DAB and NBT staining
The accumulation of H2O2 and active
oxygen species (Papageorgiou et al.) were assessed by staining the
leaves, root or stems of pepper or N. benthamiana plants with 1 mg
ml-1 diaminobenzidine (DAB) or Nitrotetrazolium Blue
chloride (NBT). After overnight treatment with DAB and NBT, the stained
leaves were cleared by boiling in [lactic: glycerol: absolute ethanol
(1: 1: 3, V: V: V)] and then destained overnight in absolute ethanol.