Radionuclide Uptake by Plants: Soil-to-Plant Transfer Factors, Kinetics of Absorption, and Internal Radionuclide Distribution of 137Cs and 40K in South American Species

Velasco, H.; Anjos, R. M.; Ayub, J. Juri

doi:10.1007/978-3-319-07665-2_6

Cited by 2 publications

(1 citation statement)

References 23 publications

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“…Potential mechanisms of plant-mediated transport of radionuclides in the soil can be broadly classified into the initial dissolution of radionuclides from the unavailable mineral forms (mobilization), followed by the uptake and accumulation of the mobilized radionuclides within the plant tissues, both of which are significantly influenced by the physiology of the plant. The plant uptake and transport of radionuclides in solution has been demonstrated in several lab-scale hydroponic studies. , A few studies also have recorded significant upward movement of radionuclides in plants growing in contaminated soils. − However, plant-mediated processes that regulate the mobilization of radionuclides at the source, and the influence of growing environments in modulating this plant-mediated radionuclide mobilization remain less explored.…”

Section: Introductionmentioning

confidence: 99%

Phosphorus Stress-Induced Changes in Plant Root Exudation Could Potentially Facilitate Uranium Mobilization from Stable Mineral Forms

Edayilam

Montgomery

Ferguson

et al. 2018

Environ. Sci. Technol.

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Apparent deficiency of soil mineral nutrients often triggers specific physio-morphological changes in plants, and some of these changes could also inadvertently increase the ability of plants to mobilize radionuclides from stable mineral forms. This work, through a series of sand-culture, hydroponics, and batch-equilibration experiments, investigated the differential ability of root exudates of Andropogon virginicus grown under conditions with variable phosphorus (P) availability (KHPO, FePO, Ca(PO), and no P) to solubilize uranium (U) from the uranyl phosphate mineral Chernikovite. The mineral form of P, and hence the bioavailability of P, affected the overall composition of the root exudates. The lower bioavailable forms of P (FePO and Ca(PO)), but not the complete absence of P, resulted in a higher abundance of root metabolites with chelating capacity at 72 hrs after treatment application. In treatments with lower P-bioavailability, the physiological amino acid concentration inside of the roots increased, whereas the concentration of organic acids in the roots decreased due to the active exudation. In batch dissolution experiments, the organic acids, but not amino acids, increase the dissolution U from Chernikovite. The root exudate matrix of plants exposed to low available forms of P induced a >60% increase in U dissolution from Chernikovite due to 5-16 times greater abundance of organic acids in these treatments. However, this was ca. 70% of the theoretical dissolution achievable by this exudate matrix. These results highlight the potential of using active management of soil P as an effective tool to alter the plant-mediated mobilization of U in contaminated soil.

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