We investigated indole-3-acetic acid (IAA) production by 57 pathovars of Pseudomonas syringae and related species. Most of those analyzed produced IAA, especially in the presence of tryptophan. Eight strains produced high IAA concentrations in the absence of Trp. The iaaM and iaaH genes of P. savastanoi pv. savastanoi were detected in a limited number of strains only, including the eight above-...

Pseudomonas syringae pv. syringae, like many plant pathogenic bacteria, secretes a 'harpin' protein that can elicit the hypersensitive response (HR), a defensive cellular suicide, in non-host plants. The harpin-encoding hrpZ gene is located in an operon that also encodes Hrp secretion pathway components and is part of the functional cluster of hrp genes carried on cosmid pHIR11 that enables sap...

Many strains of Pseudomonas syringae pv. syringae produce one of four classes of small cyclic lipodepsinonapeptides: syringomycins, syringostatins, syringotoxins, or pseudomycins. These metabolites are phytotoxic and growth inhibitory against a broad spectrum of fungi. Their production is dependent upon the expression of conserved biosynthesis and export genes syrB and syrD, respectively. PCR a...

The natural occurrence of Pseudomonas syringae pv. tabaci causing leaf spot symptoms in papaya seedlings is reported. The pathogen was identified through biochemical, physiological, serological, and molecular assays and artificial inoculations in papaya plants. It was also shown that the strains were pathogenic to bean and tobacco plants. The restriction patterns obtained with Afa I, Alu I, Dde...

Several pathovars of Pseudomonas syringae produce the phytotoxin coronatine (COR), which contains an unusual amino acid, the 1-amino-2-ethylcyclopropane carboxylic acid called coronamic acid (CMA), which is covalently linked to a polyketide-derived carboxylic acid, coronafacic acid, by an amide bond. The region of the COR biosynthetic gene cluster proposed to be responsible for CMA biosynthesis...

We present the first complete genome sequence of a copper-resistant biovar 5 strain of a bacterial pathogen of kiwifruit, Pseudomonas syringae pv. actinidiae. Comparison with the genome sequence of a copper-sensitive biovar 5 isolate indicates that copper resistance is encoded on a plasmid.

Pseudomonas syringae pv. tomato DC3000 contains genes for 15 sigma factors. The majority are members of the extracytoplasmic function class of sigma factors, including five that belong to the iron starvation subgroup. In this study, we identified the genes controlled by three iron starvation sigma factors. Their regulons are composed of a small number of genes likely to be involved in iron uptake.