Dimorphic growth and resting structure development in plant pathogenic verticillium species

植物致病黄萎病菌的二态性生长和休眠结构发育

• 批准号: 216879-2006
• 负责人: Dobinson, Katherine
• 金额: $ 1.27万
• 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: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366402
• 关键词: Dimorphic; growth; resting; structure; development

Verticillium dahliae, V. albo-atrum, and V. longisporum are soilborne fungi that cause vascular wilt disease in a variety of annual crops and perennials that are grown commercially in Canada and worldwide, including tomato, potato, oilseed rape, and other brassica crops.  The soil habitat of these pathogens, their inaccessibility during infection, and their ability to survive for many years in the soil, pose formidable challenges to disease control.  Few verticillium wilt-resistant cultivars are available, and chemical fumigants, which reduce levels of V. dahliae in the soil, are environmentally harmful, and destroy beneficial soil microorganisms.  Given the present and potential economic impact of the pathogen, new approaches to disease control must be considered.    One approach with much potential for disease control is to specifically target, and interfere with, the molecular processes which are critical for the growth of Verticillum in the plant, and/or its survival in the soil.  The proposed research program will focus on molecular and genetic studies of: 1) the development of the long-lived resting structures, microsclerotia or melanized mycelia, which are produced in dying plant tissues, and provide the primary source of disease inoculum, and 2) dimorphic growth (production of both yeast-like spores and mycelia), which occurs in liquid culture, and in the plant vascular system during infection.  Previous studies have shown that V. dahliae carries a gene that encodes a hydrophobin protein which is required for microsclerotia production.  The same gene has been identified in V. albo-atrum, which does not produce microsclerotia; the role of this gene in V. albo-atrum is therefore unknown.  A comparison of expression in V. albo-atrum and V. dahliae of these genes, and their respective proteins, will be carried out using reporter genes, mutational, and biochemical analysis.  In addition, DNA microarray analyses will be used to identify additional genes that are highly expressed during resting structure development and/or dimorphic growth.  Such genes will be candidates for further characterization.

大丽轮枝菌、白花轮枝菌和长孢轮枝菌是土传真菌，可在加拿大和世界各地商业种植的各种一年生作物和多年生植物中引起维管束枯萎病，包括番茄、马铃薯、油菜和其他芸苔属作物这些病原体的土壤栖息地、它们在感染期间难以接近以及它们在土壤中存活多年的能力，给疾病控制带来了巨大的挑战。抗黄萎病的品种已经存在，而化学熏蒸剂会降低土壤中大丽黄萎病的水平，对环境有害，并会破坏有益的土壤微生物。鉴于该病原体目前和潜在的经济影响，必须采取新的疾病控制方法。一种具有很大潜力的疾病控制方法是专门针对和干扰对植物中黄萎病生长至关重要的分子过程，和/或其拟议的研究计划将重点关注以下方面的分子和遗传学研究：1）长寿命休眠结构、微菌核或黑化菌丝体的发育，它们在垂死的植物组织中产生，并提供了疾病接种物，以及2）二态性生长（酵母样孢子和菌丝体的产生），发生在液体培养物中，以及感染期间的植物维管系统中。 V. dahliae 携带编码微菌核产生所需的疏水蛋白的基因 ​ 在 V. albo-atrum 中也发现了相同的基因，但该基因在 V. albo-atrum 中的作用是。因此未知，将使用报告基因、突变和生化对这些基因及其各自的蛋白质在白色葡萄球菌和大丽花葡萄球菌中的表达进行比较。此外，DNA 微阵列分析将用于鉴定在静止结构发育和/或二态性生长过程中高度表达的其他基因，这些基因将成为进一步表征的候选基因。