The reason that we did not observe a significant difference between Col-0 and cca1-1 could be due to the difference in the infection time and/or Hpa strains used - Wang et al inoculated plants with the avirulent strain Hpa Emwa1 at dawn [28] while we used Hpa Emco5 (virulent) and Emoy2 (avirulent) in the afternoon in our experiments. This evidence concerns the gene HPSE and infection.