DOI: 10.25338/b8d33c
title: Minnesota peat viromes reveal terrestrial and aquatic niche partitioning for local and global viral populations

description: Background: Peatlands are expected to experience sustained yet fluctuating
 higher temperatures due to climate change, leading to increased microbial
 activity and greenhouse gas emissions. Despite mounting evidence for viral
 contributions to these processes in thawing permafrost, little is known
 about viruses in other peatlands. More generally, soil viral biogeography
 and its potential drivers are poorly understood at both local and global
 scales. Here, 87 metagenomes and five viral size-fraction metagenomes
 (viromes) from a boreal peatland in Northern Minnesota (from the SPRUCE
 whole-ecosystem warming experiment and surrounding bog) were analyzed for
 dsDNA viral community ecological patterns, and the recovered viral
 populations (vOTUs) were compared to a database of 261,799 vOTUs from
 diverse ecosystems. Results: Within the SPRUCE experiment, viral community
 composition was significantly correlated with peat depth, soil moisture,
 and carbon chemistry, including CH4 and CO2 concentrations, but not with
 temperature during the first two years of warming treatments. Peat vOTUs
 with aquatic-like signatures (shared predicted protein content with marine
 and/or freshwater vOTUs) were significantly enriched in surface, more
 waterlogged depths. Predicted host ranges for SPRUCE vOTUs were relatively
 narrow, generally involving a single bacterial host or two hosts from the
 same genus. Of the 4,326 vOTUs recovered from SPRUCE peat, 164 were
 previously detected in other soils, mostly peatlands. None of the
 previously identified 202,372 marine and freshwater vOTUs were detected in
 SPRUCE peat, but 1.9% of 78,203 genus-level viral clusters (VCs) were
 shared between soil and aquatic environments. On a per-sample basis, vOTU
 recovery was 32-fold higher from viromes compared to total metagenomes.
 Conclusions: Results suggest strong viral species boundaries between
 terrestrial and aquatic ecosystems and to some extent between peat and
 other soils, with differences less pronounced at the genus level. The
 significant enrichment of aquatic-like vOTUs in more waterlogged peat
 suggests that viruses may also exhibit niche partitioning on more local
 scales. These patterns are presumably driven in part by host ecology,
 consistent with the predicted narrow host ranges. Although more samples
 and increased sequencing depth improved vOTU recovery from total
 metagenomes, the substantially higher per-sample vOTU recovery after viral
 particle enrichment highlights the utility of soil viromic approaches.
description: This zip package includes:  1) All vOTUs from
 the SPRUCE experiment, both predicted from viromes and total soil
 metagenomes, recovered in one or multiple samples. 2)
 All vOTUs in the Phages and
 Integrated Genomes
 Encapsidated Or
 Not (PIGEON) database.  3) A
 renaming key for the PIGEON database, with for each vOTU in the PIGEON
 database: our name for the contig, the original name for the contig as in
 the publication, and the publication the contig came from.
 4) MAGs from the 2018 metagenomes and 2015-2016 metagenomes.
 Information on binning of these MAGs can be found in supplemental tables 4
 and 5 of the manuscript. 5) A table with habitat
 origins for each of the vOTUs in the PIGEON database