Metagenomics reveals the response of desert steppe microbial communities and carbon-nitrogen cycling functional genes to nitrogen deposition

He Ye; Yu Zhao; Shilong He; Zhendan Wu; Mei Yue; Mei Hong

doi:10.3389/fmicb.2024.1369196

Metagenomics reveals the response of desert steppe microbial communities and carbon-nitrogen cycling functional genes to nitrogen deposition

Front Microbiol. 2024 Mar 26:15:1369196. doi: 10.3389/fmicb.2024.1369196. eCollection 2024.

Authors

He Ye^{1

2}, Yu Zhao^{1

2}, Shilong He^{1

2}, Zhendan Wu^{1

2}, Mei Yue^{1

2}, Mei Hong^{1

2}

Affiliations

¹ Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.
² Key Laboratory of Agricultural Ecological Security and Green Development at Universities of Inner Mongolia Autonomous Region, Hohhot, China.

Abstract

Introduction: Nitrogen (N) deposition seriously affects the function of carbon (C) and N cycling in terrestrial ecosystems by altering soil microbial communities, especially in desert steppe ecosystems. However, there is a need for a comprehensive understanding of how microorganisms involved in each C and N cycle process respond to N deposition.

Methods: In this study, shotgun metagenome sequencing was used to investigate variations in soil C and N cycling-related genes in the desert steppe in northern China after 6 years of the following N deposition: N0 (control); N30 (N addition 30 kg ha^-1 year^-1): N50 (N addition 50 kg ha^-1 year^-1).

Results: N deposition significantly increased the relative abundance of Actinobacteria (P < 0.05) while significantly decreased the relative abundances of Proteobacteria and Acidobacteria (P < 0.05). This significantly impacted the microbial community composition in desert steppe soils. The annual addition or deposition of 50 kg ha^-1 year^-1 for up to 6 years did not affect the C cycle gene abundance but changed the C cycle-related microorganism community structure. The process of the N cycle in the desert steppe was affected by N deposition (50 kg ha^-1 year^-1), which increased the abundance of the pmoA-amoA gene related to nitrification and the nirB gene associated with assimilation nitrite reductase. There may be a niche overlap between microorganisms involved in the same C and N cycling processes.

Discussion: This study provides new insights into the effects of N deposition on soil microbial communities and functions in desert steppe and a better understanding of the ecological consequences of anthropogenic N addition.

Keywords: carbon cycle function; metagenomics; nitrogen cycle function; nitrogen deposition; soil microbiome.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the National Natural Science Foundation of China (no. 31860136), the basic Scientific Research Service Fee Project of Colleges and Universities directly under the Inner Mongolia Autonomous Region, and the Inner Mongolia Autonomous Region Graduate Scientific Research Innovation project (no. B20210158Z).