Erwinia amylovora causes fire blight of apple, pear, and other rosaceous plants and elicits plant defense responses in nonhost plants. Previous research indicated that a disease specific gene, dspE, from E. amylovora is essential for pathogenicity. DspE is a homolog of AvrE of Pseudomonas syringae. The LexA yeast-two-hybrid system was used to seek DspE-interacting proteins from apple to further explore its role in pathogenicity. Bait constructs consisting of several portions of the dspE gene were made in the expression vector pGlida. A representative cDNA library of apple (Malus x domestica cv. 'Royal Gala') was constructed in the vector pB42AD. 198 putative interacting clones were selected and re-screened to yield four unique, positive clones. A Blast search of cDNA sequences of the four clones indicated that all had protein kinase domains and belonged to LRR receptor-like kinases. The full-length sequences of the four clones were identified. Further characterization of the cDNAs and the encoded kinases are underway. Studies of the gene function are in progress.