Abstract:N-acylhomoserine lactones (AHLs) serve as signal molecules of bacterial quorum sensing system, regulate virulence of several plant pathogens. The N-acylhomoserine lactonase (AHL-lactonase) hydrolyzes AHLs and attenuates the pathogenicity of plant pathogenic bacteria. A plant binary vector carrying aiiA under the control of 35s promoter was constructed into Arabidopsis thaliana by Agrobacterium mediated transformation. The homozygous transgenic plants seeds were botained by resistance screen. The gene transformation and expression was confirmed by PCR and RT-PCR respectively.The aiiA expressing transgenic A. thaliana showed an increased resistance to soft rot disease caused by Erwinia carotovora subsp.carotovora.