Effect of Silicon on Arsenic Concentration and Speciation in Different Rice Tissues

• Published in: Pedosphere Vol. 28; no. 3; pp. 511 - 520
• Main Authors: LI, Gang, ZHENG, Maozhong, TANG, Jianfeng, SHIM, Hojae, CAI, Chao
• Format: Journal Article
• Language: English
• Published: Beijing Elsevier Ltd 01.06.2018; Elsevier Science Ltd; Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021(China); Ningbo Urban Environment Observatory and Monitoring Station, Ningbo 315830(China)%Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021(China); College of Ecology and Resource Engineering, Wuyi University, Wuyishan 354300(China)%University of Macau, Taipa, Macau SAR(China)%Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021(China)
• Subjects: Accumulation; Arsenic; arsenic accumulation; contamination; Dimethylarsinic acid; Grain; health risk; Health risks; Impact analysis; inorganic arsenic; Iron; iron plaque; Plant tissues; Rice; rice grain; root surface; Silicon; Soil solution; Speciation; Studies; arsenic accumulation; root surface; health risk; iron plaque; dimethylarsinic acid; inorganic arsenic; contamination; rice grain
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(17)60409-0

Rice is a major source of inorganic arsenic (As) exposure for billions of people worldwide. Therefore, strategies to reduce As accumulation in rice should be adopted. Silicon (Si) application can effectively mitigate As accumulation in rice. In this study, a pot experiment was performed to investigate the effect of Si on As speciation and distribution in different rice tissues. The results showed that Si addition significantly increased As and Si concentrations in soil solution and Si concentration in iron plaque formed around rice root surface, whereas As in the iron plaque was significantly decreased. Total As concentrations in the stem, leaf, husk, and brown rice were remarkably decreased by 51.9%, 31.9%, 33.8%, and 24.1%, respectively, after Si addition, and inorganic As concentrations were reduced by 52.3%, 35.5%, 50.1%, and 20.1%, respectively. Moreover, both dimethylarsinic acid concentration and percentage in rice grain were significantly elevated by Si application. Therefore, Si application is promising as a way to mitigate inorganic As accumulation in rice and to reduce consumer health risk.