Temporal changes of virus-like particle abundance in cropland and prairie soils

Authors: CORNELL, CAROLYN - University Of Oklahoma; ZHANG, YA - University Of Oklahoma; VAN NOSTRAND, JOY - University Of Oklahoma; Wagle, Pradeep; XIAO, XIANGMING - University Of Oklahoma; JIZHONG, ZHOU - University Of Oklahoma

Submitted to: mSphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2021
Publication Date: 6/2/2021
Citation: Cornell, C., Zhang, Y., Van Nostrand, J., Wagle, P., Xiao, X., Jizhong, Z. 2021. Temporal changes of virus-like particle abundance in cropland and prairie soils. mSphere. 6(3). Article e01160-20.

Interpretive Summary: Conversion of land alters the physiochemical and biological environments by not only changing the aboveground community, but also by modifying the soil environment for viruses and microbes. Viruses are an important part of soil functions in terrestrial ecosystems. However, viral abundance data in soils are extremely limited, and even less is known about their responses to the disturbances associated with land use and management. This study examined annual dynamics of viral abundance in soils from a native tallgrass prairie and two croplands, conventional till winter wheat and no-till canola, in Oklahoma. Virus-like particles (VLP) abundance varied across sites, and showed clear seasonal shifts. The VLP significantly correlated with environmental variables that were generally reflective of land use including air temperature, soil nitrogen, and plant canopy coverage. Structural equation modeling supported the effects of land use on soil communities by emphasizing interactions between management, environmental factors, and viral and bacterial abundance. Abundance of viruses and potential hosts both decreased with increasing amounts of management input with the prairie site continually having greater abundance than the croplands. The study provides important insights into the temporal dynamics of viral abundance and the structure of viral communities in response to the common practice of turning native habitats into arable soils.

Technical Abstract: During the last several decades, viruses have been increasingly recognized for their abundance, ubiquity, and important roles in different ecosystems. Despite known contributions to aquatic systems, few studies examine viral abundance and community structure over time in terrestrial ecosystems. The effects of land conversion and land management on soil microbes have been previously investigated, but their effects on virus population are not well studied. This study examined annual dynamics of viral abundance in soils from a native tallgrass prairie and two croplands, conventional till winter wheat and no-till canola, in Oklahoma. Virus-like particles (VLP) abundance varied across sites, and showed clear seasonal shifts. The VLP significantly correlated with environmental variables that were generally reflective of land use including air temperature, soil nitrogen, and plant canopy coverage. Structural equation modeling supported the effects of land use on soil communities by emphasizing interactions between management, environmental factors, and viral and bacterial abundance. Between the viral metagenomes from the prairie and tilled wheat field, 1,231 unique viral operational taxonomic units (vOTUs) were identified and only five were shared that were rare in the contrasting field. Only 13% of the vOTUs had similarity to previously identified viruses in the Reference Sequence database with only 7% having known taxonomic classification. Together, our findings indicate land use and tillage practices influence virus abundance and community structure. Analyses of viromes over time and space are vital to viral ecology in providing insight on viral communities and key information on interactions between viruses, their microbial hosts, and the environment.