Microbial diversity within the Trichodesmium holobiont
Microbial diversity within the Trichodesmium holobiont
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DOI：
10.1111/1462-2920.13513
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发表时间：
2016-12-01
影响因子：
5.1
通讯作者：
Dyhrman, Sonya T.
中科院分区：
文献类型：
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作者：
Rouco, Monica;Haley, Sheean T.;Dyhrman, Sonya T.
束毛藻属的固氮蓝藻在热带和亚热带贫营养海洋的生产力中起着至关重要的作用。这些种群的生态成功可能与Trichodesmium holobiont内发生的各种微生物相互作用有关，特别是Trichodesmium和异养细菌epibiont之间。然而，Trichodesmium holobiont的组成和微生物聚集的过程没有很好的记录。在这里，我们使用高分辨率的16S rDNA扩增子测序来研究不同海洋区域和菌落形态（泡芙和木筏）的束毛藻和相关表生生物的多样性。束毛藻进化枝I（即，t. thiebautii样）占主导地位的殖民地在所有的海洋盆地，无论形态，虽然束毛藻群落结构显着变化之间的形态在一些地区。平均而言，α变形菌（即，Thalassobius），γ-变形菌门（即，假交替单胞菌属（Pseudoalteromonas），鞘氨醇杆菌属（Sphingobacteria）（即，微棘藻和弧菌）和黄细菌占主导地位的表生体社区，但社区组成和结构显着不同的地区。从两个殖民地形态的epibionts在北大西洋和北太平洋的分类和功能不同。这些研究结果表明，殖民地类型可能会定义两个不同的生态位和epibiont组合可能会被部分驱动的选择过程中，epibiont选择根据他们对殖民地代谢的影响。
Nitrogen-fixing cyanobacteria in the genus Trichodesmium play a critical role in the productivity of the tropical and subtropical oligotrophic oceans. The ecological success of these populations is likely associated with the diverse microbial interactions occurring within the Trichodesmium holobiont, especially between Trichodesmium and heterotrophic bacterial epibionts. Yet, the composition of the Trichodesmium holobiont and the processes governing microbial assemblage are not well documented. Here, we used high-resolution 16S rDNA amplicon sequencing to examine the diversity of Trichodesmium and associated epibionts across different ocean regions and colony morphologies (puffs and rafts). Trichodesmium Clade I (i.e., T. thiebautii-like) dominated the colonies in all ocean basins regardless of morphology, although the Trichodesmium community structure significantly varied between morphologies in some regions. On average, Alphaproteobacteria (i.e., Thalassobius), Gammaproteobacteria (i.e., Pseudoalteromonas), Sphingobacteria (i.e., Microscilla and Vibrio) and Flavobacteria dominated the epibiont communities, but community composition and structure significantly differed between regions. Epibionts from the two colony morphologies were taxonomically and functionally distinct in the North Atlantic and North Pacific. These findings suggest that the colony types might define two distinct niches and that epibiont assemblage might be driven in part by selective processes, where epibionts are selected according to their influence on colony metabolism.