Regulation of Coronatine Biosynthesis in Pseudomonas Syringae

丁香假单胞菌中冠菌素生物合成的调控

• 批准号: 9316488
• 负责人: Carol Bender
• 金额: $ 30.28万
• 依托单位: Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-02-01 至 1998-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316488&HistoricalAwards=false
• 关键词: Regulation; Coronatine; Biosynthesis; Pseudomonas; Syringae

9316488 Bender The phytotoxin coronatine is an important virulence factor in several plant disease caused by the phytopathogenic bacterium, Pseudomonas syringae. Fundamental to understanding the molecular basis of pathogenicity is to determine how virulence factors are modulated. Furthermore, the organization and function of genes required for biosynthesis of bacterial phytotoxins has not been intensively studied. A long-term goal of this research is to elucidate mechanisms that regulate coronatine production in P. syringae. Coronatine has a unique structure derived from two unrelated biosynthetic pathways: coronafacic acid (CFA) is of polyketide origin, whereas coronamic acid (CMA), is an ethylcyclopropyl amino acid derived from isoleucine. These two components are substrate feeding studies and complementation analyses have been used to identify regions of the coronatine biosynthetic cluster required for CFA and CMA production and the coupling (cpl) gene which catalyze amide bond formation. In this work, Northern blot analyses and transcriptional fusions will be utilized to elucidate the transcriptional organization and regulation of the coronatine biosynthetic cluster. The nature of the cpl promoter and factors which regulated the cpl transcript will be identified using primer extension, deletion analysis and gene fusions. The protein product of cpl will be overproduced and used to study its enzymatic activity in vitro. The results will significantly enhance our understanding of the regulatory controls and biosynthetic mechanisms employed in phytotoxin production. This work is part of an international collaborative effort to understand the mode of action, biosynthesis, and regulation or coronatine production in P. syringae. %%% This research will aid in our understanding of how some bacteria are able to infect plants while others cannot. ***

9316488 Bender植物毒素冠菌素是由植物病原细菌假单胞菌引起的几种植物病害中的重要毒力因子。 理解致病性的分子基础的基础是确定毒力因子是如何被调节的。 此外，细菌植物毒素生物合成所需的基因的组织和功能尚未得到深入研究。 这项研究的一个长期目标是阐明调节P. pastingae中冠菌素产生的机制。 冠菌素具有源自两个不相关的生物合成途径的独特结构：冠那酸（CFA）是聚酮化合物来源的，而冠那酸（CMA）是源自异亮氨酸的乙基环丙基氨基酸。 这两个组成部分是底物补料研究，互补分析已用于鉴定CFA和CMA生产所需的冠菌素生物合成簇的区域以及催化酰胺键形成的偶联（cpl）基因。 在这项工作中，北方印迹分析和转录融合将被用来阐明冠菌素生物合成簇的转录组织和调控。 cpl启动子的性质和调节cpl转录的因子将通过引物延伸、缺失分析和基因融合来鉴定。 cpl的蛋白产物将被过量生产并用于体外酶活性的研究。 这些结果将大大提高我们对植物毒素生产中的调控和生物合成机制的理解。 这项工作是国际合作努力的一部分，旨在了解P. dogingae中的作用模式，生物合成和调节或coronatine生产。 这项研究将有助于我们了解一些细菌如何能够感染植物，而另一些则不能。 ***