Abstract:

【Objective】 The effects of postharvest treatment with propylene and 1-MCP on ethylene production and expressions of ACS and ACO genes in Fupingjianshi persimmon (Diospyros kaki L.) fruit were investigated. 【Method】 Fruits were treated with propylene and 1-MCP, than stored at 20℃, ethylene released rate of the treated fruits were measured at regular intervals and RNA was extracted for Northern blotting analysis. 【Result】 Treatment with propylene accelerated the expression of ACS and ACO genes and enhanced the ethylene biosynthesis, while treatment with 1-MCP inhibited the expression of two genes and their ethylene biosynthesis. Furthermore, different effects on expressions caused by treatments with propylene and 1-MCP existed in various fruit tissues. The inhibitory effect on ACS and ACO genes by 1-MCP was the strongest in pulp and core tissues, followed by pericarp and the area near fruit stalk while the enhanced effect on ACS and ACO genes by propylene increased from pulp, core, and pericarp to the area near fruit stalk. Expression of each member of ACS and ACO families in various tissues were also completely different, ACS3 gene just expressed in the area near fruit stalk and didn’t express in other tissues, but ACS2 gene expressed in four tissues by treatment with propylene.【Conclusion】 Treatment with propylene accelerated the expression of ACS and ACO genes, while treatment with 1-MCP inhibited the expression of ACS and ACO genes. Different effects on expressions caused by treatments with propylene and 1-MCP existed in various fruit tissues. Expression of each member of ACS and ACO families in various tissues were also completely different.

Key words: persimmon(Diospyros kaki L.), propylene, 1-MCP, ACC synthases, ACC oxidases