Fig 3. Histones and DNA contribute to the bactericidal activity of pea root border cells.
(A) Histone H4, a component of the root cap secretome, is bactericidal to R. solanacearum. Percent live bacteria in the presence of histone H4 was determined by the BacLight LIVE/DEAD staining kit. A standard curve of percentage of live cells relative to SYTO9/PI fluorescence intensity was constructed using known ratios of live/dead bacteria (R2 = 0.99). The experiment was repeated twice, each with three technical replicates. (B) Bactericidal activity of root border cells on R. solanacearum. This effect was blocked by addition of either anti-Histone H4 antibody or DNase I. Asterisks indicate treatment significantly different from the bacteria-only control (one-way ANOVA, **** p<0.0001). Bars represent the mean of at least three independent experiments, each comprised of six technical replicates.