Saline lakes on the Qinghai-Tibet Plateau harbor unique viral assemblages mediating microbial environmental adaption

SUMMARY The highest plateau on Earth, Qinghai-Tibet Plateau, contains thousands of lakes with broad salinity and diverse and unique microbial communities. However, little is known about their co-occurring viruses. Herein, we identify 4,560 viral Operational Taxonomic Units (vOTUs) from six viromes of three saline lakes on Qinghai-Tibet Plateau, with less than 1% could be classified. Most of the predicted vOTUs were associated with the dominant bacterial and archaeal phyla. Virus-encoded auxiliary metabolic genes suggest that viruses influence microbial metabolisms of carbon, nitrogen, sulfur and lipid, the antibiotic resistance mediation, and their salinity adaption. The six viromes clustered together with the ice core viromes and bathypelagic ocean viromes, and might represent a new viral habitat. This study has revealed the unique characteristics and potential ecological roles of DNA viromes in the lakes of the highest plateau and established a foundation for the recognition of the viral roles in plateau lake ecosystems.