The Enzymatic Degradation of Quorum-Sensing Signals to Decrease Bacterial Phytopathogenicity

Quorum-sensing (QS) allows bacterial populations to coordinate gene expression in a cell-density dependent manner and plays a significant role in plant pathogenesis. In gram-negative bacteria, QS is mediated by signaling molecules called acyl-homoserine lactones (AHLs). Our technological innovation is the use of an AHL-degrading enzyme to inactivate the AHL signals of bacterial phytopathogens and reduce their abilities to cause plant disease. Our first objective is to produce the enzyme in both bacterial and plant systems and test its efficacy against signal molecules. Our second objective is to test the ability of the enzyme to reduce disease caused by numerous phytopathogens, either through exogenous application of the heterologous protein or through the use of a producing bacterial strain as a biocontrol agent. Our goals are to demonstrate that the enzymatic degradation of AHLs can be utilized for the control of diseases and to understand the importance of quorum-sensing signal degradation in bacterial infection.