中文摘要：

[目的]研究草莓采后成熟衰老过程中NADK活性与NAD（H）、NADP（H）及活性氧代谢和膜氧化产物变化的关系,以探讨NADK在非跃变型果实成熟衰老过程中的作用,为调控果实的成熟衰老提供理论依据.[方法]将从果园采回的草莓果实贮藏于不同的温度下并进行每天取样,研究草莓果实在低温（4℃）、常温（20℃）贮藏期间成熟衰老过程中NAD激酶（NADK）活性及其底物NAD（H）、产物NADP（H）以及超氧阴离子O2^-·过氧化氢（H2O2）、膜氧化产物丙二醛（MDA）含量的变化并分析NADK 与上述指标的关系.[结果]草莓果实在低温（4℃）贮藏时,其NADK活性比常温（20℃）贮藏的高,NAD（H）含量则相应比常温贮藏的低,NADP（H）含量则高于常温下的;同时,在常温贮藏期间果实O2^-·生成速率和H2O2含量、膜氧化产物MDA含量均比低温贮藏的高,暗示NADK可能通过影响NAD（H）、NADP（H）的含量及比例来调控O2^-·生成速率和H2O2含量,从而调控果实的成熟衰老.[结论]非跃变型果实草莓采后成熟衰老过程中,保持较高的NADK活性有利于延缓果实的成熟衰老,降低NADK活性可导致NAD和NAD（H）含量的积累,进而加速电子传递,产生大量的活性氧O2^-·和H2O2,从而促进膜过氧化作用和积累较多的MDA,最终导致果实衰老变质.

英文摘要：

[Objective] Studies on the relationship between NAD Kinase and NAD（H）, NADP（H） and active oxygen during ripening and senescence of post-harvested strawberry fruit were conducted to investigate the function of NADK during ripening and senescence of non-climactic fruit. [ Method ]Strawberry fruit was harvested from the orchard and stored at different temperature. The changes of NADK activity, the content ofNAD（H）, NADP（H）, H2O2 and malondialdehyde（MDA）, and O2^-· production rate during ripening and senescence of post-harvested strawberry fruit at 4℃ and 20℃ were investigated by sampling everyday and analyzing the relationship between NAD Kinase and others. [ Result ] The NADK activity and the NADP（H） content of strawberry fruit at low temperature （4℃） were higher than those at 20℃, however, the NAD （H） content at 4℃ was lower than that at 20℃. Meanwhile, the O2^-· production rate and the H2O2 and MDA content at 4℃ were lower than those at 20℃. The results suggested that NADK might be involved in ripening and senescence of post-harvest strawberry fruit by regulating the content and proportion ofNAD （H） and NADP（H） , the O2^-· production rate and content of H2O2. [Conclusion] Keeping high activity of NADK was beneficial to postpone the ripening and senescence of non-climactic fruit after harvested. Reducing activity of NADK led to probably accumulation of NAD and NAD （H） to promote transduction of electron, to produce large amount of active oxygen O2^-· and H2O2, to enhance super-oxidation of membrane, to enhance accumulation of MDA and in the ripening and senescence of fruit.