Full life cycle of uranium toward ore-soil-root-shoot system: A comprehensive review

Uranium is a naturally occurring radionuclide with chemical toxicity, derived from deposits formed through complex processes. In recent years, uranium utilization activities have increased uranium levels in the soil environment, posing serious threats to soil quality, food safety, and human health. Phytoextraction of uranium contamination is currently a cutting-edge topic that has attracted significant attentions. To date, several studies have examined the behavior and impact of uranium in various aspects of its mineralization and "soil-plant" system. Accordingly, we focused on the full life cycle of uranium within the "ore-soil-root-shoot" system, based on published work from 2015 to 2024, to provide an updated review of significant research findings and theories. Here, we present the following key aspects: (i) the factors influencing uranium mineralization, including material sources, transport processes, and precipitation mechanism; (ii) both natural and anthropogenic sources that contribute uranium entry into the soil; (iii) uranium toxicity generated by its radio- and chemo-toxicities; (iv) the toxic effects of uranium and plant detoxification; (v) the internal mechanisms of uranium uptake and translocation by plant roots; and (vi) the role of transpiration in the transport of uranium from roots to the aboveground plant parts. Phytoextraction is an eco-friendly and efficient method for remediation of uranium-contaminated soils, and combined measures such as chelating agents' application and microbial inoculation are effective to obtain the satisfying results. We also identify and summarize the gaps in current research, providing a reference for future related studies.