2019 ASHS Annual Conference

Peppers are a subtropical crop, they suffer from a chilling injury in the postharvest process. The commercial values of peppers are lowered due to the seed browning which is one of typical chilling symptoms caused by the chilling temperature. This study was performed to investigate the seed browning of the hot pepper due to chilling injury and related substances and genes in aspect of the hormonal interactions. The hot pepper 'JoongAng' was placed in four closed chambers: control, exo-methyl jasmonate (MeJA) treatment, exo-methyl salicylate (MeSA) treatment, and combination (MeJA+MeSA) treatment. The peppers were treated with 50 μM of MeJA and 250 μM of MeSA at 20 °C for 16 hours. After the treatments, the peppers were stored for 25 days at 2 °C. The rate of seed browning as a measure of chilling injury, the content analysis of endo-salicylate and endo-jasmonate, and the qPCR of genes involved in the synthesis and signaling of jasmonate and salicylate were analyzed. The seed browning rate was increased by the MeSA treatment and decreased by the MeJA treatment. The difference in the content of salicylate was not observed in all treatments. The jasmonate content analysis was carried out but was not quantifiable due to their small amounts. While the genes related to ROS scavenging were highly expressed in the MeSA treatment, the genes related to the jasmonte systhesis were highly expressed in the MeJA treatment according to the qPCR results.Thus, it can be inferred that a chilling injury in hot peppers is induced by the MeSA treatment and reduced by the MeJA treatment. 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).