Dissection of an EDM2-dependent signaling mechanism mediating resistance to Hyaloperonospora parasitica in Arabidopsis

植物对病原微生物的免疫通常是由抗病基因(又名R-基因)介导的。R基因编码的蛋白质在与病原体分子特定的相互作用时触发免疫反应。每种植物都配备了大量的R基因，以保护它免受各种病原体的侵袭。本项目以模式植物拟南芥的EDM2基因为研究对象。此前已有研究表明，EDM2通过激活某些R基因而促进植物免疫。然而，这一过程的机械细节尚不清楚。研究人员的初步结果表明，EDM2控制着染色质的状态。染色质由DNA和各种DNA结合蛋白组成。如果给定基因的染色质状态是紧凑的，那么相应的基因是不活跃的。基因的激活需要通过放松蛋白质与DNA的结合来解压其染色质。利用分子生物学和生物化学的方法，研究人员将研究EDM2是如何控制R基因的染色质状态的。根据他们的初步结果，他们推测，EDM2编码的蛋白质通过与某些R基因上染色质的特定特征对接而被招募到这些基因上，并对这些基因的染色质进行局部修改。除了深入了解EDM2的功能及其在植物免疫中的作用外，这个项目还将拓宽我们对染色质动力学的理解。这些知识将有助于开发新的策略，以提高作物的抗病能力和其他重要性状。此外，该项目将为博士后科学家以及本科生提供培训。

Immunity of plants against pathogenic microorganisms is often mediated by disease resistance genes (aka R-genes). R-genes encode proteins that trigger immune responses upon specific interactions with pathogen molecules. Each plant is equipped with a large number of R-genes that protect it against a wide variety of pathogens. This project is focused on the EDM2 gene of the model plant species Arabidopsis. EDM2 has previously been shown to contribute to plant immunity by activating some R-genes. However, mechanistic details of this process are unknown. Preliminary results of the investigators indicate that EDM2 controls the status of chromatin. Chromatin consists of DNA and various DNA-bound proteins. If the chromatin status of a given gene is compact, the respective gene is inactive. Activation of a gene requires de-compaction of its chromatin by loosening the binding of proteins to its DNA. Using methods of molecular biology and biochemistry the investigators will examine how EDM2 controls the chromatin status of R-genes. Based on their preliminary results they anticipate that the protein encoded by EDM2 is recruited to some R-genes by docking to specific features of chromatin at these genes and that it locally modifies their chromatin. Besides providing deep insight into the function of EDM2 and its role in plant immunity, this project will also widen our understanding of chromatin dynamics. This knowledge will facilitate the development of new strategies to improve disease resistance and other important traits of crop plants. Furthermore, the project will provide training to post-doctoral scientists as well as undergraduate students.