Fig. 1
Pathogenicity tests results and virulence factors profile of the analyzed Pseudomonas syringae strains. Strains sequenced in this study are indicated in bold. Strains are ordered based on the core-genome. Approximately Maximum-Likelihood phylogenetic tree constructed on the similarity of 2085 protein sequences corresponding to a total alignment length of 840,202 amino acids per genome. The local support values computed using the Shimodaira-Hasegawa test are indicated close to the nodes. The tree was generated using EDGAR v.2.2 [53]. The strain names refer to the code field from Table 1. Phylogroups (PGs) are reported on the left and are separated by horizontal dashed lines whereas clades are reported on the right and are separated by horizontal dotted lines. Results of the pathogenicity tests performed on immature cherry fruitlets, peach and almond detached leaves are reported in the first three columns (see graphical legend). No pathogenicity test was performed for strains displaying a X sign in a white square. A strain was defined as possessing T3SS2, a second cluster encoding for a type III 3 secretion system (T3SS) homologous to the one found in rhizobia, if at least 22 out of the 27 genes constituting this system were retrieved. Presence (black) and absence (white) of clusters for biosynthesis and regulations of the known phytohormones (pink) and phytotoxins (blue) is also reported. The generation time in hours was derived from the slope of the logarithmic (log10) growth curve. IaaM (tryptophan monooxygenase) and IaaH (indoleacetamide hydrolase) are responsible for the synthesis of auxin whereas IaaL (indole-acetic acid-lysine synthase) is conjugating auxin to lysine decreasing the concentration of the active form of auxin. Locus tags used for the genotypic screening are reported in Additional file 1: Tables S1 and S2. N.D.: not determined