Viruses in Soil: A Review of Methods, Distribution and Ecological Functions

Viruses are the most abundant and active biological organisms in soil ecosystems. However, their spatial distribution and ecological functions remain inadequately addressed owing to a lack of systematic analysis and the complexity of the soil matrix. Therefore, this review systematically summarizes current knowledge of soil viruses through an examination of research methods, spatiotemporal distribution, and ecological functions. Our review indicates that current progress of soil viruses remains constrained by technological inconsistencies and difficulties in viral isolation techniques within complex soil matrices. Therefore, viral distribution analyses are largely limited to small-scale sections of agricultural land, forest, pastureland, and grassland. There is insufficient exploration of viral distribution across large-scale geographic areas and desert soil environments, as well as RNA virus diversity. The characteristics of soil viral communities are primarily influenced by environmental factors such as temperature, moisture, and pH. Overall, we conclude that soil viruses are pivotal drivers of microbial community dynamics and biogeochemical cycling, although our comprehensive understanding is severely bottlenecked by complex soil matrices and inconsistent viral isolation methodologies. Future research should focus on methodological innovations such as long-read sequencing and single-cell approaches to decipher virus-host interaction networks and their ecological roles across large-scale and extreme environments.