Related Experiment Video

Updated: Jul 3, 2026

Qualitative and Quantitative Analysis of Siderophore Production from Pseudomonas aeruginosa
05:09

Qualitative and Quantitative Analysis of Siderophore Production from Pseudomonas aeruginosa

Published on: March 15, 2024

Positive regulation of pyoluteorin biosynthesis in Pseudomonas sp. M18 by quorum-sensing regulator VqsR

Xianqing Huang1, Xuehong Zhang, Yuquqn Xu

  • 1Key Laboratory of Microbial Metabolism, Ministry of Education, College of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.

Journal of Microbiology and Biotechnology
|July 18, 2008
PubMed

Insights

The study identifies VqsR as a key regulator for pyoluteorin (Plt) production in Pseudomonas sp. M18. Inactivating vqsR significantly reduced Plt, demonstrating its essential role in antibiotic biosynthesis.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Pseudomonas sp. M18 is a biocontrol rhizobacterium known for producing pyoluteorin (Plt) and phenazine-1-carboxylic acid (PCA).
  • These antibiotics confer antagonism against soilborne phytopathogens, highlighting their agricultural importance.
  • Quorum sensing (QS) systems regulate bacterial behaviors, including antibiotic production.

Purpose of the Study:

  • To identify and characterize the role of the luxR-type quorum-sensing regulatory gene, vqsR, in Pseudomonas sp. M18.
  • To elucidate the specific contribution of VqsR to the biosynthesis of Plt and other secondary metabolites.
  • To compare the regulatory mechanism of vqsR in strain M18 with that in other Pseudomonas species.

Main Methods:

  • Gene identification and characterization of vqsR downstream of the Plt gene cluster.
  • Construction and analysis of a vqsR-inactivated mutant.
  • Complementation of the mutant by introducing the vqsR gene via plasmid pME6032.
  • Quantitative analysis of Plt and PCA production and their biosynthetic gene expression.
  • Assessment of N-acylhomoserine lactone (HSL) production and rhlI gene expression.

Main Results:

  • Identification and characterization of vqsR, a luxR-type QS gene, located downstream of the Plt gene cluster in Pseudomonas sp. M18.
  • A vqsR-inactivated mutant showed significantly decreased Plt production and biosynthetic gene expression, which was restored upon complementation.
  • VqsR mutation did not affect PCA production, HSL production (C4 and C8-HSLs), or rhlI gene expression.
  • VqsR mutation had no apparent impact on Plt-specific ABC transporters or global regulators like GacA, RpoS, and RsmA.

Conclusions:

  • VqsR is identified as a specific regulator of pyoluteorin (Plt) production in Pseudomonas sp. M18.
  • The regulatory mechanism of vqsR in strain M18 differs from that observed in Pseudomonas aeruginosa.
  • VqsR's role appears specific to Plt biosynthesis, independent of PCA production and other QS systems in this strain.

More Related Videos

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds07:13

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds

Published on: August 8, 2025

Synthesis and Assay of Vibrio Quorum Sensing Inhibitors03:29

Synthesis and Assay of Vibrio Quorum Sensing Inhibitors

Published on: May 31, 2024

Related Concept Videos

Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Bacterial Signaling01:30

Bacterial Signaling

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
Prokaryotic Transcriptional Activators and Repressors01:58

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...