Functional genomics of Pseudozyma flocculosa, a biocontrol agent of powdery mildews

白粉病生物防治剂絮状假酵母的功能基因组学

• 批准号: RGPIN-2016-05235
• 负责人: Bélanger, Richard
• 金额: $ 3.72万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=645022
• 关键词: Functional; genomics; Pseudozyma; flocculosa; biocontrol

Practical application of biological control of plant pathogens 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 25 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 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; 2) the association of specific enzymatic activities distinguishing the glycolipid structures produced by P. flocculosa and U. maydis; 3) the complete sequencing and genomic annotation of P. flocculosa, the first such report for a biocontrol agent; and 4) the comparative analysis of P. flocculosa genome with that of related Ustilaginales, U. maydis, Sporisorium reilianum and U. hordei, aimed at identifying the genetic factors that confer specific lifestyles in fungi. This latter achievement is perceived as a major breakthrough since it opens new opportunities to understand the subtle factors that make phylogenetically related fungi adopt opposite lifestyles. In the context of this application and in direct link with our recent progress, the objectives are: 1) to carry out the first full transcriptomic analysis of a tritrophic interaction BCA-fungal pathogen-plant using the system P. flocculosa-Blumeria graminis-barley; 2) with a specific emphasis on the unique factors discovered in the genome of P. flocculosa, to identify the determinant(s) that confer P. flocculosa, its biocontrol activity on powdery mildew fungi; 3) to identify the functional virulence factors of powdery mildew fungi by deductive analysis of their repression under P. flocculosa attack; 4) to understand the plant's role in sustaining the BCA-plant pathogen interaction; and 5) to conduct functional analyses of biocontrol determinants (genes) through reverse genetics in P. flocculosa and/or complementation in 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 and those that regulate the pathogenicity of powdery mildew fungi against plants, and 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.**

植物病原菌生物防治的实际应用前提是彻底了解这些现象背后的遗传、分子和生态事件。在过去的25年里，这一挑战一直是申请人实验室开展的研究活动的焦点。在前一期中，我们在阐明控制白粉病真菌天然拮抗剂--絮状假丝酵母生防特性的复杂因素方面取得了一些重大进展。具有特别重要意义的是，我们报道了以下内容：1)涉及絮凝素生物合成的基因和基因簇的发现，并建立了与系统发育相关的植物病原体模式真菌玉米黑粉菌(Ustilago Maydis)的密切联系；2)特定酶活性的关联，以区分由簇状拟青霉和玉米拟青霉产生的糖脂结构；3)絮状拟青霉的完整测序和基因组注释，这是生防剂的首次报道；以及4)絮状拟青霉基因组与相关的玉米黑粉菌、玉米黑粉菌、雷氏孢子菌和玉米黑粉菌的基因组比较分析，旨在确定导致真菌特定生活方式的遗传因素。后一项成就被认为是一项重大突破，因为它为理解使系统发育相关的真菌采取相反生活方式的微妙因素提供了新的机会。在这一应用的背景下，并与我们最近的研究进展相联系，目标是：1)首次利用簇毛疫霉-白粉菌-大麦系统对BCA-真菌病原菌-植物三营养互作进行全转录分析；2)重点研究在簇毛疫霉基因组中发现的独特因子，以确定赋予簇毛疫霉的决定基因(S)及其对白粉病真菌的生防活性；3)通过演绎分析白粉菌在丛丛疫霉侵袭下的抑制作用，鉴定其功能毒力因子；4)了解植物在维持BCA-植物病原菌相互作用中的作用；5)通过反向遗传学对丛枝疫霉的生防决定基因(基因)进行功能分析和/或对小麦草的互补作用。这些目标的实现将产生关于以下方面的新的和独特的信息：调节丛枝疫霉生防活性的遗传决定因素和调节白粉病真菌对植物的致病性的遗传决定因素，以及这些决定因素的表达(或抑制)如何影响真菌生态。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系统发育相关的真菌作为生防剂或植物病原体的内在遗传因素提供独特的数据。