Pectobacterium carotovorum is a plant pathogen that causes bacterial soft rot in many agriculturally-relevant crops, including potatoes, carrots, and lettuce. Bacterial soft rot is responsible for severe economic losses each year; therefore, it is crucial to identify targets for combatting infection. Understanding the way that P. carotovorum mounts an attack against its host is pivotal to developing methods of control. Interestingly, P. carotovorum infections are stimulated by low-oxygen conditions, making its oxygen-sensing pathways a prime target for potential drugs. A key O2-sensing protein in P. carotovorum is a globin-coupled sensor (PccGCS) with three characteristic domains: a globin domain that binds oxygen, a middle domain of unknown function, and a diguanylate cyclase output domain that produces cyclic di-GMP (c-di-GMP), an important bacterial second messenger involved in biofilm formation. We have demonstrated that the deletion of PccGCS modulates P. carotovorum virulence by downregulating virulence factor excretion and significantly decreasing aerobic motility while having no effect on anaerobic motility. In addition, deletion of PccGCS results in increased levels of extracellular N-acylhomoserine lactone (AHL) production, while maintaining intracellular AHL levels. As AHLs are quorum sensing signals involved in regulating virulence, we are working to elucidate the links between O2-dependent globin coupled sensor signaling and quorum sensing pathways.

Elucidating the role of globin coupled sensors in Pectobacterium carotovorum virulence and quorum sensing pathways

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.