Biocontrol properties of pseudozyma flocculosa a natural antagonist of powdery mildew fungi

白粉病真菌天然拮抗剂絮状假酶的生物防治特性

• 批准号: 42188-2006
• 负责人: Bélanger, Richard
• 金额: $ 3.19万
• 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: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=330970
• 关键词: Biocontrol; properties; pseudozyma; flocculosa; natural

Practical application of biological control of plant pathogens presupposes a thorough understanding of the chemical, biochemical and molecular 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 16 years. In the previous installment, we have made some important strides toward elucidating key factors governing the biocontrol properties of Pseudozyma flocculosa, a natural antagonist of powdery mildew fungi. Of particular significance, we reported: 1) the structure of an unusual glycolipid accounting for the biocontrol activity of P. flocculosa; 2) the optimization of a genetic transformation system by insertional mutagenesis; 3) the development of a novel technique, reversed intron PCR, that allowed the differentiation of P. flocculosa from other related species and among geographically distinct isolates of P. flocculosa; 4) the antifungal activity of flocculosin against yeast strains of medical importance; and 5) successful expression of foreign genes in P. flocculosa including GFP. In the context of this application and on the basis of our recent progress, the objectives are: 1) to generate and characterize mutants defective for flocculosin production 2) to study and compare potential gene(s) involved in glycolipid production in P. flocculosa and U. maydis; 3) to generate GFP-mutants in both wild type (Wt) and tox- strains of P. flocculosa; 4) to conduct spatio-temporal studies to compare the ecological behavior of P. flocculosa Wt and tox- strains transformed with GFP and 5) to determine the relevance of flocculosin (and related glycolipids) as a fitness determinant in the ecology of P. flocculosa isolates. Fulfillment of these objectives will generate novel and original information with regards to: the genetic determinants that regulate the biocontrol activity of P. flocculosa against powdery mildews and other phyllosphere inhabitants; these results will have far reaching impact into the study of powdery mildew diseases in general and into the study of the genetic, chemical and ecological properties of microbial biocontrol agents, concerns of key importance for their eventual use and manipulation.

植物病原体生物防治的实际应用前提是对这些现象背后的化学、生化和分子事件有透彻的了解。这一挑战一直是申请人实验室在过去16年中开展的研究活动的焦点。在上一篇文章中，我们在阐明控制白粉病真菌天然拮抗剂假酶（Pseudozyma cullosa）生物防治特性的关键因素方面取得了一些重要进展。特别有意义的是，我们报道了：1)一种特殊的糖脂结构，说明了絮凝草的生物防治活性；2)利用插入诱变优化遗传转化系统；3)利用反向内含子PCR技术实现了絮状假蝇与其他亲缘种以及地理上不同的絮状假蝇分离株之间的分化；4)絮凝素对药用酵母菌的抑菌活性；5)包括GFP在内的外源基因在絮藻中的成功表达。在这一应用的背景下，并根据我们最近的进展，目标是：1)产生和表征絮凝蛋白生产缺陷突变体；2)研究和比较絮凝蛋白和酵母中参与糖脂生产的潜在基因；3)在野生型（Wt）和毒株中产生gfp突变体；4)进行时空研究，比较用GFP转化的絮凝菌Wt和tox菌株的生态行为；5)确定絮凝素（及其相关糖脂）在絮凝菌分离株生态学中的适应度决定因素的相关性。实现这些目标将产生关于以下方面的新颖和原始的信息：调节絮凝假单胞菌对白粉病和其他层状圈居民的生物防治活性的遗传决定因素；这些结果将对一般白粉病的研究和微生物生物防治剂的遗传、化学和生态特性的研究产生深远的影响，对其最终使用和操作具有关键重要性。