Characterization of Arabidopsis thaliana Mutants with Enhanced Disease Susceptibility

从拟南芥Glazebrook技术区分离到9723493个具有增强感病(EDS)表型的突变体，其中一些为NPR1等位基因，另一些为PAD基因等位基因。已知NPR1基因参与了系统获得性抗性的调节，PAD基因参与了植保素的合成，这是一种已知的防御反应。此外，EDS4基因控制防御基因PR1和PR5的表达，以应对细菌病原体的感染。因此，EDS突变定义了在植物抵御病原体攻击中具有重要作用的基因。Eds突变体的特性将有助于鉴定在植物抗病中发挥重要作用的新基因。EDS基因将被定位，并根据它们对防御基因表达和系统获得性抗性建立的影响进行表征。将确定受EDS突变影响的病原体范围，并将使用基于地图的方法克隆EDS4。非技术部分植物抵御病原体攻击的反应没有经过严格的遗传分析，部分原因是植物寄主已被用于抗病的分子和生化分析，由于大的或多倍体的基因组和长的世代时间，这些都是遗传研究的困难课题。模式植物拟南芥的使用使基因研究变得可行。因此，现在有了一种强大的方法来识别植物中尚未与已知的生化或分子遗传反应相关的调节因子和其他防御反应成分*

9723493 Glazebrook Technical section Mutants of Arabidopsis thaliana with a phenotype of enhanced disease susceptibility (eds) were isolated and some were identified as alleles of NPR1 and others as alleles of PAD genes. NPR1 genes are known to be involved in the regulation of systematic acquired resistance and the PAD genes in the phytoalexin synthesis, a known defense response. In addition the EDS4 gene controls expression of the defense genes PR1 and PR5 in response to infection by a bacterial pathogen. Thus, the eds mutations define genes with important roles in plant defense against pathogen attack. The characterization of eds mutants will lead to identification of novel genes that play major roles in plant disease resistance. The EDS genes will be mapped and characterized in relation to their effect on defense gene expression and establishment of systemic acquired resistance. The range of pathogens that are affected by the eds mutations will be determined and EDS4 will be cloned using a map-based approach. Non-technical section The responses by which plants defend themselves from pathogen attack have not been subjected to rigorous genetic analysis, in part because the plant hosts have been used in molecular and biochemical analysis of disease resistance are difficult subjects for genetic studies due to large or polyploid genomes and long generation times. The use of the model plant, Arabidopsis thaliana, has made genetic studies feasible. Therefore, a powerful approach is now available for identifying regulatory factors and other defense response components in plants that are not already correlated with a known biochemical or molecular genetic response ***