INTERACTIONS BETWEEN AGROBACTERIUM AND HOST PLANTS

农杆菌和寄主植物之间的相互作用

• 批准号: 3467820
• 负责人: Stephen C. Winans
• 金额: $ 12.32万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3467820
• 关键词: Agrobacterium tumefaciens; Escherichia coli; aminoacid; aminosugar; bacterial genetics; bacterial proteins; computer assisted sequence analysis; crown gall; electrofocusing; gene expression; genetic manipulation; host organism interaction; mutant; phenols; protein reconstitution; regulatory gene; stress proteins; transcription factor

Agrobacterium tumefaciens, a gram negative soil bacterium that can live in parasitic association with higher plants, will be used to understand how disease-causing microbes and their hosts interact, and may also provide fundamental insights about how cells and organisms gain and process information from their surroundings. Agrobacterium senses wounded plants susceptible to infection by perceiving a class of phenolic compounds, while it senses tumorous plant tissues that are a consequence of infection by perceiving a class of derivatized amino acids and sugars known as opines. Two proteins (VirA and VirG) are required for the first of these recognition systems, and we will test the hypotheses that one of these is an environmental sensor, while the other is a transcriptional activator. We will determine whether the putative environmental sensor has a binding site for inducers, and whether it (like several homologous proteins) is capable of autophosphorylation. We will also obtain point mutants in each of these proteins that are constitutively active. To facilitate all these studies, we will attempt to reconstruct this regulatory system in E. coli. We will also study a separate regulatory system which regulates the virG promoter, identifying both cis- and trans-acting elements. Another set of T-plasmid encoded genes is inducible by opines, and little is known about the proteins mediating this response. We will identify trans-acting factors required to regulate opine-inducible genes, and subclone and sequence them. Finally and most importantly we will identify and characterize new loci which are induced by opines. By analyzing their predicted amino acid sequence and by characterizing stains with mutations in each of these genes we will gain insights about their role in the maintenance of this parasitic association.

根癌农杆菌，一种能存活的革兰氏阴性土壤细菌 寄生与高等植物的联系，将被用来理解 致病微生物和它们的宿主如何相互作用，也可能 提供关于细胞和有机体如何获得和 处理来自周围环境的信息。农杆菌感官 通过感知一类受感染的植物而受伤的植物 酚类化合物，当它感觉到肿瘤植物组织是一个 感知一类衍生氨基的感染后果 酸和糖，也就是所谓的眼镜蛇。两种蛋白质(Vira和Virg)是 第一个识别系统所需的，我们将测试 假设其中一个是环境传感器，而 另一种是转录激活剂。我们将确定是否 推测的环境传感器具有诱导剂的结合位点，并且 它(像几种同源蛋白质一样)是否能够 自动磷酸化。我们还将在每一个中获得点突变 具有结构性活性的蛋白质。为了促进所有这些 通过研究，我们将尝试在E. Coli.我们还将研究建立一个单独的监管制度，以规范 病毒启动子，识别顺式和反式作用元件。 另一组T-质粒编码基因可被观点诱导，以及 人们对介导这种反应的蛋白质知之甚少。我们会 确定调节观点诱导物所需的反式作用因素 基因，亚克隆和测序。最后，也是最重要的是，我们 将识别和表征由观点诱导的新的基因座。通过 分析它们预测的氨基酸序列，并通过表征 这些基因中每一个都有突变的菌株，我们将获得关于 他们在维持这种寄生联系方面的作用。