Molecular and Physiological Characterization of Pseudomonas syringae pv. tomato and Pseudomonas syringae pv. maculicola Strains That Produce the Phytotoxin Coronatine

Comparison of the complete genome sequences of Pseudomonas syringae pv. syringae B728a and pv. tomato DC3000.

The complete genomic sequence of Pseudomonas syringae pv. syringae B728a (Pss B728a) has been determined and is compared with that of P. syringae pv. tomato DC3000 (Pst DC3000). The two pathovars of this economically important species of plant pathogenic bacteria differ in host range and other interactions with plants, with Pss having a more pronounced epiphytic stage of growth and higher abiot...

Characterization of alginate lyase from Pseudomonas syringae pv. syringae.

The gene encoding alginate lyase (algL) in Pseudomonas syringae pv. syringae was cloned, sequenced, and overexpressed in Escherichia coli. Alginate lyase activity was optimal when the pH was 7.0 and when assays were conducted at 42 degrees C in the presence of 0.2 M NaCl. In substrate specificity studies, AlgL from P. syringae showed a preference for deacetylated polymannuronic acid. Sequence a...

Assessment of Resistance to Antibiotics in Pseudomonas syringae pv. syringae Phytotoxin Secretion Mutants

Novel virulence gene of Pseudomonas syringae pv. tomato strain DC3000.

Previously, we conducted a mutant screen of Pseudomonas syringae pv. tomato strain DC3000 to identify genes that contribute to virulence on Arabidopsis thaliana plants. Here we describe the characterization of one mutant strain, DB4H2, which contains a single Tn5 insertion in PSPTO3576, an open reading frame that is predicted to encode a protein belonging to the TetR family of transcriptional r...

Regulation of alginate biosynthesis in Pseudomonas syringae pv. syringae.

Both Pseudomonas aeruginosa and the phytopathogen P. syringae produce the exopolysaccharide alginate. However, the environmental signals that trigger alginate gene expression in P. syringae are different from those in P. aeruginosa with copper being a major signal in P. syringae. In P. aeruginosa, the alternate sigma factor encoded by algT (sigma22) and the response regulator AlgR1 are required...