Laboratory of Pesticide Science, Department of Crop Science, Agricultural University of Athens, Athens, Greece.
Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Athens, Greece.
Pestic Biochem Physiol. 2018 Jun;148:50-61. doi: 10.1016/j.pestbp.2018.03.015. Epub 2018 Apr 3.
Fungal metabolomics is a field of high potential but yet largely unexploited. Focusing on plant-pathogenic fungi, no metabolomics studies exist on their resistance to fungicides, which represents a major issue that the agrochemical and agricultural sectors are facing. Fungal infections cause quantitative, but also qualitative yield losses, especially in the case of mycotoxin-producing species. The aim of the study was to correlate metabolic changes in Fusarium graminearum strains' metabolomes with their carbendazim-resistant level and discover corresponding metabolites-biomarkers, with primary focus on its primary metabolism. For this purpose, comparative H NMR metabolomics was applied to a wild-type and four carbendazim-resistant Fusarium graminearum strains following or not exposure to the fungicide. Results showed an excellent discrimination between the strains based on their carbendazim-resistance following exposure to low concentration of the fungicide (2 mg L). Both genotype and fungicide treatments had a major impact on fungal metabolism. Among the signatory metabolites, a positive correlation was discovered between the content of F. graminearum strains in amino acids of the aromatic and pyruvate families, l-glutamate, l-proline, l-serine, pyroglutamate, and succinate and their carbendazim-resistance level. In contrary, their content in l-glutamine and l-threonine, had a negative correlation. Many of these metabolites play important roles in fungal physiology and responses to stresses. This work represents a proof-of-concept of the applicability of H NMR metabolomics for high-throughput screening of fungal mutations leading to fungicide resistance, and the study of its biochemical basis, focusing on the involvement of primary metabolism. Results could be further exploited in programs of resistance monitoring, genetic engineering, and crop protection for combating fungal resistance to fungicides.
真菌代谢组学是一个具有巨大潜力但尚未得到充分开发的领域。本研究聚焦于植物病原真菌，针对其对杀菌剂的抗性，尚无代谢组学研究。杀菌剂抗性是农业化学和农业部门面临的主要问题之一。真菌感染会导致定量和定性的产量损失，尤其是产真菌毒素的物种。本研究的目的是将禾谷镰刀菌菌株代谢组中的代谢变化与其多菌灵抗性水平相关联，并发现相应的代谢物生物标志物，主要关注其初级代谢物。为此，采用比较 H NMR 代谢组学方法，对野生型和 4 株多菌灵抗性禾谷镰刀菌菌株进行了研究，这些菌株在暴露于低浓度杀菌剂（2 mg/L）前后的代谢组学变化。结果表明，基于菌株在暴露于低浓度杀菌剂后的多菌灵抗性，能够对菌株进行很好的区分。基因型和杀菌剂处理对真菌代谢有很大的影响。在有显著差异的代谢物中，发现禾谷镰刀菌菌株中芳香族和丙酮酸家族氨基酸、l-谷氨酸、l-脯氨酸、l-丝氨酸、焦谷氨酸和琥珀酸的含量与多菌灵抗性水平呈正相关，而 l-谷氨酰胺和 l-苏氨酸的含量与多菌灵抗性水平呈负相关。这些代谢物在真菌生理学和应对胁迫反应中发挥着重要作用。本工作证明了 H NMR 代谢组学在高通量筛选导致杀菌剂抗性的真菌突变体及其生化基础研究中的适用性，重点关注了初级代谢物的参与。研究结果可进一步用于抗性监测、遗传工程和作物保护计划，以应对真菌对杀菌剂的抗性。
