Dpt. Fisiología, Genética y Microbiología, University of Alicante, San Vicente del Raspeig, Spain.
Mathematics and Computer Science Dept, University of the Balearic Islands, Palma, Spain.
Microbiome. 2024 Oct 29;12(1):222. doi: 10.1186/s40168-024-01921-x.
Extensive research on the diversity and functional roles of the microorganisms associated with reef-building corals has been promoted as a consequence of the rapid global decline of coral reefs attributed to climate change. Several studies have highlighted the importance of coral-associated algae (Symbiodinium) and bacteria and their potential roles in promoting coral host fitness and survival. However, the complex coral holobiont extends beyond these components to encompass other entities such as protists, fungi, and viruses. While each constituent has been individually investigated in corals, a comprehensive understanding of their collective roles is imperative for a holistic comprehension of coral health and resilience.
The metagenomic analysis of the microbiome of the coral Oculina patagonica has revealed that fungi of the genera Aspergillus, Fusarium, and Rhizofagus together with the prokaryotic genera Streptomyces, Pseudomonas, and Bacillus were abundant members of the coral holobiont. This study also assessed changes in microeukaryotic, prokaryotic, and viral communities under three stress conditions: aquaria confinement, heat stress, and Vibrio infections. In general, stress conditions led to an increase in Rhodobacteraceae, Flavobacteraceae, and Vibrionaceae families, accompanied by a decrease in Streptomycetaceae. Concurrently, there was a significant decline in both the abundance and richness of microeukaryotic species and a reduction in genes associated with antimicrobial compound production by the coral itself, as well as by Symbiodinium and fungi.
Our findings suggest that the interplay between microeukaryotic and prokaryotic components of the coral holobiont may be disrupted by stress conditions, such as confinement, increase of seawater temperature, or Vibrio infection, leading to a dysbiosis in the global microbial community that may increase coral susceptibility to diseases. Further, microeukaryotic community seems to exert influence on the prokaryotic community dynamics, possibly through predation or the production of secondary metabolites with anti-bacterial activity. Video Abstract.
由于气候变化导致珊瑚礁迅速全球衰退，与造礁珊瑚相关的微生物多样性和功能角色的广泛研究得到了推动。几项研究强调了珊瑚相关藻类（共生藻）和细菌的重要性及其在促进珊瑚宿主适应性和生存能力方面的潜在作用。然而，复杂的珊瑚整体生物群超出了这些成分，还包括原生动物、真菌和病毒等其他实体。虽然每个成分都在珊瑚中单独进行了研究，但全面了解它们的集体作用对于全面理解珊瑚的健康和恢复力至关重要。
对 Oculina patagonica 珊瑚微生物组的宏基因组分析表明，曲霉属、镰刀菌属和罗氏菌属真菌以及链霉菌属、假单胞菌属和芽孢杆菌属原核生物是珊瑚整体生物群的丰富成员。本研究还评估了在三种胁迫条件下微真核生物、原核生物和病毒群落的变化：水族箱限制、热应激和弧菌感染。一般来说，胁迫条件导致红杆菌科、黄杆菌科和弧菌科家族的增加，同时链霉菌科减少。同时，微真核生物物种的丰度和丰富度显著下降，珊瑚自身、共生藻和真菌产生抗菌化合物的基因减少。
我们的研究结果表明，珊瑚整体生物群的微真核生物和原核生物成分之间的相互作用可能会被胁迫条件（如限制、海水温度升高或弧菌感染）破坏，导致全球微生物群落失调，从而增加珊瑚对疾病的易感性。此外，微真核生物群落似乎对原核生物群落动态产生影响，可能通过捕食或产生具有抗菌活性的次生代谢物。
