Genome-wide analysis of multidrug efflux in the plant-pathogenic bacterium Pseudomonas syringae

多药外排转运体(MDE)是细菌对抗生素产生耐药性的主要原因。与众所周知的MDE在临床相关微生物中的作用相反，人们对环境细菌中的MDE转运蛋白知之甚少。本项目旨在鉴定和确定植物病原菌紫丁香假单胞菌中所有MDE泵的特征，并深入了解它们的调节和自然功能。MDE泵可能通过保护它们免受植物抗菌剂的伤害，在紫丁香根结线虫对其各自寄主植物的适应中发挥重要作用。紫丁香疫霉可细分为致病变种(致病变种)，根据寄主范围的不同而不同。三种不同丁香疫霉致病变种的现有基因组序列将被用来开发一个微阵列，其中包含包括MDE系统在内的所有运输蛋白家族成员的基因。这些微阵列将用于鉴定在抗生素、抗菌植物代谢物和植物体内处理后表达的转运蛋白。待测试的紫丁香菌菌株感染属于不同植物科的植物，每种植物产生不同光谱的抗微生物代谢产物。因此，植物携带的代谢物的多样性将被筛选为MDE转运蛋白的底物，这可能有助于阐明MDE系统对宿主特异性的贡献。可能的MDE蛋白将被克隆，以确定底物特异性，寻找天然底物，并研究其转录调控。由于不是所有的MDE转运体对抗生素的反应都表现出表达增加，我们将进一步克隆和DFG研究提案-Matthias Ullrich-在植物病原体中的多药外排3表征那些显示出与其他生物已知的MDE泵序列相似的基因。突变将被用来揭示这些转运蛋白在发病机制中的作用。

Multidrug efflux (MDE) transporters are major contributors to bacterial resistance towards antibiotics. In contrast to the well-understood role of MDE in clinically relevant microbes, only little is known about MDE transporters in environmental bacteria. This project aims to identify and characterize all MDE pumps in the plant pathogen Pseudomonas syringae and to gain in-depth knowledge about their regulation and natural functions. MDE pumps may play an important role in the adaptation of P. syringae to its respective host plants by protecting them against plant antimicrobials. P. syringae is sub-divided into pathogenic variants (pathovars) which vary according to their host range. Available genome sequences of three different P. syringae pathovars will be used to develop a microarray containing genes of all members of transport protein families that include MDE systems. The microarrays will be used to identify transporters that are expressed after treatment with antibiotics, antimicrobial plant metabolites, and in planta. The to-be-tested P. syringae strains infect plants belonging to different plant families, each producing a different spectrum of antimicrobial metabolites. Thus, the diversity of plantborne metabolites will be screened as substrates of MDE transporters potentially shedding light on the contribution of MDE systems on host specificity. Putative MDE proteins will be cloned to determine substrate specificity, to search for natural substrates, and to study their transcriptional regulation. Because not all MDE transporters might show an increased expression in response to antibiotics, we will furthermore clone and DFG Research proposal - Matthias Ullrich - Multidrug efflux in plant pathogens 3 characterize genes that show sequence similarities to known MDE pumps from other organisms. Mutagenesis will be used to reveal the role of these transporters during pathogenesis.