College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Key Laboratory of the State Forestry and Grassland Administration for Soil and Water Conservation in Southern Red Soil Region, Fuzhou, 350002, China.
College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111308. doi: 10.1016/j.ecoenv.2020.111308. Epub 2020 Sep 15.
Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator; however, the effects of Pb contamination on P. crinitum rhizosphere soil enzymatic activities and microbial composition remain largely unexplored. Thus, an indoor experiment was conducted by cultivating P. crinitum seedlings and exposing them to four Pb concentrations (0, 1,000, 2000 and 3000 mg/kg Pb). Protease, urease, acid phosphatase and invertase activities were determined using standard methods while soil bacterial composition was determined by 16 S rDNA sequencing. The results showed that rhizosphere soil acid phosphatase activity significantly increased with increasing Pb concentration, while urease activity was significantly greater in rhizosphere soil contaminated with 1000 and 2000 mg/kg than in the control. There was a clear shift in bacterial composition during phytoremediation by P. crinitum. Compared to the control, Bacteroidetes was more abundant in all Pb-contaminated soils, Actinobacteria was more abundant in 1000 mg/kg Pb-treated soil, and Firmicutes was more abundant in 3000 mg/kg Pb-treated soil. Positive correlations were observed between dominant bacterial phyla and soil enzyme activities. Metabolic pathways, such as ABC transporter, quinine reductase, and ATP-binding protein were significantly increased in rhizosphere soil bacteria with Pb contamination. In conclusion, Pb contamination differentially influenced the activities of rhizosphere soil enzymes, specifically increasing acid phosphatase and urease activities, and alters the dominance of soil bacteria through up-regulation of genes related to some metabolic pathways. The strong correlations between dominant bacterial phyla and enzymatic activities suggest synergetic effects on the growth of P. crinitum during Pb contamination.
粗毛鸭茅草是一种很有前景的铅（Pb）超积累植物，但 Pb 污染对粗毛鸭茅草根际土壤酶活性和微生物组成的影响在很大程度上仍未得到探索。因此，通过室内培养粗毛鸭茅草幼苗并将其暴露于 4 种 Pb 浓度（0、1000、2000 和 3000mg/kg Pb）进行了一项实验。采用标准方法测定蛋白酶、脲酶、酸性磷酸酶和转化酶的活性，同时通过 16S rDNA 测序来测定土壤细菌组成。结果表明，根际土壤酸性磷酸酶活性随 Pb 浓度的增加而显著增加，而根际土壤中脲酶活性在受 1000 和 2000mg/kg Pb 污染时明显大于对照。在粗毛鸭茅草的植物修复过程中，细菌组成发生了明显的变化。与对照相比，所有 Pb 污染土壤中 Bacteroidetes 的丰度都更高，1000mg/kg Pb 处理的土壤中 Actinobacteria 的丰度更高，而 3000mg/kg Pb 处理的土壤中 Firmicutes 的丰度更高。优势细菌门与土壤酶活性之间存在显著的正相关关系。根际土壤细菌中与 ABC 转运蛋白、奎宁还原酶和 ATP 结合蛋白相关的代谢途径显著增加。在 Pb 污染的根际土壤中，土壤酶活性受到不同程度的影响，特别是酸性磷酸酶和脲酶活性增加，通过上调与某些代谢途径相关的基因改变了土壤细菌的优势地位。优势细菌门与酶活性之间的强相关性表明，在 Pb 污染期间，对粗毛鸭茅草的生长具有协同作用。
