Wang Mingzhu, Xiao Yufang, Li Yun, Liu Jianv
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), China; College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), China; College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
Plant Physiol Biochem. 2023 Mar;196:350-360. doi: 10.1016/j.plaphy.2023.01.062. Epub 2023 Feb 1.
Galaxolide (HHCB) and polystyrene (PS) microplastics or nanoplastics have been widely recognized as emerging pollutants. However, very few efforts have been made to remove these contaminants from the environment using eco-friendly materials such as plant materials. Therefore, this study sought to investigate the physiological and biochemical effects and tolerance mechanisms of Mirabilis jalapa L. upon exposure to HHCB and PS. Our findings demonstrated that this ornamental plant was tolerant to HHCB and PS exposure. HHCB treatment increased antioxidant enzyme activity. However, superoxide dismutase (SOD) activity increased by 206.85% when the plants were treated with 0.5 mg L HHCB alone, whereas co-exposure to 0.5 mg L HHCB and 500 nm PS increased SOD activity by 93.82%. Contaminant exposure also affected photosynthetic parameters such as stomatal conductance and transpiration rate. In contrast, net photosynthetic rate and photosynthetic pigment content were not significantly affected. HHCB aggregated heavily in the roots of the plant. Moreover, 500 nm PS could be absorbed by the root and transported to the shoot, and 5 μm PS would be transferred to the shoot under the carrying effect of HHCB. Co-exposure to HHCB and PS significantly changed the glyoxylate and dicarboxylate metabolism, alanine, aspartate, and glutamate metabolism, and glycine, serine, and threonine metabolism pathways, thus affecting carbohydrate synthesis and energy metabolism in M. jalapa. These results provide a basis for the development of HHCB and PS remediation strategies using M. jalapa, an ornamental plant that is not only tolerant to organic contaminants but can also beautify the environment.
佳乐麝香（HHCB）以及聚苯乙烯（PS）微塑料或纳米塑料已被广泛认定为新兴污染物。然而，利用植物材料等环保材料从环境中去除这些污染物的相关研究却很少。因此，本研究旨在探究紫茉莉在接触HHCB和PS时的生理生化效应及耐受机制。我们的研究结果表明，这种观赏植物对HHCB和PS具有耐受性。HHCB处理提高了抗氧化酶活性。然而，当植株单独用0.5 mg/L HHCB处理时，超氧化物歧化酶（SOD）活性增加了206.85%，而当同时接触0.5 mg/L HHCB和500 nm的PS时，SOD活性增加了93.82%。污染物暴露还影响了光合参数，如气孔导度和蒸腾速率。相比之下，净光合速率和光合色素含量未受到显著影响。HHCB在植株根部大量聚集。此外，500 nm的PS可被根部吸收并转运至地上部分，而5μm的PS在HHCB的携带作用下会转移至地上部分。HHCB和PS共同暴露显著改变了乙醛酸和二羧酸代谢、丙氨酸、天冬氨酸和谷氨酸代谢以及甘氨酸、丝氨酸和苏氨酸代谢途径，从而影响了紫茉莉的碳水化合物合成和能量代谢。这些结果为利用紫茉莉开发HHCB和PS修复策略提供了依据，紫茉莉这种观赏植物不仅耐受有机污染物，还能美化环境。
