Viromics to close gaps on soil

Funding period: 2024-2027
Lead: Mamadou Lamine Fall
Total GRDI funding: $1,803,000

Soils and their resident microbial communities are the foundation of food webs. These microorganisms play a crucial role in nutrient cycling, maintenance of soil fertility, and soil carbon sequestration. Importance of soil microorganisms in agriculture has been recognized for more than a century. However, there is no single biotic or abiotic factor that is consistently the most important in determining the composition of the soil microbiome. All living microorganisms in soil have common ground, they are all infected by viruses hence virus can be the cornerstone of bioindicators of soil health. An integrative perspective of how viruses shape the soil microbiome, and the components thereof, across the soil is not yet available. Given the central role of microbes to carbon (C) processing in soil, it was recently shown that viruses infecting these microbes impact carbon and nitrogen cycling. Thus, considering these overlooked effects in ecosystem models can enhance our ability to forecast ecosystem responses to climate change and improve their predictions. In agricultural soil, most of the studies have focused exclusively on bacteria, archea, nematodes and fungi to understand the soil microbiome function ignoring the role of the most abundant and diverse biological units in the biosphere, viruses. Whereas the soil bacteria, fungi and nematodes are increasingly addressed in agricultural soil, there is a lack of knowledge about the role of their associated virome (all viruses infecting them). To understand the extent to which the virome influence soil microbiomes and impacts soil C and N cycling, we recently developed a transformative wet lab methodology to capture and study soil viruses. We will first capitalize on this new developed tool to characterize the soil virome and develop in-house bioinfomartic tools to retrieve the viral signature from existing AAFC soil microbiome data. This project will be undertaken in three contrasting cropping systems (improved rotation system of potato, perennial cropping system (grapevine) and 30-years old rotation system of corn/soybean), used as a proof of concept so the knowledge gained will be translated easily to other Canadian agroecosystems. This study will improve our understanding of how virus participate in the soil biogeochemical processes (C-cycling) and propose new avenues of influencing the soil bacterial population for carbon sequestration or increase of soil fertility (N-cycling).