title: Pseudomonas syringae pv. phaseolicola: from 'has bean' to supermodel.
abstract: Pseudomonas syringae pv. phaseolicola causes halo blight of the common bean, Phaseolus vulgaris, worldwide and remains difficult to control. Races of the pathogen cause either disease symptoms or a resistant hypersensitive response on a series of differentially reacting bean cultivars. The molecular genetics of the interaction between P. syringae pv. phaseolicola and bean, and the evolution of bacterial virulence, have been investigated in depth and this research has led to important discoveries in the field of plant-microbe interactions. In this review, we discuss several of the areas of study that chart the rise of P. syringae pv. phaseolicola from a common pathogen of bean plants to a molecular plant-pathogen supermodel bacterium.
  
  
  METHODS
  Bacteria; Proteobacteria, gamma subdivision; order Pseudomonadales; family Pseudomonadaceae; genus Pseudomonas; species Pseudomonas syringae; Genomospecies 2; pathogenic variety phaseolicola.
  Gram-negative, aerobic, motile, rod-shaped, 1.5 µm long, 0.7-1.2 µm in diameter, at least one polar flagellum, optimal temperatures for growth of 25-30°C, oxidase negative, arginine dihydrolase negative, levan positive and elicits the hypersensitive response on tobacco.
  
  
  METHODS
  Major bacterial disease of common bean (Phaseolus vulgaris) in temperate regions and above medium altitudes in the tropics. Natural infections have been recorded on several other legume species, including all members of the tribe Phaseoleae with the exception of Desmodium spp. and Pisum sativum.
  
  
  METHODS
  Water-soaked lesions on leaves, pods, stems or petioles, that quickly develop greenish-yellow haloes on leaves at temperatures of less than 23°C. Infected seeds may be symptomless, or have wrinkled or buttery-yellow patches on the seed coat. Seedling infection is recognized by general chlorosis, stunting and distortion of growth.
  
  
  BACKGROUND
  Seed borne and disseminated from exudation by water-splash and wind occurring during rainfall. Bacteria invade through wounds and natural openings (notably stomata). Weedy and cultivated alternative hosts may also harbour the bacterium.
  
  
  RESULTS
  Some measure of control is achieved with copper formulations and streptomycin. Pathogen-free seed and resistant cultivars are recommended.
  
  
  BACKGROUND
  Pseudomonas-plant interaction http://www.pseudomonas-syringae.org/; PseudoDB http://xbase.bham.ac.uk/pseudodb/; Plant Associated and Environmental Microbes Database (PAMDB) http://genome.ppws.vt.edu/cgi-bin/MLST/home.pl; PseudoMLSA Database http://www.uib.es/microbiologiaBD/Welcome.html.
authors: Centre for Research in Plant Science, University of the West of England, Bristol BS16 1QY, UK. dawn.arnold@uwe.ac.uk
authors: Dawn L
authors: DL
authors: Arnold
authors: Helen C
authors: HC
authors: Lovell
authors: Robert W
authors: RW
authors: Jackson
authors: John W
authors: JW
authors: Mansfield
mesh_terms: D007887:Fabaceae / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology; D044224:Pseudomonas syringae / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*