School of Economic Law of Shanghai University of Political Science and Law, No. 7989, Waiqingsong Road, Qingpu District, Shanghai, 201701, China.
Institute of Tropical Eco-Agriculture, Yunnan Academy of Agricultural Sciences, Kunming, 651300, Yunnan Province, China.
Sci Rep. 2024 Oct 22;14(1):24883. doi: 10.1038/s41598-024-76517-4.
The pollution by heavy metals in coastal waters has gradually intensified due to industrial development. In this study, physiological responses of Ulva lactuca, one of the most common green seaweeds with important ecological and economic value in the global intertidal zone, to acute copper stress were investigated. Results showed that an increase in copper ions concentration significantly inhibited photosynthetic activity and inorganic nitrogen utilization by U. lactuca but, increased its respiration. Copper stress limited the activity and gene expression of enzymes related to carbon and nitrogen assimilation of U. lactuca. Under moderate copper stress, U. lactuca had higher soluble carbohydrate and soluble protein contents, whereas under high copper stress, these components decreased sharply. Copper stress increased malonaldehyde content, and relative electrical conductivity in U. lactuca, but changes in antioxidant enzyme activities were not significant and even slightly decreased. Moreover, the contents of 8-hydroxy-deoxyguanosine and polyADP ribose polymerase in U. lactuca increased by high Cu concentration culture, indicating that oxidative damage caused by high Cu level involved its DNA damage and interfered with DNA repair in the alga. Copper stress seemed to be more damaging to the carbon assimilation process of U. lactuca, resulting in weakened resistance to copper stress and lower growth rate. This reflected the threat of coastal high copper stress to intertidal biodiversity. This provided ecological reference for the assessment of offshore heavy metal pollution represented by copper.
由于工业发展，沿海水域的重金属污染逐渐加剧。本研究以全球潮间带分布广泛、具有重要生态和经济价值的大型绿藻浒苔为材料，探讨了铜胁迫对其生理响应。结果表明，铜离子浓度增加显著抑制了浒苔的光合作用和无机氮利用，但增加了其呼吸作用。铜胁迫限制了浒苔碳氮同化相关酶的活性和基因表达。在适度铜胁迫下，浒苔的可溶性糖和可溶性蛋白含量较高，而在高铜胁迫下，这些成分急剧下降。铜胁迫增加了浒苔丙二醛含量和相对电导率，但抗氧化酶活性变化不显著，甚至略有下降。此外，高 Cu 浓度培养下浒苔 8-羟基脱氧鸟苷和多聚 ADP 核糖聚合酶的含量增加，表明高 Cu 水平引起的氧化损伤涉及其 DNA 损伤，并干扰了藻类的 DNA 修复。铜胁迫似乎对浒苔的碳同化过程造成更大的破坏，导致其对铜胁迫的抵抗力减弱，生长速度降低。这反映了沿海高铜胁迫对潮间带生物多样性的威胁。这为以铜为代表的近海重金属污染评估提供了生态参考。
