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Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice?
Selenium plays an important, but vastly neglected role in human nutrition with a narrow gap between dietary deficiency and toxicity. For a potential biofortification of food with Se, as well as for toxicity-risk assessment in sites contaminated by Se, modelling of local and global Se cycling is esse...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6474650/ https://www.ncbi.nlm.nih.gov/pubmed/31002711 http://dx.doi.org/10.1371/journal.pone.0214219 |
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author | Nothstein, Alexandra K. Eiche, Elisabeth Riemann, Michael Nick, Peter Maier, Philipp Tenspolde, Arne Neumann, Thomas |
author_facet | Nothstein, Alexandra K. Eiche, Elisabeth Riemann, Michael Nick, Peter Maier, Philipp Tenspolde, Arne Neumann, Thomas |
author_sort | Nothstein, Alexandra K. |
collection | PubMed |
description | Selenium plays an important, but vastly neglected role in human nutrition with a narrow gap between dietary deficiency and toxicity. For a potential biofortification of food with Se, as well as for toxicity-risk assessment in sites contaminated by Se, modelling of local and global Se cycling is essential. As bioavailability of Se for rice plants depends on the speciation of Se and the resulting interactions with mineral surfaces as well as the interaction with Se uptake mechanisms in plants, resulting plant Se content is complex to model. Unfortunately, simple experimental models to estimate Se uptake into plants from substrates have been lacking. Therefore, a mass balance of Se transfer between lithosphere (represented by kaolinite), hydrosphere (represented by a controlled nutrient solution), and biosphere (represented by rice plants) has been established. In a controlled, closed, lab-scale system, rice plants were grown hydroponically in nutrient solution supplemented with 0–10 000 μg L(-1) Se of either selenate or selenite. Furthermore, in a series of batch experiments, adsorption and desorption were studied for selenate and selenite in competition with each of the major nutrient oxy-anions, nitrate, sulfate and phosphate. In a third step, the hydroponical plants experiments were coupled with sorption experiments to study synergy effects. These data were used to develop a mass balance fitting model of Se uptake and partitioning. Adsorption was well-described by Langmuir isotherms, despite competing anions, however, a certain percentage of Se always remained bio-unavailable to the plant. Uptake of selenate or selenite by transporters into the rice plant was fitted with the non-time differentiated Michaelis-Menten equation. Subsequent sequestration of Se to the shoot was better described using a substrate-inhibited variation of the Michaelis-Menten equation. These fitted parameters were then integrated into a mass balance model of Se transfer. |
format | Online Article Text |
id | pubmed-6474650 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-64746502019-05-03 Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? Nothstein, Alexandra K. Eiche, Elisabeth Riemann, Michael Nick, Peter Maier, Philipp Tenspolde, Arne Neumann, Thomas PLoS One Research Article Selenium plays an important, but vastly neglected role in human nutrition with a narrow gap between dietary deficiency and toxicity. For a potential biofortification of food with Se, as well as for toxicity-risk assessment in sites contaminated by Se, modelling of local and global Se cycling is essential. As bioavailability of Se for rice plants depends on the speciation of Se and the resulting interactions with mineral surfaces as well as the interaction with Se uptake mechanisms in plants, resulting plant Se content is complex to model. Unfortunately, simple experimental models to estimate Se uptake into plants from substrates have been lacking. Therefore, a mass balance of Se transfer between lithosphere (represented by kaolinite), hydrosphere (represented by a controlled nutrient solution), and biosphere (represented by rice plants) has been established. In a controlled, closed, lab-scale system, rice plants were grown hydroponically in nutrient solution supplemented with 0–10 000 μg L(-1) Se of either selenate or selenite. Furthermore, in a series of batch experiments, adsorption and desorption were studied for selenate and selenite in competition with each of the major nutrient oxy-anions, nitrate, sulfate and phosphate. In a third step, the hydroponical plants experiments were coupled with sorption experiments to study synergy effects. These data were used to develop a mass balance fitting model of Se uptake and partitioning. Adsorption was well-described by Langmuir isotherms, despite competing anions, however, a certain percentage of Se always remained bio-unavailable to the plant. Uptake of selenate or selenite by transporters into the rice plant was fitted with the non-time differentiated Michaelis-Menten equation. Subsequent sequestration of Se to the shoot was better described using a substrate-inhibited variation of the Michaelis-Menten equation. These fitted parameters were then integrated into a mass balance model of Se transfer. Public Library of Science 2019-04-19 /pmc/articles/PMC6474650/ /pubmed/31002711 http://dx.doi.org/10.1371/journal.pone.0214219 Text en © 2019 Nothstein et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Nothstein, Alexandra K. Eiche, Elisabeth Riemann, Michael Nick, Peter Maier, Philipp Tenspolde, Arne Neumann, Thomas Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title | Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title_full | Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title_fullStr | Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title_full_unstemmed | Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title_short | Coupling Langmuir with Michaelis-Menten—A practical alternative to estimate Se content in rice? |
title_sort | coupling langmuir with michaelis-menten—a practical alternative to estimate se content in rice? |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6474650/ https://www.ncbi.nlm.nih.gov/pubmed/31002711 http://dx.doi.org/10.1371/journal.pone.0214219 |
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