Differential responses of cherry tomato cultivars to preharvest methyl jasmonate across harvest cycles: Impacts on antioxidants, amino acids, and GABA

Abstract

This study investigated the effect of preharvest methyl jasmonate (MeJA) applications on the quality attributes, amino acids, secondary metabolites, and antioxidant activities of three cherry tomato cultivars, namely ‘Jocheong’ (green), ‘Black Q’ (black), and ‘Snacktom’ (red), cultivated hydroponically in a controlled greenhouse. Fruits were harvested across three successive cycles following three rounds of 0.25 mM MeJA spray at one-week intervals. Physicochemical traits, amino acids, chlorophylls, anthocyanins, lycopene, β-carotene, phenolics, flavonoids, vitamin C, and antioxidant capacities with four assays were analyzed. Results revealed strong cultivar- and harvest cycle-dependent responses. ‘Black Q’ showed superior firmness, chlorophyll, anthocyanin, and vitamin C content; ‘Snacktom’ excelled in β-carotene, total phenolics, and antioxidant activity, while ‘Jocheong’ displayed the highest accumulation of γ-aminobutyric acid (GABA) and essential amino acids under MeJA treatment. Notably, MeJA application enhanced amino acids and antioxidants most effectively during the later harvest, suggesting a requirement for physiological development of the crop or accumulated stress responsiveness. These findings emphasize the need for cultivar-specific and stage-specific elicitor strategies for producing value-added cherry tomatoes.