National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
Key Laboratory of Karst Georesources and Environment, Ministry of Education, College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, PR China.
Ecotoxicol Environ Saf. 2024 Mar 1;272:116081. doi: 10.1016/j.ecoenv.2024.116081. Epub 2024 Feb 8.
Selenium (Se) is a trace element that is essential for human health. Daily dietary Se intake is governed by the food chain through soil-plant systems. However, the cadmium (Cd) content tends to be excessive in seleniferous soil, in which Se and Cd have complex interactions. Therefore, it is a great challenge to grow crops containing appreciable amounts of Se but low amounts of Cd. We compared the effects of five Se-transforming bacteria on Se and Cd uptake by Brassica rapa L. in a native seleniferous Cd-polluted soil. The results showed that three Se-oxidizing bacteria (LX-1, LX-100, and T3F4) increased the Se content of the aboveground part of the plant by 330.8%, 309.5%, and 724.3%, respectively, compared to the control (p < 0.05). The three bacteria also reduced the aboveground Cd content by 15.1%, 40.4%, and 16.4%, respectively (p < 0.05). In contrast, the Se(IV)-reducing bacterium ES2-45 and weakly Se-transforming bacterium LX-4 had no effect on plant Se uptake, although they did decrease the aboveground Cd content. In addition, the three Se-oxidizing bacteria increased the Se available in the soil by 38.4%, 20.4%, and 24.0%, respectively, compared to the control (p < 0.05). The study results confirm the feasibility of using Se-oxidizing bacteria to simultaneously enhance plant Se content and reduce plant Cd content in seleniferous Cd-polluted soil.
硒（Se）是一种对人体健康至关重要的微量元素。人体每日的硒摄入量由食物链通过土壤-植物系统来控制。然而，在富硒土壤中，镉（Cd）的含量往往过高，硒和镉之间存在复杂的相互作用。因此，在含有适量硒但镉含量低的土壤中种植作物是一项巨大的挑战。我们比较了五种硒转化细菌对 Brassica rapa L. 在原生富硒镉污染土壤中对硒和镉吸收的影响。结果表明，三种硒氧化细菌（LX-1、LX-100 和 T3F4）分别使植物地上部分的硒含量比对照增加了 330.8%、309.5%和 724.3%（p<0.05）。这三种细菌还分别使地上部分的镉含量降低了 15.1%、40.4%和 16.4%（p<0.05）。相比之下，Se(IV)-还原菌 ES2-45 和弱硒转化菌 LX-4 对植物硒吸收没有影响，尽管它们确实降低了地上部分的镉含量。此外，与对照相比，这三种硒氧化菌分别使土壤中有效硒增加了 38.4%、20.4%和 24.0%（p<0.05）。研究结果证实了使用硒氧化菌同时提高富硒镉污染土壤中植物硒含量和降低植物镉含量的可行性。
