几种典型土壤中病毒多样性及其分布特征

Viruses are usually composed of a small piece of nucleic acid surrounded by the coat protein, and have been recognized as the simplest known living organism to date. Viruses are only organic macromolecules when staying in the environments, because they lack intergral enzyme systems and energy transformation systems. However, once infected host cells, viruses could be resuscitated and start to replicate themselves. Despite their dependence on host cells to survive, viruses are also the most ubiquitous living organisms, and important drivers influencing microbial community and ecosystem functioning. However, our understanding of the microbial ecology of environmental viruses has not kept pace with the rapid advances in studies on bacteria and eukaryotes, owing to lack of universal phylogenetic biomarker. With the progress of high-throughput sequencing technologies in recent years, a large amount of new viruses and genes have been discovered and identified, which highly contributed to the development of virus ecology. By taking several typical soils as the research object, the aims of this project is first to establish the system of molecular methods of soil viral ecology, and second to investigate the diversity and distribution of viruses in several typical soils, and third to explore the relationship between viral diversity and soil environmental factors, which could reveal the key factors affecting the distribution of viruses and potential ecological driving mechanisms. Complete understanding of virus survival and propagation mechanisms in the environment, thereby providing evidence for controlling and application of soil viruses in our country.

病毒是目前所知的最简单的生命单元，通常由外壳蛋白和包裹在外壳蛋白内的核酸两部分组成，本身缺乏完整的酶系统及能量转化系统只有侵染宿主后才具有生命特征，进行复制。病毒也是地球上最丰富的生物实体，是微生物群落和功能的重要影响因素。尽管病毒在生态系统中发挥着重要的作用，但因病毒间缺少通用的标记基因，病毒生态学的研究远远滞后于细菌和真核生物。近年来高通量测序技术的发展应用帮助人们发现和认识了许多未知的新病毒和基因，直接推动了病毒生态学的发展。因此，本项目拟以我国几种典型土壤为研究对象，探索在实验室建立系统的土壤病毒生态学分子方法，并在此基础上深入研究几种典型土壤中的病毒多样性及分布特征，探讨病毒的多样性与土壤环境因子之间的相互关系，从而揭示影响病毒生态分布的关键因子及潜在的驱动机制。理解不同类型病毒在环境中的生存和传播机制，为我国环境中病毒的控制及应用提供依据。

病毒是地球上丰度最高的生物实体，是微生物群落和功能的重要影响因素。尽管病毒在生态系统中发挥着重要的作用，但因病毒间缺少通用的标记基因，病毒生态学的研究远远滞后于细菌和真核生物。本项目在实验室建立了土壤病毒生态学研究平台，包括土壤病毒的提取、形态观察、病毒DNA提取、宏基因组测序及生物信息学分析。基于该平台，研究了我国10个省和自治区的19份不同类型土壤样品（10份农田土壤，9份非人为干扰的自然土壤）的宏病毒组。研究结果共注释到了19个dsDNA病毒科和9个ssDNA病毒科，其中ssDNA病毒主要以微小病毒科和环状病毒科为主，而dsDNA病毒中则是有尾噬菌体目（包括长尾病毒科、短尾病毒科和肌尾病毒科）占据优势。同时，我们还鉴定到了大量病毒scaffolds推测它们可能是属于新的病毒基因组。统计学分析表明土壤有效磷和EC值是影响病毒群落组成的主要环境因子。本研究通过构建土壤病毒生态学研究方法，对我国代表性土壤类型下的土壤宏病毒组特征进行了初步研究，探讨病毒在环境中的分布特征，可为土壤病毒的防控及开发利用提供理论依据。