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）的特征是在被“不相容”病原体（一种只在另一种植物中引起疾病的微生物）侵入的部位植物细胞的快速、局部死亡，并且与对许多线虫、真菌、病毒和细菌的抗性有关。由假单胞菌和其他植物病原细菌引起的HR的诱导由hrp基因控制，hrp基因也是这些细菌在其各自的宿主植物中增殖和致病性所必需的。这项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基因的表型依赖性的一般基础。我们预期（i）Harpin是P. lingae菌株启动与植物的代谢活性相互作用所需的，（ii）HrpH和几种其他Hrp蛋白是Harpin分泌所需的，（iii）Harpin产生必须被仔细调节以成功致病，和（iv）Avr蛋白依赖于Hrp分泌系统和/或Harpin来产生它们的表型。这项工作将涉及潜在的三个菌株的P. lingae：（i）P.s. Escherichinae 61的hrp基因簇已被广泛鉴定，其独特之处在于，它在非病原体如E.杆菌(ii)P.S.大豆小种4，其在获得克隆的avrB基因后变得与Rpg 1大豆栽培品种不相容，和（iii）P.s.番茄DC 3000，其与拟南芥的相容性通过获得avrB而逆转。该项目的早期工作将决定P.S.大豆小种4或P.s.番茄DC 3000将是Avr蛋白功能的工作重点。我们打算（1）描述P. S。本研究从一级序列、激发子活性结构域和亚细胞定位三个方面对61 hrpZ基因及其编码的harpin蛋白进行了比较。(2)测定hrpH和hrpZ突变对P.s.烟草61与大豆和烟草（或P.s.番茄DC 3000与A. thaliana或P.s.大豆的大豆小种4）。(3)克隆并表征P.s.大豆小种4（或P.s.番茄DC 3000）hrpZ基因，构建harpin缺陷的衍生物，过量产生harpin，产生harpin而不是harpin，或含有hrpZ启动子- uida反式融合体;确定这些衍生物（有或没有avrB+质粒）在烟草和差异宿主栽培品种上的表型。由于Hrp分泌蛋白的同源物存在于一些动物病原体中，这些假设的成功测试应该对解决细菌致病性的研究产生广泛的影响。***