Only in recent years have metagenomic methods enabled characterization of soil phage communities. However, more than their presence in the soil, it is the rate of phage turnover (new phage production through infection) that is related to their ecological function. These dynamics are almost entirely unknown. By combining recent advances in diffusive isotopic labelling with metagenomic sequencing through 18O and 13C DNA stable isotope probing, this project will for the first time open a view on phage dynamics in undisturbed soil. We will measure phage turnover in natural soil and determine whether plant roots accelerate this, which could enhance plant nutrient availability. Further, the project will reveal the dynamics of phage populations along growing roots and how they respond to root carbon inputs under current and future concentrations of atmospheric CO2. These results will show how viruses contribute to plant-soil interactions and provide new insight into ecological mechanisms of plant nutrition under global change.
