Regulation of quorum sensing in Pseudomonas.

Bacteria use small signal molecules in order to monitor their population density and coordinate gene regulation in a process called quorum sensing. In Gram-negative bacteria, the most common signal molecules are acylated homoserine lactones. Several Pseudomonas species produce acylated homoserine lactones that control important functions including pathogenicity and plant growth promotion. Many reports indicate that the quorum sensing systems of Pseudomonas are significantly regulated and interconnected with regulons of other global regulators. The integration of quorum sensing into additional regulatory circuits increases the range of environmental and metabolic signals beyond that of cell density, as well as further tuning the timing of the response. This review will focus on the regulation of quorum sensing in Pseudomonas, highlighting a complex response that might serve a given species to adapt in its particular environment.