Exploiting Novel Pseudomonas Syringae Bacteriocins as Antibacterials

This invention relates to a method of controlling phytopathogens through bacteriocin-mediated inhibition of bacterial plant pathogens. This method reduces the number of bacteria found on the surface of a plant. Specifically, this invention relates in one embodiment to Pseudomonas syringae (P. syringae) strains tailored to controlling phytopathogens.

Background:

Pseudomonas syringae (P. syringae) is a phenotypically and ecologically diverse plant pathogen able to infect an array of host plants. Species of P. syringae is divided (largely based on phenotype) into 50 pathovars that cause a variety of diseases (such as bacterial speck, spot, blight, galls, and cankers) on a remarkable range of plant hosts including apples, beans, cucumbers, oats, peas, tomato, tobacco, and rice, as well as other ornamental and crop plants. P. syringae causes economically important crop losses in the U.S. including losses to various fruit trees, cruciferous, and tomatoes, among others. In addition to current crop losses sustained by P. syringae, this group of closely related pathogens present a perpetual risk to worldwide agriculture because of their high degree of genomic plasticity where they regularly acquire genetic material from environmental sources.
 

Control strategies that have been historically used, including copper-based bactericides and antibiotics (chiefly oxytetracycline and streptomycin), have largely lost their efficacy due to the acquisition and dissemination of resistance genes in pathogen populations. Alternative methods for controlling bacterial plant diseases, include cultivation of naturally resistant varieties, developing crops with enhanced resistance through traditional breeding programs, or engineering crops for resistance through introduction of resistance (R) genes.
 

Advantages:

• Invention is specific to its target spectrum, not selecting for maintenance of resistance genes within a bacterial community
• Targets receptors important for cell host fitness, making it less likely that the targeted pathogens will mutate to confer bacteriocin resistance
• Largely environmentally benign due to narrow killing activity spectra
• Can be used to target a broad range of plant pathogenic or commensal bacteria
• Non-pathogenic to humans

Applications:

• Control strategy for plant-diseases and for bacterial pathogen targeting
• Protect crops from a diver array of plant pathogens.
• Can be sold commercially to home consumers to protect their flora
• These bacteriocins and their peptide compositions can be used to inhibit bacterial plant pathogens and control phytopathogens in the agricultural market