Research shows a diversified, dynamic, active, and spatially structured soil virosphere capable of quick environmental responses
Numerous communities of microorganisms, such as bacteria, fungus, protists, and viruses, can be found in soils. The way these small organisms interact affects how well soils can store carbon underneath.
The spatial patterns and dynamics of viral populations in soil, however, are not well understood.
Recent findings from the Lawrence Livermore National Laboratory (LLNL) and collaborators demonstrate that severe dispersal constraints exist at the local scale for grassland viral ecosystems, which are highly spatially stratified within a single field. In the Proceedings of the National Academy of Sciences, the study is published.
As LLNL scientist and co-author Jennifer Pett-Ridge put it, “Knowing the composition and turnover of viral communities throughout place and time is crucial to begin unraveling what constrains host-virus interactions in soil.” We discovered that the soil’s “virosphere” is extremely varied, dynamic, active, and spatially organized. It also seems to be able to respond quickly to changing climatic conditions, particularly the amount of rainfall.
Physical, chemical, and biological heterogeneity exist in soils. In addition to supporting a diverse range of properties, the complicated network of aggregates and pore spaces that makes up the soil matrix also limits the movement of microbes.
Viruses have a wide range of effects on host metabolism, evolution, and Earth’s biogeochemical cycles through infection and mortality of other microorganisms. Soil viruses are so numerous that it suggests they are probably important to terrestrial ecosystems.
Reduced precipitation has been demonstrated to alter the composition of the soil bacterial population in previous studies regarding manipulation of rainfall. It was unknown until recently if these changes might be related to modifications in the soil virosphere, but recent observations point to water availability as a potential key factor in the formation of soil viral communities.
In the latest study, the scientists discovered that when subjected to climatic conditions like drought, viruses adapt more quickly than their microbial hosts. The viral community changed as soil moisture dropped, and viruses that are known to infect actinobacteria that have adapted to dryness became more prevalent.
LLNL scientist and co-author Katerina Estera-Molina said, “Despite significant spatial mobility, viruses responded effectively to changing environmental conditions.”
In several square meter annual grassland plots in Hopland, California, the researchers investigated soil viruses. These plots were kept up for the three years preceding to the study with either 50% or the full complement of the typical annual rainfall.
We can better understand the possible impact of a changing climate on host-virus interactions and potential downstream implications on the soil-carbon cycle by characterizing the compositional response of soil viral communities to reduced precipitation, according to Pett-Ridge.
Christian Santos-Medellín et al. (2022). Spatial turnover of soil viral populations and genotypes overlain by cohesive responses to moisture in grasslands, Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2209132119
Abstract Viruses infecting prokaryotic cells (phages) are the most abundant entities of the biosphere and contain a largely uncharted wealth of genomic diversity. They play a critical role in the biology of their hosts and in ecosystem functioning at large. The classical approaches studying phages require isolation from a pure culture of the host. Direct … Continue reading
Numerous communities of microorganisms, such as bacteria, fungus, protists, and viruses, can be found in soils. The way these small organisms interact affects how well soils can store carbon underneath. The spatial patterns and dynamics of viral populations in soil, however, are not well understood. Recent findings from the Lawrence Livermore National Laboratory (LLNL) and … Continue reading