Silicon reduces toxicity and accumulation of arsenic and cadmium in cereal crops: A meta-analysis, mechanism, and perspective study

• Published in: The Science of the total environment Vol. 918; p. 170663
• Main Authors: Huang, Fengyu, Li, Zimin, Yang, Xing, Liu, Hongjie, Chen, Li, Chang, Nan, He, Haoran, Zeng, Yi, Qiu, Tianyi, Fang, Linchuan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.03.2024
• Subjects: arsenic; bioavailability; biomass; cadmium; Cereal crop; corn; environment; food safety; food security; Gene expression; gene expression regulation; human health; meta-analysis; Oryza sativa; rice; Silicon; Toxic metal; Toxicity; Transfer; Triticum aestivum; wheat; Zea mays; Transfer; Silicon; Toxic metal; Gene expression; Toxicity; Cereal crop
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.170663

Arsenic (As) and cadmium (Cd) are two toxic metal(loid)s that pose significant risks to food security and human health. Silicon (Si) has attracted substantial attention because of its positive effects on alleviating the toxicity and accumulation of As and Cd in crops. However, our current knowledge of the comprehensive effects and detailed mechanisms of Si amendment is limited. In this study, a global meta-analysis of 248 original articles with over 7000 paired observations was conducted to evaluate Si-mediated effects on growth and As and Cd accumulation in rice (Oryza sativa L.), wheat (Triticum aestivum L.), and maize (Zea mays L.). Si application increases the biomass of these crops under As and/or Cd contamination. Si amendment also decreased shoot As and Cd accumulation by 24.1 % (20.6 to 27.5 %) and 31.9 % (29.0 to 31.9 %), respectively. Furthermore, the Si amendment reduced the human health risks posed by As (2.6 %) and Cd (12.9 %) in crop grains. Si-induced inhibition of Cd accumulation is associated with decreased Cd bioavailability and the downregulation of gene expression. The regulation of gene expression by Si addition was the driving factor limiting shoot As accumulation. Overall, our analysis demonstrated that Si amendment has great potential to reduce the toxicity and accumulation of As and/or Cd in crops, providing a scientific basis for promoting food safety globally. [Display omitted] •A meta-analysis quantifies the Si-mediated effects on limiting As and Cd accumulation in crops.•Si NMs showed stronger effects on decreasing the shoot As and Cd accumulation than that of other Si types.•Si increased soil available As and Cd concentration, and improved overall soil quality.•Si regulated multiple genes expression of transporters involving the uptake and transfer of As and Cd in crop tissues.