Effects of heavy metals on bacterial community structure in the rhizosphere of Salsola collina and bulk soil in the Jinchuan mining area

It is important to understand the changes in microbial properties of plant rhizospheres to elucidate the interaction between heavy metals and plant communities. In this study, high throughput sequencing method was used to analyze the effects of heavy metals on rhizosphere microbial community structure of the autochthonous plant Salsola collina in the Jinchuan mining area. The operational taxonomic units (OTU) number and species diversity, and richness of the bacterial community in the rhizosphere of Salsola collina were higher than those of the bulk soil. Proteobacteria, Actinobacteria, and Firmicutes were the major bacterial phyla, and Salsola collina, Kaistobacter, Citrobacter, Acinetobacter and Pseudomonas were the main genera. Principal component analysis (PCA) and unweighted pair group method using arithmetic average (UPGMA) cluster analysis showed that there were significant differences in bacterial community structure between site and between rhizosphere and bulk soil. The moisture content, total nitrogen, phosphorus, magnesium, nickel, chromium, lead, and zinc contents, and pH had significant effects on species richness of the bacterial community, with total phosphorus content having a significant effect on species diversity. The finding of this study could be used as an important guideline for bioremediation of heavy metals in mining area.