FIGURE 3.

Accumulation of GABA in individual Arabidopsis leaves after MecWorm treatment and Spodoptera littoralis short-term feeding assay. (A) Leaves of 4-week old Arabidopsis thaliana plants in growing order, from the oldest to the youngest. (B) Mean (±SE, n = 5) levels of GABA were determined in individual leaves of untreated control plants (white) and plants after treatment with MecWorm for 1.5 h (black). In treated plants, leaf 8 was subjected to mechanical damage (indicated by arrow) and systemic leaves 5, 9, and 11, and treated leaf 8 were analyzed for GABA level. (C) Mean (±SE, n = 5) levels of GABA were determined in individual leaves of untreated control plants (white) and plants after feeding of third instar S. littoralis larvae for 1.5 h (black). Significant differences between the GABA level were analyzed by t-test (for each leaf separately, p < 0.05, Mann–Whitney U-test), ^∗P ≤ 0.05; ^∗∗P ≤ 0.01; ^∗∗∗P ≤ 0.001. No significant difference in GABA concentration was found between untreated genotypes.