Ripening and ethylene production affected by 1-MCP in different parts of kiwifruit during postharvest storage

Ethylene plays an important role in kiwifruit ripening. However, it is unclear whether there are differences in ethylene production in different parts of kiwifruit during postharvest ripening. Kiwifruit were treated with 0.5 μL L−1 1-MCP for 12 h at 20°C and stored at 20 ± 1°C. The results showed the firmness, soluble sugar, total soluble solids (TSS), and AcACS1 and AcETR2 gene expressions were the highest in the core, and starch, AcACO2, and AcACO3 gene expressions were the highest in the seedless pulp at harvest. Starch content and firmness decreased significantly, and soluble sugar content, TSS, AcACO2, and AcETR2 gene expressions increased significantly in all parts during postharvest ripening. On the other hand, 1-MCP can significantly inhibit these changes in the fruits during ripening. The respiration rate and AcACS1 gene expression increased first and then reduced in all parts and were suppressed by 1-MCP. Ethylene was detected in the core and seeded pulp at 3 and 9 d of storage, respectively, but not in the seedless pulp. Overall, the results suggested there are differences in softening, ethylene production, and related gene expression in different parts of kiwifruit at harvest and during postharvest ripening, and 1-MCP inhibited softening and ethylene production of kiwifruit during postharvest ripening.