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。
[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.
出处
《中国农业科学》
CAS
CSCD
北大核心
2007年第2期352-357,共6页
Scientia Agricultura Sinica
基金
国家自然科学基金资助项目(30360069)
贵州大学博士基金项目
关键词
草莓
成熟衰老
NAD激酶
NAD(H)
NADP(H)
活性氧
Strawberry （Fragaria ananassa Duch.）
Ripening and senescence
NAD kinase
NAD（H）
NADP（H）
Active oxygen
