Cai Lanlan, Xu Bu, Li Huifang, Xu Yongle, Wei Wei, Zhang Rui
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China.
Microbiol Spectr. 2023 Mar 6;11(2):e0520322. doi: 10.1128/spectrum.05203-22.
Estuaries are one of the most highly productive and economically important ecosystems at the continent-ocean interface. Estuary productivity is largely determined by the microbial community structure and activity. Viruses are major agents of microbial mortality and are key drivers of global geochemical cycles. However, the taxonomic diversity of viral communities and their spatial-temporal distribution in estuarine ecosystems have been poorly studied. In this study, we investigated the T4-like viral community composition at three major Chinese estuaries in winter and in summer. Diverse T4-like viruses, which were divided into three main clusters (Clusters I to III), were revealed. The Marine Group of Cluster III, with seven identified subgroups, was the most dominant (averaging 76.5% of the total sequences) in the Chinese estuarine ecosystems. Significant variations of T4-like viral community composition were observed among estuaries and seasons, with higher diversity occurring in winter. Among various environmental variables, temperature was a main driver of the viral communities. This study demonstrates viral assemblage diversification and seasonality in Chinese estuarine ecosystems. Viruses are ubiquitous but largely uncharacterized members of aquatic environments that cause significant mortality in microbial communities. Recent large-scale oceanic projects have greatly advanced our understanding of viral ecology in marine environments, but those studies mostly focused on oceanic regions. There have yet to be spatiotemporal studies of viral communities in estuarine ecosystems, which are unique habitats that play a significant role in global ecology and biogeochemistry. This work is the first comprehensive study that provides a detailed picture of the spatial and seasonal variation of viral communities (specifically, T4-like viral communities) in three major estuarine ecosystems in China. These findings provide much-needed knowledge regarding estuarine viral ecosystems, which currently lags in oceanic ecosystem research.
河口是大陆与海洋交界处生产力最高且经济上最重要的生态系统之一。河口的生产力很大程度上由微生物群落结构和活性决定。病毒是微生物死亡的主要因素，也是全球地球化学循环的关键驱动因素。然而，河口生态系统中病毒群落的分类多样性及其时空分布研究甚少。在本研究中，我们调查了中国三个主要河口冬季和夏季类似T4病毒的群落组成。结果显示了多样的类似T4病毒，它们被分为三个主要簇（簇I至簇III）。簇III的海洋类群有七个已鉴定的亚群，是中国河口生态系统中最主要的类群（平均占总序列的76.5%）。在不同河口和季节间观察到类似T4病毒群落组成有显著变化，冬季的多样性更高。在各种环境变量中，温度是病毒群落的主要驱动因素。本研究证明了中国河口生态系统中病毒组合的多样性和季节性。病毒在水生环境中无处不在，但大多未被表征，它们在微生物群落中会导致大量死亡。近期的大规模海洋项目极大地推进了我们对海洋环境中病毒生态学的理解，但这些研究大多集中在海洋区域。河口生态系统作为在全球生态和生物地球化学中发挥重要作用的独特栖息地，尚未有对其病毒群落的时空研究。这项工作是首次全面研究，详细描绘了中国三个主要河口生态系统中病毒群落（具体为类似T4病毒的群落）的空间和季节变化。这些发现提供了关于河口病毒生态系统急需的知识，目前这方面在海洋生态系统研究中滞后。
