为探讨切分加速茭白衰老和品质劣变的分子生物学机制,应用双向电泳(two-dimensional electrophoresis,2-DE)结合质谱鉴定技术,研究了完整(对照)和鲜切茭白常温(25℃)贮藏期间蛋白质组的动态变化.结果显示:2-DE凝胶上可检测到约660个蛋白点,其中鲜切茭白39个蛋白表达量达到2.0倍以上显著差异(P＜0.05),经基质辅助激光解吸电离飞行时间质谱分析成功鉴定出35个蛋白.按照其功能可分为7类,即信号转导(8.6％)、代谢(22.9％)、细胞结构(8.6％)、胁迫响应与防御(31.4％)、蛋白质合成(11.4％)、衰老(5.7％)和功能未知蛋白(11.4％).完整茭白贮藏期间,14个蛋白表达上调,21个蛋白表达下调.在21个表达下调的蛋白中,鲜切诱导了其中6个蛋白(植物基础分泌蛋白、腺苷激酶、C2结构域蛋白、Ⅲ类过氧化物酶、LbH_gamma_ CA_like、小G蛋白Ras)的上调表达,表明这6个蛋白可能在伤害响应中发挥重要作用.同时,鲜切还显著增强了14个上调表达蛋白和其余15个下调表达蛋白的上升或下降趋势.以上差异表达蛋白的功能分析表明,鲜切加速茭白衰老和品质劣变可能与伤害信号产生和转导、自由基损伤加剧、碳水化合物和核酸分解代谢加速、能量代谢平衡失调及细胞结构降解密切相关.%In order to explore the molecular mechanism by which fresh-cut handling accelerates the senescence and quality deterioration of Zizania latifolia,the dynamic proteome changes of whole (control) and fresh-cut Z.latifolia during storage at room temperature (25 ℃) for 0,3 and 5 days were investigated by using two-dimensional electrophoresis (2-DE).Approximately 660 protein spots were detected on the gels.Totally 39 spots showed a significant (P ＜ 0.05)change in protein abundance based on 2.0-fold difference of which 35 were successfully identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry compared to the whole Z.latifolia.They could be categorized into seven functional groups,including signal transduction (8.6％),metabolism (22.9％),cell structure (8.6％),stress response and defense (31.4％),protein synthesis (11.4％),senescence (5.7％),and unclear functional proteins (11.4％).During storage,the expressions of 14 spots increased while the other 21 were down-regulated in the whole stem.Meanwhile,six spots (plant basic secretory protein,adenosine kinase,C2 domain,class Ⅲ peroxidases,LbH_gamma_CA_like,and small Rasrelated GTP-binding protein),which were down-regulated in whole Z.latifolia,were up-regulated in fresh-cut Z.latifolia during storage,suggesting that these proteins may play important roles in the response to wounding stress.Also,fresh-cut significantly promoted the tendency for 14 up-regulated and other 15 down-regulated proteins.These results imply that the promotion of senescence and quality deterioration of Z.latifolia after fresh-cut processing may be due to the production and transduction of wounding signals,the acceleration of carbohydrate and nucleotide catabolism,the disorder of energy homeostasis and the enhancement of free radical damage,as well as the degradation of cell structure.
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