AUTHOR=Ye He , Zhao Yu , He Shilong , Wu Zhendan , Yue Mei , Hong Mei 

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

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1369196

DOI=10.3389/fmicb.2024.1369196

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>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.</p></sec><sec><title>Methods</title><p>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<sup>−1</sup> year<sup>−1</sup>): N50 (N addition 50 kg ha<sup>−1</sup> year<sup>−1</sup>).</p></sec><sec><title>Results</title><p>N deposition significantly increased the relative abundance of <italic>Actinobacteria</italic> (<italic>P</italic> &lt; 0.05) while significantly decreased the relative abundances of <italic>Proteobacteria</italic> and <italic>Acidobacteria</italic> (<italic>P</italic> &lt; 0.05). This significantly impacted the microbial community composition in desert steppe soils. The annual addition or deposition of 50 kg ha<sup>−1</sup> year<sup>−1</sup> 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<sup>−1</sup> year<sup>−1</sup>), which increased the abundance of the <italic>pmoA-amoA</italic> gene related to nitrification and the <italic>nirB</italic> gene associated with assimilation nitrite reductase. There may be a niche overlap between microorganisms involved in the same C and N cycling processes.</p></sec><sec><title>Discussion</title><p>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.</p></sec>