The antioxidant glutathione (GSH) mitigates adverse physio-metabolic effects and defends against abiotic types of stress, such as cadmium (Cd) stress. However, its function and role in resisting Cd phytotoxicity by leveraging plant antioxidant-scavenging, redox-regulating, and hormone-balancing systems have not been comprehensively and systematically demonstrated in the Cd-hyperaccumulating plant Brassica napus L. cv. Tammi (oilseed rape). In this study, the effects of exogenously applied GSH to the leaves of B. napus seedlings exposed to Cd (10 μM) were investigated. As a result, Cd stress alone significantly inhibited growth and increased the levels of reactive oxygen species (ROS) and the bioaccumulation of Cd in the seedlings compared with those in unstressed controls. Furthermore, Cd stress induced an imbalance in plant stress hormone levels and decreases in endogenous GSH levels and GSH redox ratios, which were correlated with reductions in ascorbate (AsA) and/or nicotinamide adenine dinucleotide phosphate (NADPH) redox states. However, the exogenous application of GSH to Cd-stressed B. napus seedlings reduced Cd-induced ROS levels and enhanced antioxidant-scavenging defenses and redox regulation by both increasing seedling AsA, GSH, and NADPH concentrations and rebalancing stress hormones, thereby enhancing Cd uptake and accumulation. These results demonstrate that GSH improved plant redox status by upregulating the AsA-GSH-NADPH cycle and reestablishing normal hormonal balance. This indicates that exogenously applied GSH can mitigate Cd phytotoxicity in B. napus and possibly other plants. Therefore, GSH can potentially be applied to Cd-polluted soil for plant remediation.

抗氧化剂谷胱甘肽 (GSH) 可减轻不利的生理代谢作用并抵御非生物类型的压力，例如镉 (Cd) 压力。然而，其利用植物抗氧化清除、氧化还原调节和激素平衡系统在抗镉植物毒性方面的功能和作用尚未在镉超富集植物中得到全面和系统的证明。欧洲油菜L.简历 Tammi（油菜）。在本研究中，外源施用 GSH 对植物叶片的影响油菜研究了暴露于 Cd (10 μM) 的幼苗。因此，与未受胁迫的对照相比，单独的 Cd 胁迫显着抑制了生长并增加了幼苗中活性氧 (ROS) 的水平和 Cd 的生物积累。此外，镉胁迫引起植物应激激素水平的不平衡以及内源性 GSH 水平和 GSH 氧化还原比率的降低，这与抗坏血酸 (AsA) 和/或烟酰胺腺嘌呤二核苷酸磷酸 (NADPH) 氧化还原状态的减少有关。然而，GSH 在 Cd 胁迫下的外源应用油菜幼苗通过增加幼苗 AsA、GSH 和 NADPH 浓度以及重新平衡应激激素来降低 Cd 诱导的 ROS 水平并增强抗氧化清除防御和氧化还原调节，从而增强 Cd 的吸收和积累。这些结果表明，GSH 通过上调 AsA-GSH-NADPH 循环和重建正常的激素平衡来改善植物氧化还原状态。这表明外源施用 GSH 可以减轻 Cd 的植物毒性。油菜可能还有其他植物。因此，谷胱甘肽可潜在地应用于受镉污染的土壤进行植物修复。