Proteomic And DNA Methylation Changes In An Elite Rice Induced By Space Environment

Mutagenic factors of space environment influence organisms on different aspects. In this study, we evaluated proteomic and DNA methylation alteration of M1 generation of elite rice, Songjing-6, induced by space flight. Results of 2-D protein electrophoresis showed that, among proteomes of 5 individuals tested, 3 showed more down-regulations than up-regulation; 1 revealed more up-regulations than down-regulations, and up and down regulations of 1 were equal. These consistent with the results of MSAP (methylation–sensitive amplification polymorphism) experiments that 3 individuals with more down-regulations of proteins showed higher methylation rate at CCGG sites in genome; 1 with more up-regulations showed higher de-methylation rate. And 1 with equal on up and down regulations of proteins, the methylation and de-methylation rates were equal. Since DNA methylation was reported as negative regulation of gene expression, we assumed that space flight may influence the methylation of rice genomic DNA, thus regulating the levels of encoded proteins. Our results provided a potential mechanism connecting epigenetic changes and proteomic alterations of rice induced by space flight.