珊瑚礁生态系统病毒研究进展

A review of recent researches on viruses in coral reef ecosystem

病毒对珊瑚礁生态系统中的生物进化、生物地球化学循环、珊瑚疾病等方面具有重要的生态影响。随着珊瑚礁的全球性退化,病毒在珊瑚礁生态系统中的功能与危害日益显现。综述了珊瑚礁生态系统中病毒的研究现状与进展,包括:(1)珊瑚礁病毒的多样性与分布特征(水体、宿主、核心病毒组);(2)珊瑚礁病毒的生态功能(感染方式、促进生物进化、生物地球化学循环);(3)珊瑚礁病毒对全球气候变化的响应(热压力、珊瑚疾病)。总体而言,珊瑚礁生态系统具有极高的病毒多样性,所发现的60个科占已知所有病毒科数量的58%。珊瑚的核心病毒组主要由双链DNA病毒、单链DNA病毒、单链逆转录病毒所组成,珊瑚黏液层对病毒具有富集作用。“Piggyback-the-Winner”(依附-胜利)是病毒在珊瑚礁中主要的生物动力学模式,其可通过水平基因迁移的方式促进礁区生物进化。病毒可通过裂解细菌与浮游藻类的途径参与珊瑚礁的生物地球化学循环,尤其是碳循环与氮循环过程。此外,病毒还具有介导珊瑚热白化与直接引发珊瑚疾病的能力,这会影响珊瑚礁生态系统应对气候变化的适应性与恢复力。基于国际上的研究进展综述,结合南海珊瑚礁生态现状提出以下研究方向,以期促进我国珊瑚礁病毒学的发展:(1)开展南海珊瑚礁中病毒多样性的识别及其时-空分布特征研究;(2)探索病毒对南海珊瑚热白化、珊瑚疾病的介导作用及其与气候变化的关系;(3)揭示病毒对南海珊瑚礁生物地球化学循环的贡献。

Viruses have an important ecological impact on the biological evolution, biogeochemical cycle, and coral diseases in coral reef ecosystems. With the global degradation of coral reefs, the functions and hazards of viruses in coral reef regions have become increasingly prominent. In this article, recent researches on viruses in coral reef ecosystems were reviewed, which included:(1) The diversity and distribution characteristics of viruses in coral reef ecosystem(sea water, host and core coral virome);(2) Ecological function of viruses in coral reef ecosystem(infection pattern, promoting biological evolution, and biogeochemical cycle);(3) Viruses response to global climate change in coral reef ecosystem(thermal stress and coral diseases). Accordingly, coral reef ecosystems have an extremely high viral richness and diversity. About 60 virus families are reported in coral reef ecosystems around the world, which account for 58% of all known viral families. Also, the core coral virome is manly composed of double-stranded DNA virus(dsDNA virus), single-stranded DNA virus(ssDNA virus) and retrovirus. The viruses in coral surface mucus layer are more abundant and diverse, due to enrichment with viruses from around environment in coral reef ecosystem. “Piggyback-the-Winner” is the main biodynamic mode of viruses in coral reefs, which indicates that viruses can promote the evolution of organisms by horizontal gene transduction in reef regions. In addition, viruses can participate in the carbon and nitrogen cycles of coral reefs by lysing bacteria and planktonic algae, respectively, which plays an important role in biogeochemical cycles of coral reef ecosystem. It′s worth noting that viruses have ability to mediate coral thermal bleaching, which has closely associations with Phycodnaviridae and Herpesviridae. Moreover, viruses can also lead to coral diseases(e.g., white plague, white band disease and yellow blotch), which can affect the adaptability and resilience of coral reefs to global climate change. Herein, based on a systematic review of international research progress and current ecological status of coral reefs in the South China Sea, this article proposes the following research directions, in order to promote the development of coral reef virology:(1) The diversity and spatial-temporal distribution characteristics of viruses in coral reefs from the South China Sea;(2) The mediation effect of viruses on coral thermal bleaching and diseases in the South China Sea, and their relationship with intensified global climate change;(3) The contribution of viruses in biogeochemical cycles(e.g., carbon and nitrogen cycles) of coral reef ecosystems in the South China Sea.