Xiang Nuoyu, Jiang Kunwu, Hu Jie, Qin Xiaonan, Cheng Yuanyuan
School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, China.
Environ Geochem Health. 2025 Jul 24;47(8):333. doi: 10.1007/s10653-025-02652-0.
Many studies have explored silicon's (Si) impact on cadmium (Cd) accumulation in rice, but a comprehensive assessment of Si's remediation efficacy and its molecular mechanisms is lacking. This review synthesizes 25 years of research on Si's role in mitigating Cd stress, focusing on how Si application affects Cd absorption, transport, and accumulation to provide theoretical support and technical guidance for using Si in the remediation of Cd-contaminated soils and safe rice production. Both soil and foliar applications of Si fertilizers reduce Cd accumulation in rice grains, with Si showing significant effects in controlling Cd within the plant by improving rice's physiological condition under Cd stress, adjusting hormone levels, enhancing antioxidant enzyme activity, and promoting Cd chelation to the cell wall, reducing cellular damage. Si also regulates the expression of Cd transport proteins, with ten identified, five of which are particularly crucial: OsHMA2, OsNramp1, OsNramp5, OsZIP6, and OsZIP7. Six other proteins' relationship with Si remains unconfirmed and requires further investigation. Research on how Si coordinates interactions among various factors such as Cd transport proteins, antioxidant defence systems, and plant hormones to comprehensively enhance rice's resistance to Cd stress is still limited. It was revealed that foliar application of Si is more effective in reducing Cd levels in rice, while in heavily Cd-contaminated soils, soil application of Si is more effective. Future in-depth understanding of Si's role in this network will not only help reveal its multifaceted protective mechanisms but also provide new perspectives for developing more effective strategies to mitigate heavy metal pollution.
许多研究探讨了硅（Si）对水稻中镉（Cd）积累的影响，但缺乏对硅修复效果及其分子机制的综合评估。本综述综合了25年来关于硅在缓解镉胁迫中作用的研究，重点关注施硅如何影响镉的吸收、运输和积累，以为硅在镉污染土壤修复和水稻安全生产中的应用提供理论支持和技术指导。土壤施硅和叶面施硅均能降低水稻籽粒中的镉积累，硅通过改善镉胁迫下水稻的生理状况、调节激素水平、增强抗氧化酶活性以及促进镉与细胞壁螯合，减少细胞损伤，从而在控制植物体内镉方面显示出显著效果。硅还调节镉转运蛋白的表达，已鉴定出10种，其中5种尤为关键：OsHMA2、OsNramp1、OsNramp5、OsZIP6和OsZIP7。其他6种蛋白与硅的关系尚未得到证实，需要进一步研究。关于硅如何协调镉转运蛋白、抗氧化防御系统和植物激素等各种因素之间的相互作用以全面增强水稻对镉胁迫的抗性的研究仍然有限。结果表明，叶面施硅在降低水稻镉含量方面更有效，而在镉污染严重的土壤中，土壤施硅更有效。未来对硅在这一网络中作用的深入理解不仅有助于揭示其多方面的保护机制，还为制定更有效的减轻重金属污染策略提供新的视角。
