Transcriptome analysis of the differential effects of 1-MCP on the development of chilling injury in peaches harvested at early and late maturities

Peaches may suffer chilling injury (CI) during prolonged cold storage and the severity of this disorder may be affected by storage temperature, fruit maturity at harvest and treatment with 1-methylcyclopropene (1-MCP). The aim of this study was to identify how these factors affect gene expression during the onset of CI in early and late maturity ‘Zee Lady’ peaches treated with and without 1-MCP then stored at 0 or 5°C before being ripened at 20°C for 5 days. CI was assessed through reductions in juice recovery and the development of flesh browning. All of the factors listed above affected gene expression. 87 genes showed differential expression due to treatment with 1-MCP in early maturity cool stored whilst only 61 changed expression in late maturity fruit; these genes were mainly involved in membrane metabolism, cell wall synthesis and degradation and reaction to stress. 13 of these genes were common to fruit of both maturities. The development of CI was increased in 1-MCP-treated early fruit but was reduced in 1-MCP-treated late fruit compared to relevant controls. However, gene expression patterns in these fruit during CI development were consistent with the severity of CI