Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Review Article
Publication Acceptance Date: 1/31/2008
Publication Date: 6/1/2008
Citation: Lindeberg, M., Myers, C., Collmer, A., Schneider, D.J. 2008. Roadmap to new virulence determinants in Pseudomonas syringae: Insights from Comparative Genomics and Genome Organization. Molecular Plant-Microbe Interactions. 21:685-700. Interpretive Summary:
Technical Abstract: Systematic comparison of the current repertoire of virulence and host-association genes for three Pseudomonas syringae strains with complete genome sequences P. syringae pv. tomato DC3000, P. syringae pv. phaseolicola 1448A, and P. syringae pv. syringae B728a, is prompted by recent advances in virulence factor identification in P. syringae and other bacteria. Among these are genes linked to epiphytic fitness, plant- and insect-active toxins, secretion pathways, and virulence regulators. Distribution of virulence genes in relation to P. syringae genome organization was analyzed to distinguish patterns of conservation among genomes and association between genes and with mobile genetic elements. Variable regions were identified on the basis of deviation in sequence composition and gaps in syntenic alignment among the three genomes. Mapping gene location relative to the genome structure revealed strong segregation of the HrpL regulon with variable genome regions, divergent distribution patterns for toxin genes depending on association with plant or insect pathogenesis, and patterns of distribution for other virulence factors that highlight potential sources of strain-to-strain differences in host interaction. The roles of ICElands, phage, and IS elements in shaping genome structure is discussed as is distribution of genes in the variable regions of P. syringae pv. tomato DC3000 among other sequenced bacterial genomes.