Quorum Quenching\nLactonase Alters Virulence of Pectobacterium atrosepticum and Reduces Maceration\nin Potatoes

Pectobacterium atrosepticum is a\nsoft rot phytopathogenic bacterium mainly infecting potatoes. The\nvirulence of P. atrosepticum is controlled\nby quorum sensing (QS), a communication mechanism which enables bacteria\nto coordinate their behavior in a population density-dependent manner.\nInhibiting QS has gained interest as a sustainable alternative to\nconventional treatments to control pathogens in agriculture. Here,\nwe investigate the potential of a robust lactonase to inhibit P. atrosepticum virulence in vitro, combining phenotypic\nand proteomic studies. We report that exogenous lactonase treatment\nreduced the secretion of pectate lyase, cellulase, and polygalacturonase\nenzymes, leading to decreased virulence on potato tubers. Major changes\nin the P. atrosepticum proteome revealed\nthat lactonase affects the abundance of proteins with various functions,\nincluding virulence. Taken as a whole, these results suggest that\nlactonase-mediated disruption of QS in P. atrosepticum is a promising strategy to limit P. atrosepticum infections.