Insight into bacterial and archaeal community structure of Suaeda altissima and Suaeda dendroides rhizosphere in response to different salinity level

Abstract

ABSTRACT Suaeda as a halophyte with wide adaptability of salinization level plays an important role in saline soil improvement and management. To some extent, the strong salt tolerance of Suaeda is influenced by rhizobacteria. However, the effect of different Suaeda species and salinization level on the microbial community diversity still unknown. In our study, high-throughput sequencing technology was used to explore the difference in the bacterial and archaeal community diversity of Suaeda altissima and Suaeda dendroides rhizosphere under high (EC, 8–16 dS/m) and severe (EC > 16 dS/m) saline soil. The result showed that complex soil environment and Suaeda species co-shaped bacterial and archaeal community structure, and pH was one of the most important driving factors. In addition, the increase of soil salinity significantly decreased the complexity of bacterial and archaeal co-occurrence network. We explored Halomonas and Candidatus Nitrocosmicus as core microorganisms in the Suaeda rhizosphere, which may play a key ecological role in improving salt tolerance and promoting growth of Suaeda . Our study improves the macroscopic understanding of the interrelationships between soil environments-microbes-plants. IMPORTANCE Suaeda play an important ecological role in reclamation and improvement of agricultural saline soil due to strong salt tolerance. At present, research on Suaeda salt tolerance mainly focuses on the physiological and molecular regulation. However, the important role played by microbial communities in the high-salinity tolerance of Suaeda is poorly studied. Our findings have important implications for understanding the distribution patterns and the driving mechanisms of different Suaeda species and soil salinity levels. In addition, we explored the key microorganisms that played an important ecological role in Suaeda rhizosphere. We provide a basis for biological improvement and ecological restoration of salinity-affected areas.