School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Sci Total Environ. 2020 Sep 15;735:139572. doi: 10.1016/j.scitotenv.2020.139572. Epub 2020 May 21.
Metabolites in root-zone soils mediate microbe-to-microbe interactions and govern the overall microbial community. However, how chemicals relate to diversity and co-occurrence patterns of bacterial communities in root-associated soils is still poorly understood. Here, we studied the relationships of soil metabolome with bacterial community diversity and co-occurrence patterns in root-associated soils across different land types on the Tibetan Plateau. The soil metabolome mainly encompassed a range of organic acids, and sugars and sugar derivatives, which were widely negatively correlated with bacterial alpha-diversity. Compared to the investigated environmental variables, metabolites accounted more for the variations in the Shannon diversity and bacterial community compositions. Compared to sugars, organic acids accounted more for bacterial community compositions at high taxonomic ranks, while reversed at genus and species levels. The relative abundances of some bacterial genera and metabolites were closely linked to soil types and plant genotypes. The differential compounds were significantly correlated with the distinctive bacterial taxa across land types and plant genotypes. Keystone species in co-occurrence network, such as Bradyrhizobium, Bryobacter, and Microvirga were significantly correlated with sugars and organic acids. Structural equation modeling revealed that sugar metabolism can play a crucial role in altering the bacterial community diversity. This study provides new insights into the ecological mechanism that maintains bacterial community in the root-associated soils on the Tibetan Plateau.
根区土壤中的代谢物介导微生物间相互作用，并控制着整个微生物群落。然而，化学物质与根际土壤中细菌群落的多样性和共现模式之间的关系仍知之甚少。在这里，我们研究了青藏高原不同土地类型上根际土壤中代谢组与细菌群落多样性和共现模式的关系。土壤代谢组主要包括一系列有机酸、糖和糖衍生物，它们与细菌α多样性呈广泛负相关。与调查的环境变量相比，代谢物更多地解释了香农多样性和细菌群落组成的变化。与糖相比，有机酸在较高的分类等级上更多地解释了细菌群落组成，而在属和种水平上则相反。一些细菌属和代谢物的相对丰度与土壤类型和植物基因型密切相关。不同土地类型和植物基因型之间的差异化合物与特有细菌分类群显著相关。共生网络中的关键种，如Bradyrhizobium、Bryobacter 和 Microvirga，与糖和有机酸显著相关。结构方程模型显示，糖代谢可以在改变细菌群落多样性方面发挥关键作用。本研究为维持青藏高原根际土壤细菌群落的生态机制提供了新的见解。
