手性三唑类杀菌剂氟环唑对土壤微生物的立体选择性影响

Stereoselective effects of the chiral triazole fungicide epoxiconazole on soil microbes

为了研究土壤微生物对手性三唑类杀菌剂氟环唑的立体选择性响应,通过非靶向代谢组学和高通量测序联合技术探究了土壤代谢组和微生物群落对氟环唑外消旋体及对映体的响应机制。结果表明:氟环唑及其对映体处理4周后,土壤中氟环唑降解不显著,其残留能够引起土壤代谢组和土壤微生物群落组成的显著变化。土壤代谢组、细菌和真菌群落组成、PICRUSt基因功能预测的代谢途径均表现出由2R,3S-(+)-氟环唑驱动的立体选择性响应。PICRUSt基因预测表明,细菌中被显著影响的MetaCyc通路有10条,真菌中比对出22条。氟环唑外消旋体和(+)-对映体比(-)-对映体表现出对土壤微生物更显著的干扰作用(P<0.05)。氟环唑暴露引起了土壤环境中细菌和真菌群落、代谢、基因功能预测通路不同程度的立体选择性响应。鉴于土壤环境在农业生产中的重要性,土壤微生物组和代谢组的表征可以为暴露于手性三唑类农药顺式氟环唑及其对映体所带来的生态风险提供新的见解。

This study aimed to explore the response mechanism of the soil metabolome and microbial communities to epoxiconazole racemates and their enantiomers based on the stereoselective response of soil microorganisms to the chiral triazole fungicide epoxiconazole,using a combination of non-targeted metabolomics and high-throughput sequencing.No significant degradation of epoxiconazole and its enantiomers in the soil was observed after 4 weeks of treatment.This residue could cause significant changes in the soil metabolome and soil microbial community composition.The soil metabolome,bacterial and fungal community composition,and metabolic pathways predicted by the PICRUSt gene showed stereoselective responses driven by 2R,3S-(+)-epoxiconazole.The MetaCyc pathways of the significant responses of 10 and 22 strips were observed in bacteria and fungi,respectively,as shown by the results of PICRUSt gene prediction.The interference in soil microorganisms by(±)-epoxiconazole and(+)-enantiomers was more significant than by(-)-enantiomers.The bacterial and fungal communities,metabolism profile,and prediction pathways of gene function in the soil environment showed varying degrees of stereoselective response to cis-epoxiconazole.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.