本研究旨在探讨无花果叶提取物对镰刀菌的抑菌机理,为新型植物源杀菌剂的开发提供理论依据。
■通过抑制环法分析无花果叶提取物的真菌性。选择木贼镰刀菌作为从菌丝形态方面分析其真菌抑制机制的靶标,超微结构,细胞膜通透性,膜等离子体过氧化,活性氧(ROS)含量和保护酶活性的变化。这种提取物的效果在甜瓜中得到验证,使用超高效液相色谱-质谱(UPLC-MS)通过代谢物分析确定其成分。
■无花果叶提取物对镰刀菌有明显的抑制作用,差异显著(P<0.05)或极显著(P<0.01)。扫描电镜和透射电镜显示木贼菌丝表现出明显的折叠,扭曲和起皱现象,导致孢子的细胞质泄漏增加,间质血浆,和细胞核的浓度,严重损害了真菌细胞膜的完整性。碘化丙啶(PI)和荧光素二乙酸(FAD)染色证实了这种现象,细胞膜通透性和丙二醛(MDA)含量。无花果叶提取物还诱导菌丝体产生过量的H2O2,从而导致细胞膜的脂质过氧化,促进了MDA的积累,加速蛋白质水解,诱导抗氧化酶活性增加,并破坏了ROS代谢的平衡;这些发现表明真菌的生长受到抑制,这在甜瓜中得到了证实。通过广泛靶向代谢组学共检测到1,540种次级代谢产物,其中抑真菌活性物质类黄酮(15.45%),酚酸(15%),和生物碱(10.71%)占很高的百分比,这些物质的相对含量最高1,3,7,8-四羟基-2-异戊二烯基黄吨酮,分析了8-羟基喹啉和壬二酸的抗菌作用,抗炎,抗氧化剂,对植物病害的预防作用和植物获得抗性。这证实了无花果叶提取物的杀真菌特性的原因。
■无花果叶提取物具有被开发为植物来源的杀菌剂的潜力,作为甜瓜采后病原体预防和控制的新手段。
The objective of this
study was to explore the fungistatic mechanism of fig leaf extract against Fusarium and to provide a theoretical basis for the development of new plant-derived fungicides.
UNASSIGNED: The fungistaticity of fig leaf extract were analyzed by the ring of inhibition method. Fusarium equiseti was selected as the target for analyzing its fungistatic mechanism in terms of mycelial morphology, ultrastructure, cell membrane permeability, membrane plasma peroxidation, reactive oxygen species (ROS) content and changes in the activity of protective enzymes. The effect of this extract was verified in melon, and its components were determined by metabolite analysis using ultraperformance liquid chromatography‒mass spectrometry (UPLC‒MS).
UNASSIGNED: Fig leaf extract had an obvious inhibitory effect on Fusarium, and the difference was significant (P < 0.05) or highly significant (P < 0.01). Scanning and transmission electron microscopy revealed that F. equiseti hyphae exhibited obvious folding, twisting and puckering phenomena, resulting in an increase in the cytoplasmic leakage of spores, interstitial plasma, and the concentration of the nucleus, which seriously damaged the integrity of the fungal cell membrane. This phenomenon was confirmed by propidium iodide (PI) and fluorescein diacetate (FAD) staining, cell membrane permeability and malondialdehyde (MDA) content. Fig leaf extract also induced the mycelium to produce excessive H2O2,which led to lipid peroxidation of the cell membrane, promoted the accumulation of MDA, accelerated protein hydrolysis, induced an increase in antioxidant enzyme activity, and disrupted the balance of ROS metabolism; these findings showed that fungal growth was inhibited, which was verified in melons. A total of 1,540 secondary metabolites were detected by broad-targeted metabolomics, among which the fungistatic active substances flavonoids (15.45%), phenolic acids (15%), and alkaloids (10.71%) accounted for a high percentage and the highest relative content of these substances 1,3,7,8-tetrahydroxy-2- prenylxanthone, 8-hydroxyquinoline and Azelaic acid were analysed for their antimicrobial, anti-inflammatory, antioxidant, preventive effects against plant diseases and acquisition of resistance by plants. This confirms the reason for the fungicidal properties of fig leaf extracts.
UNASSIGNED: Fig leaf extract has the potential to be developed into a plant-derived fungicide as a new means of postharvest pathogen prevention and control in melon.