Molecular Genetic Analyses of Host Range in Crown Gall Tumors

冠瘿瘤宿主范围的分子遗传学分析

• 批准号: 9107110
• 负责人: Eugene Nester
• 金额: $ 27万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1995-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9107110&HistoricalAwards=false
• 关键词: Molecular; Genetic; Analyses; Host; Range

The limited host range (LHR) biovar strains of Agrobacterium tumefaciens form tumors on grapevine but on virtually no other plants. Wide host range strains (WHR) fail to induce tumors on grapevine, but often induce necrosis at the site of inoculation. We hope to understand the molecular basis of these several different interactions of LHR and WHR Agrobacterium strains with grapevines as a model system for plant microbe interactions. These studies build on the physical and functional divergence of the VirA protein in each strain and the critical role this protein plays in plant signal transduction and plant cell transformation. To distinguish transformation from tumor formation, the biological assays for plant cell transformation will be performed using a binary vector system carrying a B-glucuronidase gene behind a 35A CaMV promoter. To demonstrate the significance of the four domains of VirA with host range, we will exchange domains between WHR and LHR strains and observe the biological consequences. We will isolate and identify compounds in grapevines that induce vir genes in LHR and WHR strains and determine their sites of interaction with the VirA protein. The locus responsible for inducing the necrotic response in grapevines will be identified by mutant analysis of T-DNA.

根癌农杆菌的有限寄主范围(LHR)生物群菌株在葡萄上形成肿瘤，但几乎不在其他植物上形成肿瘤。广谱寄主菌株(WHR)在葡萄上不能诱发肿瘤，但往往在接种部位引起坏死。我们希望了解LHR和WHR农杆菌菌株与葡萄的这几种不同相互作用的分子基础，作为植物微生物相互作用的模型系统。这些研究建立在病毒蛋白在每个菌株中的物理和功能差异以及该蛋白在植物信号转导和植物细胞转化中所起的关键作用的基础上。为了区分转化和肿瘤的形成，植物细胞转化的生物学检测将使用在35A CaMV启动子后面携带B-葡萄糖苷酸酶基因的双元载体系统。为了证明病毒的四个结构域在宿主范围内的意义，我们将在WHR和LHR毒株之间交换结构域并观察其生物学后果。我们将分离和鉴定葡萄中诱导LHR和WHR菌株VIR基因的化合物，并确定它们与VirA蛋白的相互作用位置。通过对T-DNA的突变分析，将确定导致葡萄藤坏死反应的基因座。