Pathogens and R. solanacearum inoculation
The highly virulent R. solanacearum strain FJC100301 (F. F. Dang et al., 2013) was used in the present study. The bacterial cell solution used for inoculation was diluted to 108cfu ml-1 (OD600 = 0.8) or 103cfu ml-1 (OD600 = 0.3). For root inoculation of pepper or N. benthamiana plants planted in pots, the soil was watered sufficiently and the roots were wound by scissors and then 1 ml of suspension containing R. solanacearum (OD600 = 0.8) was irrigated into the soil. For leaf inoculation with R. solanacearum , 100 μl suspension ofR. solanacearum (OD600 = 0.3) was inoculated with a needle-free syringe at each inoculating site. We counted the disease index of plants in the whole infection cycle of pathogens by observation (Table S4). There were 36 plants in each population, and the average value of every three plants was taken for a group.