High diversity of root associated fungi in both alpine and arctic Dryas octopetala

<p>Abstract</p> <p>Background</p> <p><it>Dryas octopetala </it>is a widespread dwarf shrub in alpine and arctic regions that forms ectomycorrhizal (ECM) symbiotic relationships with fungi. In this study we investigated the fungal communities associated with roots of <it>D. octopetala </it>in alpine sites in Norway and in the High Arctic on Svalbard, where we aimed to reveal whether the fungal diversity and species composition varied across the Alpine and Arctic regions. The internal transcribed spacer (ITS) region of nuclear ribosomal DNA was used to identify the fungal communities from bulk root samples obtained from 24 plants.</p> <p>Results</p> <p>A total of 137 operational taxonomic units (OTUs) were detected (using 97% similarity cut off during sequence clustering) and well-known ECM genera such as <it>Cenococcum</it>, <it>Cortinarius, Hebeloma</it>, <it>Inocybe </it>and <it>Tomentella </it>occurred frequently. There was no decrease in fungal diversity with increasing latitude. The overall spatial heterogeneity was high, but a weak geographical structuring of the composition of OTUs in the root systems was observed. Calculated species accumulation curves did not level off.</p> <p>Conclusions</p> <p>This study indicates that the diversity of fungi associated with <it>D. octopetala </it>does not decrease in high latitude arctic regions, which contrasts observations made in a wide spectrum of other organism groups. A high degree of patchiness was observed across root systems, but the fungal communities were nevertheless weakly spatially structured. Non-asymptotical species accumulation curves and the occurrence of a high number of singletons indicated that only a small fraction of the fungal diversity was detected.</p

18S rDNA gene metabarcoding of microeukaryotes and epi-endophytes in the holobiome of seven species of large brown algae

Brown algae (Phaeophyceae) are habitat-forming species in coastal ecosystems and include kelp forests and seaweed beds that support a wide diversity of marine life. Host-associated microbial communities are an integral part of phaeophyte biology, and whereas the bacterial microbial partners have received considerable attention, the microbial eukaryotes associated with brown algae have hardly been studied. Here, we used broadly targeted “pan-eukaryotic” primers (metabarcoding) to investigate brown algal-associated eukaryotes (the eukaryome). Using this approach, we aimed to investigate the eukaryome of seven large brown algae that are important and common species in coastal ecosystems. We also aimed to assess whether these macroalgae harbor novel eukaryotic diversity and to ascribe putative functional roles to the host-associated eukaryome based on taxonomic affiliation and phylogenetic placement. We detected a significant diversity of microeukaryotic and algal lineages associated with the brown algal species investigated. The operational taxonomic units (OTUs) were taxonomically assigned to 10 of the eukaryotic major supergroups, including taxonomic groups known to be associated with seaweeds as epibionts, endobionts, parasites, and commensals. Additionally, we revealed previously unrecorded sequence types, including novel phaeophyte OTUs, particularly in the Fucus spp. samples, that may represent fucoid genomic variants, sequencing artifacts, or undescribed epi-/endophytes. Our results provide baseline data and technical insights that will be useful for more comprehensive seaweed eukaryome studies investigating the evidently lineage-rich and functionally diverse symbionts of brown algae.publishedVersio

Environmental impacts of aquaculture and coexcisting industries

publishedVersio

Jacobsen_Pool1_backward_reads

Bzip-compressed fastq-file containing raw sequences (backward reads) from Illumina HiSeq of pooled fungal DNA extracted from 103 samples (Pool1) of wood-inhabiting insects

Jacobsen_Pool2_forward_reads_part1

First half of the bzip-compressed fastq-file containing raw sequences (forward reads) from Illumina HiSeq of pooled fungal DNA extracted from 98 samples (Pool2) of wood-inhabiting insects. Split with HJSplit as recommended by Dryad (http://wiki.datadryad.org/Large_File_Transfer)

Jacobsen_Pool1_forward_reads

Bzip-compressed fastq-file containing raw sequences (forward reads) from Illumina HiSeq of pooled fungal DNA extracted from 103 samples (Pool1) of wood-inhabiting insects

Jacobsen_Pool2_backward_reads_part2

Second half of the bzip-compressed fastq-file containing raw sequences (backward reads) from Illumina HiSeq of pooled fungal DNA extracted from 98 samples (Pool2) of wood-inhabiting insects. Split with HJSplit as recommended by Dryad (http://wiki.datadryad.org/Large_File_Transfer)

Rep_seqs_OTUs_scata_10k

Representative sequences for OTUs as clustered by Scata (https://scata.mykopat.slu.se/) in subsampled dataset (max 10k sequences from each insect sample)

Data from: Wood-inhabiting insects can function as targeted vectors for decomposer fungi

Most wood-inhabiting fungi are assumed to be dispersed primarily by wind, with the exception of a few species involved in mutualistic relationships with insects. In this study we tested whether several species of wood-inhabiting insects can function as dispersal vectors for non-mutualistic fungi, which would indicate that wood-inhabiting fungi can benefit from targeted animal-mediated dispersal. We sampled wood-inhabiting beetles (Coleoptera) from freshly felled wood experimentally added to forests and used DNA metabarcoding to investigate the fungal DNA carried by these insects. Staphylinid beetles rarely contained fungal DNA, while Endomychus coccineus, Glischrochilus hortensis and Glischrochilus quadripunctatus frequently carried fungal DNA with a composition specific to the insect taxon. A large proportion of the obtained fungal sequences (34%) represented decomposer fungi, including well-known wood-decay fungi such as Fomitopsis pinicola, Fomes fomentarius, Trichaptum abietinum and Trametes versicolor. Scanning electron microscopy further showed that some of the fungal material was carried as spores or yeast cells on the insect exoskeletons. Our results suggest that insect-vectored dispersal is of broader importance to wood-inhabiting fungi than previously assumed

Jacobsen_mapping_file_DNA

Excel-file with tag/mid (molecular identifier) sequences, ITS-sequences, sample IDs for tags/mids and lists of repetitions and negatives