Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China.
Environ Pollut. 2021 Mar 1;272:116407. doi: 10.1016/j.envpol.2020.116407. Epub 2020 Dec 31.
The wide range of industrial applications of chromium (Cr) has led to an increasing risk of water contamination by Cr(Ⅵ). However, efficient methods to remove or decrease the toxicity of Cr(Ⅵ) in situ are lacking. The main aim of this study was to investigate the mechanisms by which selenite alleviates chromium(Ⅵ)-induced toxicity in Chlamydomonas reinhardtii. Our results showed that KCrO had toxic effects on both the structure and physiology of C. reinhardtii in a dose-dependent manner. Adding selenite significantly alleviated chromium accumulation and toxicity in cells. RNA-seq data showed that the expression level of selenoproteins such as SELENOH was significantly increased. Both SELENOH-amiRNA knockdown mutants and selenoh insertional mutant produced more reactive oxygen species (ROS) and grew slower than the wild type, suggesting that SELENOH can reduce chromium toxicity by decreasing the levels of ROS produced by Cr(Ⅵ). We also demonstrated that selenite can reduce the absorption of Cr(Ⅵ) by cells but does not affect the process of Cr(Ⅵ) adsorption and efflux. This information on the molecular mechanism by which selenite alleviates Cr(Ⅵ) toxicity can be used to increase the bioremediation capacity of algae and reduce the human health risks associated with Cr(Ⅵ) toxicity.
六价铬（Cr(Ⅵ)）在工业中的广泛应用导致了水环境污染风险的增加。然而，目前缺乏有效去除或降低 Cr(Ⅵ)原位毒性的方法。本研究的主要目的是探讨亚硒酸盐缓解莱茵衣藻中 Cr(Ⅵ)诱导毒性的机制。我们的结果表明，KCrO 以剂量依赖的方式对莱茵衣藻的结构和生理产生毒性作用。添加亚硒酸盐可显著减轻细胞内铬的积累和毒性。RNA-seq 数据显示，硒蛋白如 SELENOH 的表达水平显著增加。SELENOH-amiRNA 敲低突变体和 selenoh 插入突变体比野生型产生更多的活性氧（ROS），生长速度更慢，表明 SELENOH 可以通过降低 Cr(Ⅵ)产生的 ROS 水平来减轻铬的毒性。我们还证明，亚硒酸盐可以减少细胞对 Cr(Ⅵ)的吸收，但不影响 Cr(Ⅵ)的吸附和外排过程。这些关于亚硒酸盐缓解 Cr(Ⅵ)毒性的分子机制的信息可用于提高藻类的生物修复能力，并降低与 Cr(Ⅵ)毒性相关的人类健康风险。
