1-MCP Differentially Regulates Metabolic Responses in Stem and Calyx End Flesh Tissue of 'Empire' Apples during CA Storage

‘Empire’ apple fruit are more susceptible to flesh browning at stem-end tissues than at calyx-end if treated with 1-methylcyclopropene (1-MCP), an inhibitor of ethylene perception, prior to controlled atmosphere (CA) storage.  To better understand the metabolic changes associated with the specific tissue susceptibility to flesh browning, untargeted metabolic profiling with partial least squares (PLS) analysis has been applied to visualize changes in metabolic profile during storage.  PLS scoring plots indicated that the metabolic difference was detectable at harvest and metabolic changes occurred differentially during storage.  Amino acid levels were higher in stem-end than at calyx-end tissues, especially in 1-MCP treated fruit.