Oreiro Eula Gems, Samils Berit, Kildea Steven, Heick Thies, Hellin Pierre, Legrève Anne, Rodemann Bernd, Berg Gunilla, Jørgensen Lise N, Friberg Hanna, Berlin Anna, Zhan Jiasui, Andersson Björn
Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
TEAGASC, The Agriculture and Food Development Authority, Carlow, Ireland.
Pest Manag Sci. 2025 Feb;81(2):1103-1112. doi: 10.1002/ps.8514. Epub 2024 Nov 6.
The hemibiotrophic fungus Zymoseptoria tritici causing Septoria tritici blotch (STB), is a devastating foliar pathogen of wheat worldwide. A common group of fungicides used to control STB are the demethylation inhibitors (DMIs). DMI fungicides restrict fungal growth by inhibiting the sterol 14-α-demethylase, a protein encoded by CYP51 gene and essential for maintaining fungal cell permeability. However, the adaptation of Z. tritici populations in response to intensive and prolonged DMI usage has resulted in a gradual shift towards reduced sensitivity to this group of fungicides. In this study, 311 isolates were collected pre-treatment from nine wheat-growing regions in Europe in 2019. These isolates were analysed by high-throughput amplicon-based sequencing of nine housekeeping genes and the CYP51 gene.
Analyses based on housekeeping genes and the CYP51 gene revealed a lack of population structure in Z. tritici samples irrespective of geographical origin. Minimum spanning network (MSN) analysis showed clustering of multilocus genotypes (MLGs) based on CYP51 haplotypes, indicating an effect of selection due to DMI fungicide use. The majority of the haplotypes identified in this study have been reported previously. The diversity and frequencies of mutations varied across regions.
Using a high-throughput amplicon-sequencing approach, we found several mutations in the CYP51 gene combined in different haplotypes that are likely to cause fungicide resistance. These mutations occurred irrespective of genetic background or geographical origin. Overall, these results contribute to the development of effective and sustainable risk monitoring for DMI fungicide resistance. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
半活体营养型真菌小麦黄斑叶枯病菌（Zymoseptoria tritici）可引发小麦黄斑叶枯病（STB），是全球范围内一种极具破坏性的小麦叶部病原菌。用于防治小麦黄斑叶枯病的一类常见杀菌剂是脱甲基化抑制剂（DMIs）。DMIs杀菌剂通过抑制甾醇14-α-脱甲基酶来限制真菌生长，该酶由CYP51基因编码，对维持真菌细胞通透性至关重要。然而，由于长期大量使用DMIs，小麦黄斑叶枯病菌群体逐渐适应，对这类杀菌剂的敏感性逐渐降低。在本研究中，2019年从欧洲九个小麦种植区收集了311株预处理菌株。通过对九个管家基因和CYP51基因进行基于高通量扩增子的测序来分析这些菌株。
基于管家基因和CYP51基因的分析表明，无论地理来源如何，小麦黄斑叶枯病菌样本均缺乏群体结构。最小生成网络（MSN）分析显示，基于CYP51单倍型的多位点基因型（MLGs）聚类，表明DMI杀菌剂的使用产生了选择效应。本研究中鉴定出的大多数单倍型此前已有报道。不同区域的突变多样性和频率各不相同。
通过高通量扩增子测序方法，我们在CYP51基因中发现了几个组合在不同单倍型中的突变，这些突变可能导致杀菌剂抗性。这些突变的发生与遗传背景或地理来源无关。总体而言，这些结果有助于开展针对DMI杀菌剂抗性的有效且可持续的风险监测。© 2024作者。由John Wiley & Sons Ltd代表化学工业协会出版的《害虫管理科学》。
