Positive chemotaxis to plant apoplastic fluids of Pseudomonas syringae pv. tabaci 6605 and metabolome analysis

Pseudomonas syringae pv. tabaci 6605 ( Pta 6605) is a causal agent of wildfire disease in host tobacco plants. Although chemotaxis has been shown to be necessary for Pta 6605 in tobacco infection, the chemoattractants at the site of infection are unclear. Pta 6605 was attracted to the apoplastic fluid from not only host tobacco leaves but also non-host plant leaves, indicating that Pta 6605 is attracted to common plant metabolites. Metabolome analysis of apoplastic fluid from tobacco leaves revealed that amino acids including γ-aminobutyric acid and organic acids are abundant, suggesting that these compounds are potential chemoattractants.