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的先决条件是彻底了解这种现象背后的遗传，分子和生态事件。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。特别是发现了与絮状物合成有关的基因和一个基因簇，并与玉米黑粉菌（Ustilago maydis）建立了一种未曾预料到的紧密联系;玉米;（3）首次报道了生防植物絮花单胞菌的全序列测定和基因组注释，（4）将絮花单胞菌基因组与相关的黑粉菌目（Ustilaginales）、乌氏黑粉菌（U. p. flocculosa）基因组进行了比较分析。玉米孢霉（Sporisorium reilianum）和玉米孢霉（U. hordei，旨在确定赋予真菌特定生活方式的遗传因素。后者的成就被认为是一个重大突破，因为它为理解使遗传相关真菌采取相反生活方式的微妙因素提供了新的机会。在本申请的背景下，并与我们最近的进展直接相关，目标是：1）利用絮状疫霉-禾本科白粉病菌-大麦系统进行BCA-真菌病原体-植物三营养相互作用的第一次全转录组学分析; 2）特别强调在絮状披碱草基因组中发现的独特因子，以鉴定赋予絮状披碱草的决定因子，3）通过推导分析其在絮状披碱草（P. flocculosa）攻击下的抑制作用，鉴定白粉病真菌的功能毒力因子; 4）了解植物在维持BCA-植物病原菌相互作用中的作用; 5）通过反求遗传和互补技术对生防决定因子（基因）进行功能分析。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的生物防治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。