Project description:The signal 3-OH-PAME produced by the phc QS system in Ralstonia solanacearum is a conserved and important quorum sensing signal molecule in this genus. This signal participates in the activation of signal transduction by the PhcA regulatory factor, regulating the transcriptional control of 30% of the genes in Ralstonia solanacearum. Quorum quenching technology is a biocontrol strategy that mediates quorum sensing regulatory networks, and has achieved very significant results in the study of quenching AHL and DSF signals. Previous studies identified HS-18 as a biocontrol bacterium with quorum sensing-inhibiting effects on multiple quorum sensing signals. This study aimed to identify quorum quenching enzymes capable of degrading 3-OH PAME using HS-18, identifying six enzymes encoded by genes that exhibit degradation activity toward 3-OH PAME. Among these, gene 12725 demonstrated the most significant quorum quenching effect, while genes 24610 and 03720 also exhibited strong quorum quenching activity. Additionally, these quench enzymes can reduce the pathogenicity of Ralstonia solanacearum on tomatoes, demonstrating promising application prospects.