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The plant pathogen <i>Pectobacterium carotovorum</i> subsp. <i>carotovorum</i> (previously <i>Erwinia carotovora</i> subsp. <i>carotovora</i>) causes soft rot and stem rot diseases in a variety of crops, including Chinese cabbage, potato, and tomato. The flagellar-type III secretion systems were used by <i>Pcc</i>’s virulence mechanism to export proteins or bacteriocins to the outside of the cell. DGC, a virulence factor that cyclizes c-di-GMP, a common secondary signal in physiological processes and toxin control systems of many bacteria, was discovered in <i>Pcc</i>’s genomic DNA. The <i>dgc</i> gene in <i>Pcc</i> was blocked using the method of homologous recombination in our study. In the in vivo setting, the results demonstrated that the <i>dgc</i> knockout strain does not release low molecular weight bacteriocins. The bacteriocin gene (<i>carocin S2</i>, <i>carocin S3</i>, <i>carocin S4</i>) and the flagellar-type III secretion system genes were also unable to be transcribed by the <i>dgc</i> knockout strain in the transcription experiment. We also observed that the amount of bacteriocin expressed changed when the amount of L-glutamine in the environment exceeded a particular level. These data suggested that L-glutamine influenced physiological processes in <i>Pcc</i> strains in some way. We hypothesized a relationship between <i>dgc</i> and the genes involved in <i>Pcc</i> LMWB external export via the flagellar-type secretion system based on these findings. In this study, the current findings led us to propose a mechanism in which DGC’s cyclic di-GMP might bind to receptor proteins and positively regulate bacteriocin transcription as well as the synthesis, mobility, and transport of toxins.