查看文章

Many plant-associated bacteria produce and utilize diffusible N-acyl-homoserine lactones (AHLs) to regulate the expression of specific bacterial genes and operons. AHL-mediated regulation utilizes two genes that encode proteins similar to the LuxI/LuxR system originally studied in the marine symbiont Vibrio fischeri. The LuxI-type proteins are AHL synthases that assemble the diffusible AHL signal. The LuxR-type proteins are AHL-responsive transcriptional regulatory proteins. LuxR proteins control the transcription of specific bacterial genes in response to the levels of AHL signal. To date, AHL-mediated gene regulation has been identified in a broad range of gram-negative bacteria, most of which are host-associated. However, it seems unlikely that such a widely conserved regulatory mechanism would be limited only to host-microbe interactions. These signals probably play central roles in ecological …