<i>sX13</i> contributes to bacterial growth in culture and virulence.

<p>Growth of <i>Xcv</i> wild type 85-10 (wt), the <i>sX13</i> deletion mutant (Δ<i>sX13</i>) and Δ<i>sX13</i> containing chromosomally re-integrated <i>sX13</i> (Δ<i>sX13</i>+<i>sX13</i>_ch) in (A) complex medium NYG and (B) minimal medium MMA, respectively. Error bars represent standard deviations. Asterisks indicate statistically significant differences compared to wt (<i>t</i>-test; <i>P</i><0.05). (C) Growth of <i>Xcv</i> 85-10 (wt) and Δ<i>sX13</i> in leaves of susceptible ECW pepper plants. Data points represent the mean of three different samples from three different plants of one experiment. Standard deviations are indicated by error bars. (D) Plant infection assay. <i>Xcv</i> strains 85-10 (wt) and Δ<i>sX13</i> carrying the empty vector (pB) or the sX13 expression construct (p<i>sX13</i>) and strains additionally expressing HrpG* (p<i>hrpG*</i>) were inoculated at a density of 4×10⁸ (left panel) and 10⁸ cfu/ml (right panel), respectively, into leaves of susceptible ECW and resistant ECW-10R pepper plants. Disease symptoms in ECW were photographed 9 days post inoculation (dpi). The HR was visualized by ethanol bleaching of the leaves 3 dpi (left panel) and 18 hours post inoculation (right panel), respectively. Dashed lines indicate the inoculated areas. All experiments were performed at least three times with similar results.