Dissecting Phytophthora Resistance In Soybean Using Expression Profiling and Analysis of Quantitative Trait Loci.

一些植物抗病基因（主要抗性基因）赋予对特定病原体的高水平抗性。 这些基因在过去十年中得到了很好的研究。然而，主要的抗性基因通常仅对病原体的特定菌株有效，因此当新的病原体菌株出现时，它们在田间变得无效。 相比之下，部分或定量抗性对病原体的所有菌株都有效，尽管提供的保护水平较低。 多个基因赋予部分抗性，每个基因的贡献很小，使这些基因的研究复杂化。 因此，对它们如何运作的了解较少。本研究的目的是了解大豆对卵菌病原体大豆疫霉（Phytophthora sojae）的数量抗性机制，大豆疫霉是最具破坏性的大豆病害之一。卵菌是一种类似真菌的生物，实际上与褐藻（如海带和硅藻）关系最密切。 疫霉菌病原体攻击数千种植物物种，包括许多重要作物。两种方法将结合起来，以确定和表征定量抗性基因。 首先，将分析在对疫霉属的数量抗性方面不同的大豆栽培品种之间的遗传杂交，以鉴定大豆中有助于抗性的遗传基因座（称为数量性状基因座或QTL）。 第二，将使用杂交微阵列来测定感染期间数千个大豆和疫霉基因的表达水平，以确定由不同数量抗性位点贡献的抗性机制。将分析病原体基因表达模式以确定植物防御机制对病原体的影响。总体而言，预计这项研究将为植物防御机制带来新的见解，为大豆研究人员和育种家提供新的遗传和基因组资源，并为基因表达数据分析提供新的统计工具。

Some plant disease resistance genes (major resistance genes) confer high levels of resistance against particular pathogens. These genes have been well studied over the past decade. Major resistance genes, however, are generally effective only against specific strains of a pathogen, and so become ineffective in the field when new pathogens strains appear. In contrast, partial or quantitative resistance is effective against all strains of a pathogen, albeit providing a lower level of protection. Multiple genes confer partial resistance, each making minor contributions, complicating the study of these genes. As a result, less is known about how they operate. The goal of this project is to understand the mechanisms of quantitative resistance of soybean against the oomycete pathogen Phytophthora sojae, which is one of the most damaging soybean diseases. Oomycetes are fungus-like organisms that are actually most closely related to brown algae such as kelp and diatoms. Phytophthora pathogens attack thousands of plant species, including many important crops. Two approaches will be combined to identify and characterize quantitative resistance genes. First, genetic crosses between soybean cultivars differing in their quantitative resistance to Phytophthora will be analyzed to identify genetic loci (called quantitative trait loci or QTL) in soybean that contribute to resistance. Second, the expression levels of thousands of soybean and Phytophthora genes during infection will be assayed using hybridization microarrays to determine the mechanisms of resistance contributed by different quantitative resistance loci. Pathogen gene expression patterns will be analyzed to determine the impact of plant defense mechanisms on the pathogen. Overall, it is anticipated that this research will result in new insights into plant defense mechanisms, new genetic and genomic resources for soybean researchers and breeders, and new statistical tools for analysis of gene expression data.