Janbazi Zahra, Zarinkamar Fatemeh, Mohsenzadeh Sasan
Department of Plant Biology, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran.
Department of Biology, College of Science, Shiraz University, Shiraz, Iran.
Sci Rep. 2025 Jul 13;15(1):25313. doi: 10.1038/s41598-025-09879-y.
Polycyclic aromatic hydrocarbons (PAHs) induce oxidative stress in plant cells. Naphthalene is a well-known low molecular weight hydrocarbon. This compound elevates the levels of reactive oxygen species and malondialdehyde in plants. The aim of this study is to investigate the expression of antioxidant enzymes, including glutathione S-transferase, as well as and the anatomical changes in purslane plants in response to naphthalene stress, and to assess their role in mitigating the harmful effects of this substance and its absorption. Four concentrations of naphthalene (0, 15, 30, and 60 ppm) were tested in quadruplicate across 16 hydroponic containers. The gene expression of all four enzymes significantly increased in both roots and shoots under moderate and severe stress conditions. Specifically, the expression of glutathione S-transferase in roots and shoots significantly increased by 80.85 and 78.59%, respectively in response to severe stress compared to the control group. Furthermore, the gene expressions of catalase, superoxide dismutase, and ascorbate peroxidase in roots significantly increased by 64.53, 82.87, and 70.23%, respectively under severe stress conditions. In the shoots, the corresponding increases in expression were 72.14, 71.42 and 78.81%. Furthermore, exposure to naphthalene resulted in distinct anatomical changes in both roots and shoots. The epidermal and parenchyma cells in both structures exhibited a reduction in size and increased sinuosity. Moreover, the number of vascular bundles in the shoots increased. These findings underscore the robust antioxidant defense system and anatomical adaptability of purslane, enabling it to thrive in environments contaminated with naphthalene. This resilience highlights the potential application of purslane in the phytoremediation of naphthalene- polluted ecosystems.
多环芳烃（PAHs）会在植物细胞中引发氧化应激。萘是一种著名的低分子量烃类化合物。该化合物会提高植物体内活性氧物质和丙二醛的水平。本研究的目的是调查抗氧化酶（包括谷胱甘肽S-转移酶）的表达情况，以及马齿苋植株在萘胁迫下的解剖学变化，并评估它们在减轻该物质的有害影响及其吸收方面的作用。在16个水培容器中，对四种浓度的萘（0、15、30和60 ppm）进行了四次重复测试。在中度和重度胁迫条件下，所有四种酶的基因表达在根和地上部分均显著增加。具体而言，与对照组相比，在重度胁迫下，根和地上部分谷胱甘肽S-转移酶的表达分别显著增加了80.85%和78.59%。此外，在重度胁迫条件下，根中过氧化氢酶、超氧化物歧化酶和抗坏血酸过氧化物酶的基因表达分别显著增加了64.53%、82.87%和70.23%。在地上部分，相应的表达增加分别为72.14%、71.42%和78.81%。此外，接触萘会导致根和地上部分出现明显的解剖学变化。两种结构中的表皮细胞和薄壁细胞尺寸减小且弯曲度增加。此外，地上部分的维管束数量增加。这些发现强调了马齿苋强大的抗氧化防御系统和解剖学适应性，使其能够在被萘污染的环境中茁壮成长。这种适应能力突出了马齿苋在萘污染生态系统植物修复中的潜在应用价值。
