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.
