Methyl Jasmonate: A Key Regulator of Postharvest Fruit Quality Maintenance and Its Crosstalk with Phytohormones

Methyl jasmonate (MeJA) is a volatile phytohormone that regulates diverse physiological processes and mediates plant responses to various external stressors. Recently, MeJA has emerged as a promising postharvest alternative for the improvement of fruit quality. Here, we reviewed the research progress on the application of exogenous MeJA to postharvest fruits, focusing on its regulatory roles in regulating fruit ripening, improving postharvest fruit quality, alleviating postharvest chilling injury, and controlling postharvest diseases. The potential physiological and biochemical mechanisms mainly include: (1) inducing endogenous JA biosynthesis; (2) mediating JA signaling transduction; (3) enhancing antioxidant capacity; (4) inducing the defense system; (5) regulating sucrose metabolism; and (6) modulating energy metabolism. Additionally, a specific finding is the possible crosstalk of applications of MeJA and various phytohormones during postharvest fruit storage, which provides a new method and insight for the fruit quality industry.