| 1. |
- Pent, Mari, et al.
(author)
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Host genetic variation strongly influences the microbiome structure and function in fungal fruiting-bodies
- 2018
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In: Environmental Microbiology. - : WILEY. - 1462-2912 .- 1462-2920. ; 20:5, s. 1641-1650
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Journal article (peer-reviewed)abstract
- Despite increasing knowledge on host-associated microbiomes, little is known about mechanisms underlying fungus-microbiome interactions. This study aimed to examine the relative importance of host genetic, geographic and environmental variations in structuring fungus-associated microbiomes. We analyzed the taxonomic composition and function of microbiomes inhabiting fungal fruiting-bodies in relation to host genetic variation, soil pH and geographic distance between samples. For this, we sequenced the metagenomes of 40 fruiting-bodies collected from six fairy rings (i.e., genets) of a sapro-trophic fungus Marasmius oreades. Our analyses revealed that fine genetic variations between host fungi could strongly affect their associated microbiome, explaining, respectively, 25% and 37% of the variation in microbiome structure and function, whereas geographic distance and soil pH remained of secondary importance. These results, together with the smaller genome size of fungi compared to other eukaryotes, suggest that fruiting-bodies are suitable for further genome-centric studies on hostmicrobiome interactions.
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| 2. |
- Vowles, Tage, et al.
(author)
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Complex effects of mammalian grazing on extramatrical mycelial biomass in the Scandes forest-tundra ecotone
- 2018
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In: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 8:2, s. 1019-1030
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Journal article (peer-reviewed)abstract
- Mycorrhizal associations are widespread in high-latitude ecosystems and are potentially of great importance for global carbon dynamics. Although large herbivores play a key part in shaping subarctic plant communities, their impact on mycorrhizal dynamics is largely unknown. We measured extramatrical mycelial (EMM) biomass during one growing season in 16-year-old herbivore exclosures and unenclosed control plots (ambient), at three mountain birch forests and two shrub heath sites, in the Scandes forest-tundra ecotone. We also used high-throughput amplicon sequencing for taxonomic identification to investigate differences in fungal species composition. At the birch forest sites, EMM biomass was significantly higher in exclosures (1.36 +/- 0.43g C/m(2)) than in ambient conditions (0.66 +/- 0.17g C/m(2)) and was positively influenced by soil thawing degree-days. At the shrub heath sites, there was no significant effect on EMM biomass (exclosures: 0.72 +/- 0.09g C/m(2); ambient plots: 1.43 +/- 0.94). However, EMM biomass was negatively related to Betula nana abundance, which was greater in exclosures, suggesting that grazing affected EMM biomass positively. We found no significant treatment effects on fungal diversity but the most abundant ectomycorrhizal lineage/cortinarius, showed a near-significant positive effect of herbivore exclusion (p=.08), indicating that herbivory also affects fungal community composition. These results suggest that herbivory can influence fungal biomass in highly context-dependent ways in subarctic ecosystems. Considering the importance of root-associated fungi for ecosystem carbon balance, these findings could have far-reaching implications.
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