The molecular characteristics of the ethylene-forming enzymes of strains of Pseudomonas syringae were tested. The ethylene-producing activities of the nine strains as measured in vivo and in vitro were similar, except for that of P. syringae pv. mori M5. A polyclonal antibody and a DNA probe for the ethylene-forming enzyme from P. syringae pv. phaseolicola PK2 were prepared to investigate homol...

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...

The bean (Phaseolus spp.) plant pathogen Pseudomonas syringae pv. phaseolicola is characterized by the ability to produce phaseolotoxin (Tox(+)). We recently reported that the majority of the Spanish P. syringae pv. phaseolicola population is unable to synthesize this toxin (Tox(-)). These Tox(-) isolates appear to lack the entire DNA region for the biosynthesis of phaseolotoxin (argK-tox gene ...

Many plant pathogens suppress antimicrobial defenses using virulence factors that modulate endogenous host defenses. The Pseudomonas syringae phytotoxin coronatine (COR) is believed to promote virulence by acting as a jasmonate analog, because COR-insensitive 1 (coil) Arabidopsis thaliana and tomato mutants are impaired in jasmonate signaling and exhibit reduced susceptibility to P. syringae. T...

Age-related resistance (ARR) has been observed in a number of plant species; however, little is known about the biochemical or molecular mechanisms involved in this response. Arabidopsis becomes more resistant, or less susceptible, to virulent Pseudomonas syringae (pv tomato or maculicola) as plants mature (in planta bacterial growth reduction of 10- to 100-fold). An ARR-like response also was ...

Pseudomonas syringae pv. actinidiae is a reemerging pathogen which causes bacterial canker of kiwifruit (Actinidia sp.). Since 2008, a global outbreak of P. syringae pv. actinidiae has occurred, and in 2010 this pathogen was detected in New Zealand. The economic impact and the development of resistance in P. syringae pv. actinidiae and other pathovars against antibiotics and copper sprays have ...

Strains of Pseudomonas syringae pv. syringae resistant to copper, streptomycin, or both compounds were recovered from symptomless and diseased tissue of four woody hosts in three nurseries in Oklahoma. In strains resistant to copper and streptomycin (Cur Smr), resistance to both compounds was cotransferred with a single plasmid which was either 68, 190, or 220 kilobase pairs (kb). All Cus Smr s...

To assess the role of MORC1 in epigenetics in relation to plant immunity, genome-wide chromatin accessibility was compared between mock- or Pseudomonas syringae pv. tomato-inoculated wild type (WT) Arabidopsis, the morc1/2 double mutant, or both. Most changes in chromatin accessibility, scored by DNase I hypersensitive sites (DHSs), were located in the promoters of genes and transposable elemen...