Arefi Sorur, Khara Jalil
Department of Biology, Faculty of Sciences, Urmia University, Urmia, Iran.
Sci Rep. 2025 Sep 1;15(1):32256. doi: 10.1038/s41598-025-17608-8.
Copper (Cu) stress, an abiotic stressor, can severely damage plant cells. At elevated concentrations, copper becomes a toxic element within plants, triggering the generation of oxidative molecules and disrupting enzymatic activities. Salicylic acid (SA) is a plant growth regulator, while sodium nitroprusside (SNP) is a nitric oxide-releasing compound. Both play critical functions in modulating plant metabolism, growth, development, and mechanisms. They also influence gene expression and signaling pathways, with context-dependent effects that may be beneficial or detrimental. The application of these compounds at appropriate doses significantly contributes to alleviating abiotic stresses in various plant species, particularly by counteracting the toxic effects. In this study, the individual and simultaneous effects of SA (500 µM) and SNP (150 µM), alongside varying concentrations of copper sulfate (600 and 1200 µM), were evaluated on the physiological and morphological responses of the Clemson variety of okra (Abelmoschus esculentus) in a hydroponic culture system. The experiments were conducted using a completely randomized design with three replicates per treatment. High copper concentrations reduced growth parameters and essential nutrient levels while increasing malondialdehyde (MDA), hydrogen peroxide (H₂O₂), cell death, protein content, proline, soluble carbohydrates, enzyme activities, and copper content in the shoots and roots of okra plants compared to the control. In contrast, foliar application of SA and SNP improved the uptake of essential elements, increasing Mg by up to 41%, Fe by 51%, and Zn by 50%. It also enhanced antioxidant enzyme activities (67-92%) and significantly reduced copper concentration (58%), MDA content (15%), H₂O₂ levels (26%), and cell death (49%) in the shoots and roots of okra plants. Therefore, based on the results, the individual and combined application of SA and SNP significantly mitigated the adverse effects of copper sulfate stress, improving tolerance of okra plants. According to the findings of this study, SA demonstrated a considerably greater effect compared to SNP in enhancing the resistance of okra plants to copper-induced stress.
铜（Cu）胁迫作为一种非生物胁迫因素，会严重损害植物细胞。在浓度升高时，铜会成为植物体内的有毒元素，引发氧化分子的产生并扰乱酶活性。水杨酸（SA）是一种植物生长调节剂，而硝普钠（SNP）是一种释放一氧化氮的化合物。二者在调节植物代谢、生长、发育及机制方面均发挥着关键作用。它们还会影响基因表达和信号通路，其影响取决于具体情况，可能有益也可能有害。以适当剂量施用这些化合物对减轻各种植物物种的非生物胁迫有显著作用，尤其是通过抵消毒性作用。在本研究中，在水培系统中评估了SA（500微摩尔）和SNP（150微摩尔）以及不同浓度硫酸铜（600和1200微摩尔）对克莱姆森品种秋葵（黄秋葵）生理和形态反应的单独及联合影响。实验采用完全随机设计，每个处理重复三次。与对照相比，高铜浓度降低了秋葵植株地上部和根部的生长参数及必需营养元素水平，同时增加了丙二醛（MDA）、过氧化氢（H₂O₂）、细胞死亡、蛋白质含量、脯氨酸、可溶性碳水化合物、酶活性及铜含量。相比之下，叶面喷施SA和SNP提高了必需元素的吸收，镁含量增加高达41%，铁含量增加51%，锌含量增加50%。它还增强了抗氧化酶活性（67 - 92%），并显著降低了秋葵植株地上部和根部的铜浓度（58%）、MDA含量（15%）、H₂O₂水平（26%）及细胞死亡（49%）。因此，基于这些结果，SA和SNP的单独及联合施用显著减轻了硫酸铜胁迫的不利影响，提高了秋葵植株的耐受性。根据本研究结果，在增强秋葵植株对铜诱导胁迫的抗性方面，SA的效果比SNP显著得多。
