Synergistic inhibitory effect of 1-methylcyclopropene (1-MCP) and chlorine dioxide (ClO2) treatment on chlorophyll degradation of green pepper fruit during storage

[Display omitted] •The efficiency of 1-MCP + ClO2 was better than that of 1-MCP or ClO2 alone.•All treatments suppressed the genes expression related to chlorophyll degradation.•1-MCP and ClO2 play different regulatory roles in the chlorophyll breakdown pathway. Degreening indicates the ripening and senescence process of green pepper fruit, which mainly results from chlorophyll degradation. To date, however, the effect of 1-Methylcyclopropene (1-MCP) alone or in combination with chlorine dioxide (ClO2) on the chlorophyll degradation pathway of green pepper at the molecular level remains scarce. In this study, green peppers were treated with 1 μL L−1 1-MCP, 30 μL L−1 ClO2 alone and 1 μL L−1 1-MCP plus 30 μL L−1 ClO2, respectively and stored at 20 °C for 12 d. The results showed that 1-MCP + ClO2 combination was superior in inhibiting color changes, decreasing the respiration rate, and exhibiting chlorophyll content as compared with 1-MCP or ClO2 alone. Further study on the expression of genes related to chlorophyll degradation pathway revealed that pheophytinase (PPH), pheophorbide a oxygenase (PAO) and red chlorophyll catabolite reductase (RCCR) were suppressed by all treatments. The efficiency of the combined treatment (1-MCP + ClO2) was better than that of 1-MCP or ClO2 alone. While the expression of chlorophyllase (CLH) was not affected by ClO2, but was significant suppressed by 1-MCP and 1-MCP + ClO2. Therefore, our results indicate the different regulatory roles of 1-MCP and ClO2 on the chlorophyll degradation pathway and provide an efficient method to preserve green pepper.