Molecular Genetic Analyses of Host Range in Crown Gall Tumors

土壤杆菌的有限宿主范围（LHR）生物变型菌株 根瘤菌在葡萄藤上形成肿瘤，但几乎没有在其他植物上形成肿瘤。 植物 宽宿主范围菌株（WHR）不能诱导肿瘤 葡萄藤，但往往诱导坏死的接种部位。 我们希望了解这几个的分子基础 LHR和WHR农杆菌菌株与 葡萄藤作为植物微生物相互作用的模型系统。 这些 研究建立在VirA的物理和功能差异上， 每种菌株中的蛋白质及其在 植物信号转导和植物细胞转化。 到 将转化与肿瘤形成区分开来， 植物细胞转化的测定将使用 在35 A后携带B-葡萄糖醛酸酶基因的二元载体系统 CaMV启动子。 为了证明这四个领域的重要性， 的VirA与主机范围，我们将交换域之间的WHR和 LHR菌株，并观察生物学后果。 我们将 分离和鉴定葡萄藤中诱导VIR基因化合物 在LHR和WHR菌株中，并确定其相互作用位点 病毒A蛋白 负责诱导 葡萄藤中的坏死反应将通过突变体 T-DNA分析

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.