State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
Department of Environmental Sciences, Government College University Faisalabad, Faisalabad 38000, Pakistan; Department of Biological Sciences and Technology, China Medical University, Taichung 40402, Taiwan.
J Hazard Mater. 2024 Dec 5;480:136209. doi: 10.1016/j.jhazmat.2024.136209. Epub 2024 Oct 19.
Heavy metals like cadmium (Cd) contamination occur in conjunction with the rising CO threatening food security and safety. Foliar application of 24-Epibrassinolide (EBR) was found to ameliorate Cd stress and improve nutrient availability in crops. However, its role under elevated CO is currently unknown. Accordingly, a pot experiment was conducted in open-top chambers (CO at 400 and 600 μmol mol) to determine the protective effect of EBR on wheat plants under different Cd concentrations (0, 2, and 4 mg kg) in soil. The foliar application of EBR significantly improved growth, biomass, photosynthesis, proline, total phenol, and total soluble protein in Cd stress treatments under elevated CO. Simultaneously, it significantly (p ≤ 0.05) increased catalase (42.89 %), superoxide dismutase (26.53 %), peroxidase (28.10 %), and ascorbate peroxidase (61.70 %) while reduced malondialdehyde (35.53 %), hydrogen peroxide (19.94 %), and electrolyte leakage (23.55 %) under elevated CO compared to ambient CO conditions. Furthermore, EBR and elevated CO interactively showed a maximum reduction in Cd concentrations and accumulation in the wheat roots (39.74,41.63 %), shoots (46.83,44.87 %), and grains (27.52,29.06 %) respectively. Elevated CO and Cd stress interactively showed a significant reduction in nutrient content. Conversely, the EBR application recovered and significantly increased calcium, magnesium, iron, zinc, and copper content in wheat roots, shoots, and grains. Our findings inferred that EBR foliar application reduced Cd toxicity and improved plant growth and nutritional quality under elevated CO.
重金属如镉（Cd）污染与 CO 浓度升高同时发生，威胁着食品安全和安全。叶面喷施 24-表油菜素内酯（EBR）被发现可减轻 Cd 胁迫并提高作物养分供应。然而，其在升高的 CO 下的作用目前尚不清楚。因此，在开顶式气室（CO 为 400 和 600 μmol mol）中进行了盆栽实验，以确定 EBR 在不同土壤 Cd 浓度（0、2 和 4 mg kg）下对小麦植株的保护作用。EBR 的叶面喷施显著改善了 CO 升高下 Cd 胁迫处理中小麦的生长、生物量、光合作用、脯氨酸、总酚和总可溶性蛋白。同时，它还显著（p≤0.05）增加了过氧化氢酶（42.89%）、超氧化物歧化酶（26.53%）、过氧化物酶（28.10%）和抗坏血酸过氧化物酶（61.70%），同时降低了丙二醛（35.53%）、过氧化氢（19.94%）和电解质渗漏（23.55%）在 CO 升高条件下与大气 CO 条件相比。此外，EBR 和升高的 CO 之间存在交互作用，可最大程度地减少小麦根系（39.74、41.63%）、茎叶（46.83、44.87%）和籽粒（27.52、29.06%）中的 Cd 浓度和积累。升高的 CO 和 Cd 胁迫之间存在显著的交互作用，会降低养分含量。相反，EBR 的应用恢复并显著增加了小麦根系、茎叶和籽粒中钙、镁、铁、锌和铜的含量。我们的研究结果推断，EBR 叶面喷施可降低 Cd 毒性，并在升高的 CO 下提高植物生长和营养品质。
