Exogenous methyl jasmonate enhances phytochemicals and delays senescence in harvested strawberries by modulating GABA shunt pathway

• Methyl jasmonate induced gamma aminobutyric acid synthesis in strawberry fruit. • Methyl jasmonate reduced decay incidence and maintained fruit quality. • Methyl jasmonate enhanced fruit different antioxidants and phenolics accumulation. • Methyl jasmonate at 10 µM was most effective in maintaining fruit quality. In order to illustrate the relationship between methyl jasmonate (MeJA) and gamma aminobutyric acid (GABA) in maintaining the quality and improving the postharvest life of strawberry fruit, the harvested fruit were treated with MeJA for 16 h at 20 °C and stored at 3 ± 0.5 °C for 12 days. MeJA enhanced the expression levels of GABA shunt pathway-related genes, including glutamate decarboxylase, GABA transaminase, and succinic semialdehyde dehydrogenase, leading to an increase in GABA accumulation. Treated fruit showed higher levels of total acids, anthocyanins, total phenolics, antioxidants, and phenylalanine ammonia-lyase activity, and lower levels of cell membrane deterioration, total soluble solids, polyphenol oxidase activity and decay incidence rate. The results suggest that the positive effects of MeJA in extending the fruit postharvest life, enhancing phytochemical compounds, and decreasing the decay incidence rate may be due to the effects on motivating GABA shunt pathway and PAL enzyme activity.