Table1_LC-MS based metabolomics identification of natural metabolites against Fusarium oxysporum.xlsx

Fusarium is a soil-borne pathogen that poses a serious threat to the quality and yield of hundreds of crops worldwide, particularly tobacco production. Using metabolomics technology, we investigated natural metabolites from disease-conducting soil (DCS) and disease-suppressing soil (DSS) of tobacco rhizosphere as fungicides to control tobacco Fusarium wilt (TFW), which is mainly caused by Fusarium oxysporum. Furthermore, the antifungal mechanisms of these natural metabolites were preliminarily elucidated through various assessments, including antifungal activity determination, chemotaxis effect tests, PI staining experiments, and measurements of extracellular conductivity and protein content. Metabolomics results showed that the DCS with three different disease grades (G1, G5 and G9 groups) had significantly higher levels of 15, 14 and 233 differential rhizosphere metabolites (DRMs) and significantly lower levels of 72, 152 and 170 DRMs compared to the DSS (G0 group). According to KEGG pathway analysis, these DRMs were found to be enriched in the caffeine metabolism, biosynthesis of phenylpropanoids, galactose metabolism and tyrosine metabolism, etc. Linustatin, scopoletin and phenylpropiolic acid were picked out from these DRMs and found to have suppressive activity against F. oxysporum through correlation analysis and antifungal experiments. The three DRMs showed strong inhibitory effects on the growth and spore germination of F. oxysporum at concentrations of 0.5 mM or higher in each test period. Furthermore, F. oxysporum showed a phobotaxis effect against these three DRMs at concentrations as low as 0.25 mM. Finally, we found that the three DRMs had an inhibitory effect on F. oxysporum by destroying the integrity of the cell membrane and increasing the membrane permeability of F. oxysporum. This study firstly reports the inhibition activity of phenylpropiolic acid and linustatin on F. oxysporum, providing a practical and environmentally friendly method for biocontrol of TFW by using natural fungicides.

曲霉菌作为一种土壤传播的病原体，对全球数百种作物的品质与产量构成严重威胁，尤其是烟草生产。本研究利用代谢组学技术，对烟草根际土壤中的病害传导土壤（DCS）和病害抑制土壤（DSS）中的天然代谢物进行了研究，以作为防治烟草曲霉菌萎蔫病（TFW）的杀菌剂，TFW主要由尖孢镰刀菌引起。此外，通过包括杀菌活性测定、趋化性效应测试、PI染色实验以及细胞外导电性和蛋白质含量测量等多种评估方法，初步阐明了这些天然代谢物的抗真菌机制。代谢组学结果显示，与病害抑制土壤（G0组）相比，具有三种不同病害等级（G1、G5和G9组）的病害传导土壤中，15、14和233种差异根际代谢物（DRMs）的水平显著升高，而72、152和170种DRMs的水平则显著降低。根据KEGG通路分析，这些DRMs被发现富集于咖啡因代谢、苯丙素类生物合成、半乳糖代谢和酪氨酸代谢等途径。从这些DRMs中筛选出的林可霉素、欧前胡素和苯丙烯酸，通过相关性分析和抗真菌实验发现，它们对尖孢镰刀菌具有抑制作用。这三种DRMs在所有测试周期中，在0.5 mM或更高的浓度下均表现出对尖孢镰刀菌生长和孢子萌发的强烈抑制作用。此外，尖孢镰刀菌在0.25 mM的低浓度下对这些三种DRMs表现出趋性反应。最终，我们发现这三种DRMs通过破坏细胞膜完整性和增加尖孢镰刀菌的膜通透性，对尖孢镰刀菌具有抑制作用。本研究首次报道了苯丙烯酸和林可霉素对尖孢镰刀菌的抑制作用，为利用天然杀菌剂进行TFW的生物防治提供了一种实用且环保的方法。