"Killing the winner" only? The virome of grassland soils under different land use intensity as the driver for microbial community structure and function (KiWion)

仅仅是“杀死胜利者”吗？

• 批准号: 325073562
• 负责人: Professor Dr. Antonis Chatzinotas
• 金额: --
• 依托单位: Department für Funktionelle und Evolutionäre Ökologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325073562?language=en
• 关键词: Killing; winner; only; virome; grassland

Soils, although intensively studied with respect to their microbiology, are lagging virus ecology research compared to marine and freshwater systems. Indeed, soils harbour high numbers of viruses and virus - to - bacteria ratios (VBR) in soil seem to vary much more than in aquatic environments, frequently exceeding these by 1 to 2 orders of magnitude. Variations in virus populations are partly explained by differences in soil pH, water and organic content, hinting at land use differences posing a significant influence on virus diversity and viral - host interactions. With up to 68% of soil bacteria potentially containing inducible prophages, there is indication that the heterogeneous soil environment and the patchy distribution of soil microbial communities select for lysogenic rather than lytic reproduction in soil viruses, with the consequence, that prevalent lysogenic relationships increase the probability of transferring genetic information between phage and prokaryotic hosts by transduction. And indeed, the viral metagenomes analysed, show that up to 50% consists of transduced bacterial and archaeal genes. Although we assume that viruses in soil significantly contribute to host dynamics (Killing the Winner Hypothesis) and adaptation (Red Queen Hypothesis), ecosystem functioning, and biogeochemical processes similar to aquatic systems, the type and frequency of interactions are poorly understood and empirical data are missing. We hypothesize that transduction plays a very important role for resilience in soils under strong land use intensity, since in these soils i) diversity of soil microbes is lower and thus the ecosystem might be more sensitive to changing conditions and ii) the activity of soil microbes is particularly higher which may increase transduction rates, as the replication of the virus in the host requires metabolically active cells. To investigate the guiding hypothesis we will analyse the 150 plots within the Biodiversity Exploratories with a specific focus on grassland ecosystems under different land use intensity. We will investigate the relation between land use intensity, vegetation period, site specific conditions and the number of viruses. We will further describe the composition of the soil viromes as well as major functional traits of prokaryotic origin carried by viruses. Host - virus interaction studies and infection networks derived from CRISPR like structures in the prokaryotic hosts will provide information on community ecology. Finally, we will isolate viruses infecting dominating bacterial groups common to the different grassland soils (e.g. Pseudomonadaceae) for studying their cross - infection potentials.

与海洋和淡水系统相比，土壤对其微生物学进行了深入研究，但仍在病毒生态学研究。实际上，土壤具有大量的病毒和病毒 - 与 - 土壤中的细菌比（VBR）的变化远大于水生环境，通常超过1到2个数量级。病毒群体的变化部分是由土壤pH，水和有机含量的差异的部分解释，暗示了土地使用差异对病毒多样性和病毒 - 宿主相互作用产生重大影响。有多达68％的土壤细菌可能含有诱导的预言，有迹象表明，异质的土壤环境和土壤微生物群落的斑驳分布选择了土壤病毒中的裂解性而非裂解的繁殖，因此，流行的裂解关系增加了通过转导在噬菌体和原核宿主之间转移遗传信息的概率。实际上，已经分析的病毒宏基因组表明，多达50％的细菌和古细菌基因组成。尽管我们假设土壤中的病毒显着有助于宿主动态（杀死获胜者假设）和适应性（红皇后假设），生态系统功能和与水生系统相似的生物地球化学过程，但相互作用的类型和频率是众所周知的，经验数据是很众所周知的。丢失的。我们假设转导对土壤强度强度下的土壤的弹性起着非常重要的作用，因为在这些土壤中i）土壤微生物的多样性较低，因此生态系统可能对变化的条件更敏感，并且ii）土壤微生物的活性。特别较高，这可能会增加转导率，因为宿主中病毒的复制需要代谢活性细胞。为了研究指导假设，我们将分析生物多样性探索者中的150个地块，并在不同的土地使用强度下特别关注草原生态系统。我们将研究土地使用强度，植被期，特定地点条件与病毒数量之间的关系。我们将进一步描述土壤病毒瘤的组成以及由病毒携带的原核生物的主要功能性状。宿主 - 源自CRISPR的病毒相互作用研究和感染网络，例如原核宿主中的结构，将提供有关社区生态学的信息。最后，我们将分离出感染不同草原土壤（例如假核科）共有的主要细菌群的病毒，以研究其交叉感染潜力。