Department of Plant Biology, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran.
Department of Biology, Scholl of Sciences, Shiraz University, Shiraz, Iran.
Environ Sci Pollut Res Int. 2024 Sep;31(44):56079-56090. doi: 10.1007/s11356-024-34909-z. Epub 2024 Sep 10.
This study is aimed to explore the potential of purslane (Portulaca oleracea L.) as a phytoremediation candidate for the removal of naphthalene in a hydroponic system; moreover, the impacts of naphthalene on the physiological and biochemical characteristics of the plant were investigated. Four different naphthalene concentrations (0, 15, 30, and 60 ppm) were selected for the experiments, with an additional control treatment without plants containing 60 ppm naphthalene. Each treatment, utilizing a total of 20 hydroponic containers, consisted of 4 replicates. The results indicated that naphthalene led to a reduction in root and shoot growth. The root weight decreased from 17 mg in the control group to 6 mg in the 60 ppm naphthalene treatment, while the shoot weight decreased from 107.5 mg in the control group to 65.7 mg in the 60 ppm naphthalene treatment. Besides, the different naphthalene concentrations had an impact on the photosynthetic pigments. Compared to the control treatment, under severe stress conditions, chlorophyll a decreased by 51.85%, chlorophyll b decreased by 48.14%, and carotenoids decreased by 54.59%; however, anthocyanin, compared to the control treatment, increased by 30.1% under severe stress conditions. The presence of naphthalene also resulted in increased levels of malondialdehyde, hydrogen peroxide, and proline in both roots and shoots at various naphthalene concentrations. In roots, malondialdehyde increased by 40.74%, HO increased by 3%, and proline increased by 75.6%, while malondialdehyde increased by 43.16%, HO increased by 5.34%, and proline increased by 59.48% in shoots under severe stress conditions and compared to the control treatment. Root and shoot protein levels decreased by 64.49% and 32.26%, respectively. Furthermore, the antioxidant enzymes of glutathione S-transferase, superoxide dismutase, catalase, and ascorbate peroxidase showed increased activities in both roots and shoots under severe naphthalene stress conditions. Purslane demonstrated the ability to remove approximately 80% of naphthalene from the medium. In conclusion, this plant has an effective participation in naphthalene uptake and mitigates the adverse effects of naphthalene by enhancing antioxidant enzyme and proline activities.
本研究旨在探索马齿苋（Portulaca oleracea L.）作为一种植物修复候选物的潜力，用于去除水培系统中的萘；此外，还研究了萘对植物生理生化特性的影响。选择了四个不同的萘浓度（0、15、30 和 60 ppm）进行实验，此外还有一个不含植物的含有 60 ppm 萘的对照处理。每个处理使用总共 20 个水培容器，包含 4 个重复。结果表明，萘会导致根和茎的生长减少。根重从对照组的 17mg 降至 60ppm 萘处理组的 6mg，而茎重从对照组的 107.5mg 降至 60ppm 萘处理组的 65.7mg。此外，不同的萘浓度对光合色素有影响。与对照处理相比，在严重胁迫条件下，叶绿素 a 减少了 51.85%，叶绿素 b 减少了 48.14%，类胡萝卜素减少了 54.59%；然而，在严重胁迫条件下，与对照处理相比，花青素增加了 30.1%。萘的存在还导致在不同萘浓度下根和茎中的丙二醛、过氧化氢和脯氨酸水平升高。在根中，丙二醛增加了 40.74%，HO 增加了 3%，脯氨酸增加了 75.6%，而在严重胁迫条件下和与对照处理相比，丙二醛增加了 43.16%，HO 增加了 5.34%，脯氨酸增加了 59.48%。根和茎中的蛋白质水平分别下降了 64.49%和 32.26%。此外，在严重萘胁迫条件下，根和茎中的谷胱甘肽 S-转移酶、超氧化物歧化酶、过氧化氢酶和抗坏血酸过氧化物酶等抗氧化酶的活性均增加。马齿苋表现出从介质中去除约 80%萘的能力。总之，该植物通过增强抗氧化酶和脯氨酸的活性，有效地参与了萘的吸收，并减轻了萘的不利影响。
