The RT reaction was performed at

50°C for 30 min. PCR amplification was performed at 94°C for 2 min for 1 cycle; 94°C for 30 s, 55–58°C for 30 s, and 72°C for 1.0 min for 20–28 cycles; and 72°C for 10 min for 1 cycle . Molecular biology techniques Routine techniques were performed using buy MK-8776 standard protocols [69]. Genomic DNA of P. syringae pv. phaseolicola NPS3121 was isolated as described previously [70]. PCR products were amplified with Platinum supermix (Invitrogen). Primers were designed using Vector NTI Software (Invitrogen), with reference to the previously reported sequence of the 1448A strain (Gene Bank S3I-201 supplier accession no. CP000058) [18]. The oligonucleotide primers used in this study are listed in Additional file 1. Motility assays To evaluate the motility of P. syringae pv. phaseolicola NPS3121 and the influence of temperature on this process, three strategies were used. The SIS3 swimming and swarming motility of P. syringae pv. phaseolicola NPS3121 were assessed on semisolid KB plates containing 0.3% and 0.5% agar, respectively, as described in previous studies [41, 42]. The cells were grown in KB broth overnight

at 28°C, and harvested and resuspended in KB to OD600 = 1. 50 μL of bacterial suspensions were inoculated on filter disks (6 mm in diameter) and placed in the center of the plate. Plates were incubated for 24 h at 28°C and 18°C before photography. A second strategy was performed to evaluate the swimming and swarming motility of P. syringae pv. phaseolicola NPS3121. To ensure that the bacteria were in the same physiological condition as when the transcriptome analysis was performed, the P. syringae pv. phaseolicola NPS3121 strain was grown in M9 media at 28°C and 18°C until they reached the transition phase. Bacterial DAPT suspensions (50 μL) were inoculated on filter disks (6 mm in diameter) and placed in the center of semisolid M9 plates containing 0.3%, 0.4%, and 0.5% agar. Plates were incubated for 48 h at 28°C and 18°C. Finally, motility was also evaluated using the stab technique in semisolid

KB and M9 media (0.3% and 0.5% agar) in glass tubes. The tubes were incubated at 28°C and 18°C for 48 h. As controls, we used the P. syringae strains pv. tomato DC3000 and pv. tabaci PTBR2004. Experiments were performed three times with three replicates per treatment. Quantification of siderophores Siderophore production into the culture supernatant by bacterial strains was determined using chrome azurol S (CAS) liquid assays as previously described [71]. Briefly, the P. syringae pv. phaseolicola NPS3121 strain was grown in M9 media at 28°C and 18°C until they reached the transition phase. The supernatant was recovered by centrifugation at 8,000 rpm for 15 min at 4°C and filtered through a 0.45-μm-pore-size filter (Millipore). For siderophore quantification, a standard curve was prepared with desferoxamine mesylate. Experiments were performed three times with four replicates per treatment.