Metagenomic insights into viral and microbial genes of Russian High-Arctic soil microbiomes

Abstract High-Arctic soils are extreme ecosystems where microbial and viral roles remain poorly studied. Climate-driven vegetation expansion may alter these environments, but its impact is unknown. We generate a shotgun metagenomic database from four High-Arctic islands, comparing vegetated and unvegetated sites at two depths (0–2 cm and 30–50 cm). We analyse the functional gene potential, including biosynthetic gene clusters (BGCs) and antibiotic resistance genes (ARGs) in metagenome-assembled genomes (MAGs), and assess viral diversity. Vegetated soils at 30–50 cm were enriched in genes for carbon/nitrogen cycling, energy production, and carbohydrate metabolism, indicating enhanced nutrient inputs. Conversely, unvegetated soils show higher BGC and ARG richness, reflecting microbial competition under nutrient limitation. Viral richness decreases in surface vegetated soils, while diversity and giant virus (Nucleocytoviricota) abundance increase with depth. These findings reveal how vegetation and soil depth modulate microbiomes and viromes, critical for predicting ecosystem trajectories in a warming world.