Effects of salt stress on the rhizosphere soil microbial communities of Suaeda salsa (L.) Pall. in the Yellow River Delta

Abstract

Studies have shown that the microbiome of saline-tolerant plants plays a significant role in promoting salt stress in non-saline-tolerant plants, but the microorganisms are still unclear. In the present study, the microbial diversity changes in Suaeda salsa (L.) Pall. in the Yellow River Delta region were investigated. In the bacterial community, the dominant bacteria in the rhizosphere soil of the low-saline soil (YDL), moderate-saline soil (YDM), and high-saline soil (YDH) groups were Proteobacteria, Chloroflexi, Bacteroidota, and Actinobacteriota (at the phylum level), while Ascomycota and Basidiomycota were the dominant fungi in the fungal community. At the family level, with the increase of salinity, the relative abundance of Rhodobacteraceae (bacterial community), Thermoascaceae, and Phaffomycetaceae (fungal community) gradually increased; and to the best of our knowledge, there are no reports on the relationship between Thermoascaceae and Phaffomycetaceae families with salt stress. At the genus level, Salinimicrobium (bacterial community) was the dominant bacterium in the rhizosphere soil of the YDL, YDM, and YDH groups, while with the increase of salinity, the relative abundance of Byssochlamys and Wickerhamomyces (fungal community) gradually increased, and to the best of our knowledge there are no reports on the relationship between Byssochlamys and salt stress. Salinity mainly affected the bacterial community abundance, but it had little effect on the fungi community abundance. The bacterial community of the YDH group was dominated by bacteria of unknown origin (52.76%), while bacteria of unknown origin accounted for 26.46% and 20.78% of the bacterial communities in the YDM and YDL groups, respectively. The fungi community of the YDH group was dominated by YDL group fungi (relative abundance of 44.44%), followed by YDM group fungi (29.42%) and fungi of unknown origin (26.14%). These results provide a better understanding of the rhizosphere microbial diversity of saline–alkali-tolerant plants, laying a foundation for developing a saline–alkali-tolerant plant microbiome.