关键词: 牡丹, 切花, 乙烯, 1-MCP, 开花, 衰老, ACS酶活性, ACO酶活性

Abstract:

Tree peony cut flower (Paeonia suffruticosa 'Luo Yang Hong') harvested in the first grade of flower opening index was taken as material to investigate the influence of exogenous ethylene and ethylene action inhibitor 1-MCP on flower opening index, diameter increasing rate, vase life, endogenous ethylene production and ethylene biosynthetic enzymes activities of ACC synthase (ACS) and ACC oxidase (ACO) during postharvest opening and senescence. The results showed that 10 μL·L^-1 ethylene treatment for 6 h hastened the process of flower opening, shortened vase life and induced petals abscission seriously after full-open; while 1.0 μL·L^-1 1-MCP retarded flower opening, prolonged flower vase life and impeded full-open of some flowers. Endogenous ethylene production was promoted by ethylene and inhibited by 1-MCP respectively, which was closely associated with the flower opening process. ACS and ACO activities analysis after different treatments indicated that changes in ACS activity were related to the endogenous ethylene production, suggesting that ACS is the main factor in the regulation of tree peony cut flower opening and senescence, which confirmed the former conclusion that ACS is the rate-limiting enzyme in plants ethylene biosynthesis.

Key words: tree peony, cut flower, ethylene, 1-MCP, flower opening, senescence, ACS enzyme activity, ACO enzyme activity