sequences with geographical and ecological metadata. The results – a total of 31,954 changes – are incorporated in and made available through the UNITE database for molecular identification of fungi (http://unite.ut.ee), including standalone FASTA files of sequence data for local BLAST searches, use in the next-generation sequencing analysis platforms QIIME and mothur, and related applications. The present initiative is just a beginning to cover the wide spectrum of plant pathogenic fungi, and we invite all researchers with pertinent expertise to join the annotation effort.
126 citations
TL;DR: Most biogeographic regions exhibited substantial phylogenetic clustering suggesting a strong impact of dispersal limitation over a large geographic scale, however, in northern Holarctic regions, phylogenetic distances and phylogenetic grouping of isolates indicate multiple recent dispersal events.
Abstract: Compared with plants and animals, large-scale biogeographic patterns of microbes including fungi are poorly understood. By the use of a comparative phylogenetic approach and ancestral state reconstructions, we addressed the global biogeography, rate of evolution and evolutionary origin of the widely distributed ectomycorrhizal (EcM) /sebacina lineage that forms a large proportion of the Sebacinales order. We downloaded all publicly available internal transcribed spacer (ITS) sequences and metadata and supplemented sequence information from three genes to construct dated phylogenies and test biogeographic hypotheses. The /sebacina lineage evolved 45-57Myr ago that groups it with relatively young EcM taxa in other studies. The most parsimonious origin for /sebacina is inferred to be North American temperate coniferous forests. Among biogeographic traits, region and biome exhibited stronger phylogenetic signal than host family. Consistent with the resource availability (environmental energy) hypothesis, the ITS region is evolving at a faster rate in tropical than nontropical regions. Most biogeographic regions exhibited substantial phylogenetic clustering suggesting a strong impact of dispersal limitation over a large geographic scale. In northern Holarctic regions, however, phylogenetic distances and phylogenetic grouping of isolates indicate multiple recent dispersal events.
59 citations
TL;DR: The results suggest that Alnus species exert strong phylogenetically determined selection pressure on compatible Actinobacteria in Frankia communities and their biogeographic patterns.
Abstract: Macroecological patterns of microbes have received relatively little attention until recently. This study aimed to disentangle the determinants of the global biogeographic community of Alnus-associated actinobacteria belonging to the Frankia alni complex. By determining a global sequence similarity threshold for the nitrogenase reductase (nifH) gene, we separated Frankia into operational taxonomic units (OTUs) and tested the relative effects of Alnus phylogeny, geographic relatedness, and climatic and edaphic variables on community composition at the global scale. Based on the optimal nifH gene sequence similarity threshold of 99.3%, we distinguished 43 Frankia OTUs from root systems of 22 Alnus species on four continents. Host phylogeny was the main determinant of Frankia OTU-based community composition, but there was no effect on the phylogenetic structure of Frankia. Biogeographic analyses revealed the strongest cross-continental links over the Beringian land bridge. Despite the facultative symbiotic nature of Frankia, phylogenetic relations among Alnus species play a prominent role in structuring root-associated Frankia communities and their biogeographic patterns. Our results suggest that Alnus species exert strong phylogenetically determined selection pressure on compatible Actinobacteria.
40 citations