Shenzhen Public Platform for Screening & Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, People's Republic of China.
Department of Earth System Science, Tsinghua University of Education Key Laboratory for Earth System Modeling, Beijing, 100084, People's Republic of China.
Environ Microbiol. 2020 May;22(5):1944-1962. doi: 10.1111/1462-2920.15009. Epub 2020 Apr 19.
Coral associated microorganisms, especially some opportunistic pathogens can utilize quorum-sensing (QS) signals to affect population structure and host health. However, direct evidence about the link between coral bleaching and dysbiotic microbiomes under QS regulation was lacking. Here, using 11 opportunistic bacteria and their QS products (AHLs, acyl-homoserine-lactones), we exposed Pocillopora damicornis to three different treatments: test groups (A and B: mixture of AHLs-producing bacteria and cocktail of AHLs signals respectively); control groups (C and D: group A and B with furanone added respectively); and a blank control (group E: only seawater) for 21 days. The results showed that remarkable bleaching phenomenon was observed in groups A and B. The operational taxonomic units-sequencing analysis shown that the bacterial network interactions and communities composition were significantly changed, becoming especially enhanced in the relative abundances of Vibrio, Edwardsiella, Enterobacter, Pseudomonas, and Aeromonas. Interestingly, the control groups (C and D) were found to have a limited influence upon host microbial composition and reduced bleaching susceptibility of P. damicornis. These results indicate bleaching's initiation and progression may be caused by opportunistic bacteria of resident microbes in a process under regulation by AHLs. These findings add a new dimension to our understanding of the complexity of bleaching mechanisms from a chemoecological perspective.
珊瑚相关微生物，特别是一些机会致病菌，可以利用群体感应（QS）信号来影响种群结构和宿主健康。然而，关于 QS 调控下珊瑚白化与失调微生物组之间联系的直接证据还很缺乏。在这里，我们使用了 11 种机会致病菌及其 QS 产物（AHLs，酰基高丝氨酸内酯），将 P. damicornis 暴露于三种不同的处理中：实验组（A 和 B：分别是 AHLs 产生菌混合物和 AHLs 信号鸡尾酒）；对照组（C 和 D：分别在 A 和 B 组中添加呋喃酮）；以及空白对照组（E：仅用海水），持续 21 天。结果表明，A 组和 B 组出现了明显的白化现象。操作分类单元测序分析表明，细菌网络相互作用和群落组成发生了显著变化，尤其是 Vibrio、Edwardsiella、Enterobacter、Pseudomonas 和 Aeromonas 的相对丰度显著增加。有趣的是，对照组（C 和 D）对宿主微生物组成的影响有限，且降低了 P. damicornis 的白化易感性。这些结果表明，白化的启动和进展可能是由居住在珊瑚中的机会致病菌在 AHLs 调控下的过程引起的。这些发现从化学生态学的角度增加了我们对白化机制复杂性的理解。
