Plant-bacterial pathogen interaction modified in transgenic tomato plants expressing the Gox gene encoding glucose oxidase

Transgenic tomato (L. esculentum Mill.) plants containing the Gox gene encoding glucose oxidase from Aspergillus niger were obtained in two near isogenic lines (NIL) except for the Pto gene (“Riogrande” +/+ and “Rimone” Pto/Pto). T3 transgenic plants possessing a single Gox gene copy were tested for resistance to Pseudomonas syringae pv. tomato to ascertain the role of H2O2 in plant pathogenesis response. Reactive oxygen species (ROS) such as H2O2 are generated following pathogen recognition, and they act both as cellular signalling molecules and as direct antimicrobial agents. In transgenic tomato plants, glucose oxidase generating H2O2 seems to confer to the susceptible isogenic tomato line Riogrande) the capacity to respond actively to P. syringae pv. tomato by reducing the number of viable bacterial cells in the inoculated leaves. The effect on Xanthomonas campestris pv. vesicatoria infection and the possible synergistic action between a non-specific gene as Gox, and a race-specific gene as Pto is then discussed.