Effect of 1-MCP on malic enzyme activity and ethylene production in mango during ripening.
Komal Mathur, Srivastava G. C.
Author Affiliation: Division of Plant Physiology, Indian Agricultural Research Institute, New Delhi - 110 012, India.
Indian Journal of Plant Physiology 10 : 273-275
Abstract : An experiment was conducted to study the relationship between malic enzyme and ethylene evolution in ripening mango cv. Amrapali when treated with 1-methylcyclopropene (1-MCP) compared to mature unripe fruits. The duration of 1-MCP effectivity in mango was also studied. The inhibitory effect of 1-MCP on ethylene evolution was evident from the observation that autocatalytic evolution of endogenous ethylene is completely inhibited from 8 days in 1-MCP treated mature unripe fruits of mango. The increase in endogenous ethylene was resumed 8 days after treatment with 1-MCP and thereafter the trend was similar as that of the control. In contrast, ethylene evolution started one day after harvest (DAH) in the control and exhibited a climacteric peak at 4 DAH. There was a steady increase in malic enzyme activity in CaC2-treated control set of fruits at one DAH. There was a substantial reduction in respiration within a day of treatment, after which the rate began to increase but remained considerably low compared to the control. With 1-MCP, the respiration rate was typically halved in Amrapali when compared with the control. Respiratory burst appeared only after 8 days of 1-MCP treatment indicating the inhibitory effect of 1-MCP on respiratory climacteric.