Revealing the Sources of Cadmium in Rice Plants under Pot and Field Conditions from Its Isotopic Fractionation

Qiang Dong; Cailing Xiao; Wenhan Cheng; Huimin Yu; Juan Liu; Guangliang Liu; Yanwei Liu; Yingying Guo; Yong Liang; Jianbo Shi; Yongguang Yin; Yong Cai; Guibin Jiang

doi:10.1021/acsenvironau.3c00067

Revealing the Sources of Cadmium in Rice Plants under Pot and Field Conditions from Its Isotopic Fractionation

ACS Environ Au. 2024 Feb 1;4(3):162-172. doi: 10.1021/acsenvironau.3c00067. eCollection 2024 May 15.

Authors

Qiang Dong^{1

2

3

4}, Cailing Xiao⁵, Wenhan Cheng⁶, Huimin Yu⁷, Juan Liu⁸, Guangliang Liu⁹, Yanwei Liu^{1

2}, Yingying Guo^{1

2}, Yong Liang⁵, Jianbo Shi², Yongguang Yin^{1

2

3

10

5}, Yong Cai^{1

2

9}, Guibin Jiang²

Affiliations

¹ Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
² State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ BNU-HKUST Laboratory of Green Innovation, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China.
⁵ Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, School of Environment and Health, Jianghan University, Wuhan 430056, China.
⁶ School of Resource & Environment, Anhui Agricultural University, Hefei 230036, China.
⁷ CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China.
⁸ School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
⁹ Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.
¹⁰ School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.

Abstract

The highly excessive uptake of cadmium (Cd) by rice plants is well known, but the transfer pathway and mechanism of Cd in the paddy system remain poorly understood. Herein, pot experiments and field investigation were systematically carried out for the first time to assess the phytoavailability of Cd and fingerprint its transfer pathway in the paddy system under different treatments (slaked lime and biochar amendments), with the aid of a pioneering Cd isotopic technique. Results unveiled that no obvious differences were displayed in the δ^114/110Cd of Ca(NO₃)₂-extractable and acid-soluble fractions among different treatments in pot experiments, while the δ^114/110Cd of the water-soluble fraction varied considerably from -0.88 to -0.27%, similar to those observed in whole rice plant [Δ^114/110Cd_plant-water ≈ 0 (-0.06 to -0.03%)]. It indicates that the water-soluble fraction is likely the main source of phytoavailable Cd, which further contributes to its bioaccumulation in paddy systems. However, Δ^114/110Cd_plant-water found in field conditions (-0.39 ± 0.05%) was quite different from those observed in pot experiments, mostly owing to additional contribution derived from atmospheric deposition. All these findings demonstrate that the precise Cd isotopic compositions can provide robust and reliable evidence to reveal different transfer pathways of Cd and its phytoavailability in paddy systems.