School of Metallurgy and Environment, Central South University, Changsha 410083, Hunan, PR China.
Ecology and Environment Affairs Center of Hunan Province, Changsha 410014, Hunan, PR China.
Sci Total Environ. 2024 Nov 1;949:175193. doi: 10.1016/j.scitotenv.2024.175193. Epub 2024 Jul 31.
Cadmium (Cd) and arsenic (As), two toxic elements to humans, are ubiquitously coexisting contaminant found in paddy fields. The accumulation of Cd and As in rice, a major food source for many people around the world, can pose a serious threat to food safety and human health. Therefore, it is crucial to be aware of these contaminants and take adequate measures to reduce the accumulation of these two elements in rice. Developing an effective method to simultaneously reduce the accumulation of Cd) and As in rice is challenging. In this study, a pot experiment was conducted to investigate the synergistic effects of selenium (Se), iron (Fe) and phosphorus (P) on the uptake, transport and accumulation of cadmium and arsenic in rice by analyzing the physical and chemical properties of the soil, the elemental concentrations and their interrelationships in the rice tissues, and the composition and morphology of the iron plaque (IP). The results showed that the combined treatments of Se, Fe and P had positive effects on reducing Cd and As accumulation in rice, reducing Cd concentrations in brown rice by 3.86-51.88 % and As concentrations by 25.37-40.81 %. The possible mechanisms for the reduction of As and Cd concentrations in rice grains were: (i) Combined application of Fe, P and Se can effectively reduce the soil available Cd and As concentration. (ii) Combined application significantly improved the formation of IP at the tillering stage and increased the crystalline iron oxides in IP, promoting the deposition of SiO in rice roots, thereby effectively inhibiting the uptake of Cd and As by rice roots. (iii) Interplay and interaction between elements facilitated by transporter proteins could contribute to the synergistic mitigation of Cd and As by Se, Fe and P. This study provides a valuable new approach for effective control of Cd and As concentration of rice grown in co-contaminated soil.
镉（Cd）和砷（As）是两种对人类有毒的元素，在稻田中普遍存在且相互共存。作为全世界许多人的主要食物来源，大米中 Cd 和 As 的积累会对食品安全和人类健康构成严重威胁。因此，了解这些污染物并采取适当措施减少大米中这两种元素的积累至关重要。开发一种有效方法来同时减少大米中 Cd 和 As 的积累是具有挑战性的。在本研究中，通过分析土壤理化性质、水稻组织中元素浓度及其相互关系以及铁膜（IP）的组成和形态，进行了盆栽试验，研究了硒（Se）、铁（Fe）和磷（P）对 Cd 和 As 在水稻中吸收、转运和积累的协同作用。结果表明，Se、Fe 和 P 的联合处理对降低水稻中 Cd 和 As 的积累具有积极作用，使糙米中 Cd 浓度降低 3.86-51.88%，As 浓度降低 25.37-40.81%。降低稻米中 As 和 Cd 浓度的可能机制为：（i）Fe、P 和 Se 的联合施用可有效降低土壤有效态 Cd 和 As 浓度；（ii）联合施用显著提高了分蘖期 IP 的形成，增加了 IP 中的结晶氧化铁，促进了水稻根系中 SiO 的沉积，从而有效抑制了水稻根系对 Cd 和 As 的吸收；（iii）转运蛋白介导的元素相互作用和交互作用有助于 Se、Fe 和 P 协同降低 Cd 和 As 的浓度。本研究为有效控制受污染土壤中种植的水稻 Cd 和 As 浓度提供了一种有价值的新方法。
