3.5. Cell wall softening related enzymes
It is well known that the cell wall softening related enzymes play a key role in cell wall degradation and fruit softening. Ethephon+1-MCP treatment inhibited the activities of softening related enzymes such as PL, PME, CX and PG. Compared to 1-MCP treatment, the enzyme activity of these four enzymes in ethephon
+1-MCP treated fruit increased significantly after ethephon treatment on the 14th day, and was higher than that in 1-MCP treatment during the later storage (Fig. 4).
As shown in Fig. 4A, PL activity in the control fruit gradually increased, peaked on the 15th day and then decreased. A similar change was observed in 1-MCP treated fruit and the PL activity was much lower than that in the control fruit, indicating that 1-MCP treatment significantly suppressed the activity of PL. In ethephon
+1-MCP treatment, PL activity was suppressed during the first 16 d, but after ethephon treatment on the 14th day, the PL activity increased dramatically from the 16th day and reached the peak at the 18th day, corresponding with the ethylene peak. The PL activity