Comparative genomics of Pseudomonas syringae pv. syringae strains B301D and HS191 and insights into intrapathovar traits associated with plant pathogenesis.
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. Intrapathovar comparisons of the B301D (6.09 Mb) and HS191 (5.95 Mb plus a 52 kb pCG131 plasmid) genomes to the previously sequenced B728a genome demonstrated that the shared genes encompass about 83% of each genome, and include genes for siderophore biosynthesis, osmotolerance, and extracellular polysaccharide production. Between 7% and 12% of the genes are unique among the genomes, and most of the unique gene regions carry transposons, phage elements, or IS elements associated with horizontal gene transfer. Differences are observed in the type III effector composition for the three strains that likely influences host range. The HS191 genome had the largest number at 25 of effector genes, and seven effector genes are specific to this monocot strain. Toxin production is another major trait associated with virulence of P. syringae pv. syringae, and HS191 is distinguished by genes for production of syringopeptin SP25 and mangotoxin.
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132.
Aravind
A
Ravindran
Department of Microbiology and Cell Sciences, Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850.
Neha
N
Jalan
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132.
Joshua S
JS
Yuan
Department of Microbiology and Cell Sciences, Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, Florida, 33850.
Nian
N
Wang
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, 77843-2132.
Dennis C
DC
Gross
D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D044224:Pseudomonas syringae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics*
D004269:DNA, Bacterial; D037521:Virulence Factors
Comparative genomics; Pseudomonas syringae; effector gene; genome sequence; plant pathogen