Fig 5. Expression of defense and stress marker genes in leaves infected with Xe overexpressing XopAU.

Leaves of the pepper line ECW30R were syringe-infiltrated with a 10 mM MgCl₂ mock solution (Mock) or with suspensions (1 x 10⁷ CFU/ml) of Xe strains carrying a vector either empty (EV) or for expression of XopAU-HA or XopAU_K240A-HA. (A) Total protein was extracted from the infected leaves at the indicated days post-inoculation (dpi) and immunoblotted with the indicated antibodies. Rbs, Rubisco loading control stained by Ponceau S. (B) mRNA abundance of the indicated genes in the inoculated areas was measured by qRT-PCR at 16 h post-inoculation and calculated relative to areas inoculated with the Xe strain carrying an empty vector. Values are means ± SE of three biological repeats. Asterisks indicate a significant difference (Student’s t test, p value < 0.05) relative to Xe containing an empty vector. (C) Leaves were infiltrated with bacterial suspensions (1 x 10⁵ CFU/ml) of Xe strains carrying a vector either empty (EV) or for expression of XopAU-HA or XopAU_K240A-HA, and bacterial growth was quantified at the indicated dpi. A box plot displays 25^th, 50^th (middle line) and 75^th percentiles (n = 5). Asterisks indicate a significant difference (Mann-Whitney U test, p value <0.05) relative to Xe containing an empty vector. Experiments were repeated at least three times with similar results.