The potential toxic effects of linear alkylbenzene sulfonate (LAS), widely used in commercial detergents and cleaners, on submerged macrophytes remain unclear. We conducted a two-week exposure experiment to investigate LAS toxicity on five submerged macrophytes (four native and one exotic), focusing on their growth and physiological responses. The results showed that lower concentrations of LAS (< 5 mg/L) slightly stimulated the growth of submerged macrophytes, while higher doses inhibited it. Increasing LAS concentration resulted in decreased chlorophyll content, increased MDA content and POD activity, and initially increased SOD and CAT activities before declining. Moreover, required a higher effective concentration for growth compared to native macrophytes. These findings suggest that different species of submerged macrophytes exhibited specific responses to LAS, with high doses (exceeding 5 ∼ 10 mg/L) inhibited plant growth and physiology. However, LAS may promote the dominance of surfactant-tolerant exotic submerged macrophytes in polluted aquatic environments.

中文翻译：

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沉水植物对直链烷基苯磺酸盐 (LAS) 的生长和生理反应

广泛用于商业洗涤剂和清洁剂的线性烷基苯磺酸盐（LAS）对沉水植物的潜在毒性作用仍不清楚。我们进行了为期两周的暴露实验，研究 LAS 对五种沉水植物（四种本土植物和一种外来植物）的毒性，重点关注它们的生长和生理反应。结果表明，较低浓度的LAS（<5mg/L）轻微刺激沉水植物的生长，而较高剂量则抑制其生长。 LAS浓度增加导致叶绿素含量下降，MDA含量和POD活性增加，SOD和CAT活性最初增加，然后下降。此外，与天然大型植物相比，需要更高的有效浓度才能生长。这些结果表明，不同种类的沉水植物对LAS表现出特定的反应，高剂量（超过5～10mg/L）会抑制植物的生长和生理。然而，LAS 可能会促进耐表面活性剂的外来沉水植物在受污染的水生环境中占据主导地位。