Rhizospheric microbiomes of Sorghum bicolor grown on soils with anthropogenic polyelement anomalies

Abstract

Comparative study was made of the rhizospheree microbiomes of two cultivars of sorghum (Sorghum bicolor cvs. Sucro 506 and Biomass 133) grown on soils with anthropogenic polyelement anomalies and on a background (control) soil. The study used traditional culture-based and culture-independent metagenomic approaches. In soils contaminated with heavy metals, we found decreased numbers of culturable bacteria and quantitative changes in the populations of actinomycetes and micromycetes. The relative abundance of the families whose members were able to resist heavy metals was found to increase in the rhizospheric communities. The taxonomic profile of the microbial communities at the phylum level did not differ significantly between cultivars. The Shannon diversity and the abundance of actinomycete families in the rhizosphere of cv. Biomass 133were greater than those for cv. Sucro 506. Significant differences were found between cultivars for the number of rhizospheric microorganisms resistant to heavy metals.