[Regulation of type III secretion system by Rhl and PQS quorum sensing systems in Pseudomonas aeruginosa]
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Updated: Jun 17, 2026

Detection and Quantification of Mono-Rhamnolipids and Di-Rhamnolipids Produced by Pseudomonas aeruginosa
Published on: March 29, 2024
Weina Kong1, Haihua Liang, Lixin Shen
1Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences, Northwest University, Xi'an 710069, China. douzikwn@163.com
Objective:
To investigate the relationship between quorum sensing (QS) and type III secretion system (T3SS) in Pseudomonas aeruginosa.
Methods:
We constructed several gene knockout mutants of QS systems. The promoters of the T3SS genes, exoS, exoY, exoT and exsD-pscA-L were cloned and fused upstream of the luminescence reporter gene cluster, luxCDABE. The reporter constructs were integrated on the chromosome in the wild type strain PAO1 and the QS mutants respectively, and the expression of the T3SS genes in these strains was compared.
Results:
The expression of exoS and exoT in pqsR mutant was increased significantly. The Rhl system repressed the activities of the four T3SS genes and the Las system had no effect.
Conclusion:
The results indicate that the Rhl and Pseudomonas quinolone signal (PQS) systems play an important role in regulating T3SS gene expression in Pseudomonas aeruginosa.
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