Steroid estrogens (SEs) have garnered global attention because of their potential hazards to human health and aquatic organisms at low concentrations (ng/L). The ecosystems of plateau freshwater lakes are fragile, the water lag time is long, and pollutants easily accumulate, making them more vulnerable to the impact of SEs. However, the knowledge of the impact of SEs on the growth and decomposition of phytoplankton communities in plateau lakes and the eutrophication process is limited. This study investigated the effects and mechanisms of SEs exposure on dominant algal communities and the expression of typical algal functional genes in Erhai Lake using indoor simulations and molecular biological methods. The results showed that phytoplankton were sensitive to 17β-estradiol (E2β) pollution, with a concentration of 50, and 100 ng/L E2β exposure promoting the growth of cyanophyta and chlorophyta in the short term; this poses an ecological risk of inducing algal blooms. E2β of 1000 ng/L exposure led to cross-effects of estrogenic effects and toxicity, with most phytoplankton being inhibited. However, small filamentous cyanobacteria and diatoms exhibited greater tolerance; sp. even exhibited "low inhibition, high promotion" behavior. Exposure to E2β reduced the Shannon-Wiener diversity index (), Pielou index (), and the number of dominant algal species () in phytoplankton communities, leading to instability in community succession. E2β of 50 ng/L enhanced the expression levels of relevant functional genes, such as , , , and , related to . E2β of 50 ng/L and 5 mg/L can promote the transcription of Microcystis toxins (MC) related genes (), leading to more MC production by algal cells.

中文翻译：

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17β-雌二醇干扰下高原湖泊浮游植物群落演替及关键功能基因表达的响应


类固醇雌激素（SE）因其低浓度（ng/L）对人类健康和水生生物的潜在危害而引起了全球关注。高原淡水湖泊生态系统脆弱，水滞时间长，污染物容易积累，更容易受到SEs的影响。然而，关于SEs对高原湖泊浮游植物群落生长和分解以及富营养化过程的影响的认识还很有限。本研究采用室内模拟和分子生物学方法，研究了SEs暴露对洱海优势藻类群落以及典型藻类功能基因表达的影响和机制。结果表明，浮游植物对17β-雌二醇（E2β）污染敏感，浓度为50、100 ng/L的E2β暴露在短期内促进蓝藻和绿藻的生长；这造成了引发藻华的生态风险。 1000 ng/L 的 E2β 暴露会导致雌激素效应和毒性的交叉效应，大多数浮游植物受到抑制。然而，小型丝状蓝藻和硅藻表现出更强的耐受性。 sp。甚至表现出“低抑制、高促进”的行为。暴露于E2β会降低浮游植物群落中的Shannon-Wiener多样性指数()、Pielou指数()和优势藻类数量()，导致群落演替不稳定。 50 ng/L 的 E2β 增强了相关功能基因的表达水平，例如与 相关的 、 、 、 和 。 50 ng/L 和 5 mg/L 的 E2β 可以促进微囊藻毒素 (MC) 相关基因的转录 ()，导致藻细胞产生更多的 MC。