Interplay Between Microorganisms and Vanadium: Adaptation and Transformation Dynamics in Soil-Plant Systems

Soil-plant system play an essential role in distribution and transformation of vanadium (V). V shapes the diversity of soil communities, while soil microorganisms mediate V transformation. Plants also absorb V from surrounding soil. However, the study of microbial response to V stress in different soil-plant compartments is limited, and the metabolic functions driving V transformation across these systems remain elusive. The study investigates the distribution of V in soil-plant systems nearby a V smelter. 16S rRNA sequencing and metagenomics are utilized to reveal the microbial adaptation and V transformation in bulk soil, rhizosphere, and endosphere. Bothriochloa ischaemum (L.) Keng. (BK) exhibits higher phytoextraction potential (TF = 0.74 0.26). Environmental variables, including pH, V, OM, and AP, show significant (p < 0.05) influence in soil community composition, with homogeneous selection governing the assembly processes in bulk soil and rhizosphere, while stochastic process dominates endospheric assembly. Metagenomic investigation revealed a coordinated metabolic pathway between functional taxa in soil and plants, which lead to root uptake and translocation. V stress is mitigated through Nocardioide, Microvirga, and Solirubrobacter, putatively harboring V(V) reduction genes narG and mtrC in soil. In rhizosphere, citrate synthase gltA and alkaline phosphatase phoD exhibit functional potential to facilitate formation of V-complexation to increase V mobility. In endoshere, endophytic Enterobacter further detoxifies V(V), and likely promotes V translocation through siderophore biosynthesis gene, iucA. These findings enhance our understanding on both microbial adaptation to V stress and modulations of V transformation in soil-plant systems, which is instrumental in developing mitigation plan for V contaminated sites.