Beet M14 Strain Of Floral Organ-specific Expression Studies Of The Protein

Apomixis is an asexual reproductive process by which plants produce seed without fertilization through female syngamy that produces embryos genetically identical to the maternal parent. It preserves heterozygosity vigor , maintains superior genotypes and changes the breeding production process by parthenogenetic embryo development. Therefore, the research on apomixis has far-reaching economic significance in the agricultural production and breeding work.The plant apomixis research to date mainly focuses on the level of the genome, but the gene expressed information obtained from the level of the genome is not sufficient to reveal the exact function of the gene. Therefore, in order to have comprehensive and thorough understanding to the life complex activity, the research on protein expression patterns and functional mode of life sciences has become the inevitable trend of development.Apomictic monosomic addition line M14 of Beta corolliflora Zoss. was the progeny from the hybridization of Beta vulgaris L. and Beta corolliflora Zoss. in sugar beet. Constituted of the normal 18 Beta vulgaris L. chromosomes with the No.9 chromosome of Beta corolliflora Zoss., M14 was found having a chromosome transmission frequency 96.5%, thus M14 is a precious material for research of apomixis. This research take apomictic monosomic addition line M14 and the normal cultivation beet as materials, and was carried on differential proteomic analysis by two-dimensional gel electrophoresis technology. Through improving and optimizing the floral organs of sugar beet protein extraction method and two-dimensional gel electrophoresis conditions,a high resolution and reproducible 2-DE analysis systerm was established, and we have generated high resolution and reproducible 2-DE maps for two type floral organs of sugar beet with different pH range.Using Imagemaster 2D gel analysis software, 1109±48 spots and 1006±37 spots were reproducibly detected across three replicate gels of apomictic and sexual floral organs of sugar beet, respectively. Ninety-six protein spots showed reproducible and statistically significant changes in M14 compared to B. vulgaris. Of them, 18 were unique to apomictic floral organs and five were only presented in sexual floral organs. Of the 830 common spots, 27 were found to be up-regulated and 46 were down-regulated in apomictic floral organs compared to sexual floral organs when p-value of 0.05 was used as the threshold. Protein spots from the gels were subjected to in-gel digestion and MS analysis. A total of 72 protein spots were identified by MS and MASCOT database searching. All of the unique ESTs sequences obtained by SSH and DDRT-PCR experiments were compared to the protein sequences identified by proteomics using BlastX. With an E-value less than 1e-7 as a criterion for significance, six proteins which were differences in protein expression between M14 and B. vulgaris, and two proteins only expressed in M14 showed significant match.The identified proteins were classified into 10 groups according to the functional categories established by Bevan et al. The results showed that the differentially expressed proteins involved in a wide range of cellular processes, such as metabolism, energy, protein synthesis, stress and defense etc.Identification of the differentially expressed proteins provides a good foundation for comprehensive and in-depth study of the apomixis molecular mechanism, and specific protein expression pattern in monosomic addition line M14.