Characterization of the molecular pathways that direct development and pathogenicity in the vascular wilt fungus Verticillium dahliae

维管束枯萎病真菌大丽黄萎病指导发育和致病性的分子途径的表征

• 批准号: 216879-2012
• 负责人: Dobinson, Katherine
• 金额: $ 1.82万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=506337
• 关键词: Characterization; molecular; pathways; direct; development

Verticillium dahliae is a filamentous fungus that causes vascular wilt of a broad range of economically important annual and perennial crops. During infection the fungus is confined to the plant's water-conducting (vascular) system, growing dimorphically (in two forms), as hyphal and yeast-like cells. In the late stages of disease V. dahliae escapes from the vascular system into the surrounding tissues where it produces its survival structures. These hardy, pigmented clusters of cells are dispersed into the soil with plant debris, can survive for at least a decade in the soil, and are the primary source of disease inoculum. The molecular pathways involved in development of these structures, and in planta dimorphic growth offer attractive potential targets for disease control. In previous studies in my lab we showed that both a hydrophobic protein (hydrophobin VDH1) and the process of autophagy (the cells' intracellular recycling system) are essential for survival structure development. The other important discovery was that VDH1 is recognized by the plant during the early phase of infection to induce plant defence responses, but that the plant is unable to sustain those defences. Molecular strategies will be used to address two major objectives in of the proposed research. The first will be to better define the survival structure developmental pathway, and to identify steps in the pathway that could potentially be blocked to prevent survival structure formation and/or pathogen colonization of the plant. The second objective will be to determine the roles of as-yet uncharacterized V. dahliae hydrophobins during survival structure development and in plant recognition to induce plant defences. Studies will be initiated to determine what molecular mechanism(s) the pathogen uses to thwart the plant defence responses that are triggered by recognition of the pathogen. The results of the proposed research would provide knowledge for future development of new, and badly needed disease control strategies to manage verticillium wilt. The resulting data are also anticipated to be relevant to studies of other pathogenic fungi for which the plant vascular system is the preferred environmental niche.

大丽黄萎病是一种丝状真菌，可引起多种具有重要经济意义的一年生和多年生作物的维管枯萎病。 在感染过程中，真菌被限制在植物的导水（维管）系统中，以菌丝和酵母样细胞的形式双态生长（以两种形式）。 在疾病的后期阶段，大丽花弧菌从血管系统逃逸到周围组织，并在那里产生其生存结构。 这些耐寒、有色素的细胞簇与植物碎片一起分散到土壤中，可以在土壤中存活至少十年，并且是疾病接种物的主要来源。 参与这些结构发育和植物二态性生长的分子途径为疾病控制提供了有吸引力的潜在靶点。 在我实验室之前的研究中，我们表明疏水蛋白（疏水蛋白 VDH1）和自噬过程（细胞的细胞内回收系统）对于生存结构的发育至关重要。 另一个重要的发现是，VDH1 在感染的早期阶段被植物识别以诱导植物防御反应，但植物无法维持这些防御。 分子策略将用于解决拟议研究的两个主要目标。 第一个是更好地定义生存结构发育途径，并确定途径中可能被阻断的步骤，以防止植物的生存结构形成和/或病原体定植。 第二个目标是确定尚未表征的大丽花疏水蛋白在生存结构发育和植物识别以诱导植物防御过程中的作用。 将启动研究以确定病原体使用什么分子机制来阻止由病原体识别引发的植物防御反应。 拟议研究的结果将为未来开发新的、急需的疾病控制策略来管理黄萎病提供知识。 预计所得数据也与其他病原真菌的研究相关，植物维管系统是这些病原真菌的首选环境生态位。