Figure 1.

Enhanced JA Accumulation and JA-Responsive Gene Expression in Pseudomonas DC3000–Infected Arabidopsis NahG Plants.

(A) Endogenous levels of free and conjugated SA in wild-type Col-0 (open squares) and SA-degrading NahG (open circles) plants after inoculation with the bacterial pathogen Pseudomonas DC3000. Error bars represent se (n = 5).

(B) JA levels in Pseudomonas DC3000–infected Col-0 (open squares) and NahG (open circles) plants. The experiment was performed three times with similar results.

(C) RNA gel blot analysis of SA-responsive (PR-1) and JA-responsive (LOX2, VSP, and PDF1.2) genes during pathogen infection.

Plants were inoculated with virulent Pseudomonas DC3000 by dipping the leaves in a bacterial suspension containing 2.5 × 10⁷ colony-forming units/mL. At different days after inoculation (dpi), leaves were harvested for SA, JA, and RNA extraction. To check for equal loading, RNA gel blots were stripped and hybridized with a gene-specific probe for β-tubulin (TUB). Transcript levels of the constitutively expressed TUB gene decreased during the course of the infection process as a result of progressing cell death. FW, fresh weight.