Role of new bacterial surfactins in the antifungal interaction between Bacillus amyloliquefaciens and Fusarium oxysporum
Role of new bacterial surfactins in the antifungal interaction between Bacillus amyloliquefaciens and Fusarium oxysporum
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DOI：
10.1111/j.1365-3059.2011.02561.x
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发表时间：
2012-08
期刊：
影响因子：
2.7
通讯作者：
D. Vitullo;A. Pietro;A. Romano;V. Lanzotti;G. Lima
中科院分区：
文献类型：
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作者：
D. Vitullo;A. Pietro;A. Romano;V. Lanzotti;G. Lima
本研究旨在探讨从果园土壤中分离到的解淀粉芽孢杆菌新菌株BO7对番茄枯萎病菌的拮抗作用机制。番茄属(Lycopsici)BO7能显著降低番茄黄萎病的发病率，对番茄黄萎病具有较强的体外抑制活性。扫描电子显微镜显示，BO7细胞能够附着在真菌菌丝上，并有效地定植在番茄根部。低分子量组分的BO7培养滤液对Fol表现出较高的抗真菌活性，导致生长抑制和菌丝形态的显著变化。三种结构相关的表面素脂多肽被鉴定为生物活性部分的主要成分，并测定了它们对Fol的抑制活性。其中一种化合物对表面蛋白家族的脂肽具有很强且罕见的抗真菌活性，占BO7培养滤液的大部分抑制活性。在一组测试的Fol基因敲除分离株中，细胞壁结构改变的突变株对细菌化合物的敏感性增加。这些结果表明，真菌细胞壁可能在FOL对来自解淀粉芽孢杆菌的细菌表面蛋白的敏感性中起关键作用。
The aim of this work was to investigate the major mechanisms involved in antagonism of BO7, a novel strain of Bacillus amyloliquefaciens isolated from orchard soil, against the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici (Fol). BO7 markedly reduced the incidence of Fol vascular wilt on tomato plants and displayed strong in vitro inhibitory activity against Fol. Scanning electron microscopy demonstrated the ability of BO7 cells to adhere to fungal hyphae and to efficiently colonize tomato roots. The low molecular weight fraction of BO7 culture filtrate displayed high antifungal activity against Fol, resulting in growth inhibition and dramatic alterations of hyphal morphology. Three structurally related surfactin lipopeptides, identified as the major components of the bioactive fraction, were assayed for their inhibitory activity against Fol. One of these compounds exerted a strong and uncommon antifungal activity for lipopeptides of the surfactin family, accounting for most of the inhibitory activity of the BO7 culture filtrate. Among a collection of Fol knockout isolates tested, mutants altered in cell wall structure showed increased sensitivity to the bacterial compounds. These results suggest that the fungal cell wall might have a key role in the sensitivity of Fol towards bacterial surfactins from B. amyloliquefaciens.