Cadmium (Cd) is a widely distributed soil contaminant which induces oxidative damage and is therefore toxic to plants. Although selenium oxyanions such as selenite (SeO₃^2-) and selenate (SeO₄^2-) 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 SeO₃^2- 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 SeO₃^2-.

镉（Cd）是一种分布广泛的土壤污染物，会引起氧化损伤，因此对植物有毒。尽管亚硒酸硒（SeO ₃ ^2-）和硒酸根（SeO ₄ ^2-）等硒氧阴离子可以减轻Cd对植物的胁迫，但尚不清楚硒纳米颗粒（SeNPs）是否能够做到这一点。本研究表明SeNPs和SeO ₃ ^2-均对甘蓝型油菜具有积极作用L.在镉胁迫下的生长。使用氧化应激检测分析，全基因组RNA测序和RT-qPCR阐明了潜在的机制。通过抑制NADPH氧化酶（BnaRBOHC，BnaRBOHD1和BnaRBOHF1）和乙醇酸氧化酶（BnaGLO）的表达，硒的施用，特别是以SeNPs的形式，减少了Cd诱导的活性氧的产生。），从而减少氧化蛋白和膜脂质的损害。此外，SeNPs通过减少Cd积累，维持细胞内钙稳态，促进二硫键形成并恢复叶片表面的蜡质外层来提高对Cd胁迫的抵抗力。尽管两种形式的硒都降低了Cd毒性，但与SeO ₃ ^2-相比，SeNPs的有益浓度范围更广。