scholarly journals Global diversity and biogeography of the Zostera marina mycobiome

2020 ◽  
Author(s):  
Cassandra L. Ettinger ◽  
Laura E. Vann ◽  
Jonathan A. Eisen

AbstractSeagrasses are marine flowering plants that provide critical ecosystem services in coastal environments worldwide. Marine fungi are often overlooked in microbiome and seagrass studies, despite terrestrial fungi having critical functional roles as decomposers, pathogens or endophytes in global ecosystems. Here we characterize the distribution of fungi associated with the seagrass, Zostera marina, using leaves, roots, and rhizosphere sediment from 16 locations across its full biogeographic range. Using high throughput sequencing of the ribosomal internal transcribed spacer (ITS) region and 18S ribosomal RNA gene, we first measured fungal community composition and diversity, then we tested hypotheses of neutral community assembly theory and the degree to which deviations suggested amplicon sequence variants (ASVs) were plant-selected or dispersal-limited, and finally we identified a core mycobiome and investigated the global distribution of differentially abundant ASVs. Our results show that the fungal community is significantly different between sites and follows a weak, but significant pattern of distance decay. Generally, there was evidence for both deterministic and stochastic factors contributing to community assembly of the mycobiome. The Z. marina core leaf and root mycobiomes are dominated by unclassified Sordariomycetes spp., unclassified Chytridiomycota lineages (including Lobulomycetaceae spp.), unclassified Capnodiales spp. and Saccharomyces sp. A few ASVs (e.g. Lobulomyces sp.) appear restricted to one or a handful of locations (e.g. possibly due to local adaptation, deterministic dispersal limitation or seasonal bloom events), while others (e.g. Saccharomyces sp.) are more ubiquitous across all locations suggesting a true global distribution and possible plant-selection. Fungal guilds associated with Z. marina were only weakly identified (10.12% of ITS region and 3.4% 18S rRNA gene ASV guild assignments were considered highly probable) including wood saprotrophs, ectomycorrhizal fungi, endophytic fungi and plant pathogens. Our results are similar to those found for other seagrass species. It is clear from the many unclassified fungal ASVs and fungal functional guilds, that our knowledge of marine fungi is still rudimentary. Further studies characterizing seagrass-associated fungi are needed to understand the roles of these microorganisms generally and when associated with seagrasses.

Author(s):  
Cassandra L. Ettinger ◽  
Laura E. Vann ◽  
Jonathan A. Eisen

Seagrasses are marine flowering plants that provide critical ecosystem services in coastal environments worldwide. Marine fungi are often overlooked in microbiome and seagrass studies, despite terrestrial fungi having critical functional roles as decomposers, pathogens or endophytes in global ecosystems. Here we characterize the distribution of fungi associated with the seagrass, Zostera marina, using leaves, roots, and rhizosphere sediment from 16 locations across its full biogeographic range. Using high throughput sequencing of the ribosomal internal transcribed spacer (ITS) region and 18S ribosomal RNA gene, we first measured fungal community composition and diversity. We then tested hypotheses of neutral community assembly theory and the degree to which deviations suggested amplicon sequence variants (ASVs) were plant-selected or dispersal-limited. Finally, we identified a core mycobiome and investigated the global distribution of differentially abundant ASVs. We found that the fungal community is significantly different between sites and that the leaf mycobiome follows a weak, but significant pattern of distance decay in the Pacific Ocean. Generally, there was evidence for both deterministic and stochastic factors contributing to community assembly of the mycobiome, with most taxa assembling through stochastic processes. The Z. marina core leaf and root mycobiomes were dominated by unclassified Sordariomycetes spp., unclassified Chytridiomycota lineages (including Lobulomycetaceae spp.), unclassified Capnodiales spp. and Saccharomyces sp. It is clear from the many unclassified fungal ASVs and fungal functional guilds, that knowledge of marine fungi is still rudimentary. Further studies characterizing seagrass-associated fungi are needed to understand the roles of these microorganisms generally and when associated with seagrasses. Importance Fungi have important functional roles when associated with land plants, yet very little is known about the roles of fungi associated with marine plants, like seagrasses. In this study, we report the results of a global effort to characterize the fungi associated with the seagrass, Zostera marina, across its full biogeographic range. Although we defined a putative global core fungal community, it is apparent from the many fungal sequences and predicted functional guilds that had no matches to existing databases, that general knowledge of seagrass-associated fungi and marine fungi generally is lacking. This work serves as an important foundational step towards future work investigating the functional ramifications of fungi in the marine ecosystem.


2019 ◽  
Author(s):  
Cassandra L. Ettinger ◽  
Jonathan A. Eisen

AbstractSeagrasses are globally distributed marine flowering plants that are foundation species in coastal ecosystems. Seagrass beds play essential roles as habitats and hatcheries, in nutrient cycling and in protecting the coastline from erosion. Although many studies have focused on seagrass ecology, only a limited number have investigated their associated fungi. In terrestrial systems, fungi can have beneficial and detrimental effects on plant fitness. However, not much is known about marine fungi and even less is known about seagrass associated fungi. Here we used culture-independent sequencing of the ribosomal internal transcribed spacer (ITS) region to characterize the taxonomic diversity of fungi associated with the seagrass, Zostera marina. We sampled from two Z. marina beds in Bodega Bay over three time points to investigate fungal diversity within and between plants. Our results indicate that there are many fungal taxa for which a taxonomic assignment cannot be made living on and inside Z. marina leaves, roots and rhizomes and that these plant tissues harbor distinct fungal communities. The most prevalent ITS amplicon sequence variant (ASV) associated with Z. marina leaves was classified as fungal, but could not initially be assigned to a fungal phylum. We then used PCR with a primer targeting unique regions of the ITS2 region of this ASV and an existing primer for the fungal 28S rRNA gene to amplify part of the 28S rRNA gene region and link it to this ASV. Sequencing and phylogenetic analysis of the resulting partial 28S rRNA gene revealed that the organism that this ASV comes from is a member of Novel Clade SW-I in the order Lobulomycetales in the phylum Chytridiomycota. This clade includes known parasites of freshwater diatoms and algae and it is possible this chytrid is directly infecting Z. marina leaf tissues. This work highlights a need for further studies focusing on marine fungi and the potential importance of these understudied communities to the larger seagrass ecosystem.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Domínguez ◽  
Manuel Aira ◽  
Keith A. Crandall ◽  
Marcos Pérez-Losada

AbstractWastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.


2018 ◽  
Vol 84 (9) ◽  
Author(s):  
Wen Chen ◽  
Sarah Hambleton ◽  
Keith A. Seifert ◽  
Odile Carisse ◽  
Moussa S. Diarra ◽  
...  

ABSTRACTSpore samplers are widely used in pathogen surveillance but not so much for monitoring the composition of aeromycobiota. In Canada, a nationwide spore-sampling network (AeroNet) was established as a pilot project to assess fungal community composition in air and rain samples collected using three different spore samplers in the summers of 2010 and 2011. Metabarcodes of the internal transcribed spacer (ITS) were exhaustively characterized for three of the network sites, in British Columbia (BC), Québec (QC), and Prince Edward Island (PEI), to compare performance of the samplers. Sampler type accounted for ca. 20% of the total explainable variance in aeromycobiota compositional heterogeneity, with air samplers recovering more Ascomycota and rain samplers recovering more Basidiomycota. Spore samplers showed different abilities to collect 27 fungal genera that are plant pathogens. For instance,Cladosporiumspp.,Drechsleraspp., andEntylomaspp. were collected mainly by air samplers, whileFusariumspp.,Microdochiumspp., andUstilagospp. were recovered more frequently with rain samplers. The diversity and abundance of some fungi were significantly affected by sampling location and time (e.g.,AlternariaandBipolaris) and weather conditions (e.g.,MycocentrosporaandLeptosphaeria), and depended on using ITS1 or ITS2 as the barcoding region (e.g.,EpicoccumandBotrytis). The observation that Canada's aeromycobiota diversity correlates with cooler, wetter conditions and northward wind requires support from more long-term data sets. Our vision of the AeroNet network, combined with high-throughput sequencing (HTS) and well-designed sampling strategies, may contribute significantly to a national biovigilance network for protecting plants of agricultural and economic importance in Canada.IMPORTANCEThe current study compared the performance of spore samplers for collecting broad-spectrum air- and rain-borne fungal pathogens using a metabarcoding approach. The results provided a thorough characterization of the aeromycobiota in the coastal regions of Canada in relation to the influence of climatic factors. This study lays the methodological basis to eventually develop knowledge-based guidance on pest surveillance by assisting in the selection of appropriate spore samplers.


2021 ◽  
Author(s):  
Haiyan Duan ◽  
Minghua Ji ◽  
Ai Chen ◽  
Shiqiu Xie ◽  
Junsong Sun ◽  
...  

Abstract Co-composting of recycled cow manure and waste bedding material has been used to convert both agricultural wastes to biofertilizers. This study explored the succession of microbial community, metabolic function and substances conversion capacities during 60 days’ co-composting using high throughput sequencing technology. The study revealed that co-composting of cow manure and bedding material waste at a ratio of 1.32 (CM+B) had the highest efficiency among four treatments. The bacterial and fungal community diversity changed significantly during the co-composting of CM+B group, and the major phyla included Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria and Ascomycota. PICRUSt and FUNGuild analysis showed that carbohydrate, lipid metabolism and especially nitrogen fixation were enhanced in the thermophilic phase, while animal and plant pathogens were not detected after the co-composting. Wood saprotrophs became the dominant fungal group (89.1%) in the maturation phase. Canonical correlation analysis (CCA) and redundancy analysis (RDA) confirmed that temperature influenced bacterial community succession more than it influenced fungal community succession. Ruminiclostridium had a significantly positive relationship with temperature (p_value < 0.05), while pH and C/N had significant effect on the fungal (p_value < 0.05), and Penicillium and Mortierella were significantly related to moisture (p_value < 0.05). This work describes an efficient methodology to deal with co-composting systems that had been successfully applied in agricultural wastes treatment, enabling further understanding in mechanisms underlying the substance conversion and the involved microbial community succession in sophisticated composting system.


2016 ◽  
Vol 82 (9) ◽  
pp. 2632-2643 ◽  
Author(s):  
Hui Sun ◽  
Eeva Terhonen ◽  
Andriy Kovalchuk ◽  
Hanna Tuovila ◽  
Hongxin Chen ◽  
...  

ABSTRACTBoreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P< 0.001) and tree species (P< 0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P< 0.04). The availability of soil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera ofAgaricomycotinaidentified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands.


2020 ◽  
Vol 96 (11) ◽  
Author(s):  
Mathilde Borg Dahl ◽  
Matthias Krebs ◽  
Martin Unterseher ◽  
Tim Urich ◽  
Greta Gaudig

ABSTRACT The drainage of peatlands for their agricultural use leads to huge emissions of greenhouse gases. One sustainable alternative is the cultivation of peat mosses after rewetting (‘Sphagnum farming’). Environmental parameters of such artificial systems may differ from those of natural Sphagnum ecosystems which host a rich fungal community. We studied the fungal community at a 4 ha Sphagnum farming field site in Northwestern Germany and compared it with that of natural Sphagnum ecosystems. Additionally, we asked if any fungi occur with potentially negative consequences for the commercial production and/or use of Sphagnum biomass. Samples were collected every 3 months within 1 year. High-throughput sequencing of the fungal ITS2 barcode was used to obtain a comprehensive community profile of the fungi. The dominant taxa in the fungal community of the Sphagnum farming field site were all commonly reported from natural Sphagnum ecosystems. While the taxonomic composition showed clear differences between seasons, a stable functional community profile was identified across seasons. Additionally, nutrient supply seems to affect composition of fungal community. Despite a rather high abundance of bryophyte parasites, and the occurrence of both Sphagnum-species-specific and general plant pathogens, their impact on the productivity and usage of Sphagnum biomass as raw material for growing media was considered to be low.


Author(s):  
Kaire Loit ◽  
Liina Soonvald ◽  
Alar Astover ◽  
Eve Runno-Paurson ◽  
Maarja Öpik ◽  
...  

The rhizosphere fungal community can play an important role in determining plant growth and health. In this study, using high-throughput sequencing, we investigated the fungal diversity and community composition in the roots and rhizosphere soil of 21 potato (Solanum tuberosum L.) cultivars. The samples were collected at three different sampling points. Furthermore, we assessed the differences in both diversity and composition of pathogen and saprotroph communities. In soil and roots, the fungal richness and relative abundance of pathogens and saprotrophs were mainly affected by sampling time. However, root fungal communities were also significantly affected by cultivar. The most substantial effect of cultivar was on root pathogen diversity. Moreover, the occurrence of most pathogens strongly varied among cultivars. Soil fungal community composition was primarily determined by sampling time; whereas in roots, the primary determinant was cultivar. Our results demonstrate changes in fungal communities over the potato growing season, as well as highlight the importance of potato cultivar on root fungal communities, and emphasise their importance in plant breeding.


Author(s):  
Tânia F. L. Vicente ◽  
Micael F. M. Gonçalves ◽  
Cláudio Brandão ◽  
Cátia Fidalgo ◽  
Artur Alves

Fungal communities associated with macroalgae remain largely unexplored. To characterize algicolous fungal communities using culture dependent methods, macroalgae were collected from different sampling sites in the Ria de Aveiro estuary, Portugal. From a collection of 486 isolates that were obtained, 213 representative isolates were selected through microsatellite-primed PCR (MSP-PCR) fingerprinting analysis. The collection yielded 33 different genera, which were identified using the ITS region of the rDNA. The results revealed that the most abundant taxa in all collections were Acremonium-like species: Alternaria, Cladosporium, Leptobacillium and Penicillium. The fungal community composition varied with macroalgae species. Through multilocus phylogenetic analyses based on ITS, tub2, tef1-α and actA sequences, in addition to detailed morphological data, we propose Cladosporium rubrum sp. nov. (type strain=CMG 28=MUM 19.39) and Hypoxylon aveirense sp. nov. (type strain=CMG 29=MUM 19.40) as novel species.


Botany ◽  
2014 ◽  
Vol 92 (4) ◽  
pp. 303-311 ◽  
Author(s):  
Steven W. Kembel ◽  
Rebecca C. Mueller

The aerial surface of plants, known as the phyllosphere, represents a widespread and diverse habitat for microbes, but the fungal communities colonizing the surface of leaves are not well characterized, and how these communities are assembled on hosts is unknown. We used high-throughput sequencing of fungal communities on the leaves of 51 tree species in a lowland tropical rainforest in Panama to examine the influence of host plant taxonomy and traits on the fungi colonizing the phyllosphere. Fungal communities on leaves were dominated by the phyla Ascomycota (79% of all sequences), Basidiomycota (11%), and Chytridiomycota (5%). Host plant taxonomic identity explained more than half of the variation in fungal community composition across trees, and numerous host functional traits related to leaf morphology, leaf chemistry, and plant growth and mortality were significantly associated with fungal community structure. Differences in fungal biodiversity among hosts suggest that individual tree species support unique fungal communities and that diverse tropical forests also support a large number of fungal species. Similarities between phyllosphere and decomposer communities suggest that fungi inhabiting living leaves may have significant roles in ecosystem functioning in tropical forests.


Sign in / Sign up

Export Citation Format

Share Document