FIGURE 7.

Effect of tAPX silencing on the response to SA. Seventeen-day-old IS-GUS-2-17 and IS-tAPX-19-23 plants were sprayed with a 100 μm estrogen and kept under NL for 48 h. A, levels of free and total SA in the IS-GUS-2-17 and IS-tAPX-19-23 plants before and after estrogen treatment were measured as described under “Experimental Procedures.” B, 48 h after treatment with estrogen, IS-GUS-2-17 and IS-tAPX-19-23 plants were sprayed with a 100 μm SA. The transcript levels of PR1 and PR2, SA-responsive genes, were measured by q-PCR. Error bars indicate S.D. (n = 3). Significant differences: *, p < 0.05 versus the value for IS-GUS-2-17 plants.