Fig. 3.

Accumulation of reactive oxygen species (ROS) and cell death in SA signalling mutants. Leaves from Col-0, nudt7-1, eds1-2, and sid2-1 plants were treated with 2 µl of P. brassicae egg extract for 72h. Histochemical staining of leaves with nitroblue tetrazolium (NBT) to detect O₂ ^– (A), 3,3-diaminobenzidine (DAB) to detect H₂O₂ (B), and trypan blue to detect cell death (D) was performed. Control plants (CTL) were not treated and stained after 72h. For all stainings, leaves from 3–5 different plants per genotype were used. Panels are close-up photographs of the spotted area. This experiment was repeated twice with similar results. All images were taken with the same magnification. Bar=1mm.