Effects of 1-Methylcyclopropene on NO Content,NOS Activity,and H₂O₂ Content in

Studies were conducted over the effects of 1-methylcycolpropene (1-MCP) treatment on postharvest life of Suli pears (Pyrus bretschneideri Rehd.) stored at room and cold temperatures on nitric oxide (NO),nitric oxide synthase (NOS) activity,and hydrogen dioxide (H2O2).Results showed that the 1-MCP treatment had little effect on total soluble solids (TSS) at both room and cold temperatures.1-MCP delayed softening of Suli pear fruits,decreased respiratory rate and H2O2 accumulation,and increased NO and NOS activity at room temperature storage,while the effect of cold temperature storage was relatively inferior.There was a significant positive correlation between NOS activity and NO content.It is concluded that 1-MCP had effects on endogenous NO content and accumulation of H2O2.Similarly,H2O2 acting as a signaling molecule via regulating NO level affects the ripening and senescence of Suli pears.