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Over 30 closed and draft <i>P. syringae</i> genome sequences are now publically available with 57 Type III effector families confirmed and likely representing the near-complete super-repertoire for the species. The type III effectors have proven to be important tools for deconvoluting the intricate network of defense responses in diverse host plants, and the accumulated data on their activities have revealed the central role they play in suppression of the 2-layered plant defense response composed of PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). A core set of effectors is widely distributed among the sequenced strains and acts by disrupting vesicular trafficking critical to effective PTI, while other less well-conserved effectors inhibit various stages in PAMP perception through interference with signaling kinases. As host plants have evolved to recognize and trigger immunity in response to PTI-suppressing effectors, additional effectors have been deployed by the pathogen to disrupt ETI, contributing to an endless evolutionary cycle of detection and evasion. Insights into coordinated functional roles of individual effectors are revealed through analysis of effector family distribution among the major <i>P. syringae</i> clades and by disassembly and reassembly of the effector repertoire of <i>P. syringae</i> pv <i>tomato</i> DC3000. Distribution of effectors among sequenced genomes and documentation of their cellular locations, molecular functions, and involvement in diverse biological processes as captured using Gene Ontology Annotation can be found at the PPI Website (http://www.pseudomonas-syringae.org/).<p><p>Keywords: