The Interactions of Pseudomonas Syringae Harpins, HRP Secretion Proteins, and AVR Proteins in Eliciting Either theHypersensitive Response or Pathogenesis in Higher Plants

丁香假单胞菌 Harpins、HRP 分泌蛋白和 AVR 蛋白在高等植物中引起过敏反应或发病机制中的相互作用

• 批准号: 9305178
• 负责人: Alan Collmer
• 金额: --
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9305178&HistoricalAwards=false
• 关键词: Interactions; Pseudomonas; Syringae; Harpins; HRP

9305178 Collmer The hypersensitive response (HR) of higher plants is characterized by the rapid, localized death of plant cells at the site of invasion by an "incompatible" pathogen (a microorganism that causes disease only in another plant) and is associated with resistance against many nematodes, fungi viruses and bacteria. Elicitation of the HR by Pseudomonas syringae and other plant pathogenic bacteria is controlled by hrp genes, which are also required for the multiplication and pathogenicity of these bacteria in their respective host plants. The overall goal of the research is to use two recent advances to dissect the functions of the hrp genes and to determine the general basis for the phenotypic dependence of avr genes on hrp genes. We expect that (i) harpins are needed for P. syringae strains to initiate a metabolically active interaction with the plant, (ii) HrpH and several other Hrp proteins are needed for the secretion of harpin, (iii) harpin production must be carefully regulated for successful pathogenesis, and (iv) Avr proteins depend on the Hrp secretion system and/or harpin to produce their phenotypes. The work will involve potentially three strains of P. syringae: (i) P.s. syringae 61, whose cloned cluster of hrp genes has been extensively characterized and is unique in that, it functions in nonpathogens like E. coli. (ii) P.s. glycinea race 4, which becomes incompatible with Rpg1 soybean cultivars upon acquisition of the cloned avrB gene, and (iii) P.s. tomato DC3000, whose compatibility with Arabidopsis thaliana is reversed by acquisition of avrB. Early work on the project will determine whether P.s. glycinea race 4 or P.s. tomato DC3000 will be the focus of work on Avr protein function. We intend to (1) Characterize the P.s. syringae 61 hrpZ gene and the encoded harpin with respect to primary sequence, elicitor-active domains, and subcellular location. (2) Determine the relative effects of hrpH and hrpZ mutations on the initial interac tion of P.s. syringae 61 with bean and tobacco (or of P.s. tomato DC3000 with A. thaliana or of P.s. glycinea race 4 with soybean). (3) Clone and characterize the P.s. glycinea race 4 (or P.s. tomato DC3000) hrpZ gene, construct derivatives that are deficient in harpin overproduce harpin produce harpin instead of harpin or contain a hrpZ promoter- uida fusion in trans; determine the phenotype of these derivatives (with or without an avrB+ plasmid) on tobacco and differential host cultivars. %%% Because homologs of Hrp secretion proteins are present in some animal pathogens, successful testing of these hypothesis should have a broad impact on research addressing bacterial pathogenicity. ***

9305178 Collmer 高等植物的过敏反应 (HR) 的特点是在“不相容”病原体（一种仅在另一种植物中引起疾病​​的微生物）入侵部位植物细胞快速、局部死亡，并且与抗性相关许多线虫、真菌、病毒和细菌。丁香假单胞菌和其他植物病原菌引发 HR 是由 hrp 基因控制的，这些基因也是这些细菌在各自宿主植物中繁殖和致病性所必需的。该研究的总体目标是利用两项最新进展来剖析 hrp 基因的功能，并确定 avr 基因对 hrp 基因表型依赖性的一般基础。我们预计 (i) 丁香假单胞菌菌株需要 harpin 来启动与植物的代谢活性相互作用，(ii) harpin 的分泌需要 HrpH 和其他几种 Hrp 蛋白，(iii) 必须仔细调节 harpin 的产生成功的发病机制，以及 (iv) Avr 蛋白依赖于 Hrp 分泌系统和/或 harpin 来产生其表型。这项工作可能涉及三种丁香假单胞菌菌株：(i) P.s.。 syringae 61 的 hrp 基因克隆簇已被广泛表征，其独特之处在于它在大肠杆菌等非病原体中发挥作用。 (ii) P.s.大豆小种 4，在获得克隆的 avrB 基因后与 Rpg1 大豆品种不相容，以及 (iii) P.s.番茄 DC3000，其与拟南芥的相容性通过获取 avrB 被逆转。该项目的早期工作将决定 P.s.大豆小种 4 或 P.s.番茄DC3000的工作重点将是Avr蛋白功能。我们打算 (1) 描述 P.s. 的特征。丁香菌 61 hrpZ 基因和编码的 harpin 的一级序列、激发子活性结构域和亚细胞位置。 (2)确定hrpH和hrpZ突变对P.s.初始相互作用的相对影响。丁香 61 与豆类和烟草（或 P.s. 番茄 DC3000 与拟南芥或 P.s. 甘氨酸 4 种与大豆）。 (3) 克隆并表征 P.s.甘氨酸小种4(或P.s.番茄DC3000)hrpZ基因，构建缺乏harpin的衍生物、过量产生harpin、产生harpin而不是harpin或含有反式hrpZ启动子-uida融合体；确定这些衍生物（有或没有 avrB+ 质粒）在烟草和差异宿主品种上的表型。 %%% 由于 Hrp 分泌蛋白的同源物存在于一些动物病原体中，因此成功测试这些假设应该会对解决细菌致病性的研究产生广泛的影响。 ***