Contrasting viral diversity and potential biogeochemical impacts in paddy and upland soils

Viruses are ubiquitous and believed to play pivotal roles in soil ecosystems. However, variations in composition and function of viruses in adjacent paddy and upland soils remain largely unexplored. Thus, we aimed to compare the viral diversity and function in four pairs of paddy and upland soil samples by linking soil viromes with soil properties. Microviridae was the most abundant virus family in both soil samples. The proportion of Genomoviridae was larger, and that of Siphoviridae was smaller in upland soils. Moreover, upland soils harbored more virulent viruses, whereas paddy soils harbored more temperate viruses and viral genera. Available phosphorus content and pH were the dominant factors contributing to the viral community structures in upland and paddy soils, respectively. Viruses in upland soils encoded metabolic genes for degrading cell components, whereas viruses in paddy soils encoded genes for metabolizing amino acids. Additionally, viruses in paddy fields carried more carbohydrate-active enzyme genes and had broader host ranges. Hence, given the concentration of dissolved organic carbon, the difference in viral lifestyles between upland and paddy soils suggest that viral-induced cell lysis can influence nutrient availability. These findings provide a scientific basis for increasing virus-mediated microbial-derived carbon storage in soils by regulating nutrient availability.