The Regulated Effect of Ethylene and 1-MCP on the Lignification of Postharvest Green Asparagus (Asparagus Officinalis L.)

摘要

Effects of ethylene and ethylene perception inhibitor 1-methylcyclopropene (1-MCP) on phenol, lignin, oxygen contents and enzyme activities involved in lignification, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), cinnamyl alcohol dehydrogenase (CAD), peroxidase (POD )in harvested asparagus cv. Mary Washington 500 spears were evaluated. Lignin, phenol or active oxygen content was enhanced by ethylene and reduced by 1-MCP treatment significantly. Ethylene treatment increased the activity of PPO, CAD and POD. however 1-MCP treatment significantly increased the activity of PPO and CAD, and delayed the acticvity of POD. The lignin accumulation in postharvest green asparagus can be declined significantly by suppressed POD activity and active oxygen content. Exogenous ethylene or 1-MCP may regulate the deposition of lignin through up-regulation of enzyme activity and active oxygen production. Besides of enzymic toughening, a free radical phenol coupling mechanism is suggested as being responsible for lignification of asparagus.