Fruit of cv. Monthong durian (Durio zibethinus Murr.) were treated for 12 h with 0 (control) and 500 nL L1
1-methylcyclopropene (1-MCP) at 25 C and were then stored at a temperature of 15C. The fruit were
transferred from a temperature of 15 C to a temperature of 25 C within a 3-day interval. 1-MCP
treatment did not affect the relatively low rate of ethylene production in fruit stored at a temperature of
15 C. In contrast, 1-MCP delayed the dramatic increase in ethylene production in fruit that were
transferred from a temperature of 15 C to a temperature of 25 C. It is well known that the peel (husk)
produces much more ethylene than the pulp, hence, the effects of 1-MCP on the peel will likely
overshadow any effect on the pulp. In the peel, 1-MCP had no effect on 1-aminocyclopropene-1-
carboxylic acid (ACC) synthase activity, but decreased ACO activity. ACC levels in the peel were not
affected by the treatment at 25 C. In the pulp, by contrast, ACO activity was not affected, but ACS activity
was not inhibited at 25 C and ACC levels were found to be lower, after the 1-MCP treatment. It was
concluded that 1-MCP seems to inhibit ethylene production of durian mainly by preventing an increase in
ACC oxidase activity in the peel.
ã 2015