Cadmium alters the rhizosphere bacterial community structure in blueberry roots and increases the content of lipids in the soil

Vaccinium spp. Is a small berry that grows in acidic environments. Relying on the exchange of nutrients and defense against adverse environments through the root system microbiota, bacteria play an important role. As a widely distributed pollutant, the mobility and bioavailability of Cd are enhanced in acidic environments, which can affect the community composition of blueberry root microbiota and alter the composition of soil metabolites. Therefore, studying the changes in the bacterial microbiota of blueberry roots and soil metabolomics under Cd stress can provide a foundation for the development of blueberry microbial fertilizers and the management of soil Cd pollution. In this study, 16 S rDNA sequencing and untargeted metabolomics were used to analyze the rhizosphere, root surface and root endophytic bacterial diversity as well as soil metabolites of Vaccinium spp. Under cadmium (Cd) contamination. The results indicate that the addition of cadmium (Cd) significantly reduces the & alpha;-diversity of the rhizosphere, rhizoplane, and endophytic bacteria in blueberries and has a significant impact on the dominant bacterial species. With the application of Cd, the relative abundance of the dominant taxa such as Diplorickettsiaceae_unclassified, Legionella, Streptomyces and Rhodanobacter decreased significantly at the genus level and turned into general or rare bacterial taxa. Meanwhile, the relative abundance of LWQ8_unclassified, WPS-2_unclassified, Acetobacteraceae_unclassified, Acidibacter, Acidiphilium and Granulicella with extreme tolerances increased significantly and gradually became the dominant taxa. Of the 364 metabolites in the soil, 31 varied significantly as the structure of the rhizosphere bacterial community changed. Among them, the lipids and lipid-like molecules clade showed the greatest variation in species and a significant increase in content. It was also associated with changes in bacterial taxa such as Tundrisphaera, Spirochaetaceae_unclassified, Dyella and CHAB_XI_27_unclassified.