Fig. 5. Differential expression of SlPub24 in the resistant line PI 114490 and the susceptible line OH 88119 during infection by Xanthomonas euvesicatoria pv. perforans race T3 strain Xv829 is caused by sequence variation in the promoter.

a Expression of SlPub24 in PI 114490 and OH 88119 at various time points after spray inoculation with Xv829. b Schematic diagram of the vector construct. pSlPub24PI::GUS: The SlPub24 promoter isolated from PI 114490 was fused with the GUS reporter. pSlPub24OH::GUS: The SlPub24 promoter isolated from OH 88119 was fused with the GUS reporter. GUS β-glucuronidase, LB left border, NOS-T Nos terminator, RB right border. Agrobacterium tumefaciens GV3101 was used as a negative control, and pCaMV35S::GUS was used as a positive control. c GUS activity in leaves of Nicotiana benthamiana transiently expressing the pSlPub24PI::GUS or pSlPub24OH::GUS constructs. Error bars represent the SD (n = 6). d GUS activity in tomato leaves transiently expressing the pSlPUB24OH::GUS and pSlPUB24PI::GUS constructs at various hours after spray inoculation of Xv829. Agrobacterium strains carrying the constructs were infiltrated into tomato leaves at 48 h before inoculation with Xv829. e Schematic diagram of the vector construct. SlPub24PI::CDS-PI: the SlPup24 coding sequence (CDS) from PI 114490 driven by promoter from PI 114490; SlPub24PI::CDS-OH: the SlPub24 CDS from OH 88119 driven by promoter from PI 114490; SlPub24OH::CDS-PI: the SlPub24 CDS from PI 114490 driven by promoter from OH 88119. f Bacterial population in leaves of OH 88119 plants transiently expressing constructs SlPub24PI::CDS-PI, SlPub24PI::CDS-OH, and SlPub24OH::CDS-PI. Error bars represent the SD (n = 6). The asterisks indicate statistical significance by t test (*P < 0.05)