College of Resources and Environmental Sciences, Henan Agricultural University, Zhengzhou, 450002, PR China.
College of Resources and Environmental Sciences, Henan Agricultural University, Zhengzhou, 450002, PR China.
Ecotoxicol Environ Saf. 2019 Nov 15;183:109562. doi: 10.1016/j.ecoenv.2019.109562. Epub 2019 Aug 19.
Presence of cadmium (Cd) in food poses serious risks to human health. Understanding the effects of zinc (Zn) on Cd absorption by crops could help provide a theoretical basis for the treatment with Zn on contaminated soils. In this study, two wheat varieties, differing in grain-Cd accumulation ability (L979, a Cd low-accumulation variety, and H27, a high-accumulation variety) were selected to investigate the effect of Zn addition on Cd toxicity. Cd was applied to nutrient solutions at 0 and 10 μM, and added Zn were 0, 50 and 100 μM. Zn supplements alleviated decreases in biomass induced by Cd toxicity for both varieties, and both varieties had different reduced concentrations of Cd in their shoots. Application of 50 μM Zn to H27 resulted in a 17% decrease in Cd concentrations. When treated with 100 μM Zn, only L979 showed a reduction in Cd concentration. The higher proportion of Cd in the soluble fraction was found in L979. In addition, ion-selective scanning at the root-surface indicated that Zn supplements reduced net root Cd flux by 55% for L979, and 69% for H27. These mitigating effects of Zn in both varieties involved mechanisms related to photosynthesis, root growth, and antioxidant production. Additionally, both Zn available in the medium and absorbed in plant tissue causes antagonistic effects on Cd absorption for wheat. It seemed that vacuolar compartmentation could contribute Cd detoxification especially for low accumulation variety.
食物中镉（Cd）的存在对人类健康构成严重威胁。了解锌（Zn）对作物吸收 Cd 的影响可以为受污染土壤用 Zn 处理提供理论依据。本研究选用两个小麦品种（L979，低积累 Cd 品种；H27，高积累 Cd 品种），研究 Zn 对 Cd 毒性的影响。在营养液中分别添加 0 和 10 μM 的 Cd，添加 Zn 为 0、50 和 100 μM。Zn 缓解了 Cd 毒性对两种品种生物量的降低作用，两种品种地上部 Cd 浓度均降低。H27 用 50 μM Zn 处理后 Cd 浓度降低了 17%。当用 100 μM Zn 处理时，只有 L979 表现出 Cd 浓度降低。L979 中的可溶性 Cd 比例较高。此外，根表面离子选择性扫描表明，Zn 处理使 L979 的根 Cd 净通量降低了 55%，H27 降低了 69%。这两种品种中 Zn 的缓解作用涉及与光合作用、根生长和抗氧化剂产生有关的机制。此外，介质中可利用的 Zn 和植物组织中吸收的 Zn 对小麦吸收 Cd 具有拮抗作用。液泡区隔化可能有助于 Cd 解毒，尤其是对低积累品种。
