1-MCP和乙烯利处理对采后菠萝蜜果实活性氧代谢的影响

Effects of 1-MCP and Ethephon Treatment on Reactive Oxygen Metabolism of Postharvest Jackfruit

以‘海大2号’菠萝蜜果实为材料,研究0.5 mg/L1-MCP(1-甲基环丙烯)和1 000 mg/L乙烯利处理对菠萝蜜果实活性氧代谢的影响,并探讨其与活性氧、活性氧清除酶和还原物质的关系,为菠萝蜜果实的保鲜提供理论依据。结果表明:随着菠萝蜜果实的成熟衰老,LOX(脂氧合酶)活性迅速增加,H2O2(过氧化氢)和MDA(丙二醛)含量快速积累,CAT(过氧化氢酶)和APX(抗坏血酸过氧化物酶)活性不断下降,SOD(超氧化物歧化酶)、POD(过氧化物酶)活性和GSH(谷胱甘肽)、还原型ASA(还原型抗坏血酸)含量均呈现先升后降的变化趋势。乙烯利处理极显著提高了LOX活性和降低了POD、APX和贮藏前期SOD活性,加快了贮藏中期H2O2和MDA含量的积累。1-MCP处理极显著降低了LOX活性和H2O2、MDA的含量,减少了活性氧产生,同时极显著提高了SOD、CAT活性和贮藏后期的POD、APX活性及GSH、还原型ASA含量,增强了活性氧清除能力。这些结果表明,乙烯利和1-MCP对菠萝蜜果实成熟衰老过程中活性氧的产生、保护酶活性及还原物质含量起重要调控作用。

The effects of 0.5 mg/L 1-MCP and 1 000 mg/L ethephon treatment on the active oxygen metabolism in harvested ‘ Haida No.2＇ jackfruit during storage at ambient temperature（ 22 ±1）℃ and its relation to reactive oxygen species, defense enzyme activities and antifungal substance contents involved were investigated to provide a theoretical basis for preservation of jackfruit. The results showed that with the ripening of jackfruit fruits, LOX activity, contents of H2 O2 and MDA increased rapidly. The activities of CAT and APX continuously decreased and the activities of SOD, POD and contents of GSH and ASA increased first and then decreased. Ethephon treatment significantly enhanced LOX activity and reduced POD, APX and pre-storage SOD activity, accelerated the accumulation of H2 O2 and MDA in the middle of storage. 1-MCP treatment decreased the production of reactive oxygen species by very noticeably reducing the activity of LOX and the contents of H2 O2 and MDA. At the same time, it enhanced the reactive oxygen scavenging capacity by significantly increased the activities of SOD, CAT, POD, APX and contents of GSH and reduced ASA. These results suggest that ethephon and 1-MCP play an important role in regulating the production of reactive oxygen species, the activity of protective enzymes and the content of reducing substances in the ripening of jackfruit.