关键词: 茭白, 鲜切, 衰老, 品质劣变, 蛋白质组学

Abstract: 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.

Key words: Zizania latifolia, fresh-cut, senescence, quality deterioration, proteomics