Adsorption of OP1-related bacteriophages requires the gene encoding a TonB-dependent receptor-like protein in Xanthomonasoryzae pv. oryzae

Xanthomonas oryzae pv. oryzae strain T7174R is lysed by bacteriophage OP_1h and OP_1h2. Three mutants tolerant to both OP_1h and OP_1h2 were isolated by transposon mutagenesis. The mutants had an insertion of the transposon in XOO1687, which is predicted to encode a TonB-dependent receptor gene. Plasmid pHMIroNB that contained XOO1687 of T7174R was constructed, and the mutant was transformed with the plasmid. The transformant recovered sensitivity to OP_1h and OP_1h2. Electron microscopic analysis demonstrated that OP_1h and OP_1h2 can adsorb to the wild type and the transformant, but they could not adsorb to the phage-tolerant mutant. These results suggest that the TonB-dependent receptor gene relates to adsorption and infection of T7174R by OP_1h2 and OP_1h. Y. Inoue and S. Tsuge have contributed equally to this work.