Decaying signals: will understanding bacterial-plant communications lead to control of soft rot?

Soft rot pathogens cause significant losses worldwide in fruit and vegetable production during the growing season and after harvest. These pathogens engage in molecular interactions with their plant hosts via acyl-homoserine lactone (AHL) quorum sensing, pectin metabolites, phenolic acids, and auxin. The AHL-based interactions can be disrupted enzymatically or with chemical inhibitors, which in some cases, leads to disease control. Since the wisdom of disrupting AHL-based quorum sensing for control of an agricultural problem is questionable when this may be a useful target for control of human pathogens, development of other control mechanisms more specific to plant pathogens would be beneficial. The recent identification of plant-specific compounds used in plant-bacterial interactions, such as auxin, o-coumaric acid, t-cinnamaic acid, as well as analogs that inhibit pathways induced by these compounds, may lead to novel control mechanisms aimed specifically at managing plant-infecting bacteria.