Pseudomonas syringae is a member of an important group of Gram-negative bacterial pathogens of plants and animals that depend on a type III secretion system to inject virulence effector proteins into host cells. In P. syringae, hrp/hrc genes encode the Hrp (type III secretion) system, and avirulence (avr) and Hrp-dependent outer protein (hop) genes encode effector proteins. The hrp/hrc genes of...

Previously we revealed that flagellin proteins in Pseudomonas syringae pv. tabaci 6605 (Pta 6605) were glycosylated with a trisaccharide, modified viosamine (mVio)-rhamnose-rhamnose and that glycosylation was required for virulence. We further identified some glycosylation-related genes, including vioA, vioB, vioT, fgt1, and fgt2. In this study, we newly identified vioR and vioM in a so-called ...

Coronamic acid (CMA; 2-ethyl-1-aminocyclopropane 1-carboxylic acid) is an intermediate in the biosynthesis of coronatine (COR), a chlorosis-inducing phytotoxin produced by Pseudomonas syringae pv. glycinea PG4180. Tn5 mutagenesis and substrate feeding studies were previously used to characterize regions of the COR biosynthetic gene cluster required for synthesis of coronafacic acid and CMA, whi...

Pseudomonas syringae strains deliver variable numbers of type III effector proteins into plant cells during infection. These proteins are required for virulence, because strains incapable of delivering them are nonpathogenic. We implemented a whole-genome, high-throughput screen for identifying P. syringae type III effector genes. The screen relied on FACS and an arabinose-inducible hrpL sigma ...

Pseudomonas syringae pv. syringae is a common plant-associated bacterium that causes diseases of both monocot and dicot plants worldwide. To help delineate traits critical to adaptation and survival in the plant environment, we generated complete genome sequences of P. syringae pv. syringae strains B301D and HS191, which represent dicot and monocot strains with distinct host specificities. Intr...

Syringomycin is a lipodepsinonapeptide phytotoxin synthesized by Pseudomonas syringae pv. syringae on multienzymatic peptide synthetases. Sequence analysis of the interval between the syrB and syrD genes of P. syringae pv. syringae strain B301D revealed a 1,059-bp open reading frame (ORF), designated syrP. The predicted product of this ORF was a 39.6-kDa protein consisting of 353 amino acid res...

Pseudomonas aeruginosa and the phytopathogen P. syringae produce the exopolysaccharide alginate, which is a copolymer of D-mannuronic and L-guluronic acids. One of the key regulatory genes controlling alginate biosynthesis in P. aeruginosa is algT, which encodes the alternate sigma factor, sigma(22). In the present study, the algT gene product from P. syringae pv. syringae showed 90% amino acid...

Strains of Pseudomonas syringae able to grow on minimal medium containing 500 mg/litre of copper sulphate were selected from a collection of streptomycin-resistant strains isolated in New Zealand. From one of these copper-resistant strains a 1.3 kb fragment of DNA was isolated by PCR using primers designed on genes reported to be associated with copper resistance. Sequencing of this fragment re...