Molecular Analysis of Avirulence and Basic Pathogenicity Genes in Xanthomonas Campestris pv Vesicatoria

野油菜黄单胞菌致病变种（Xanthomonascampestrispv.） 引起过敏反应的近- 辣椒等基因抗病品种或广泛 不同的物种是由特定的存在控制的， 无毒基因 在本提案中，我们计划描述 小种特异性无毒基因avrBs 1和avrBs 2，以及 非宿主无毒基因avrZ的独特类别的成员。 的 这些基因的分子特征将提供一个坚实的 分子基础可以让我们比较 蛋白质产品和调节的相似性或差异性 无毒基因的表达。 这些特征 基因及其多克隆抗血清的产生 各自的蛋白质将使我们能够设计 实验来阐明参与的生化过程， 细胞识别和随后的信号转导 负责引发植物防御机制的过程。 Hrp基因簇的互补性分析及其在水稻育种中的应用 与特定无毒基因可能的功能关系 将通过定义这一遗传组织来解决。 DNA区域和特定突变对DNA的影响。 无毒基因表达的调控。 最后我们将 研究寄主范围的分子遗传控制 排除在X。C.非宿主种属上的水疱病， 决定植物宿主基因的遗传模式， 确定阻力。 许多植物病原体遵循“基因对基因”的关系， 它们是否会在特定的环境中引起疾病 寄主植物品系。 只有当病原体 携带一个特定的等位基因的一个自己的基因，当 宿主携带了自身基因的一个特定等位基因。 任何 这些特定病原体的其他等位基因的组合， 宿主基因排除疾病。 这种遗传关系 四十年来一直被理解，但生物化学功能 参与决定发生的基因 疾病仍然完全不清楚。 斯塔斯卡维奇博士 是最早成功分离出 植物病原体的疾病决定基因。 在这 他将描述这些基因的产物， 为了解分子生物学奠定基础 宿主-病原体相互作用的基础。 除了其 内在的生物学兴趣，这项工作也有明显的 对今后努力控制植物的实际重要性 疾病

The ability of avirulent isolate of Xanthomonas campestris pv. vesicatoria to induce a hypersensitive reaction on near- isogenic resistant cultivars of Capsicum annuum or widely divergent species is controlled by the presence of specific avirulence genes. In this proposal, we plan to characterize the race-specific avirulence genes, avrBs1 and avrBs2, and a member of unique class of non-host avirulence genes, avrZ. The molecular characterization of these genes will provide a solid molecular foundation which will allow us to compare structural similarities or differences in protein products and regulation of avirulence gene expression. The characterization of these genes and the production of polyclonal antisera to their respective proteins will put us into a position to design experiments to elucidate the biochemical processes involved in cellular recognition and the subsequent signal transduction processes responsible for eliciting plant defence mechanisms. The complementation analysis of the Hrp gene cluster and its possible functional relationship with specific avirulence genes will addressed by defining the genetic organization of this region of DNA and the effects of specific mutations on the regulation of avirulence gene expression. Finally, we will investigate the molecular genetic control of host range exclusion in X. c. vesicatoria on non-host species and determine the inheritance patterns of plant host genes that determine resistance. Many plant pathogens follow a "gene-for-gene" relationship with regard to whether or not they cause disease in a particular strain of host plant. Disease ensues only when the pathogen carries a specific allele of one of its own genes, and when the host carries a specific allele of one of its own genes. Any combination of other alleles of these particular pathogen and host genes precludes disease. This genetic relationship has been understood for forty years, but the biochemical functions of the genes involved in the determination of the occurrence of disease have remained completely obscure. Dr. Staskawicz has been one of the first investigators to succeed in isolating disease- determining genes from a plant pathogen. In this project he will characterize the products of these genes, in order to lay the foundation for understanding of the molecular basis of the host-pathogen interaction. Apart from its intrinsic biological interest, this work also has obvious practical importance for future efforts to control plant diseases.