Elucidating in planta target genes of Ralstonia solanacearum TALE-like proteins

阐明植物中青枯菌 TALE 样蛋白的靶基因

• 批准号: 262924427
• 负责人: Professor Dr. Thomas Lahaye
• 金额: --
• 依托单位: Abteilung für Allgemeine Genetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/262924427?language=en
• 关键词: Elucidating; planta; target; genes; Ralstonia

Ralstonia solanacearum, the causal agent of bacterial wilt disease, is a quarantine organism in the USA and EU that ranks among the most devastating microbial pathogens in crop plants. We aim to study the interaction between R. solanacearum and its host plants at the molecular level and anticipate that our findings will enable us, in the long run, to develop effective countermeasures against this devastating pathogen. The effector proteins injected by bacterial pathogens into host cells either promote disease or trigger plant immunity. They are thus key determinants for the outcome of plant-microbe interactions. In the framework of this proposal we will study RipTALs, one class of effectors that are widespread in R. solanacearum and that share homology with Transcription Activator Like Effectors (TALEs) from the bacterial genus Xanthomonas.The TALE code describes the correlation of defined amino acids in a given TALE DNA binding domain with specific DNA bases in its effector binding element (EBE). This allows in silico prediction of EBEs for TALEs of known sequence. In preliminary studies we showed that, like for TALEs, RipTAL EBEs can be predicted with the TALE code. Furthermore RipTALs, like TALEs are injected into host cells and are capable of transcriptionally activating promoters bearing a predicted EBE. It is thus conceivable that RipTALs, like TALEs, transcriptionally activate host genes to promote susceptibility in host plants. Given that R. solanacearum is a root pathogen, while xanthomonads typically infect aerial tissues, it is conceivable that they promote disease by activation of host susceptibility (S) genes that encode functionally distinct proteins.We aim to identify RipTAL activated host S genes that promote bacterial disease when being transcriptionally upregulated by a given RipTAL. Once host S genes have been isolated and functionally validated we want to clarify how S gene products promote R. solanacearum disease at the molecular level.R. solanacearum strains isolated from all over the world can be subdivided into four phylotypes, which correlate with their geographical origin. Notably R. solanacearum phylotypes I, II and IV contain RipTALs that differ in their N- and C-terminal regions and their predicted EBEs. Till now molecular studies of RipTALs have been conducted almost exclusively on RipTALs from phylotype I. In the framework of this proposal we aim to also characterize RipTALs from phylotype II and IV strains with the long term goal to identify and characterize corresponding host S genes and gene products.In summary we aim to identify and characterize host S genes that are activated by RipTALs from diverse R. solanacearum phylotypes. We anticipate that our findings will provide insights into the disease strategies of R. solanacearum, aiding the development of efficient countermeasures to protect crop plants.

青枯雷尔氏菌（Ralstonia solanacearum）是细菌性枯萎病的病原体，在美国和欧盟是检疫性生物，在作物中是最具破坏性的微生物病原体之一。我们的目的是研究R.我们在分子水平上研究了青枯菌及其宿主植物，并预计我们的研究结果将使我们能够从长远来看制定针对这种毁灭性病原体的有效对策。由细菌病原体注入宿主细胞的效应蛋白促进疾病或触发植物免疫。因此，它们是植物-微生物相互作用结果的关键决定因素。在这个建议的框架中，我们将研究RipTAL，一类在R中广泛存在的效应子。青枯菌及其与来自细菌黄单胞菌属的转录激活因子样效应子（TALE）具有同源性。TALE代码描述了给定TALE DNA结合结构域中定义的氨基酸与其效应子结合元件（EBE）中特定DNA碱基的相关性。这允许计算机模拟预测已知序列的TALE的EBE。在初步研究中，我们表明，与TALE一样，RipTAL EBE可以用TALE代码预测。此外，RipTAL，像TALE一样，被注射到宿主细胞中，并且能够转录激活携带预测的EBE的启动子。因此可以想象，RipTAL与TALE一样，转录激活宿主基因以促进宿主植物的易感性。考虑到R.青枯菌是一种根病原体，而黄单胞菌通常感染气生组织，可以想象，它们通过激活宿主易感性（S）基因来促进疾病，这些基因编码功能不同的蛋白质。我们的目标是鉴定RipTAL激活的宿主S基因，这些基因在被给定的RipTAL转录上调时促进细菌疾病。一旦宿主S基因被分离并功能验证，我们希望阐明S基因产物如何促进R。在分子水平上对青枯菌病害进行了研究。从世界各地分离的青枯菌菌株可分为四个类型，这与它们的地理来源有关。特别是R。青枯菌I型、II型和IV型含有RipTAL，其N-和C-末端区域以及其预测的EBE不同。到目前为止，RipTAL的分子研究几乎完全是在RipTAL I型上进行的。在这个提议的框架中，我们的目标也是表征来自RipTAL II型和IV型菌株的RipTAL，长期目标是鉴定和表征相应的宿主S基因和基因产物。青枯菌系统型。我们预计，我们的研究结果将提供深入了解的疾病战略的R。青枯菌，帮助制定有效的对策，以保护作物植物。