A research team led by Prof. SUN Chaomin from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), has unveiled the crucial role of viruses in deep-sea carbon cycling and microbial community structure. Their findings were published in Nature Communications.
Viruses are the ocean's most abundant biological entities, with an estimated 10^30 individuals globally and biomass second only to prokaryotes. Beyond their classic role in host lysis, they influence microbial communities and biogeochemical cycles through horizontal gene transfer and metabolic reprogramming via auxiliary metabolic genes (AMGs). Their ecological functions across extreme deep-sea habitats—hydrothermal vents, cold seeps, and trenches—remain one of oceanography's final frontiers.
"Our current understanding is fragmented at best," said Dr. WANG Chong, first author of the study. Mapping viral diversity hotspots and decoding their functional signatures isn't just academic curiosity—it's a scientific imperative to solve vital puzzles in marine carbon cycling.
The researchers explored viral communities across four deep-sea sites: a fading cold seep, a site further away, a newly forming cold seep, and a seamount. Using advanced genetic techniques, they uncovered vast viral diversity—including many unknown DNA/RNA viruses—in sediments. RNA viruses showed unique host preferences and lifestyles compared to DNA viruses. Critically, active viral genes boosted host digestion of tough organic matter, proving viruses drive carbon processing.
Dr. WANG noted, "This is our first deep dive into the viral frontier of the deep sea. While we have long recognized the exceptional capacity of deep-sea microbes to break down complex organic matter, this study connects the dots – revealing how viruses actively collaborate with their hosts to drive this process."
By investigating diverse cold seep and seamount sediments, the study reveals the significant potential of viruses to assist hosts in metabolizing complex organic matter, offering new perspectives on energy flow and material cycling in these extreme environments.
Representative images of virus-like particles. (Image by IOCAS)
(Text by WANG Chong)
Media Contact:
ZHANG Yiyi
Institute of Oceanology
E-mail: zhangyiyi@qdio.ac.cn
(Editor: ZHANG Yiyi)