Cadmium transfer in contaminated soil-rice systems: Insights from solid-state speciation analysis and stable isotope fractionation

Wiggenhauser, Matthias; Aucour, Anne‐Marie; Bureau, Sarah; Campillo, Sylvain; Télouk, Philippe; Romani, Marco; Feng, Jian; Landrot, Gautier; Sarret, Géraldine

doi:10.1016/j.envpol.2020.115934

Cited by 72 publications

(144 citation statements)

References 69 publications

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…We defined the period between flowering and maturity as grain filling period. Part of the data presented for the flowering stage was already published in Wiggenhauser et al (2021) ; details are given in the legends and footnotes of the figures and tables, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…The soil was sampled from a rice production area in Northern Italy, Briona. The soil texture consists of >50% sand, the cation exchange capacity was 46.2 ± 5.2 [mmolc (kg soil) –1 ], the maximal water holding capacity was 0.60 [L water (kg soil) –1 ], and the soil pH was at 4.9 ( Wiggenhauser et al, 2021 ). About 15 portions of soil each containing ∼15 kg of fresh soil were taken from randomly distributed spots from the rice field in autumn 2017.…”

Section: Methodsmentioning

confidence: 99%

“…It is taken up by rice with root membrane transporters that are thought to target cationic nutrients such as manganese (Mn), iron (Fe), zinc (Zn), and calcium (Ca) ( Ishimaru et al, 2006 ; Nakanishi et al, 2006 ; Lee and An, 2009 ; Takahashi et al, 2011 ; Sasaki et al, 2012 ; Chen et al, 2018 ). In the roots, Cd is partially separated from nutrients by being transported into the vacuoles by metal pumps and by binding Cd to stable sulfur (S) containing low molecular weight organic ligands ( Ueno et al, 2010 ; Cao et al, 2018 ; Cai et al, 2019 ; Wiggenhauser et al, 2021 ). The fraction of Cd in the root that is still mobile can be exported from the root cytosol via xylem into the shoot by metal pumps ( Nocito et al, 2011 ; Satoh-Nagasawa et al, 2012 ).…”

Section: Introductionmentioning

confidence: 99%

“…Only a few studies have determined the Cd storage forms in rice. Synchrotron X-ray absorption spectroscopy (XAS) revealed that more than 90% of Cd was bound to S groups in roots that grew on Cd-contaminated conditions ( Yamaoka et al, 2010 ; Yan et al, 2016 ; Wiggenhauser et al, 2021 ). In stems, leaves, and nodes, Cd bound to S donors (Cd–S) was found in all cases, but unlike the root, Cd bound to oxygen (O) donors (Cd–O) was, in some cases, the major binding form of Cd to the shoots (up to 94%) ( Yamaoka et al, 2010 ; Yamaguchi et al, 2012 ; Yan et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

“…An approach to study the role of Cd storage forms in plants on the dynamics within rice could be the combination of Cd mass balances, X-ray absorption near edge structure (XANES) spectroscopy, and Cd isotope fractionation ( Ryan et al, 2013 ; Aucour et al, 2015 , 2017 ; Zelano et al, 2020 ; Wiggenhauser et al, 2021 ). The XAS measurements deliver snapshots of the speciation of metals, i.e., of the metal storage forms in plants while Cd mass balances and Cd isotopes can provide information on the dynamics of metals in soil–plant systems.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Changes of Cadmium Storage Forms and Isotope Ratios in Rice During Grain Filling

et al. 2021

Self Cite

View full text Add to dashboard Cite

Rice poses a major source of the toxic contaminant cadmium (Cd) for humans. Here, we elucidated the role of Cd storage forms (i.e., the chemical Cd speciation) on the dynamics of Cd within rice. In a pot trial, we grew rice on a Cd-contaminated soil in upland conditions and sampled roots and shoots parts at flowering and maturity. Cd concentrations, isotope ratios, Cd speciation (X-ray absorption spectroscopy), and micronutrient concentrations were analyzed. During grain filling, Cd and preferentially light Cd isotopes were strongly retained in roots where the Cd storage form did not change (Cd bound to thiols, Cd–S = 100%). In the same period, no net change of Cd mass occurred in roots and shoots, and the shoots became enriched in heavy isotopes (Δ114/110Cdmaturity–flowering = 0.14 ± 0.04‰). These results are consistent with a sequestration of Cd in root vacuoles that includes strong binding of Cd to thiol containing ligands that favor light isotopes, with a small fraction of Cd strongly enriched in heavy isotopes being transferred to shoots during grain filling. The Cd speciation in the shoots changed from predominantly Cd–S (72%) to Cd bound to O ligands (Cd–O, 80%) during grain filling. Cd–O may represent Cd binding to organic acids in vacuoles and/or binding to cell walls in the apoplast. Despite this change of ligands, which was attributed to plant senescence, Cd was largely immobile in the shoots since only 0.77% of Cd in the shoots were transferred into the grains. Thus, both storage forms (Cd–S and Cd–O) contributed to the retention of Cd in the straw. Cd was mainly bound to S in nodes I and grains (Cd–S > 84%), and these organs were strongly enriched in heavy isotopes compared to straw (Δ114/110Cdgrains/nodes–straw = 0.66–0.72‰) and flag leaves (Δ114/110Cdgrains/nodes–flag leaves = 0.49–0.52‰). Hence, xylem to phloem transfer in the node favors heavy isotopes, and the Cd–S form may persist during the transfer of Cd from node to grain. This study highlights the importance of Cd storage forms during its journey to grain and potentially into the food chain.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%