Abstract The objective of this research was to determine the role that ethylene plays in superoxide dismutase (SOD) gene expression of apple fruit (Malus × domestica Borkh.) during ripening. Apple fruit at commercial maturity were treated with ethylene antagonists 1-methylcyclopropene (1-MCP) and stored at shelf temperature of 20 °C. Our data indicated that application of 1-MCP resulted in a reduced rate of softening and a delayed peak of ethylene and respiration. 1-MCP treatment reduced accumulation of superoxide anion (O2 −) and hydrogen peroxide (H2O2) in both peel and pulp, enhanced SOD activity in pulp and peel to varying degrees during ripening. Expression of Cu/ZnSOD2, Cu/ZnSOD3, Cu/ZnSOD5, Cu/ZnSOD6, Cu/ZnSOD8, MnSOD2, MnSOD7 and MnSOD9 in pulp was enhanced by treatment with 1-MCP during the early ripening period, and conversely, their expression in pulp was reduced by it during the late ripening period compared to control group. Most SOD genes presented a fluctuating pattern of expression in peel after 1-MCP treatment during ripening. Expression of Cu/ZnSOD10 and MnSOD7 in peel was promoted by 1-MCP treatment during the late ripening period, while expression of MnSOD4 and FeSOD1 in peel was generally enhanced by it during the entire shelf life period compared with controls. Our results suggested that ethylene played a role in regulating SOD genes expression in both pulp and peel of ripening apple fruit.

中文翻译：

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1-甲基环丙烯（1-MCP）处理下苹果果实成熟过程中超氧化物歧化酶（SOD）基因的全基因组鉴定及其表达谱

摘要 本研究的目的是确定乙烯在苹果果实（Malus ×domestica Borkh.）成熟过程中超氧化物歧化酶（SOD）基因表达中的作用。商业成熟的苹果果实用乙烯拮抗剂 1-甲基环丙烯 (1-MCP) 处理，并在 20 °C 的货架温度下储存。我们的数据表明，1-MCP 的应用导致软化速率降低以及乙烯和呼吸的延迟峰值。1-MCP 处理减少了果皮和果肉中超氧阴离子 (O2 -) 和过氧化氢 (H2O2) 的积累，在成熟过程中不同程度地增强了果肉和果皮中的 SOD 活性。在早熟期间用 1-MCP 处理提高了纸浆中 Cu/ZnSOD2、Cu/ZnSOD3、Cu/ZnSOD5、Cu/ZnSOD6、Cu/ZnSOD8、MnSOD2、MnSOD7 和 MnSOD9 的表达，反之，与对照组相比，它们在晚熟期间在果肉中的表达降低。大多数 SOD 基因在成熟过程中经过 1-MCP 处理后在果皮中表现出波动的表达模式。与对照相比，1-MCP 处理在晚熟期间促进了果皮中 Cu/ZnSOD10 和 MnSOD7 的表达，而在整个货架期内，果皮中 MnSOD4 和 FeSOD1 的表达普遍增强。我们的研究结果表明，乙烯在调节成熟苹果果实的果肉和果皮中 SOD 基因的表达中发挥了作用。与对照相比，1-MCP 处理在晚熟期间促进了果皮中 Cu/ZnSOD10 和 MnSOD7 的表达，而在整个货架期内，果皮中 MnSOD4 和 FeSOD1 的表达普遍增强。我们的研究结果表明，乙烯在调节成熟苹果果实的果肉和果皮中 SOD 基因的表达中发挥了作用。与对照相比，1-MCP 处理在晚熟期间促进了果皮中 Cu/ZnSOD10 和 MnSOD7 的表达，而在整个货架期内，果皮中 MnSOD4 和 FeSOD1 的表达普遍增强。我们的研究结果表明，乙烯在调节成熟苹果果实的果肉和果皮中 SOD 基因的表达中发挥了作用。