Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250013, China.
Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250013, China.
Ecotoxicol Environ Saf. 2021 Apr 1;212:112016. doi: 10.1016/j.ecoenv.2021.112016. Epub 2021 Feb 4.
The effects of Bacillus subtilis inoculation on the growth and Cd uptake of alfalfa were evaluated in this research using pot experiments, and the relevant biochemical mechanisms were first investigated by combined microbial diversity and nontarget metabolomics analyses. The results indicated that inoculation with alfalfa significantly decreased the amount of plant malondialdehyde (MDA) and improved the activities of plant antioxidant enzymes and soil nutrient cycling-involved enzymes, thereby promoting biomass by 29.4%. Inoculation also increased Cd bioavailability in rhizosphere soil by 12.0% and Cd removal efficiency by 139.3%. The biochemical mechanisms included enhanced bacterial diversity, transformed microbial community composition, regulated amounts of amino acids, fatty acids, carbohydrates, flavonoids and phenols in rhizosphere soil metabolites, and modulations of the corresponding Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These responses were beneficial to microbial activity, nutrient cycling, and Cd mobilization, detoxification, and decontamination by alfalfa in soil. This study, especially the newly identified differential metabolites and metabolic pathways, provides new insights into mechanism revelation and strategy development in microbe-assisted phytomanagement of heavy metal-contaminated soils.
本研究通过盆栽实验评估了枯草芽孢杆菌接种对紫花苜蓿生长和 Cd 吸收的影响，首次通过结合微生物多样性和非靶向代谢组学分析研究了相关的生化机制。结果表明，接种紫花苜蓿显著降低了植物丙二醛（MDA）的含量，提高了植物抗氧化酶和土壤养分循环相关酶的活性，从而使生物量增加了 29.4%。接种还增加了根际土壤中 Cd 的生物有效性 12.0%，并提高了 Cd 的去除效率 139.3%。生化机制包括增强细菌多样性、改变微生物群落组成、调节根际土壤代谢物中氨基酸、脂肪酸、碳水化合物、类黄酮和酚类物质的含量，以及调节相应的京都基因与基因组百科全书（KEGG）途径。这些响应有利于微生物活性、养分循环以及 Cd 在土壤中的迁移、解毒和清除。本研究特别是新鉴定的差异代谢物和代谢途径，为揭示微生物辅助重金属污染土壤植物管理的机制和制定策略提供了新的见解。
