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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615575
• 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.

植物病原体生物防治的实际应用需要对这些现象背后的遗传、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25年中开展的研究活动的焦点。在本期中，我们在阐明控制白粉病真菌天然拮抗剂 Pseudozyma floculates 的生物防治特性的复杂因素方面取得了一些重大进展，特别重要的是，我们报告了以下内容： 1) 发现了参与絮菌素生物合成的基因和基因簇，并与系统发育相关的植物病原体模型真菌玉米黑粉菌 (Ustilago maydis) 建立了未被怀疑的密切联系；2) 区分絮​​菌素产生的糖脂结构的特定酶活性的关联U. maydis；3) P. floculates 的完整测序和基因组注释，这是第一个生物防治剂的此类报告；4)对絮状黑粉菌基因组与相关黑粉菌目、玉米黑粉菌、大孢子菌和大麦黑粉菌基因组进行比较分析，旨在确定赋予真菌特定生活方式的遗传因素，这一成就被认为是一项重大突破，因为它开辟了新的领域。有机会了解使系统发育相关的真菌采取相反生活方式的微妙因素。在本应用的背景下，并与我们最近的进展直接相关，目标是：1）进行第一个完整的研究。使用 P. floculosa-Blumeria graminis-大麦系统对 BCA-真菌病原体-植物三营养相互作用进行转录组分析；2) 特别强调在 P. floculate 基因组中发现的独特因子，以确定决定因素赋予絮状白粉菌对白粉病真菌的生物防治活性；3)通过对白粉病真菌的抑制进行演绎分析来鉴定其功能毒力因子；絮状疫霉攻击；4) 了解植物在维持 BCA 与植物病原体相互作用中的作用；5) 通过絮状疫霉的反向遗传学和/或玉蜀黍的互补对生物防治决定因素（基因）进行功能分析。这些目标的实现将产生关于以下方面的新颖且独特的信息：调节絮状疫霉生物防治活性的遗传决定因素以及调节白粉病真菌对白粉病的致病性的遗传决定因素。植物，以及这些决定因素的表达（或抑制）如何影响真菌的生态学，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个系统发育相关的内在遗传因素提供独特的数据。真菌充当生物防治剂或植物病原体。