Key Laboratory for Environmental Factors Control of Agro-product Quality Safety, Ministry of Agriculture and Rural Affairs, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, PR China.
SCIEX, Analytical Instrument Trading Co., Ltd., Beijing, 100015, China.
Chemosphere. 2022 Aug;300:134198. doi: 10.1016/j.chemosphere.2022.134198. Epub 2022 Mar 3.
The use of the chiral triazole fungicide cis-epoxiconazole in agricultural production continues to increase; however, little is known about the stereoselective and toxic responses of soil microorganisms to cis-epoxiconazole in the soil microenvironment. High-throughput sequencing and metabolomics were integrated to investigate the stereoselective response of soil microbial community structure, metabolic profile to cis-epoxiconazole exposure, and the correlation between the microbiomes and different metabolites. Soil microbial community structure and soil metabolic profile were significantly altered and exhibited significant enantioselectivity. The alpha diversity (Chao, Shannon, and Simpson diversity) of bacterial and fungus was not significantly affected, whereas the beta diversity (Bray-Curtis dissimilarity and PLS-DA) of bacterial and fungus was significantly altered in treatment of cis-epoxiconazole and its enantiomers (p-value < 0.05). The variation in bacterial and fungus community structure was the highest under (+)-enantiomer exposure, followed by exposure to racemate and (-)-enantiomer. Soil metabolomic analysis revealed that exposure to high or low doses of cis-epoxiconazole and its enantiomers resulted in different degrees of reprogramming of the soil metabolic pool. The 39 significantly changed metabolites mainly included small molecular organic acids, amino acids and their intermediates, and purine and adenosine intermediates. Six metabolic pathways were significantly disrupted. Different correlation patterns were observed between the significantly altered metabolites and microbes (p-value < 0.05) by Pearson correlation-based analysis. In conclusion, as xenobiotic pollutant, epoxiconazole altered the structure and metabolism of soil microorganisms with significant stereoselectivity mainly driven by 2R, 3S-(+)-cis-epoxiconazole. This study provided a more robust assessment of the risks of epoxiconazole exposure to soil microorganisms. Given the importance of the soil environment in agricultural production, characterization of the soil microbiome and metabolome can provide new insights into the ecological risks posed by exposure to the chiral triazole pesticide cis-epoxiconazole and its enantiomers.
农业生产中手性三唑类杀菌剂顺式环氧氯丙烷的使用不断增加；然而，对于土壤微生物在土壤微环境中对手性环氧氯丙烷的立体选择性和毒性反应知之甚少。本研究采用高通量测序和代谢组学相结合的方法，研究了土壤微生物群落结构、代谢谱对顺式环氧氯丙烷暴露的立体选择性响应，以及微生物组与不同代谢物之间的相关性。土壤微生物群落结构和土壤代谢谱发生了显著变化，并表现出显著的对映体选择性。细菌和真菌的α多样性（Chao、Shannon 和 Simpson 多样性）没有显著影响，而细菌和真菌的β多样性（Bray-Curtis 不相似性和 PLS-DA）在顺式环氧氯丙烷及其对映体处理下显著改变（p 值<0.05）。在（+）-对映体暴露下，细菌和真菌群落结构的变化最大，其次是暴露于外消旋体和（-）-对映体。土壤代谢组学分析表明，高剂量或低剂量的顺式环氧氯丙烷及其对映体暴露导致土壤代谢库的不同程度重新编程。39 种显著变化的代谢物主要包括小分子有机酸、氨基酸及其中间产物以及嘌呤和腺苷中间产物。六个代谢途径受到显著干扰。通过 Pearson 相关分析，观察到显著改变的代谢物与微生物之间存在不同的相关模式（p 值<0.05）。总之，作为一种外源性污染物，环氧氯丙烷主要受 2R,3S-(+)-顺式环氧氯丙烷的驱动，以显著的立体选择性改变了土壤微生物的结构和代谢。本研究提供了对手性三唑类农药顺式环氧氯丙烷及其对映体暴露对土壤微生物风险的更全面评估。鉴于土壤环境在农业生产中的重要性，对土壤微生物组和代谢组的特征描述可以为手性三唑类农药顺式环氧氯丙烷及其对映体暴露所带来的生态风险提供新的见解。
