Adaptive strategies of soil viruses in oligotrophic arid environments

In natural environments, viruses must adapt to changing conditions such as variations in nutrient and water availability. However, our understanding of viral adaptation to different soil conditions remains limited. We compared soil viral adaptations in nutrient-limited arid inland regions versus nutrient-rich humid coastal regions using viromics. Our results provide new evidence that viruses employed diverse strategies to persist in oligotrophic arid environments. These strategies include (i) a higher prevalence of potential lysogenic viruses; (ii) a broader host range to enhance infection chances; (iii) encoding specific auxiliary metabolic genes to enhance viral fitness by boosting host resilience against nutrient limitation and aridity; and (iv) maintaining higher micro-diversity and more genes under positive selection to improve viral responses to inhospitable conditions.