Biochemical mechanisms of rhizospheric Bacillus subtilis-facilitated phytoextraction by alfalfa under cadmium stress - Microbial diversity and metabolomics analyses
Biochemical mechanisms of rhizospheric Bacillus subtilis-facilitated phytoextraction by alfalfa under cadmium stress - Microbial diversity and metabolomics analyses
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DOI：
10.1016/j.ecoenv.2021.112016
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发表时间：
2021-02-04
影响因子：
6.8
通讯作者：
Zhang, Qiang
中科院分区：
文献类型：
--
作者：
Li, Qi;Xing, Yingna;Zhang, Qiang
采用盆栽试验研究了枯草芽孢杆菌对紫花苜蓿生长和镉吸收的影响，并结合微生物多样性和非靶代谢组学分析探讨了其相关的生化机制。结果表明，接种紫花苜蓿能显著降低植物体内丙二醛（MDA）含量，提高植物抗氧化酶和土壤养分循环相关酶的活性，使生物量提高29.4%。接种还使根际土壤Cd的生物有效性提高了12.0%，Cd去除率提高了139.3%。其生物化学机制包括细菌多样性的增强，微生物群落组成的改变，根际土壤代谢产物中氨基酸、脂肪酸、碳水化合物、黄酮类化合物和酚类化合物的含量的调节，以及相应的京都基因和基因组百科全书（KEGG）途径的调节。这些响应有利于微生物活性、养分循环以及苜蓿对土壤中Cd的迁移、解毒和净化。该研究尤其是新发现的差异代谢物和代谢途径，为重金属污染土壤微生物辅助植物修复的机理揭示和策略制定提供了新的思路。
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.