Impaired viral infection and reduced mortality of diatoms in iron-limited oceanic regions
Impaired viral infection and reduced mortality of diatoms in iron-limited oceanic regions
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DOI：
10.1038/s41561-021-00711-6
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发表时间：
2021-04-01
影响因子：
18.3
通讯作者：
Thamatrakoln, Kimberlee
中科院分区：
文献类型：
--
作者：
Kranzler, Chana F.;Brzezinski, Mark A.;Thamatrakoln, Kimberlee
硅藻的初级生产力通过硅基细胞壁的压载性质与碳输出紧密耦合，将海洋硅和碳循环联系起来。然而，尽管生产力低，铁（Fe）有限的制度被认为是“热点”的硅藻硅埋葬增强碳输出效率，提出了问题的机制驱动这些地区的地球化学。海洋病毒通常被认为是通过宿主裂解、缩短碳的营养转移和促进溶解的有机物质和相关元素在海洋表面的保留而实现生物化的催化剂。在这里，我们使用元转录组学分析硅藻和相关的病毒，沿着与一套生理和地球化学指标，研究硅藻和病毒之间的相互作用，在铁有限的制度，东北太平洋。我们发现低细胞相关的硅藻病毒的多样性和丰富度在一个长期铁有限的地区，亚北极东北太平洋。在加州海流的沿海上升流区域，短暂的铁限制也大大减少了病毒复制。这些观察结果在铁有限的文化的开花形成，中心硅藻，Chaetoceros tenuissimus，表现出延迟的病毒介导的死亡率，除了减少病毒复制。我们建议铁有限的硅藻逃脱病毒裂解和随后在海洋表面的矿化，提供了一个额外的机制，有助于提高碳输出效率和二氧化硅埋葬在铁有限的海洋制度。
Diatom primary productivity is tightly coupled with carbon export through the ballasted nature of the silica-based cell wall, linking the oceanic silicon and carbon cycles. However, despite low productivity, iron (Fe)-limited regimes are considered 'hot spots' of diatom silica burial with enhanced carbon export efficiency, raising questions about the mechanisms driving the biogeochemistry of these regions. Marine viruses are classically recognized as catalysts of remineralization through host lysis, short-circuiting the trophic transfer of carbon and facilitating the retention of dissolved organic matter and associated elements in the surface ocean. Here we used metatranscriptomic analysis of diatoms and associated viruses, along with a suite of physiological and geochemical metrics, to study the interaction between diatoms and viruses in Fe-limited regimes of the northeast Pacific. We found low cell-associated diatom virus diversity and abundance in a chronically Fe-limited region of the subarctic northeast Pacific. In a coastal upwelling region of the California Current, transient iron limitation also substantially reduced viral replication. These observations were recapitulated in Fe-limited cultures of the bloom-forming, centric diatom, Chaetoceros tenuissimus, which exhibited delayed virus-mediated mortality in addition to reduced viral replication. We suggest Fe-limited diatoms escape viral lysis and subsequent remineralization in the surface ocean, providing an additional mechanism contributing to enhanced carbon export efficiency and silica burial in Fe-limited oceanic regimes.