Wang Weiquan, Tang Kaihao, Wang Pengxia, Zeng Zhenshun, Xu Tao, Zhan Waner, Liu Tianlang, Wang Yan, Wang Xiaoxue
Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
Nat Ecol Evol. 2022 Aug;6(8):1132-1144. doi: 10.1038/s41559-022-01795-y. Epub 2022 Jun 30.
The coral reef microbiome is central to reef health and resilience. Competitive interactions between opportunistic coral pathogens and other commensal microbes affect the health of coral. Despite great advances over the years in sequencing-based microbial profiling of healthy and diseased coral, the molecular mechanism underlying colonization competition has been much less explored. In this study, by examining the culturable bacteria inhabiting the gastric cavity of healthy Galaxea fascicularis, a scleractinian coral, we found that temperate phages played a major role in mediating colonization competition in the coral microbiota. Specifically, the non-toxigenic Vibrio sp. inhabiting the healthy coral had a much higher colonization capacity than the coral pathogen Vibrio coralliilyticus, yet this advantage was diminished by the latter killing the former. Pathogen-encoded LodAB, which produces hydrogen peroxide, triggers the lytic cycle of prophage in the non-toxicogenic Vibrio sp. Importantly, V. coralliilyticus could outcompete other coral symbiotic bacteria (for example, Endozoicomonas sp.) through LodAB-dependent prophage induction. Overall, we reveal that LodAB can be used by pathogens as an important weapon to gain a competitive advantage over lysogenic competitors when colonizing corals.
珊瑚礁微生物群对珊瑚礁的健康和恢复力至关重要。机会性珊瑚病原体与其他共生微生物之间的竞争相互作用会影响珊瑚的健康。尽管多年来在基于测序的健康和患病珊瑚微生物谱分析方面取得了巨大进展，但对定殖竞争背后的分子机制的探索却少得多。在这项研究中，通过检查栖息在造礁石珊瑚丛生盔形珊瑚胃腔中的可培养细菌，我们发现温和噬菌体在介导珊瑚微生物群中的定殖竞争中起主要作用。具体而言，栖息在健康珊瑚中的无毒弧菌属的定殖能力比珊瑚病原体溶珊瑚弧菌高得多，但后者杀死前者会削弱这种优势。病原体编码的产生过氧化氢的LodAB会触发无毒弧菌属中前噬菌体的裂解周期。重要的是，溶珊瑚弧菌可以通过依赖LodAB的前噬菌体诱导胜过其他珊瑚共生细菌（例如内共生单胞菌属）。总体而言，我们揭示了LodAB可被病原体用作在定殖珊瑚时比溶源竞争者获得竞争优势的重要武器。
