3.6. Effects on ACO activity
Ethephon+1-MCP treatment suppressed and delayed the peak of ACO activity. ACO activity in ethephon+1-MCP treated fruit was higher than in 1-MCP treated fruit. As shown in Fig. 5A, the ACO activity in the control fruit were much higher than the other two treatments during the whole storage, with the peak of 59.60 mg kg 1 s 1 appearing on the 18th day. ACO activity gradually increased in ethephon+1-MCP and 1-MCP treatments, and both ethephon+1-MCP and 1-MCP treatments suppressed the ACO activity. 1-MCP alone more severely suppressed the activity than the ethephon+1-MCP treatment (Fig. 5A).
3.7. Effects on ACS activity
Both ethephon+1-MCP and 1-MCP treatments suppressed the ACS activity and delayed the peak of enzyme activity, and 1-MCP imposed a severer suppression than ethephon+1-MCP treatment. In the control fruit, the activity peak appeared on the 12th day, with a value of 8.70 mg kg 1 s 1. The ACS activity in ethephon+1- MCP and 1-MCP treatments gradually increased throughout the storage period without any peak (Fig. 5B).
Both ethephon+1-MCP and 1-MCP treatments played a role in suppressing ACO and ACS activities, so reduced the ethylene production. However, the activities of ACO and ACS in ethephon+1- MCP treated fruit were higher than that in 1-MCP treatment, which was good for the ripening process after ethephon treatment.