• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >An antifungal secondary metabolite from Lysobacter enzymogenes strain C3: Isolation, biological activity, mode of action and potential use in plant disease control.
【24h】

An antifungal secondary metabolite from Lysobacter enzymogenes strain C3: Isolation, biological activity, mode of action and potential use in plant disease control.

机译：溶菌酶基因C3菌株的抗真菌次生代谢产物：分离，生物活性，作用方式和在植物病害控制中的潜在用途。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Lysobacter enzymogenes strain C3 is a biological control agent against fungal pathogens. Its activity was attributed previously to multiple antifungal lytic enzymes. In this study, a heat stable antibiotic (HSAF) was also found to be responsible for antifungal activity in vitro. HSAF was extracted from C3 culture fluid by ammonium sulfate precipitation and solubilization in methanol and was further isolated by TLC and HPLC. The purified antibiotic was active against a wide range of fungal and oomycete species but not against Saccharomyces cerevisiae or bacteria. It inhibited spore germination and disrupted hyphal polarity in vitro. These effects also were observed when HSAF was applied to tall fescue leaves. In addition, it inhibited appressorium formation and suppressed leaf spot development by Bipolaris sorokiniana. Aspergillus nidulans was used as a model to investigate its mode of action. barA and basA mutants were identified that were resistant and hypersensitive to HSAF respectively. Supplementation experiments suggest HSAF targets BarA-dependent ceramide synthesis, whereas a second ceramide synthase, LagA, is not a likely target for HSAF. HSAF also induced abnormal cell wall thickening at hyphal tips and septa in A. nidulans. beta-1,3-glucan was accumulated in thickened area while there was an apparent reduction in chitin levels. A similar pattern of cell wall deposition was observed in mutants in which synthesis of ceramide or phytosphingosine are impaired. In addition, exogenous supplementation of dihydrosphingosine and phytosphingosine mimicked HSAF effects. Supplementation with phytoceramide reversed some of the effects of HSAF, restoring hyphal polarity but having no effects on HSAF-induced cell wall thickening. These results suggest that HSAF-induced depletion of ceramide is involved in disruption of hyphal polarity, while accumulation of sphingoid bases rather than depletion of ceramide is the cause of HSAF-induced cell wall thickening.
机译：溶菌酶基因菌株C3是针对真菌病原体的生物防治剂。其活性先前归因于多种抗真菌裂解酶。在这项研究中，还发现了一种热稳定的抗生素（HSAF）在体外具有抗真菌活性。通过硫酸铵沉淀和在甲醇中的溶解从C3培养液中提取HSAF，并通过TLC和HPLC进一步分离。纯化的抗生素对多种真菌和卵菌具有活性，但对酿酒酵母或细菌没有活性。它在体外抑制孢子萌发并破坏菌丝极性。当将HSAF应用于高羊茅叶片时，也观察到了这些效果。此外，它还抑制了Bipolaris sorokiniana的前肢形成和叶斑发育。构巢曲霉被用作研究其作用方式的模型。鉴定出分别对HSAF具有抗性和高度敏感性的barA和basA突变体。补充实验表明，HSAF靶向BarA依赖的神经酰胺合成，而第二种神经酰胺合酶LagA不太可能成为HSAF的靶标。 HSAF还诱导构巢曲霉菌丝尖端和隔膜的异常细胞壁增厚。 β-1,3-葡聚糖聚集在增厚区域，而几丁质水平却明显降低。在突变体中观察到了类似的细胞壁沉积模式，在突变体中神经酰胺或植物鞘氨醇的合成受到损害。此外，外加二氢鞘氨醇和植物鞘氨醇可模仿HSAF的作用。补充植物神经酰胺可逆转HSAF的某些作用，恢复菌丝极性，但对HSAF诱导的细胞壁增厚没有影响。这些结果表明，HSAF诱导的神经酰胺耗竭与菌丝极性的破坏有关，而鞘氨醇碱的积累而不是神经酰胺的耗竭是HSAF诱导的细胞壁增厚的原因。

著录项

  • 作者

    Li, Shaojie.;

  • 作者单位

    The University of Nebraska - Lincoln.;

  • 授予单位 The University of Nebraska - Lincoln.;
  • 学科 Biology Microbiology.
  • 学位 Ph.D.
  • 年度 2005
  • 页码 196 p.
  • 总页数 196
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 微生物学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号