Microbial community structure and environmental adaptation in rhizosphere and non-rhizosphere soils of halophytic plants in the Ebinur Lake wetland

Abstract

Aims

Soil microorganisms have a direct impact on both soil and plant health. This study aimed to investigate the diversity, composition, and ecological functions of bacterial and fungal communities in the rhizosphere and non-rhizosphere soils of Karelinia caspia (KC) and Haloxylon ammodendron (HA) in the Ebinur Lake wetland. The focus was on understanding microbial responses to environmental factors and the interactions shaping soil ecosystem stability.

Methods

Microbial diversity and composition were analyzed using high-throughput sequencing of bacterial 16S rRNA and fungal ITS genes. Soil physicochemical properties were measured to assess environmental influences. Co-occurrence networks were constructed to identify key taxa and their interactions, and redundancy analysis was applied to elucidate relationships between microbial communities and environmental variables.

Results

Dominant bacterial phyla in both rhizosphere and non-rhizosphere soils were Actinobacteriota, Bacteroidota, and Proteobacteria, while the dominant fungal phylum was Ascomycota. Rhizosphere soils exhibited higher microbial diversity and network complexity than non-rhizosphere soils. Total potassium, Available potassium and electrical conductivity were the main environmental factors shaping rhizosphere microbial communities, while Total nitrogen, Alkali-hydrolyzable nitrogen played a more significant role in non-rhizosphere soils. Co-occurrence network analysis revealed distinct patterns, with rhizosphere networks demonstrating greater complexity and non-rhizosphere networks showing higher stability.

Conclusions

This study underscores the adaptability of microbial communities in rhizosphere and non-rhizosphere soils under saline-alkaline conditions, highlighting the roles of plant types and environmental factors in shaping community structure. These findings offer vital insights into the role of microbial diversity in maintaining ecosystem stability and lay a foundation for developing effective wetland conservation strategies.