Microbiol Res. 2026 May 22;310:128560. doi: 10.1016/j.micres.2026.128560. Online ahead of print.
ABSTRACT
Heavy metal (HM) contamination in mining soils threatens ecological security and agricultural sustainability worldwide. Phytoremediation is frequently constrained by low plant accumulation efficiency and poor environmental adaptability of plant growth-promoting bacteria in multi-metal contaminated environments. The microbial mechanisms underlying Paenibacillus polymyxa WZ14 enhances multi-HMs (Cd, Pb, Cu) accumulation in diverse leguminous plants remain unclear. A pot experiment combined with 16S rRNA high-throughput Illumina MiSeq sequencing and multivariate statistical analyses was coupled with investigate the regulatory effects of WZ14 inoculation on strengthening leguminous plant (Robinia pseudoacacia L., Sophora xanthantha, Cajanus cajan L., and Albizia kalkora Roxb) HMs accumulation and the underlying microbial mechanisms. In this study, WZ14 inoculation significantly increased the concentrations and total uptake of Cd, Pb and Cu in four leguminous plants, with the strongest enhancement effect on S. xanthantha (Cd, Pb, and Cu uptake increased by 92.78%, 66.26%, and 117.92%, respectively). This promotion effect exhibited distinct plant species specificity and HM type dependence. Besides, WZ14 reshaped rhizosphere microbial community structure, increased relative abundance of HM-responsive dominant genera (Sphingomonas and Flavobacterium increased by 5.06%-31.03% and 8.64%-73.05%, respectively), enhanced microbial co-occurrence network modularity and cooperative interactions. PLS-PM analysis further clarified that available phosphorus, Sphingomonas and Flavisolibacter were the key factors regulating plant HMs uptake, and confirmed the chain regulatory pathway of soil nutrients-dominant genera-plant HMs uptake. Conclusively, this study clarifies the microbial-mediated regulatory mechanism of HMs uptake between P. polymyxa WZ14 and leguminous plants, providing a reliable and environmentally friendly new strategy for the ecological remediation of multi-HM contaminated soils.
PMID:42184460 | DOI:10.1016/j.micres.2026.128560
