Effects of 1-MCP on volatile production and transcription of ester biosynthesis related genes under cold storage in ‘Ruanerli’ pear fruit (Pyrus ussuriensis Maxim.)

Abstract

Fruit of Pyrus ussuriensis Maxim. produces an intense aroma accompanied by elevated ethylene levels and fruit firmness loss. Although 1-methylcyclopropene (1-MCP) treatment is an effective method to delay fruit ripening, the effect on aroma of pear fruit remains unknown so far. In this study, fruit of ‘Ruanerli’ pear (P. ussuriensis) were treated by 1-MCP under room temperature, and then transferred to cold storage. Changes in the total volatile concentrations and the volatile composition were detected during storage. Although the amount of total volatiles increased during storage in 1-MCP treated fruit, concentrations of both total volatiles and esters were lower in 1-MCP treated fruit compared with control. The effect of 1-MCP on ester production was stronger than on aldehydes. Different transcript patterns of ester biosynthesis related genes were observed in 1-MCP treated fruit. During the storage period, the transcript levels of PuLOXs and PuAAT were inhibited dramatically in 1-MCP treated fruit. However, the transcript levels of PuADHs were not suppressed in treated pear fruit during storage. Treatment with 1-MCP effectively prolonged the storage time and delayed the fruit firmness loss in pear fruit. The lower content of total volatiles and esters may be ascribed to the suppression of PuLOXs and PuAAT genes.