Induction of Plant Resistance Reactions by Pseudomonas syringae

丁香假单胞菌诱导植物抗性反应

• 批准号: 8716967
• 负责人: Steven Hutcheson
• 金额: $ 21.75万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8716967&HistoricalAwards=false
• 关键词: Induction; Plant; Resistance; Reactions; Pseudomonas

A primary mechanism through which plants prevent colonization by potentially pathogenic microorganisms is the hypersensitive response (HR), a rapid, local necrosis accompanied by the production of antimicrobial compounds. Previous genetic studies with Pseudomonas syringae pathovars (host range variants of P.syringae) suggest that elicitation of the HR by incompatible bacterial pathogens is controlled by two types of genes: hrp (necessary for any plant reaction) and avr (affecting host range). The nature of the elicitor(s) remains unknown. The interaction of P.syringae with tobacco suspension culture cells provides an ideal system to investigate the elicitation of the HR by bacteria. Cultured tobacco cells rapidly respond to incompatible bacteria by a K+ efflux/H+ influx exchange response (XR) that is physiologically, genetically and developmentally similar to the in planta HR. In studies thus far this lab has: 1) cloned an apparent set of hrp/avr genes from P.syringae pv. syringae (Pss61) that are phenotypically expressed in the saprophytes, Escherichia coli and P. fluorescens, thus simplifying subsequent genetic analyses; 2) observed that Pss61 containing the cloned wild-type hrp/avr genes produce a stronger XR than wild-type Pss61, suggesting that elicitor production can be enhanced by genetic manipulation; and 3) identified in vitro conditions for preinducing the bacterial elicitor of the XR. These findings provide powerful new tools to investigate the bacterial signals governing host range and pathogenicity. The goal of this investigation is to isolate and characterize biochemically the bacterial elicitors involved in the induction of plant responses. The proposed experiments will define the genetic units present in the hrp/avr clone and use reporter gene fusions to elucidate the regulation of functional loci and characterize the protein products.***//

植物防止定植的主要机制 潜在致病微生物的作用是 超敏反应（HR），快速局部坏死 伴随着抗微生物化合物的产生。 先前对假单胞菌致病变种的遗传研究 (host范围变种）表明， 由不相容的细菌病原体引起的HR得到控制 由两种类型的基因：hrp（任何植物反应所必需的） 和AVR（影响主机范围）。 的性质 激发子仍然未知。 P. lingae的相互作用 烟草悬浮培养细胞提供了一种理想的 系统来研究细菌对HR的诱导作用。 培养的烟草细胞对不相容的 细菌通过K+流出/H+流入交换反应（XR）， 在生理遗传和发育上都很相似 在迄今为止的研究中，该实验室有：1） 克隆了一组明显的hrp/avr基因。 Pss 61），其表型表达于 因此， 简化随后的遗传分析; 2）观察到， 含有克隆的野生型hrp/avr基因的pss 61产生一种 比野生型Pss 61更强的XR，表明激发子 可以通过基因操纵提高产量;以及3） 确定了用于预诱导细菌的体外条件 XR的激发子。 这些发现提供了强大的新 研究控制宿主的细菌信号的工具 范围和致病性。 这次调查的目的是 分离并从生物化学上鉴定细菌 参与诱导植物反应的激发子。 的 拟议的实验将确定存在于 HRP/AVR克隆并使用报告基因融合来阐明 功能位点的调节和表征 蛋白质产品。*//