Functional genomics of the biocontrol agent-plant pathogen interaction pseudozyma flucculosa-powdery mildews

生物防治剂-植物病原体相互作用的功能基因组学假酶-白粉病

• 批准号: 42188-2011
• 负责人: Bélanger, Richard
• 金额: $ 3.42万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568890
• 关键词: Functional; genomics; biocontrol; agent; plant

Practical application of biological control of plant pathogens, either through the use of natural enemies or through the induction of the plant's natural defense mechanisms, presupposes a thorough understanding of the genetic, molecular and ecological events underlying such phenomena. This challenge has been the focal point of the research activities carried out in the applicant's laboratory over the last 20 years. In the previous installment, we have made some major strides toward elucidating the complex factors governing the biocontrol properties of Pseudozyma flocculosa, a natural antagonist of powdery mildew fungi. Of particular significance, we reported the following: 1) the development of GFP-transformants to study the tritrophic interaction P. flocculosa-plant-powdery mildew ; 2) the antifungal and antibacterial activity of flocculosin, an important secondary metabolite secreted by the BCA, against pathogen strains of medical importance; 3) the development of a novel technique to transform Pseudozyma spp.; 4) the discovery and description of catabolitic activities by the BCA against flocculosin and 5) identification of nutritional and ecological factors linked with the specific biocontrol activity of P. flocculosa through proteomic and genomic analyses; and 6) discovery of genes and a gene cluster involved in flocculosin biosynthesis and establishment of an unsuspected close link with the phylogenetically related plant pathogen model fungus Ustilago maydis. This latter achievement is perceived as a major breakthrough since it opens the way to 1) a privileged look into the genome of P. flocculosa based on the sequenced genome of U. maydis and 2) to comparative functional genomic analyses that will define the subtle genetic and evolutive events that make a fungus a beneficial BCA or a plant pathogen. In the context of this application and on the basis of our recent progress, the objectives are: 1) to complete the genome assembly of Pseudozyma flocculosa; 2) to carry out genomic annotation of P. flocculosa with particular emphasis on the gene cluster regulating flocculosin synthesis and the similar cluster regulating ustilagic synthesis in U. maydis; and 3) to conduct comparative functional genomic analyses with the aim to identify the specific components that confer different lifestyles to P. flocculosa and U. maydis. Fulfillment of these objectives will generate novel and distinctive information with regards to: the genetic determinants that regulate the biocontrol activity of P. flocculosa against powdery mildew fungi; how expression (or repression) of these determinants influence the ecology of fungi. These results will have far reaching impact into the field of plant pathology as our model will provide unique data into the intrinsic genetic factors that separate and modulate two phylogenetically related fungi to behave as biocontrol agent or plant pathogen.

无论是通过利用天敌还是通过诱导植物的自然防御机制，植物病原体生物控制的实际应用都需要对这种现象背后的遗传、分子和生态事件有透彻的了解。这一挑战一直是申请人实验室在过去20年中开展的研究活动的焦点。在前一部分中，我们已经取得了一些重大的进展，阐明了复杂的因素控制的生物控制性能的Pseudozyma flocculosa，一种天然拮抗剂的白粉病真菌。本论文主要研究了以下几个方面的内容：1）利用GFP转化子研究絮状酵母-植物-白粉病的三营养相互作用; 2）由BCA分泌的重要次级代谢产物絮凝菌素对重要医学病原菌的抗真菌和抗细菌活性; 3）建立了一种新的转化Pseudozyma spp.的技术; 4)发现并描述了BCA对絮状物蛋白的分解活性; 5）通过蛋白质组学和基因组学分析鉴定了与絮状物蛋白的特异性生物防治活性相关的营养和生态因子; 6）发现了参与絮状物蛋白生物合成的基因和基因簇，并建立了与植物遗传学相关的植物病原体模式真菌玉米黑粉菌（Ustilago maydis）的意料之外的密切联系。后者的成就被认为是一个重大的突破，因为它开辟了一条道路，1）特权的基因组研究的基础上，美国的基因组测序的絮状花。2）比较功能基因组分析，其将定义使真菌成为有益的BCA或植物病原体的微妙遗传和进化事件。在本申请的背景下，基于我们最近的进展，目标是：1）完成Pseudozyma flocculosa的基因组组装; 2）进行Pseudozyma flocculosa的基因组注释，特别是在U.玉米;进行比较功能基因组学分析，旨在确定赋予絮状滨藜和乌桕不同生活方式的特定组分。玉米粉这些目标的实现将产生新的和独特的信息方面：调节P. flocculosa对白粉病真菌的生物防治活性的遗传决定因素;这些决定因素的表达（或抑制）如何影响真菌的生态。这些结果将对植物病理学领域产生深远的影响，因为我们的模型将为分离和调节两种遗传相关真菌作为生物防治剂或植物病原体的内在遗传因素提供独特的数据。