Diversity and evolution of Pseudomonas syringae type III effectors (RO1GM066025)

描述(申请人提供)：病原菌使用各种毒力机制感染宿主，包括人类。基于多个致病菌株基因组测序的比较研究表明，细菌物种拥有一个比任何单一细菌的基因组大得多的泛基因组。本研究主要研究丁香假单胞菌与植物的相互作用。紫丁香疫霉利用进化上保守的III型分泌系统将被称为III型效应蛋白的毒力因子输送到宿主植物细胞中。这类致病细菌提供了一套很好的基因组和遗传学工具来分析寄主和病原菌的共同进化，从基因组组织和水平基因流动到病原菌毒力蛋白与其寄主靶标之间的相互作用。利用III型分泌系统的动物病原体包括沙门氏菌、耶尔森氏菌、志贺氏菌。和致病性大肠杆菌。因此，这项研究的结果将为这些细菌及其动物宿主(包括人类)的进化和机制研究提供信息。第一个资助期专门用于快速鉴定丁香疫霉III型效应基因及其产物的方法。完成了主要目标，并促进了更多侧重于特定III型效应(毒力)因子家族的生物学研究。在这次竞争性更新中，建议继续使用功能基因组学和高通量下一代基因组测序来剖析紫丁香疫霉毒力的机制和进化。此外，这一建议提供了可信的证据，表明可以使用比较基因组学和分子进化方法来识别新的候选毒力基因。 我们的最终目标是鉴定丁香疫霉的泛基因组，并在整个泛基因组中表征III型效应器和新的毒力因子。这一目标将提供方法和数据，为每年继续导致世界各地数百万人死亡和患病的人类细菌病原体的类似研究提供信息。 项目简介：病原菌使用各种毒力机制感染宿主，包括人类。细菌病原体导致各种人类疾病，每年导致世界各地数百万人死亡。植物的细菌性疾病也很重要，它们每年导致全球价值数十亿美元的农作物损失。因此，农作物减产进一步直接增加了对人类健康的威胁，特别是在发展中国家，人类和植物的细菌病原体带来的疾病压力汇聚在一起。农作物的损失也与人类健康有关，因为这些损失的农作物在被感染之前使用了宝贵的水，使其无法用作食物或饲料。因此，农作物损失会影响人类的用水效率，从而影响人类健康。植物病原体和动物病原体包括沙门氏菌、耶尔森氏菌、志贺氏菌。致病性大肠杆菌都使用类似的机制感染宿主。因此，这项研究的结果将为这些细菌及其动物宿主(包括人类)的进化和机制研究提供信息。

DESCRIPTION (provided by applicant): Pathogenic bacteria use various virulence mechanisms to infect hosts, including humans. Comparative studies based on genome sequencing of multiple pathogenic strains have suggested that bacterial species possess a pan-genome that is much larger than the genome of any single bacterium. This research focuses on the interaction between Pseudomonas syringae and plants. P. syringae delivers virulence factors called type III effector proteins into host plant cells using an evolutionarily conserved type III secretion system. This genus of pathogenic bacteria provides an excellent set of genomic and genetic tools to analyze co-evolution of host and pathogen, from the level of genome organization and horizontal gene flow down to the level of the interaction between pathogen virulence proteins and their host targets. Animal pathogens that utilize the type III secretion system include Salmonella spp., Yersinia spp., Shigella spp. and pathogenic E. coli. Thus, the results from this research will inform evolutionary and mechanistic studies of these bacteria and their animal hosts, including humans. The first grant period was devoted to methods for rapidly identifying P. syringae type III effector genes and their products. The main goals were completed and additional biological studies focused on particular type III effector (virulence) factor families was facilitated. In this competitive renewal, it is proposed to continue to use functional genomics and high throughput next generation genome sequencing to dissect both the mechanisms and evolution of virulence in P. syringae. In addition, this proposal presents plausible evidence that comparative genomics and molecular evolutionary methods can be used to identify novel candidate virulence genes. Our ultimate goal is to identify the pan genome of P. syringae and characterize both type III effectors and novel virulence factors across this pan-genome. This goal will provide both methods and data that will inform similar studies of human bacterial pathogens that continue to kill and sicken millions each year around the world. Project Narrative: Pathogenic bacteria use various virulence mechanisms to infect hosts, including humans. Bacterial pathogens cause a variety of human diseases and kill millions of people each year around the world. Bacterial disease of plants is also important, and they lead to loss of crops with values of several billion dollars worldwide each year. Crop loss further therefore directly adds to threats to human health, particularly in developing countries where the disease pressure from both bacterial pathogens of humans and of plants converge. Loss of crops is also tied to human health because those lost crops used precious water before they were infected and rendered useless as food or fodder. Thus, crop loss impacts human health by impacting water use efficiency in human populations. Plant pathogens like the one that is the focus of this proposal and animal pathogens including Salmonella spp., Yersinia spp., Shigella spp. and pathogenic E. coli all use a similar mechanism to infect their hosts. Thus, the results from this research will inform evolutionary and mechanistic studies of these bacteria and their animal hosts, including humans.