Comparative Analyses of Resistance Gene Evolution

我们将利用比较基因组学方法来了解决定主要细菌病原体与不同作物物种之间相互作用结果的进化力量和遗传事件。 广泛的遗传机制已被证明影响植物抗病性的进化。 越来越明显的是，不同的机制可能是重要的，在不同的阶段，影响不同的部分的抗性蛋白，抗性基因可能会表现出不同的进化速度。 这些不同的进化速度可能是指示不同的特征的病原体配体检测和建议不同的功效在疾病控制strategies.We将表征相关系列的细菌蛋白参与致病性，植物靶标，它们相互作用，和植物抗性基因，检测这些基因。这将通过以下方式实现：1）鉴定细菌病原体假单胞菌属的四种菌株和物种中的大多数所谓的“III型效应物”基因; 2）通过分析莴苣、番茄和拟南芥的不同种质以及对至少五种其它作物物种的较不详细的分析来确定植物检测这些效应物蛋白的能力的遗传变异; 3）从拟南芥和作物物种中分离这些效应子的植物靶标的子集; 4）表征已知和新的抗性基因以及编码靶蛋白的基因的速率和进化，并将进化速率与检测到的配体的流行和适合度贡献相关联。 这将提供一个相关的系列，这三个相互作用的阻力决定因素和矩阵之间的相互作用。 这也将有助于深入了解非抗性的基础和抗性基因的潜在持久性。了解抗病性的分子决定因素具有实际和根本的重要性。 番茄和番茄是美国十大最有价值的作物之一，抗病性是作物改良计划中最重要的农业性状之一。 了解植物-病原体相互作用特异性的分子基础和导致抗性的事件将为在裤子中开发更持久的抗病性和减少化学保护剂的使用提供新的可能性。

We will utilize a comparative genomics approach to understand the evolutionary forces and genetic events that have determined the outcome of the interactions between a major group of bacterial pathogens and diverse crop species. A broad range of genetic mechanisms has been shown to influence the evolution of disease resistance in plants. It is becoming apparent that different mechanisms may have been important at different stages and influence different parts of the resistance protein and that resistance genes may exhibit different rates of evolution. These different rates of evolution may be indicative of different characteristics of the pathogen ligands detected and suggest different efficacies in disease control strategies.We will characterize related series of bacterial proteins involved in pathogenicity, the plant targets they interact with, and the plant resistance genes that detect these genes. This will be done by: 1) identifying the majority of the so-called "Type III effector" genes in four strains of strains and species of the bacterial pathogen Pseudomonas; 2) determining the genetic variation in the plants ability to detect these effector proteins by analysis of diverse germplasm of lettuce, tomato, and Arabidopsis as well as a less detailed analysis of at least five other crop species; 3) isolating a subset of the plant targets of these effectors from Arabidopsis and the crop species; 4) characterizing the rates and evolution of known and novel resistance genes as well as the genes encoding the target proteins and to correlate the rates of evolution with the prevalence and fitness contribution of the ligands detected. This will provide a related series of these three interacting determinants of resistance and a matrix of the interactions between them. This will also provide insights into the basis of non-resistance and the potential durability of resistance genes.Understanding the molecular determinants of disease resistance has practical as well as fundamental importance. Lettuce and tomato are two of the top ten most valuable crops in the US and disease resistance is one of the most agriculturally important traits targeted in crop improvement programs. Understanding the molecular basis of specificity in plant-pathogen interactions and the events resulting in resistance will provide new possibilities for developing more durable disease resistance in pants and decrease the use of chemical protectants.