Soil microorganisms are pivotal in the global carbon cycle, but the viruses that affect them and their impact on ecosystems are less understood. In this study, we explored the diversity, dynamics, and ecology of soil viruses through 379 metagenomes collected annually from 2010 to 2017. These samples spanned the seasonally thawed active layer of a permafrost thaw gradient, which included palsa, bog, and fen habitats. We identified 5051 virus operational taxonomic units (vOTUs), doubling the known viruses for this site. These vOTUs were largely ephemeral within habitats, suggesting a turnover at the vOTU level from year to year. While the diversity varied by thaw stage and depth-related patterns were specific to each habitat, the virus communities did not significantly change over time. The abundance ratios of virus to host at the phylum level did not show consistent trends across the thaw gradient, depth, or time. To assess potential ecosystem impacts, we predicted hosts in silico and found viruses linked to microbial lineages involved in the carbon cycle, such as methanotrophy and methanogenesis. This included the identification of viruses of Candidatus Methanoflorens, a significant global methane contributor. We also detected a variety of potential auxiliary metabolic genes, including 24 carbon-degrading glycoside hydrolases, six of which are uniquely terrestrial. In conclusion, these long-term observations enhance our understanding of soil viruses in the context of climate-relevant processes and provide opportunities to explore their role in terrestrial carbon cycling.

中文翻译：

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永久冻土融化梯度的病毒生态学和 7 年时间动态


土壤微生物在全球碳循环中至关重要，但影响它们的病毒及其对生态系统的影响却鲜为人知。在这项研究中，我们通过 2010 年至 2017 年每年收集的 379 个宏基因组探索了土壤病毒的多样性、动态和生态学。这些样本跨越了永久冻土解冻梯度的季节性解冻活动层，其中包括帕尔萨、沼泽和沼泽栖息地。我们确定了 5051 个病毒操作分类单元 (vOTU)，使该站点的已知病毒数量增加了一倍。这些 vOTU 在栖息地内基本上是短暂的，这表明 vOTU 水平每年都会发生变化。虽然多样性因解冻阶段而异，并且与深度相关的模式因每个栖息地而异，但病毒群落并没有随着时间的推移而发生显着变化。病毒与宿主在门水平上的丰度比在解冻梯度、深度或时间上并未表现出一致的趋势。为了评估潜在的生态系统影响，我们通过计算机预测了宿主，并发现了与参与碳循环（例如甲烷氧化和甲烷生成）的微生物谱系相关的病毒。其中包括对全球重要甲烷贡献者Candidatus Methanoflorens 病毒的鉴定。我们还检测到了多种潜在的辅助代谢基因，包括 24 种碳降解糖苷水解酶，其中 6 种是陆地独有的。总之，这些长期观察增强了我们对气候相关过程背景下的土壤病毒的理解，并为探索其在陆地碳循环中的作用提供了机会。