The Heredity Of Protein Expression In Height-mutation Rice And The Characteristic Of Susceptible Proteins Induced By Space Flight

Space environment can cause mutation of plant seeds, which can be maintained in the offspring. These characteristics are applied into space breeding. Former research in our group shows that space flight can induce genetic mutation in rice seed, which displays height difference. For understanding the mutation mechanism, we analyzed the genomic scale mutation and methylation changes in the special sites. The results shows that the rice samples be exposed to the universal space have more mutation and methylation sites than unexposed samples and the ones with significant phenotype changes show high variation than the others in the same group. Moreover the mutation rate is related to the methylation rate. The sequence analysis of genomic mutaion and genomic methylation shows that the mutant sites often occur in the genome of repeat sequences area, and genome methylation change occur in coding-sequence. As we known, genome methylation plays an important role in regulating gene expression. Maybe rice genome methylation change, which induced by space flight, will affect the gene expression, cause proteome changes.Therefore, in order to further understand the mechanism of space environment susceptible protein change, we studyed the protein expression of the M2 generation groups with and without mutation in phenotypes MSP4 and MSP10 plant by SZ-VI flight.Analying the up-regulated and down-regulated proteins,as same as the previous research, the numbe of down-regulated proteins is more than up-regulated ones. Comparing the protein expression with the control group, the differences between mutation in phenotype are significantly greater than the normal phenotype ones.The results show that the proteins expression changed in M1 generation groups in both MSP4 and MSP10 also discovered in M2 generation groups, including Rubisco activate enzymes,Putative 33 kDa oxygen evolving protein of photosystemâ…¡protein,Cysteine synthase A,S-like RNase homologue, Putative Photosystem I reaction center subunit IV. These results indicate these proteins change can be maintained in M2 generation except Rubisco activate enzymes. These features of proteins change are similar with methylation change.These characteristics of rice idicate space flight result in mutations in Ml generation may because of affecting the function protein expression by changing the genome methylation.We compare the proteins expression change in both Ml and M2 generations,Rubisco activate enzymes down express in M1,while up express in M2; Putative 33 kDa oxygen evolving protein of photosystem II protein are down express in both M1 and M2; Cysteine synthase A and S-like RNase homologue are both down express in M1, no change significantly in M2. Putative Photosystem I reaction center subunit IV are down express in M1 and M2. In addition,we found some susceptibility proteins to space environment, these proteins including Cytoplasmic malate dehydrogenase, Rubisco small subunit and S-like RNase homologue.These proteins expression in MSP4 and MSP10 in M2 generation and the previous results are consistent. The results show that the three proteins may be the space environment or radiation treatment susceptible proteins.