磺胺甲恶唑胁迫下人工湿地植物与根际微生物的响应

Responses of plants and rhizosphere microorganisms in constructed wetlands under sulfamethoxazole stress

  • 摘要: 为探究磺胺甲恶唑 (sulfamethoxazole,SMX) 胁迫下人工湿地植物与根际微生物的响应机制,对不同浓度SMX在5种植物与根际微生物联合修复中的去除效率进行表征;依据SMX的去除效率,对唐菖蒲和风车草的根系活力、活性氧与抗氧化系统进行研究,同步分析其根际微生物群落在SMX和温度胁迫下的响应特征。结果表明:5种人工湿地植物与根际微生物联合修复中,唐菖蒲、风车草对SMX的去除率较高,平均值分别为40.38%、44.70%。当SMX浓度超过30 mg/L时,与0 mg/L时相比较,唐菖蒲、风车草的根系活力受到抑制,分别下降了69.77%、67.26%;随着SMX浓度的升高,唐菖蒲和风车草的活性氧含量分别增加了69.08%、72.67%,抗氧化酶活性降低了19.32%、24.83%;与常温条件(20~25 ℃)相比,低温条件下(4~12 ℃)下唐菖蒲、风车草的活性氧含量分别增加了2.26%、1.98%,抗氧化酶活性降低了47.72%、44.42%。高通量测序技术对根际微生物群落的测定结果表明,高浓度SMX对植物根际微生物群落多样性与物种丰富度有抑制作用,利用PICRUSt功能预测软件对微生物群落功能预测发现,以氨基酸和碳水化合物代谢功能为主的微生物细菌相对丰度较高。

     

    Abstract: In order to explore the response mechanism of plants and rhizosphere microorganisms in constructed wetlands under the stress of sulfamethoxazole (SMX), the removal efficiency of different concentrations of SMX in the combined remediation of five plants and rhizosphere microorganisms was characterized. According to the removal efficiency of SMX, the root activity, reactive oxygen species and antioxidant system of Gladiolus hybridus and Cyperus alternifolius were studied, and the response characteristics of their rhizosphere microbial community under SMX and temperature stress were analyzed simultaneously. The results showed that the removal rates of SMX by Gladiolus hybridus and Cyperus alternifolius were the highest in the five constructed wetland plants and rhizosphere microorganisms, with an average of 40.38% and 44.70%, respectively. When SMX concentration was higher than 30 mg/L, the root activity of Gladiolus hybridus and Cyperus alternifolius was inhibited, which was 69.77% and 67.26% lower than that of 0 mg/L, respectively. With the increase of SMX concentration, the reactive oxygen species (ROS) content of Gladiolus hybridus and Cyperus alternifolius increased by 69.08% and 72.67% compared with 0 mg/L, respectively, but the antioxidant enzyme activities decreased by 19.32% and 24.83%, respectively. Compared with normal temperature (20-25 ℃), the ROS content of Gladiolus hybridus and Cyperus alternifolius increased by 2.26% and 1.98%, and the antioxidant enzyme activity decreased by 47.72% and 44.42%, respectively, under low temperature (4-12 ℃). The measurement results of the rhizosphere microbial community by high-throughput sequencing technology showed that high concentrations of SMX inhibited the diversity and species richness of the plant rhizosphere microbial community. PICRUSt function prediction software was used to predict the microbial community function, and it was found that the relative abundance of microbes with amino acid and carbohydrate metabolism was higher.

     

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