Diversity and evolution of P syringae type III effectors

丁香假单胞菌III型效应子的多样性和进化

• 批准号: 6730041
• 负责人: JEFFERY L. DANGL
• 金额: $ 28.87万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6730041
• 关键词: Arabidopsis; Pseudomonas; bacteria infection mechanism; bacterial genetics; bacterial proteins; biochemical evolution; bioinformatics; flow cytometry; functional /structural genomics; gene induction /repression; genetic models; genetic promoter element; genetic screening; green fluorescent proteins; high throughput technology; host organism interaction; molecular cloning; nucleic acid sequence; open reading frames; operon; pathologic process; phenotype; protein structure function; transcription factor; virulence

DESCRIPTION (provided by applicant): Identification of virulence factors is a necessary first step to study the mechanisms and evolution of pathogenicity. We propose to compare the type III disease effector proteins from a phylogenetically diverse set of plant pathogenic Pseudomonads chosen to represent the most broad distribution of the species possible. P. syringae is an ideal model organism to study the distribution and evolution of type III effectors. Type III effectors interact with cellular host targets, and modulate host defense responses or metabolism in a manner conducive to pathogen proliferation. Most of the P. syringae effectors have not yet been characterized, and we remain naive as to the collective diversity of host cellular functions they manipulate. Although the functions of P. syringae effector proteins during disease remain poorly understood, they can often be monitored via their phenotypes following in planta expression of a given type III effector. Bacterial pathogens of both animals, such as Salmonella spp., Yersinia spp., Shigella spp. and pathogenic E. coli also rely on type III secretion systems for pathogenesis. Thus, our results will inform studies of these bacteria and their animal hosts, including humans. Because P. syringae is pathogenic on a variety of distantly related plant hosts, many of which can be genetically manipulated, our system has advantages over models of type III pathogenesis of animals, which generally focus only on strains pathogenic on phylogenetically related mammalian hosts. We have devised and implemented a high throughput Fluorescence Activated Cell Sorter (FACS) based experimental approach to capture all of the type III effectors from the genome of any given P. syringae isolate. We chose 13 P syringae isolates that are pathogens of an evolutionarily diverse set of host plants. We intend to sieve through these 13 genomes to describe their suites of type III effectors. We further intend to begin dissection of their effects on host cell biology, using the easily manipulated Arabidopsis plant as a model where appropriate. This proposal is highly interdisciplinary, drawing on methodologies and expertise in microbiology, bioinformatics and plant-pathogen interactions in conjunction with high throughput bacterial cell sorting using the FACS. Our work will broadly impact the understanding of a widely distributed pathogenicity mechanism that affects both human health and agriculture. Additionally, our work may have relevance in biodefense with respect to basic understanding of pathogenesis in bacteria that can potentially be weaponized.

描述（由申请人提供）： 毒力因子的鉴定是研究致病机制和致病性进化的必要的第一步。我们建议比较III型疾病的效应蛋白，从一组不同的植物病原性假单胞菌选择代表最广泛的分布的物种可能。P. lingae是研究III型效应子分布和进化的理想模式生物。 III型效应子与细胞宿主靶标相互作用，并以有利于病原体增殖的方式调节宿主防御反应或代谢。大多数的P. pastingae效应器尚未被表征，我们仍然天真，以集体多样性的宿主细胞功能，他们操纵。 虽然在疾病过程中P. erichingae效应蛋白的功能仍然知之甚少，但它们通常可以通过给定III型效应物在植物中表达后的表型来监测。 两种动物的细菌病原体，如沙门氏菌属，耶尔森氏菌属，志贺菌和致病性E.大肠杆菌也依赖III型分泌系统致病。因此，我们的研究结果将为这些细菌及其动物宿主（包括人类）的研究提供信息。由于P. p. lingae对各种远缘植物宿主具有致病性，其中许多可以被遗传操纵，因此我们的系统具有优于动物III型发病机制的模型的优势，该模型通常仅关注对遗传相关的哺乳动物宿主致病的菌株。 我们已经设计并实施了一种基于高通量荧光激活细胞分选仪（FACS）的实验方法，以从任何给定的P. eriningae分离株的基因组中捕获所有III型效应物。我们选择了13个P. p. lingae分离株，它们是进化上多样化的宿主植物的病原体。我们打算筛选这13个基因组来描述它们的III型效应子。我们还打算开始解剖它们对宿主细胞生物学的影响，在适当的情况下使用容易操作的拟南芥植物作为模型。 该提案是高度跨学科的，借鉴了微生物学，生物信息学和植物-病原体相互作用的方法和专业知识，并结合使用FACS的高通量细菌细胞分选。 我们的工作将广泛影响对影响人类健康和农业的广泛分布的致病机制的理解。此外，我们的工作可能与生物防御有关，因为我们对可能被武器化的细菌的发病机理有基本的了解。