Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
College of Agriculture and Forestry Science, Linyi University, Linyi 276002, China; State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
J Hazard Mater. 2021 Sep 5;417:125900. doi: 10.1016/j.jhazmat.2021.125900. Epub 2021 Apr 16.
Cadmium (Cd) is a widely distributed soil contaminant which induces oxidative damage and is therefore toxic to plants. Although selenium oxyanions such as selenite (SeO) and selenate (SeO) can alleviate Cd stress to plants, it is not known whether selenium nanoparticles (SeNPs) are able to do the same. The present study demonstrated the positive impact of both SeNPs and SeO on Brassica napus L. growth under conditions of Cd stress. Underlying mechanisms were elucidated using an oxidative stress detection assay, whole-genome RNA sequencing, and RT-qPCR. Application of selenium, especially in the form of SeNPs, decreased Cd-induced reactive oxygen species production by inhibiting the expression of NADPH oxidases (BnaRBOHC, BnaRBOHD1, and BnaRBOHF1) and glycolate oxidase (BnaGLO), thereby decreasing oxidative protein and membrane lipid damage. In addition, SeNPs improved resistance to Cd stress by decreasing Cd accumulation, maintaining intracellular calcium homeostasis, promoting disulfide bond formation, and restoring the waxy outer layer of the leaf surface. Although both forms of selenium decreased Cd toxicity, the beneficial concentration range was more extensive for SeNPs than for SeO.
镉（Cd）是一种广泛分布的土壤污染物，会诱导氧化损伤，因此对植物有毒。尽管硒的含氧阴离子，如亚硒酸盐（SeO）和硒酸盐（SeO），可以减轻植物的 Cd 胁迫，但目前尚不清楚硒纳米颗粒（SeNPs）是否也能做到这一点。本研究表明，在 Cd 胁迫条件下，SeNPs 和 SeO 对油菜（Brassica napus L.）生长都有积极影响。通过氧化应激检测、全基因组 RNA 测序和 RT-qPCR 阐明了其潜在机制。硒的应用，特别是以 SeNPs 的形式，通过抑制 NADPH 氧化酶（BnaRBOHC、BnaRBOHD1 和 BnaRBOHF1）和乙醛酸氧化酶（BnaGLO）的表达，减少了 Cd 诱导的活性氧的产生，从而减少了氧化蛋白和膜脂的损伤。此外，SeNPs 通过减少 Cd 积累、维持细胞内钙稳态、促进二硫键形成和恢复叶片表面的蜡质外层来提高对 Cd 胁迫的抗性。尽管两种形式的硒都能降低 Cd 的毒性，但 SeNPs 的有益浓度范围比 SeO 更广泛。
