The Bacterial Communities of Alaskan Mosses and Their Contributions to N2-Fixation
Background: Mosses in high latitude ecosystems harbor diverse bacterial taxa, including N2-fixers which are key contributors to nitrogen dynamics in these systems. Yet, the relative importance of moss host species, and environmental factors, in structuring these microbial communities and their N2-fixing potential remains unclear. We studied 26 boreal and tundra moss species across 24 sites in Alaska, USA from 61º to 69º N. We used cultivation-independent approaches to characterize the variation in moss-associated bacterial communities as a function of host species identity and site characteristics. We also measured N2-fixation rates via 15N2 isotopic enrichment and identified potential N2-fixing bacteria using available literature and genomic information.
Results: Host species identity and host evolutionary history were both highly predictive of moss microbiome composition, highlighting strong phylogenetic coherence in these microbial communities. Although less important, light availability and temperature also influenced composition of the moss microbiome. Finally, we identified putative N2-fixing bacteria specific to some moss hosts, including potential N2-fixing bacteria outside well-studied cyanobacterial clades.
Conclusions: The strong effect of host identity on moss-associated bacterial communities demonstrates mosses’ utility for understanding plant-microbe interactions in non-leguminous systems. Our work also highlights the likely importance of novel bacterial taxa to N2-fixation in high-latitude ecosystems.
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Posted 23 Sep, 2020
Received 19 Nov, 2020
On 19 Nov, 2020
Received 16 Nov, 2020
Received 02 Nov, 2020
On 26 Oct, 2020
On 26 Oct, 2020
Received 06 Oct, 2020
On 05 Oct, 2020
On 29 Sep, 2020
Invitations sent on 27 Sep, 2020
On 20 Sep, 2020
On 19 Sep, 2020
On 19 Sep, 2020
On 17 Sep, 2020
The Bacterial Communities of Alaskan Mosses and Their Contributions to N2-Fixation
Posted 23 Sep, 2020
Received 19 Nov, 2020
On 19 Nov, 2020
Received 16 Nov, 2020
Received 02 Nov, 2020
On 26 Oct, 2020
On 26 Oct, 2020
Received 06 Oct, 2020
On 05 Oct, 2020
On 29 Sep, 2020
Invitations sent on 27 Sep, 2020
On 20 Sep, 2020
On 19 Sep, 2020
On 19 Sep, 2020
On 17 Sep, 2020
Background: Mosses in high latitude ecosystems harbor diverse bacterial taxa, including N2-fixers which are key contributors to nitrogen dynamics in these systems. Yet, the relative importance of moss host species, and environmental factors, in structuring these microbial communities and their N2-fixing potential remains unclear. We studied 26 boreal and tundra moss species across 24 sites in Alaska, USA from 61º to 69º N. We used cultivation-independent approaches to characterize the variation in moss-associated bacterial communities as a function of host species identity and site characteristics. We also measured N2-fixation rates via 15N2 isotopic enrichment and identified potential N2-fixing bacteria using available literature and genomic information.
Results: Host species identity and host evolutionary history were both highly predictive of moss microbiome composition, highlighting strong phylogenetic coherence in these microbial communities. Although less important, light availability and temperature also influenced composition of the moss microbiome. Finally, we identified putative N2-fixing bacteria specific to some moss hosts, including potential N2-fixing bacteria outside well-studied cyanobacterial clades.
Conclusions: The strong effect of host identity on moss-associated bacterial communities demonstrates mosses’ utility for understanding plant-microbe interactions in non-leguminous systems. Our work also highlights the likely importance of novel bacterial taxa to N2-fixation in high-latitude ecosystems.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Due to technical limitations, full-text HTML conversion of this manuscript could not be completed. However, the manuscript can be downloaded and accessed as a PDF.