A Bacterial Quorum-Sensing Precursor Induces Mortality in the Marine Coccolithophore, Emiliania huxleyi.
A Bacterial Quorum-Sensing Precursor Induces Mortality in the Marine Coccolithophore, Emiliania huxleyi.
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DOI：
10.3389/fmicb.2016.00059
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发表时间：
2016
影响因子：
5.2
通讯作者：
Whalen KE
中科院分区：
文献类型：
--
作者：
Harvey EL;Deering RW;Rowley DC;El Gamal A;Schorn M;Moore BS;Johnson MD;Mincer TJ;Whalen KE
浮游植物和细菌之间的相互作用在介导海洋地球化学循环和食物网结构中起着核心作用。然而，破译这些物种间相互作用的化学驱动因素仍然具有挑战性。在这里，我们报告的分离2-庚基-4-喹诺酮（HHQ），释放的杀鱼假交替单胞菌，海洋γ-变形菌先前报道诱导浮游植物死亡率通过迄今为止未知的杀藻机制。HHQ在临床感染模型中作为抗生素和细胞间通讯中的细菌信号分子发挥作用。共培养的水华形成球石藻，Emiliania huxleyi与活P. piscicida和无细胞藻引起藻类生长的显着下降。对杀鱼原蜱外代谢组的研究表明，在纳摩尔浓度下，HHQ诱导了三种E. huxleyi。死亡率E。huxleyi在响应HHQ发生缓慢，这意味着静态增长，而不是单一的损失事件（例如，快速细胞裂解）。相比之下，海洋绿藻杜氏藻（Dunaliella tertiolecta）和硅藻（Phaeodactylum tricornutum）不受HHQ暴露的影响。这些结果表明，HHQ介导类型的域间相互作用，导致浮游植物种群动态的变化。这些化学介导的相互作用，以及其他类似的作用，最终影响大规模的海洋过程。
Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here, we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. HHQ functions as both an antibiotic and a bacterial signaling molecule in cell–cell communication in clinical infection models. Co-culture of the bloom-forming coccolithophore, Emiliania huxleyi with both live P. piscicida and cell-free filtrates caused a significant decrease in algal growth. Investigations of the P. piscicida exometabolome revealed HHQ, at nanomolar concentrations, induced mortality in three strains of E. huxleyi. Mortality of E. huxleyi in response to HHQ occurred slowly, implying static growth rather than a singular loss event (e.g., rapid cell lysis). In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures. These results suggest that HHQ mediates the type of inter-domain interactions that cause shifts in phytoplankton population dynamics. These chemically mediated interactions, and other like it, ultimately influence large-scale oceanographic processes.