| The protein contents and components in rice (Oryza sativa L.) play a significant role in the quality of rice seeds, especially the digestible protein content and its essential amino acids content. Therefore, it is essential to understand the protein contents and components of rice seed storage protein (SSPs), and to improve the nutritive composition in rice breeding.The main results are as follows:1. The glutelin subunits of cv.93-11and cv.Nipponbare selected from O. sativa L. ssp. japonica and ssp. indica were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) combining with liquid chromatography-tandem mass spectrometry (LC-MS/MS) and western blot with highly subunit-specific antibodies. The results showed that～80%of glutelin content from the total glutelin extract consisted of seven major subunits in the SwissProt database, and～10%of glutelin consisted of a member of the glutelin type-B subfamily. In addition, based on the sequence heterogeneity at the amino acid level, the glutelin components of unknown identity seem to be new members of a new glutelin subfamily. The diversity of rice glutelin subunits between japonica and indica were identified as GluA-1and GluA-3, and the diversity of the glutelin composition between japonica and indica was reflected by the difference in glutelin subunit composition between glutelin type-A and type-B and the special subunits identified as GluA-1, and the percentage composition of GluA-3and GluB-1was twice more in the indica cultivars than that in the japonica cultivars. The result also revealed that the indica cultivars were superior to the japonica cultivars in terms of the nutritional value at the lysine level. The innovation was the combination of two methods, LC-MS/MS and western blot.2. The SSPs components of thirty-five prevailing rice cultivars were analyzed. First, they were separated by SDS-PAGE, and then their protein contents were determined by the Kjeldahl and Bradford method, and finally their amino acid contents were identified using the amino acid analyzer. The results showed that four components were separated, including albumin, globulin, prolamine, and glutelin, and the glutelin was found to be the main components in a range of50-80%. Moreover, as one of the digestible proteins for human, the Lys content of the glutelin was nine times higher than the other three. In further analysis, certain relationship was found between the protein contents and the amino acid components:the glutelin content was in significantly negative relation to the prolamine content; while the Lys content showed positive relation to the total SSPs content (P<0.01). In the study, the relativity of the nutritive value will provide the theoretical evidence for rice genetics and breeding.3. DNA sequences of Glu promoters in five cultivars with difference protein contents were selected for sequence slignment analysis, which were as hybrid rice parents new rice groups were analyzed the glutelin subunits by2D-PAGE These five cultivars as hybrid rice parents breed and analysis of glutelin composition. The results showed that the transcription factors were known to play central roles in regulating gene transcription from promoters. The diversity of Glu promoters between japonica and indica were4-5mutation nucleotides. The certain protein content of the Hybrid group had the assumption at certain protein content level. |
PDF Full Text Request