Roy Krishnakali, Ghosh Dhritiman, DeBruyn Jennifer M, Dasgupta Tirthankar, Wommack K Eric, Liang Xiaolong, Wagner Regan E, Radosevich Mark
Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Knoxville, TN, United States.
Department of Statistics, Harvard University, Cambridge, MA, United States.
Front Microbiol. 2020 Jul 7;11:1494. doi: 10.3389/fmicb.2020.01494. eCollection 2020.
As reported in many aquatic environments, recent studies in terrestrial ecosystems implicate a role for viruses in shaping the structure, function, and evolution of prokaryotic soil communities. However, given the heterogeneity of soil and the physical constraints (i.e., pore-scale hydrology and solid-phase adsorption of phage and host cells) on the mobility of viruses and bacteria, phage-host interactions likely differ from those in aquatic systems. In this study, temporal changes in the population dynamics of viruses and bacteria in soils under different land management practices were examined. The results showed that bacterial abundance was significantly and positively correlated to both virus and inducible prophage abundance. Bacterial and viral abundance were also correlated with soil organic carbon and nitrogen content as well as with C:N ratio. The seasonal variability in viral abundance increased with soil organic carbon content. The prokaryotic community structure was influenced more by land use than by seasonal variation though considerable variation was evident in the early plant successional and grassland sites. The free extracellular viral communities were also separated by land use, and the forest soil viral assemblage exhibiting the most seasonal variability was more distinct from the other sites. Viral assemblages from the agricultural soils exhibited the least seasonal variability. Similar patterns were observed for inducible prophage viral assemblages. Seasonal variability of viral assemblages was greater in mitomycin-C (mitC) induced prophages than in extracellular viruses irrespective of land use and management. Taken together, the data suggest that soil viral production and decay are likely balanced but there was clear evidence that the structure of viral assemblages is influenced by land use and by season.
正如在许多水生环境中所报道的那样，最近在陆地生态系统中的研究表明，病毒在塑造原核土壤群落的结构、功能和进化方面发挥着作用。然而，鉴于土壤的异质性以及病毒和细菌移动性所面临的物理限制（即孔隙尺度水文以及噬菌体和宿主细胞的固相吸附），噬菌体 - 宿主相互作用可能与水生系统中的有所不同。在本研究中，我们考察了不同土地管理方式下土壤中病毒和细菌种群动态的时间变化。结果表明，细菌丰度与病毒和可诱导前噬菌体丰度均呈显著正相关。细菌和病毒丰度还与土壤有机碳和氮含量以及碳氮比相关。病毒丰度的季节变异性随土壤有机碳含量增加。原核生物群落结构受土地利用的影响大于季节变化，尽管在早期植物演替和草地站点存在明显的变化。游离细胞外病毒群落也因土地利用而分离，森林土壤病毒组合表现出最大的季节变异性，与其他站点更为不同。农业土壤中的病毒组合表现出最小的季节变异性。可诱导前噬菌体病毒组合也观察到类似模式。无论土地利用和管理如何，丝裂霉素 - C（mitC）诱导的前噬菌体中病毒组合的季节变异性都大于细胞外病毒。综上所述，数据表明土壤病毒的产生和衰减可能是平衡的，但有明确证据表明病毒组合的结构受土地利用和季节的影响。
