Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, 210014, People's Republic of China.
Curr Microbiol. 2018 Apr;75(4):410-419. doi: 10.1007/s00284-017-1396-6. Epub 2017 Nov 17.
Fusarium oxysporum: f. sp. niveum (Fusarium oxysporum) causes watermelon wilt, drastically reducing its yield. Thymol (5-methyl-2-(1-methylethyl) phenol, PubChem CID: 6989) has been extensively reported to have antimicrobial activity against pathogenic microorganisms. In this study, the growth of F. oxysporum was significantly inhibited by thymol in vitro. The dry weight of F. oxysporum was decreased significantly. Thymol-induced cell membrane damage was observed at 24 hpi (hours post-incubation). Therefore, the changes in the gene expression level of F. oxysporum after treatment with 80 μg/mL (average EC value) of thymol were analyzed using RNA-Seq to reveal the underlying fungicidal mechanisms of thymol. Among the 5057 differentially expressed genes (DEGs), 2440 and 2617 were up-regulated and down-regulated, respectively. Bioinformatics analysis demonstrated that the expression levels of most genes, including glycosphingolipid biosynthesis and sphingolipid metabolism, were down-regulated. However, the genes involved in antioxidant activity, chitin biosynthesis, and cell wall modification were up-regulated. These results were verified by quantitative reverse transcription PCR (qRT-PCR). According to these results, thymol produces reactive oxygen species (ROS) accumulation and destroys the integrity of the cell wall and cell membrane by inhibiting the genes involved in cell wall and cell membrane synthesis.
白 （尖孢镰刀菌） 引起西瓜枯萎病，大大降低其产量。百里香酚（5-甲基-2-（1-甲基乙基）苯酚，PubChem CID：6989）已被广泛报道具有抗病原微生物的抗菌活性。在这项研究中，百里香酚在体外显著抑制尖孢镰刀菌的生长。尖孢镰刀菌的干重显著降低。在孵育 24 小时后观察到百里香诱导的细胞膜损伤。因此，用 80μg/ml（平均 EC 值）的百里香处理后，通过 RNA-Seq 分析了 F. oxysporum 基因表达水平的变化，以揭示百里香的杀菌机制。在 5057 个差异表达基因（DEGs）中，分别有 2440 个和 2617 个基因上调和下调。生物信息学分析表明，大多数基因的表达水平下调，包括糖脂生物合成和鞘脂代谢。然而，参与抗氧化活性、几丁质生物合成和细胞壁修饰的基因上调。这些结果通过定量逆转录 PCR（qRT-PCR）得到验证。根据这些结果，百里香通过抑制细胞壁和细胞膜合成相关基因，产生活性氧（ROS）积累，并破坏细胞壁和细胞膜的完整性。
