Characterization of Avirulence Genes in Bacterial Plant Pathogens

无毒基因(AVR)存在于植物病原微生物体内，调节植物对病原菌的识别特异性，使寄主能够检测病原菌并启动主动防御机制。这项研究的长期目标是了解这种识别系统背后的分子基础及其调节的植物防御机制。基恩博士从病原菌&gt；假单胞菌&gt；&gt；丁香科&gt；的成员中克隆了几个AVR基因并进行了测序，最近观察到当细菌被接种到大豆植株中时，其中一个基因可以诱导表达。这种植物诱导表达的细菌无毒基因构成了无毒基因蛋白产物的生化功能这一迄今尚未回答的问题的重要线索。基恩博士将进一步研究细菌的AVR基因，以及它们如何参与植物对病原体的识别。他将完成另外几个AVR基因的测序和表达。他将研究&gt；avrC&gt；和其他无毒基因的诱导性，以及AVR基因与启动植物防御反应的细菌激发子的关系。

Avirulence (avr) genes occur in plant pathogenic microorganisms and modulate recognitional specificities which permit plant hosts to detect the pathogen and invoke an active defense mechanism. The long range goal of the research is to understand the molecular basis underlying this recognition system and the plant defense mechanism that it modulates. Dr. Keen has cloned and sequenced several avr genes from members of the >Pseudomonas> >syringae> group of pathogens and recently observed that one of them is inducibly expressed when bacteria are inoculated into soybean plants. This plant inducible expression of a bacterial avirulence gene constitutes an important lead in the as yet unanswered question of the biochemical function of the avirulence gene protein products. Dr. Keen will further investigate the bacterial avr genes and how they are involved in plant recognition of the pathogen. He will complete the sequencing and expression of several additional avr genes. He will study inducibility of the >avrC> and other avirulence genes, and the relationship of avr genes to bacterial elicitors which initiate the plant defense reaction.