Viral abundance, community structure and correlation with bacterial community in soils of different cover plants

Abstract

Microbial abundance, diversity, metabolic activities, and interactions are central to the ecosystem functions and biogeochemical processes in soil. Viruses can impose top-down control over microbial communities and thus regulate the microbial-mediated processes of the system. However, the understanding of the linkage between viral community, virus-host interactions and environmental conditions of soil is still lacking which imposes a major knowledge gap in microbial ecology of this complex environmental system. Here, we investigated the viral and bacterial communities under different plant cover types. Soil properties such as organic matter and nitrate content showed significant correlations with virus-like particles (VLPs) abundance, bacterial abundance, and inducible lysogenic fractions (LF) suggesting that the environmental factors might be influencing viral/bacterial abundance and reproduction strategy in soils. The bacterial communities were shaped by the land management, i.e., cover plants and agricultural practices. Soil physicochemical properties, VLP abundance, and LF were significant factors accounting for the difference of bacterial community composition in soils. The variances of the viral community composition were closely related to cover plants corresponding to similar patterns in bacterial community composition suggesting that viral and bacterial community composition are tightly linked. Our study provides insight in the ways how environmental factors shape virus-host interactions and further influence soil viruses in soil ecosystems.