Differential Proteomic Analysis of Leaf Development at Rice (Oryza sativa) Seedling Stage

To identify the function of differential expression proteins in different leaves of rice seedlings extracted from 2- to 5-leaf stages, the leaf proteins at the seedling stage of hybrid rice Shanyou 63 were studied by using the approach of plant proteomics, and those proteins were separated with two-dimensional electrophoresis （2-DE） and then analyzed with an imagemaster 2D Elite 5.0. The results showed that the 41 protein spots were detected differential expression, of which 17 new protein spots appeared after the 3-leaf stage, including 9 special protein spots, which were only detected at the 3-leaf stage. Thirteen protein spots increased first and then decreased in expression abundance gradually and finally even disappeared. For the other 11 protein spots, 3 protein spots decreased, but 6 protein spots were opposite in expression abundance, however, 2 protein spots expressed in an irregular pattern after the 2-leaf stage. Of the 41 differential leaf proteins, 15 protein spots were identified by ESI-Q MS/MS and categorized into 4 groups of functions. The results indicated that proteins were the carriers of the functions in cells, but were significantly influenced by the changes in cell function or intercellular environment; hence, the reason that caused the proteomic changes as mentioned earlier might be related to the occurrence of tillers at the rice seedling stage after the 3-leaf stage.

Effect of Ginsenoside Rbl on Expressive Proteome of Rat Neurons

[ Objective ] This study aimed to explore the effect of ginsenoside Rbl on expressive proteome of rat neurons by technologies of proteomics, bioinformat- ies and MS peptide fingerprinting. [ Method ] Rat neurons were cultured conventionally and randomly separated into two groups. The experimental group was trea- ted with 5 μg/rnl Rbl for 20 min, while control group was added with the same amount of medium. After cell lysis, the whole-cell protein was extracted. Two-di- mensional electrophoresis （2-DE） was used to separate the extracts. Differential expression of proteome between the two groups was analyzed by using ImageMaster 2D Platinum v5.0 software and the two protein spots expressed differently were selected for differential identification with MALDI-TOF-MS. [ Result] Based on the matching and comparative analysis of the protein spots, 418 protein spots were detected in experimental group, including 226 protein spots with differently expres- sive levels; according to the mass spectrometry, the two ginsenoside Rbl-related and differentially-expressed protein spots were identified as cytochrome P-450 and phosducin-like protein, and both of them were phosphorylated proteins. [ Conclusion ] This study showed that the functions of those identified proteins were in- volved in signal transduction, suggesting that the effect of ginsenoside Rbl on expressive proteome of rat neurons might be related to the corresponding signal trans- duction networks.