PDF(Pubmed)
Abstract：
Rhizoctonia solani Kühn, a plant pathogenic fungus that can cause diseases in multiple plant species is considered one of the common and destructive pathogens in many crops. This study investigated the action of antimycin A1, which was isolated from Streptomyces AHF-20 found in the rhizosphere soil of an ancient banyan tree, on Rhizoctonia solani and its mechanism. The inhibitory effect of antimycin A1 on R. solani was assessed using the comparative growth rate method. The results revealed that antimycin A1 exhibited a 92.55% inhibition rate against R. solani at a concentration of 26.66 μg/mL, with an EC50 value of 1.25 μg/mL. To observe the impact of antimycin A1 on mycelial morphology and ultrastructure, the fungal mycelium was treated with 6.66 μg/mL antimycin A1, and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed. SEM analysis demonstrated that antimycin A1 caused mycelial morphology to become stripped, rough, and folded. The mycelium experienced severe distortion and breakage, with incomplete or locally enlarged ends, shortened branches, and reduced numbers. TEM observation revealed thickened cell walls, indistinct organelle boundaries, swollen mitochondria, exosmotic substances in vesicles, slow vesicle fusion, and cavitation. Real-time quantitative PCR and enzyme activity assays were conducted to further investigate the impact of antimycin A1 on mitochondria. The physiological and biochemical results indicated that antimycin A1 inhibited complexes III and IV of the mitochondrial electron transport chain. RT-PCR analysis demonstrated that antimycin A1 controlled the synthesis of relevant enzymes by suppressing the transcription levels of ATP6, ATP8, COX3, QCR6, CytB, ND1, and ND3 genes in mitochondria. Additionally, a metabolomic analysis revealed that antimycin A1 significantly impacted 12 metabolic pathways. These pathways likely experienced alterations in their metabolite profiles due to the inhibitory effects of antimycin A1. Consequently, the findings of this research contribute to the potential development of novel fungicides.
摘要：
根瘤菌Kühn，一种可引起多种植物疾病的植物病原真菌被认为是许多作物中常见的破坏性病原体之一。这项研究调查了抗霉素A1的作用，该抗霉素A1是从古榕树根际土壤中发现的链霉菌AHF-20中分离出来的，枯丝核菌及其作用机制的研究.使用比较生长速率法评估了抗霉素A1对枯草杆菌的抑制作用。结果表明，在26.66μg/mL的浓度下，抗霉素A1对枯草杆菌的抑制率为92.55％，EC50值为1.25μg/mL。观察抗霉素A1对菌丝形态和超微结构的影响,用6.66μg/mL抗霉素A1处理真菌菌丝体，并采用扫描电子显微镜（SEM）和透射电子显微镜（TEM）。SEM分析表明，抗霉素A1导致菌丝形态剥离，粗糙，和折叠。菌丝体经历了严重的扭曲和断裂，末端不完整或局部扩大，缩短的树枝，数量减少。TEM观察显示细胞壁增厚，细胞器边界模糊，线粒体肿胀,囊泡中的外渗物质，缓慢的囊泡融合，和空化。进行实时定量PCR和酶活性测定以进一步研究抗霉素A1对线粒体的影响。生理和生化结果表明，抗霉素A1抑制线粒体电子传递链的复合物III和IV。RT-PCR分析表明，抗霉素A1通过抑制ATP6，ATP8，COX3，QCR6，CytB的转录水平来控制相关酶的合成，线粒体中的ND1和ND3基因。此外,代谢组学分析显示,抗霉素A1显著影响12条代谢途径.由于抗霉素A1的抑制作用，这些途径可能经历了其代谢物谱的改变。因此,这项研究的发现有助于新型杀菌剂的潜在开发。
