Potential application of methyl jasmonate and γ-aminobutyric acid to preserve fruit quality and alleviate postharvest chilling in Orlando tangelo

Orlando tangelo fruits, originating from tropical and subtropical regions, have demonstrated a tendency to be susceptible to chilling injury when subjected to cold storage conditions. This study investigated the effects of methyl jasmonate (MeJA) (50 mu M), gamma-aminobutyric acid (GABA) (5 mM), and MeJA (50 mu M) + GABA (5 mM) on chilling injury of Orlando tangelo fruits throughout cold storage (90 days at 3 +/- 0.5 degrees C plus 5 days at 20 degrees C, shelf life). The findings demonstrated that all treatments considerably decreased fruit weight loss. Although all treatments significantly decreased chilling injury, MeJA treatment resulted in the least amount of chilling injury. Malonaldehyde was also significantly lower in the treated fruits in comparison to the control. Maximum phenol and flavonoid were observed in the MeJA treatment, which was 1.47 and 1.63 times higher than the control fruit, respectively. On average, the antioxidant activity of the treatments was 1.33 times higher than that of the control. The treatments increased the activity of catalase (CAT) and peroxidase (POD) enzymes in fruit juice and peel. Whereas, the highest activity of CAT and POD enzymes in the peel was observed in the treatments of MeJA and MeJA + GABA, respectively. Compared to other treatments, MeJA significantly increased the activity of the CAT enzyme in the fruit peel. Even though MeJA exhibited a more pronounced positive effect, the overall results indicate that both individual treatments and MeJA + GABA could be utilized to enhance the cold tolerance of Orlando tangelo fruit during extended periods of cold storage.