CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Department of Civil and Environmental Engineering, Utah State University, Logan, UT 84322, United States; Utah Water Research Laboratory, 1600 Canyon Road, Logan, UT 84321, United States.
J Hazard Mater. 2024 Nov 5;479:135675. doi: 10.1016/j.jhazmat.2024.135675. Epub 2024 Aug 28.
The profound influences of altitude on aquatic microbiome were well documented. However, differences in the responses of different life domains (bacteria, microeukaryotes, viruses) and antibiotics resistance genes (ARGs) in glacier river ecosystems to altitude remain unknown. Here, we employed shotgun metagenomic and amplicon sequencing to characterize the altitudinal variations of microbiome and ARGs in the Rongbu River, Mount Everest. Our results indicated the relative influences of stochastic processes on microbiome and ARGs assembly in water and sediment were in the following order: microeukaryotes < ARGs < viruses < bacteria. Moreover, distinct assembly patterns of the microbiome and ARGs were found in response to differences in altitude, the latter of which shift from deterministic to stochastic processes with increasing differences in altitude. Partial least squares path modeling revealed that mobile genetic elements (MGEs) and viral β-diversity were the major factors influencing the ARG abundances. Taken together, our work revealed that altitude-caused environmental changes led to significant changes in the composition and assembly processes of the microbiome and ARGs, while ARGs had a unique response pattern to altitude. Our findings provide novel insights into the impacts of altitude on the biogeographic distribution of microbiome and ARGs, and the associated driving forces in glacier river ecosystems.
高原对水生微生物组的深远影响已有充分的文献记载。然而，冰川河流生态系统中不同生命领域（细菌、微型真核生物、病毒）和抗生素抗性基因（ARGs）对海拔的响应差异尚不清楚。在这里，我们采用鸟枪法宏基因组和扩增子测序来描述珠穆朗玛峰绒布河微生物组和 ARGs 的海拔变化。我们的结果表明，随机过程对水和沉积物中微生物组和 ARGs 组装的相对影响顺序为：微型真核生物<ARGs<病毒<细菌。此外，我们发现微生物组和 ARGs 存在不同的组装模式，以响应不同的海拔高度，后者的组装模式从确定性转变为随机性，随着海拔差异的增加而变化。偏最小二乘路径模型显示，移动遗传元件（MGEs）和病毒β多样性是影响 ARG 丰度的主要因素。总之，我们的研究结果表明，海拔引起的环境变化导致微生物组和 ARGs 的组成和组装过程发生显著变化，而 ARGs 对海拔有独特的响应模式。我们的研究结果为海拔对微生物组和 ARGs 的生物地理分布以及冰川河流生态系统中相关驱动因素的影响提供了新的见解。
