2019 ASHS Annual Conference

Pepper (Capsicum annuum L.) is one of the most important economic crops, which is sensitive to low temperature, and chilling injury easily occurs. Seed browning, which is a typical chilling injury symptom, is a major problem in the storage and distribution of hot pepper. This study was conducted to clarify the mechanism of seed browning during cold storage of pepper from the viewpoint of metabolic changes. The samples were stored at 2 °C and 10 °C for 10 days, 20 days and 30 days immediately after harvesting and polar phase compounds, phenolic compounds, fatty acids, and free amino acids were analysed. Metabolic analysis showed that the contents of tyrosine and phenylalanine, which are substrates of polyphenol oxidase and phenylalanine amino lyase, which are related to enzymatic browning, are high at 2 °C storage. Glutamate, gamma-aminobutyric acid (GABA), and isoleucine were analyzed in response to low-temperature stress. GABA was synthesized from glutamate, and jasmonic acid-Ile (JA-Ile), an active form of JA, was formed and activated by the JA signaling pathway. In order to maintain the physical properties of the cells in response to low temperature stress, the content of sucrose and glucose, which are monosaccharides and disaccharides, was found to increase. The negative correlation between linoleic acid and palmitic acid resulted in low lipid peroxidation, was converted to saturated fatty acid. Therefore, this study could explain the mechanism of the browning process and the response to cold stress in the low-temperature stored pepper from the viewpoint of metabolism, and might be a basis for improving the quality after harvest of the hot pepper and developing the low-temperature resistant pepper as new cultivars. This work was supported by the Basic Science Research Program through the National Research Foundation (NRF, 2016R1A1A1A05919210) of Korea funded by the Ministry of Education, Science, and Technology (MEST).