Figure 2.

The Enhanced Disease Resistance Mediated by edr4-1 Requires the SA Signaling Pathway.

(A) Four-week-old plants were inoculated with G. cichoracearum, and representative leaves were removed and photographed (top panels) or stained with trypan blue (bottom panels) at 8 DAI. The edr4-1-mediated resistance is suppressed by pad4, npr1, eds1, eds5, and sid2 but not by coi1 or ein2. Bar = 200 μm.

(B) Free and total SA was extracted from 4-week-old wild-type and edr4-1 leaves at 0 and 3 DAI, then the SA levels were determined by HPLC. The bars represent means and sd (n = 6). The experiment was repeated three times with similar results. The asterisks indicate statistically significant differences from the wild type (P < 0.01, Student’s t test). FW, fresh weight.