Mechanisms of Enterobacterales Plant Necrotrophy and Host Specificity: Two Types of Bacterial Necrotroph

Necrotrophic bacteria within the order Enterobacterales cause significant agricultural losses, with few effective management options available for producers. These pathogens have evolved at least two distinct strategies for infecting plants. Soft rot pathogens in the family Pectobacteriaceae, such as Dickeya and Pectobacterium , rely on secreting plant cell wall–degrading enzymes. In contrast, Pantoea necrotrophs depend on the production of phosphonate phytotoxins, a type of secondary metabolite, for their pathogenicity. This review summarizes recent discoveries on the virulence mechanisms of bacterial necrotrophs and current knowledge of factors that influence their host range and interactions with plant immune defenses. A deeper understanding of bacterial necrotroph host range determinants could inform the development and deployment of enhanced genetic resistance strategies.