TY - JOUR
T1 - Emerging investigator series
T2 - Entrapment of uranium-phosphorus nanocrystals inside root cells of: Tamarix plants from a mine waste site
AU - Rodriguez-Freire, Lucia
AU - Devore, Cherie L.
AU - El Hayek, Eliane
AU - Berti, Debora
AU - Ali, Abdul Mehdi S.
AU - Lezama Pacheco, Juan S.
AU - Blake, Johanna M.
AU - Spilde, Michael N.
AU - Brearley, Adrian J.
AU - Artyushkova, Kateryna
AU - Cerrato, José M.
N1 - Funding Information:
The authors thank the members of Laguna Pueblo for supporting this work. The authors would like to acknowledge the existing partnership with the Pueblo of Laguna Environment and Natural Resources Department. This work was supported by the National Institute of Health Centers of Excellence on Environmental Health Disparities Research (Grant numbers 1-P50-ES-026102-01 and US-EPA 836157-01), the National Institute of Environmental Health Sciences Superfund Research Program (Award 1-P42-ES-025589), and the National Science Foundation (NM EPSCoR #IIA-1301346 and CAREER 1652619). Part of this work was supported by the Virginia Tech National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), supported by the National Science Foundation (ECCS 1542100). Part of this research was carried out at the Stanford Synchrotron Radiation Light source, a national user facility operated by Stanford University on behalf of the US DOE-OBER. The views expressed in this document are solely those of the authors and do not necessarily reect those of the Agencies.
Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2021
Y1 - 2021
N2 - We investigated the mechanisms of uranium (U) uptake by Tamarix (salt cedars) growing along the Rio Paguate, which flows throughout the Jackpile mine near Pueblo de Laguna, New Mexico. Tamarix were selected for this study due to the detection of U in the roots and shoots of field collected plants (0.6-58.9 mg kg-1), presenting an average bioconcentration factor greater than 1. Synchrotron-based micro X-ray fluorescence analyses of plant roots collected from the field indicate that the accumulation of U occurs in the cortex of the root. The mechanisms for U accumulation in the roots of Tamarix were further investigated in controlled-laboratory experiments where living roots of field plants were macerated for 24 h or 2 weeks in a solution containing 100 μM U. The U concentration in the solution decreased 36-59% after 24 h, and 49-65% in two weeks. Microscopic and spectroscopic analyses detected U precipitation in the root cell walls near the xylems of the roots, confirming the initial results from the field samples. High-resolution TEM was used to study the U fate inside the root cells, and needle-like U-P nanocrystals, with diameter <7 nm, were found entrapped inside vacuoles in cells. EXAFS shell-by-shell fitting suggest that U is associated with carbon functional groups. The preferable binding of U to the root cell walls may explain the U retention in the roots of Tamarix, followed by U-P crystal precipitation, and pinocytotic active transport and cellular entrapment. This process resulted in a limited translocation of U to the shoots in Tamarix plants. This study contributes to better understanding of the physicochemical mechanisms affecting the U uptake and accumulation by plants growing near contaminated sites.
AB - We investigated the mechanisms of uranium (U) uptake by Tamarix (salt cedars) growing along the Rio Paguate, which flows throughout the Jackpile mine near Pueblo de Laguna, New Mexico. Tamarix were selected for this study due to the detection of U in the roots and shoots of field collected plants (0.6-58.9 mg kg-1), presenting an average bioconcentration factor greater than 1. Synchrotron-based micro X-ray fluorescence analyses of plant roots collected from the field indicate that the accumulation of U occurs in the cortex of the root. The mechanisms for U accumulation in the roots of Tamarix were further investigated in controlled-laboratory experiments where living roots of field plants were macerated for 24 h or 2 weeks in a solution containing 100 μM U. The U concentration in the solution decreased 36-59% after 24 h, and 49-65% in two weeks. Microscopic and spectroscopic analyses detected U precipitation in the root cell walls near the xylems of the roots, confirming the initial results from the field samples. High-resolution TEM was used to study the U fate inside the root cells, and needle-like U-P nanocrystals, with diameter <7 nm, were found entrapped inside vacuoles in cells. EXAFS shell-by-shell fitting suggest that U is associated with carbon functional groups. The preferable binding of U to the root cell walls may explain the U retention in the roots of Tamarix, followed by U-P crystal precipitation, and pinocytotic active transport and cellular entrapment. This process resulted in a limited translocation of U to the shoots in Tamarix plants. This study contributes to better understanding of the physicochemical mechanisms affecting the U uptake and accumulation by plants growing near contaminated sites.
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U2 - 10.1039/d0em00306a
DO - 10.1039/d0em00306a
M3 - Article
C2 - 33325952
AN - SCOPUS:85100989177
SN - 2050-7887
VL - 23
SP - 73
EP - 85
JO - Environmental Science: Processes and Impacts
JF - Environmental Science: Processes and Impacts
IS - 1
ER -