EmhR is an indole-sensing transcriptional regulator responsible for the indole-induced antibiotic tolerance in Pseudomonas fluorescens
Autor: | Di-Yin Li, Xiang‐Xue Jia, Jian-Ting Han, Megan L. Kempher, Wen-Juan Jia, Yong-Xing He, Meng‐Yuan Zhang, Shaomin Niu, Xu Yan, Xuanyu Tao, Hang Xu, Xiao-Quan Yu |
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Rok vydání: | 2020 |
Předmět: |
Indole test
Proteomics 0303 health sciences Rhizosphere Indoles Multidrug tolerance 030306 microbiology Operon Pseudomonas fluorescens Biology Rhizobacteria biology.organism_classification Microbiology Anti-Bacterial Agents 03 medical and health sciences Pseudomonas Pseudomonas syringae Efflux Ecology Evolution Behavior and Systematics 030304 developmental biology |
Zdroj: | Environmental microbiologyReferences. 23(4) |
ISSN: | 1462-2920 |
Popis: | Indole is well known as an interspecies signalling molecule to modulate bacterial physiology; however, it is not clear how the indole signal is perceived and responded to by plant growth promoting rhizobacteria (PGPR) in the rhizosphere. Here, we demonstrated that indole enhanced the antibiotic tolerance of Pseudomonas fluorescens 2P24, a PGPR well known for its biocontrol capacity. Proteomic analysis revealed that indole influenced the expression of multiple genes including the emhABC operon encoding a major multidrug efflux pump. The expression of emhABC was regulated by a TetR-family transcription factor EmhR, which was demonstrated to be an indole-responsive regulator. Molecular dynamics simulation showed that indole allosterically affected the distance between the two DNA-recognizing helices within the EmhR dimer, leading to diminished EmhR-DNA interaction. It was further revealed the EmhR ortholog in Pseudomonas syringae was also responsible for indole-induced antibiotic tolerance, suggesting this EmhR-dependent, indole-induced antibiotic tolerance is likely to be conserved among Pseudomonas species. Taken together, our results elucidated the molecular mechanism of indole-induced antibiotic tolerance in Pseudomonas species and had important implications on how rhizobacteria sense and respond to indole in the rhizosphere. |
Databáze: | OpenAIRE |
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