Effect of 1-Methylcyclopene on Quality and Volatile Organic Components and Related Gene Expression in ‘Xiangshui’ Pears

This study investigated the effects of 1-methylcyclopene (1-MCP) on the quality and volatile organic components (VOCs) of ‘Xiangshui’ pears during storage, and the expression of genes related to ethylene synthesis and the signal transduction pathway as well as aroma synthesis were determined by real-time polymerase chain reaction (PCR). Results showed that 1-MCP treatment significantly inhibited the decrease in fruit hardness and the increase in soluble solids content (SSC) (P < 0.05), suppressed the respiration rate and ethylene production rate, and reduced the number and amount of VOCs in the peel and pulp compared with the control group. Moreover, the expression of the ethylene synthesis genes ACS1 and ACO2, the ethylene receptor genes ETR2 and ERS1/2, the ethylene signal transduction gene EIN3, and the VOCs synthesis genes LOX1/6/8 and AAT1 were down-regulated in both the peel and pulp. Thus, 1-MCP can restrain the synthesis of VOCs and quality changes by down-regulating the expression of the ethylene synthesis and signal transduction genes and the expression of the LOX1/8 and AAT1 genes.