Figure 1.

Effect of γ-aminobutyric acid (GABA) supplementation on the endogenous levels of other amines in the leaves of healthy and ‘Ca. L. asiaticus’-infected ‘Valencia’ sweet orange (C. sinensis) after derivatization with MCF using targeted GC-MS-SIM. (A–D) Endogenous content (μg g⁻¹ FW) of detected phenolic amines (ρ-aminobenzoic acid, tyramine, synephrine, and octopamine, respectively) and (E–G) endogenous content (μg g⁻¹ FW) of detected non-proteinogenic amino acids (γ-aminobutyric acid (GABA), pyroglutamic acid, and O-acetyl serine, respectively) from healthy and ‘Ca. L. asiaticus’-infected (infected) leaves without GABA treatment (Control) or after the treatment with 10 mM GABA (treated). Data presented are the means ± standard deviation (mean ± SD) of six biological replicates (n = 6). Presented p-values are based on a two-tailed t-test to statistically compare each pair of treatments. Statistical significance was established as α_adjusted ≤ 0.0083 as calculated by Bonferroni Correction.