Agriculture and Agri-Food Canada, 430 Gouin Boulevard, Saint-Jean-sur-Richelieu, Quebec, J3B 3E6, Canada.
Département des Sciences Biologiques, Université du Québec à Montréal, 141 Avenue du Président-Kennedy, Montréal, Québec, H2X 1Y4, Canada.
Microbiology (Reading). 2023 Apr;169(4). doi: 10.1099/mic.0.001318.
Neonicotinoids, a class of systemic insecticides, have been widely used for decades against various insect pests. Previous studies have reported non-target effects of neonicotinoids on some beneficial macro- and micro-organisms. Considering the crucial role the soil microbiota plays in sustaining soil fertility, it is critical to understand how neonicotinoid exposure affects the microbial taxonomic composition and gene expression. However, most studies to date have evaluated soil microbial taxonomic compositions or assessed microbial functions based on soil biochemical analysis. In this study, we have applied a metatranscriptomic approach to quantify the variability in soil microbial gene expression in a 2 year soybean/corn crop rotation in Quebec, Canada. We identified weak and temporally inconsistent effects of neonicotinoid application on soil microbial gene expression, as well as a strong temporal variation in soil microbial gene expression among months and years. Neonicotinoid seed treatment altered the expression of a small number of microbial genes, including genes associated with heat shock proteins, regulatory functions, metabolic processes and DNA repair. These changes in gene expression varied during the growing season and between years. Overall, the composition of soil microbial expressed genes seems to be more resilient and less affected by neonicotinoid application than soil microbial taxonomic composition. Our study is among the first to document the effects of neonicotinoid seed treatment on microbial gene expression and highlights the strong temporal variability of soil microbial gene expression and its responses to neonicotinoid seed treatments.
新烟碱类杀虫剂是一类已被广泛使用数十年的系统性杀虫剂，用于防治各种虫害。先前的研究报告称新烟碱类杀虫剂对一些有益的大型和微型生物有非靶标效应。鉴于土壤微生物群在维持土壤肥力方面的关键作用，了解新烟碱类暴露如何影响微生物分类组成和基因表达至关重要。然而，迄今为止的大多数研究都评估了土壤微生物分类组成，或基于土壤生化分析来评估微生物功能。在这项研究中，我们应用宏转录组学方法来量化加拿大魁北克省 2 年大豆/玉米轮作中土壤微生物基因表达的可变性。我们确定了新烟碱类杀虫剂的应用对土壤微生物基因表达的微弱且时间不一致的影响，以及土壤微生物基因表达在月份和年份之间的强烈时间变化。新烟碱类种子处理改变了少数微生物基因的表达，包括与热休克蛋白、调节功能、代谢过程和 DNA 修复相关的基因。这些基因表达的变化在生长季节和年份之间发生变化。总的来说，土壤微生物表达基因的组成似乎比土壤微生物分类组成更具弹性，受新烟碱类杀虫剂应用的影响较小。我们的研究首次记录了新烟碱类杀虫剂种子处理对微生物基因表达的影响，并强调了土壤微生物基因表达的强烈时间变异性及其对新烟碱类杀虫剂种子处理的响应。
