Unveiling the regulatory mechanism of poly-γ-glutamic acid on soil characteristics under drought stress through integrated metagenomics and metabolomics analysis

Li Hong; Li Wei; Ge Fanglan; Li Jiao; Tu Shiheng; Yang Hong; Ren Yao; Gong Xinyue; Yao Can

doi:10.3389/fmicb.2024.1387223

Unveiling the regulatory mechanism of poly-γ-glutamic acid on soil characteristics under drought stress through integrated metagenomics and metabolomics analysis

Front Microbiol. 2024 May 1:15:1387223. doi: 10.3389/fmicb.2024.1387223. eCollection 2024.

Authors

Li Hong^{1

2}, Li Wei^{1

2}, Ge Fanglan^{1

2}, Li Jiao^{1

2}, Tu Shiheng^{1

2}, Yang Hong^{1

2}, Ren Yao^{1

2}, Gong Xinyue^{1

2}, Yao Can^{1

2}

Affiliations

¹ Key Laboratory of the Evaluation and Monitoring of Southwest Land Resources (Ministry of Education), Sichuan Normal University, Chengdu, China.
² College of Life Sciences, Sichuan Normal University, Chengdu, China.

Abstract

It is of utmost importance to understand the characteristics and regulatory mechanisms of soil in order to optimize soil management and enhance crop yield. Poly-γ-glutamic acid (γ-PGA), a stress-resistant amino acid polymer, plays a crucial role in plant drought stress resistance. However, little is known about the effects of γ-PGA on soil characteristics during drought treatments. In this study, the effects of different forms of γ-PGA on soil texture and basic physical and chemical properties under short-term drought conditions were investigated. Furthermore, the impact of γ-PGA on the microbial community and metabolic function of maize was analyzed. Under drought conditions, the introduction of γ-PGA into the soil resulted in notable improvements in the mechanical composition ratio and infiltration capacity of the soil. Concurrently, this led to a reduction in soil bulk density and improved soil organic matter content and fertility. Additionally, metagenomic analysis revealed that under drought conditions, the incorporation of γ-PGA into the soil enhanced the soil microbiota structure. This shift led to the predominance of bacteria that are crucial for carbon, nitrogen, and phosphorus cycles in the soil. Metabolomics analysis revealed that under drought treatment, γ-PGA affected soil metabolic patterns, with a particular focus on alterations in amino acid and vitamin metabolism pathways. Correlation analysis between the soil metagenome and metabolites showed that microorganisms played a significant role in metabolite accumulation. These results demonstrated that γ-PGA could improve soil characteristics under drought conditions and play an important role in soil microorganisms and microbial metabolism, providing further insights into the changes in soil characteristics under drought conditions.

Keywords: drought stress; metabonomic analysis; metagenome analysis; poly-γ-glutamic acid; soil characteristics.

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 grants from the Sichuan Province Science and Technology Support Program (2022NSFSC1720), and Chengdu Science and Technology Program (2022-YF05-00631-SN).