Zhou Jun, Zhang Chen, Du Buyun, Cui Hongbiao, Fan Xingjun, Zhou Dongmei, Zhou Jing
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resource and Environment, Anhui Science and Technology University, Fengyang, Anhui 233100, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
J Hazard Mater. 2021 Jan 15;402:123546. doi: 10.1016/j.jhazmat.2020.123546. Epub 2020 Jul 25.
Minimization of Cd accumulation in wheat is an effective strategy to prevent Cd hazard to human. This study compared and highlighted the roles of soil and foliar applications of Se and Si effects on Cd accumulation and toxicity in soft and durum wheat. Soil Se (0.5-1.0 mg kg) and Si (3-6 mg kg) applications provided an effective strategy to reduce wheat grain Cd concentrations of both wheat varieties by 59-61 % and 16-30 %, but foliar Se (0.125-0.25 mM) and Si (2.5-5 mM) application reduced grain Cd of soft wheat by 20-36 %. Both soil and foliar Se and Si applications significantly alleviated Cd toxicity by regulation of Cd transport genes, as reflected by increased the grain yield and antioxidant enzymes activities, and reduced MDA in wheat tissues. Selenium applications were more effective than Si on the reduction of Cd-induced toxicity and concentrations in soft wheat, but not in durum wheat due to more tolerant to Cd. Downregulation of influx transporter (TaNramp5) and upregulation of efflux transporter (TaTM20 and TaHMA3) in soft wheat may contribute to the Si/Se-dependent Cd mitigation and enhance the tolerance to toxic Cd. Overall, Se/Si applications, especially soil Se, can be efficiently used for reducing grain Cd uptake from Cd-contaminated soils.
使小麦中镉的积累量最小化是预防镉对人体危害的有效策略。本研究比较并突出了土壤施用和叶面喷施硒和硅对软质小麦和硬质小麦中镉积累及毒性的影响。土壤施用硒（0.5 - 1.0毫克/千克）和硅（3 - 6毫克/千克）能有效降低两个小麦品种籽粒中的镉浓度，降幅分别为59 - 61%和16 - 30%，而叶面喷施硒（0.125 - 0.25毫摩尔）和硅（2.5 - 5毫摩尔）能使软质小麦籽粒中的镉含量降低20 - 36%。土壤和叶面施用硒和硅均通过调控镉转运基因显著减轻了镉毒性，表现为小麦籽粒产量增加、抗氧化酶活性增强以及小麦组织中丙二醛含量降低。在减轻软质小麦中镉诱导的毒性和降低镉浓度方面，施用硒比施用硅更有效，但在硬质小麦中并非如此，因为硬质小麦对镉的耐受性更强。软质小麦中流入转运体（TaNramp5）的下调和流出转运体（TaTM20和TaHMA3）的上调可能有助于依赖硅/硒减轻镉毒性并增强对有毒镉的耐受性。总体而言，施用硒/硅，尤其是土壤施用硒，可有效用于减少从镉污染土壤中吸收的籽粒镉含量。
