| Abstract：Some virulence genes in bacterial community would be activated responding to N-acyl-homoserine lactones (AHLs), while Bacillus sp. can express AiiA to degrade the AHLs and thus alleviate the damage of pathogenic bacteria. In order to construct an engineering strain which can efficiently express AiiA to degrade AHLs and prevent bacterial plant diseases, P43-aiiA fragment was amplified by SOE PCR and connected to the pHY300PLK vector. Bacillus subtilis strain P43-aiiA-C11 was constructed and its AiiA enzyme activity was detected. P43-aiiA was successfully amplified and P43-aiiA-pHY300PLK was successfully transferred into C11 strain. AiiA activity detection showed that all the indicator bacteria turned blue in wild strain group, the blue of the indicator bacteria in the three parallel experimental groups became light in the middle of the strip culture medium, and all the lower colonies was white, indicating that the P43-aiiA-C11 strain has higher quenching enzyme activity than the wild strain and could obviously degrade signal molecules. Compared with the wild strain, P43-aiiA-C11 strain has significant ability to degrade AHLs. The results of this study provide an important theoretical basis for promoting the plant disease biocontrol. |
