Comparison Of Proteome In Cotton Fiber Cell During Different Development Stages

Cotton fiber is a single and highly elongated epidermal cell of the outer integuments of the ovule. As the most prevalent natural raw materials used in the textile industry, cotton fibers plays a significant role in the global economy. Growth of fiber cells can be divided into four distinct and overlapping stages: initiation, elongating, secondary cell wall synthesis and maturation. There are amount of proteins actively expressed during fiber development. Isolation and analysis of proteins expressed preferentially in cotton fiber will be helpful in further understanding the complicated process of fiber cell elongation and cellulose biosynthesis and ultimately it is good to improve cotton fiber quality and yields.Three different cotton fiber protein extraction methods were compared with Gossypium hirsutum, cv. Xuzhou 142. The effects of various lysis buffers on the two-dimensional electrophoresis(2-DE). The loading quantity of sample and staining method were also optimized for the 2-DE analysis. The results showed that, the phenol extraction of cotton fiber proteins was the best method among three methods, which can extract higher amont of protein and the electrophoresis strip of SDS-PAGE were clear. The solubility was raised that the proteins were dissolved in the mixture of thiourea and CHAPS and the more suitable loading quantity was 125μg to the pH 3~10 7 cm IPG strip. Furthermore, the protein spots were increased and the background was clear by the modified coomassie brilliant blue method. A new preparation protocol of protein extracts was initially established for 2-DE of cotton fibre proteins.A comparative proteomic analysis was performed to exhibit the protein profile differences between two stages of cotton fiber cells. The two stages are cell elongating and synthesizing primary cell walls at 10 days postanthesis (DPA), and the secondary cell wall thickening at 25 DPA. PDQuest8.0 software was used to analysis the relative abundance of different proteins between 10 and 25 DPA cotton fibers. Fifteen of the proteins which had good qualities and reproducibilities were identified by MALDI-TOF-MS. According to the NCBI database searching results, the different expression proteins were F-box family proteins, actin,β-tubulin, F1-ATP synthase subunit beta, annexin, cytosolic phosphoglycerate kinase 1, cytosolic malate dehydrogenase, adenosylhomocysteinase, putative glutamine synthetase, ATPase subunit, profilin, copper/zinc superoxide dismutase and putative 4-coumarate coA ligase. These proteins are involved in a wide range of physiological processes, such as energy metabolism, carbohydrate metabolism, cell cycle control and development.? These results provide a foundation for further studies of the protein that participate in cotton fiber development.The temporal changes of global proteomes at six representative development stages(5~30 DPA) were examined using 2-D electrophoresis. Gene-specific PCR primers were designed according to the interest proteins nucleotide sequences. Semiquantiative RT-PCR was used to analysis the 5 different proteins. The results showed that the differences were existed between protein level and transcriptional level.