Response of cbbL-harboring microorganisms to precipitation changes in a naturally-restored grassland

Na Li; Baorong Wang; Yimei Huang; Qian Huang; Feng Jiao; Shaoshan An

doi:10.1016/j.scitotenv.2022.156191

Response of cbbL-harboring microorganisms to precipitation changes in a naturally-restored grassland

Sci Total Environ. 2022 Sep 10;838(Pt 2):156191. doi: 10.1016/j.scitotenv.2022.156191. Epub 2022 May 23.

Authors

Na Li¹, Baorong Wang², Yimei Huang³, Qian Huang³, Feng Jiao⁴, Shaoshan An⁵

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China.
² State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China.
³ Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China.
⁴ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China. Electronic address: Jiaof@ms.iswc.ac.cn.
⁵ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling 712100, China. Electronic address: shan@ms.iswc.ac.cn.

PMID: 35618124
DOI: 10.1016/j.scitotenv.2022.156191

Abstract

The impact of the long-term uneven precipitation distribution model on the diversity and community composition of soil C-fixing microorganisms in arid and semiarid grasslands remains unclear. In 2015, we randomly set up five experimental plots with precipitation gradients on the natural restoration grassland of the Loess Plateau (natural precipitation, NP; ± 40% natural precipitation: decreased precipitation (DP), DP40; increased precipitation (IP), IP40; ± 80% natural precipitation: DP80; IP80). In the third and fifth years after the experimental layout (spanned two years), we explored the cbbL-genes, which are functional genes in the Calvin cycle, harboring microbial diversity and community composition under different precipitation treatments. The results showed that the increase in mean annual precipitation significantly changed the cbbL-harboring microbial alpha diversity, especially when controlling for 40% natural precipitation. The response of the dominant microbial communities to interannual increased precipitation variation shifted from Gammaproteobacteria (Bradyrhizobium) to Betaproteobacteria (Variovorax). The structural equation model showed that precipitation directly affected the cbbL-harboring microbial diversity and community composition and indirectly by affecting soil NO₃^- (mg N kg ^-1), soil organic matter, dissolved organic N content, and above- and underground biomass. In conclusion, studying how cbbL-harboring microbial diversity and community composition respond to uneven precipitation variability provides new insights into the ecological processes of C-fixing microbes in semi-arid naturally-restored grasslands dominated by the Calvin cycle.

Keywords: Bradyrhizobium; C-fixing microorganisms; Diversity; Precipitation; Semiarid; Variovorax; cbbL.

MeSH terms

Biomass
Grassland*
Microbiota*
Soil / chemistry
Soil Microbiology

Substances

Soil