Table 1.
Bacterial strains and plasmids.
Table 2.
PCR amplification of integron-related genes from streptomycin-sensitive and -resistant isolates of X. oryzae pv. oryzaea.
Figure 1.
Structural organization of integrons in four resistant isolates of Xanthomonas oryzae pv. oryzae.
A. YNA7-1 and YNA11-2; B. YNA10-2; C. YNA12-2. The complete sequences of the resistance integrons in the four resistant isolates through PCR with primer pairs TniR-a and IRI, TniaR and TniA. The resistance integrons in YNA7-1, YNA10-2, YNA11-2, and YNA12-2 contained 7790, 7162, 7790, and 7240 bp, respectively. The sequence of tni module was long and not completely shown in this figure. The sequences of the resistance integrons of YNA7-1 and YNA11-2 were identical. Compared with YNA7-1 and YNA11-2, the sequence from position 1350 to 1977 was absent in the resistance integron of YNA10-2, and the sequence from 791 to 1340 was absent in the resistance integron of YNA12-2. Location of some primers used for PCR is shown in the figure. P1 and p2 are promoter areas of integrons.
Table 3.
Characteristics of resistance integrons in four resistant isolates of X. oryzae pv. oryzae.
Table 4.
Predicted genes in resistance integrons in four resistant isolates of X. oryzae pv. oryzae and the alignment of these genes relative to those in GenBank.
Table 5.
The MIC (minimum inhibitory concentration, µg/ml) of X. oryzae pv. oxyzae isolates to diverse antibiotics.
Figure 2.
Construction and analysis of resistance gene mutants.
A. Schematic representation of homologous single recombination between a target resistance gene fragment cloned in pMD18-T and the target resistance gene in YNA11-2. Location of primers used for PCR is shown in the figure. The shaded box areas represent the target resistance gene while the lightly shaded area represents a cloned resistance gene fragment where homologous recombination occurred between pMD18-T and the genome of YNA11-2. When the mutant MaacA3 was analyzed, the primer accyan1-S, accyan1-A, accyan2-S and accyan2-A were used as the p1-S, p1-A, p2-S and p2-A, respectively. When the mutant Marr3 was analyzed, the primer arryan2-S, arryan2-A, arryan4-S and arryan4-A were used as the p1-S, p1-A, p2-S and p2-A, respectively. When the mutant MaadA1 was analyzed, the primer aadayan4-S, aadayan4-A, aadayan5-S and aadayan5-A were used as the p1-S, p1-A, p2-S and p2-A, respectively. B. Electrophoresis of three resistance genes fragments and PCR identification of three mutants. M1, DNA markers; Lane 1–3, PCR products of three resistance genes fragments FaacA3, Farr3 and FaadA1; Lane 4–9, PCR products of MaacA3 with primer pairs p1 and p2, PCR products of Marr3 with primer pairs p1 and p2, PCR products of MaadA1 with primer pairs p1 and p2; M2, DNA markers.