Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Ecotoxicol Environ Saf. 2020 Dec 15;206:111403. doi: 10.1016/j.ecoenv.2020.111403. Epub 2020 Oct 1.
The present work was aimed to study the effect of melatonin pretreatments on growth, oxidative stress modulation, cadmium (Cd) accumulation, and tolerance in mallow (Malva parviflora, Malvaceae) plants under the hydroponic system. Application of substances that can modulate the harmful effects of Cd on plant yield and reduce its accumulation in the edible parts is of particular importance. Therefore, the mallow plants pretreated with 15, 50, and 100 µM of melatonin were exposed to 50 µM Cd. Our results showed that melatonin, especially at 15 and 50 µM, led to positive effects on Cd tolerance, including a significant increase in growth, photosynthetic pigments, and soluble protein content. Exogenous melatonin could improve relative water content (RWC) and stomatal conductance in the plants treated with Cd, probably through an increase in proline. Further, lower concentrations of melatonin led to a decrease in Cd translocation to the shoots. Based on the results, melatonin considerably increased catalase (CAT), superoxide dismutase (SOD), and guaiacol peroxidase (GPX) activities as well as the production of phenols. The increased activity of antioxidant enzymes led to a decrease in electrolyte leakage (EL), lipid peroxidation, and HO content in the plants exposed to Cd stress. Under Cd stress, the increased phenols content in melatonin-pretreated plants could be due to the induction of phenylalanine ammonia-lyase (PAL) activity and an increase in shoot soluble carbohydrates. The results showed that the use of melatonin could reduce oxidative stress and improve biomass in the plants exposed to Cd. At least in our experimental conditions, this information appears to be useful for healthy food production.
本研究旨在探讨褪黑素预处理对水培体系中锦葵（Malva parviflora，锦葵科）生长、氧化应激调节、镉（Cd）积累和耐受性的影响。应用能够调节 Cd 对植物产量的有害影响并降低其在可食用部分积累的物质尤为重要。因此，用 15、50 和 100μM 褪黑素预处理的锦葵植物暴露于 50μM Cd 下。我们的结果表明，褪黑素，特别是 15 和 50μM，对 Cd 耐受性有积极影响，包括生长、光合色素和可溶性蛋白含量的显著增加。外源褪黑素可以提高 Cd 处理植物的相对含水量（RWC）和气孔导度，可能是通过脯氨酸的增加。此外，较低浓度的褪黑素导致 Cd 向地上部分的转运减少。基于这些结果，褪黑素显著增加了过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和愈创木酚过氧化物酶（GPX）的活性以及酚类物质的产生。抗氧化酶活性的增加导致 Cd 胁迫下植物电解质渗漏（EL）、脂质过氧化和 HO 含量的降低。在 Cd 胁迫下，褪黑素预处理植物中酚类物质含量的增加可能是由于苯丙氨酸解氨酶（PAL）活性的诱导和地上部可溶性碳水化合物的增加。结果表明，褪黑素的使用可以减轻 Cd 暴露下植物的氧化应激并提高生物量。至少在我们的实验条件下，这些信息似乎对生产健康食品有用。
