Guan Meiyan, Xia Yuchun, Zhang Weixing, Chen Mingxue, Cao Zhenzhen
Rice Product Quality Supervision and Inspection Center, China National Rice Research Institute, Hangzhou 310006, China.
Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China.
Foods. 2025 May 14;14(10):1747. doi: 10.3390/foods14101747.
Cadmium (Cd) pollution in paddy soils causes a great threat to safe rice production in China. In this review, we summarized the key advances in the research of Cd pollution sources and statuses in Chinese soil and rice, explore the mechanisms of Cd transformation in the rice-soil system, discuss the agronomic strategies for minimizing Cd accumulation in rice grains, and highlight advancements in developing rice cultivars with low Cd accumulation. Anthropogenic activity is a main source of Cd in farmland. Cd in soil solutions primarily enters rice roots through a symplastic pathway facilitated by transporters like OsNRAMP5, OsIRT1, and OsCd1, among which OsNRAMP5 is identified as the primary contributor. Subsequently, Cd translocation is from roots to grains through the xylem and phloem, regulated by transporters such as OsHMA2, OsLCT1, and OsZIP7. Meanwhile, Cd sequestration in vacuoles controlled by OsHMA3 plays a crucial role in regulating Cd mobility during its translocation. Cd accumulation in rice was limited by the available Cd concentration in soil solutions, Cd uptake, and translocation in rice plants. Conventional agronomic methods aimed at reducing grain Cd in rice by suppressing Cd bio-availability without decreasing soil Cd content have been proven limited in the remediation of Cd-polluted soil. In recent years, based on the mechanisms of Cd absorption and translocation in rice, researchers have screened and developed low-Cd-accumulation rice varieties using molecular breeding techniques. Among them, some new cultivars derived from the null mutants of have demonstrated a more than 93% decrease in grain Cd accumulation and can be used for applications in the next years. Therefore, the issue of Cd contamination in the rice of China may be fully resolved within a few years.
稻田土壤中的镉（Cd）污染对中国水稻安全生产构成了巨大威胁。在本综述中，我们总结了中国土壤和水稻中Cd污染源及污染状况研究的关键进展，探讨了水稻-土壤系统中Cd的转化机制，讨论了减少水稻籽粒中Cd积累的农艺策略，并强调了培育低Cd积累水稻品种方面的进展。人为活动是农田Cd的主要来源。土壤溶液中的Cd主要通过由OsNRAMP5、OsIRT1和OsCd1等转运蛋白促进的共质体途径进入水稻根系，其中OsNRAMP5被确定为主要贡献者。随后，Cd通过木质部和韧皮部从根向籽粒转运，受OsHMA2、OsLCT1和OsZIP7等转运蛋白调控。同时，由OsHMA3控制的液泡中Cd的螯合在调节Cd转运过程中的流动性方面起着关键作用。水稻中Cd的积累受土壤溶液中有效Cd浓度以及水稻植株对Cd的吸收和转运限制。旨在通过抑制Cd生物有效性而不降低土壤Cd含量来降低水稻籽粒中Cd的传统农艺方法，在Cd污染土壤修复方面已被证明效果有限。近年来，基于水稻对Cd吸收和转运的机制，研究人员利用分子育种技术筛选并培育出了低Cd积累水稻品种。其中，一些源自相关无效突变体的新品种已证明籽粒Cd积累量降低了93%以上，可在未来几年投入应用。因此，中国水稻Cd污染问题可能在几年内得到全面解决。
