Figure 2.

Expression of plant defence genes in bacterized melon plants in response to powdery mildew. Plants were bacterized and inoculated with P. fusca as described in Experimental procedures. Total RNA was isolated at different time points, and the relative expression of LOX2 (lipoxygenase 2), PR-1 and PR-9 (peroxidase) genes was analysed by quantitative RT-PCR. Expression levels were normalized to the endogenous control gen ACT1 (actin). Relative expression was calibrated to the untreated control 24 h post inoculation. Data shown represent average values from three independent experiments, with error bars depicting standard error. Asterisks indicate statistically significant different gene expression levels compared with untreated control (LSD test; P = 0.05).