Fig. 7.

Silencing of CaChitIV and/or CaPIK1 in pepper plants enhances susceptibility to infection with virulent Ds1 (compatible) and avirulent Bv5-4a (incompatible) strains of Xanthomonas campestris pv. vesicatoria (Xcv). (A) Bacterial growth in leaves of pepper plants infiltrated with empty vector control (TRV:00) or with gene silencing constructs TRV:CaChitIV, TRV:CaPIK1, or TRV:CaChitIV/TRV:CaPIK1, and then infected with Xcv (5×10⁴ cfu ml^–1). (B) Quantification of electrolyte leakage from leaves infected with Xcv (5×10⁷ cfu ml^–1). (C) Quantification of H₂O₂ accumulation in leaves infected with Xcv (5×10⁷ cfuml^–1). Data are means ±standard deviations from three, independent experiments. Letters above the bars in A–C indicate statistically significant differences between treatments, according to the LSD test (P<0.05).