Analysis Of Seed Germination Regulating Mechanism By Using Comparative Proteomics In Brassica Napus L.

Rapeseed(B.napus)is one of the most important oil crops in the world.During the storage,the protein and fatty acid components of seed will change with the prolongation of storage,which leads to the decrease of seed germination vigor.This has always been an important problem in the actual production and application of rapeseed,and the seed germination vigor is also related to crop field performance,which ultimately affects crop yield.Therefore,in order to solve the decrease of the quality and germination vigor of seeds during storage,we need to study the regulation mechanism of seed germination and germination vigor.In this study,we studied the germination process of B.napus seeds with different oil content.One hundred and thirteen(113)and one hundred and sixty-five(165)differentially expressed proteins(DEPs)were identified in germination process and germinating seed with high and low oil,respectively.These DEPs were mainly involved in storage proteins,energy metabolism,protein metabolism,defense/disease,seed maturation,sugar and carbohydrate metabolism,lipid metabolism,amino acid metabolism,cell growth/division,and some unknown functional proteins.In this study,the main innovative piontsare as follow,1.During the process of seed germination and post-germination seedling growth of B.napus,the mobilization of storage reserves and the defense system correlated with the sulfur amino acid metabolism-related proteins and myrosinase-binding protein are activated and induced.These processes may be helpful in the seed germination and seedling construction.Meantime,the ripening process may also reproduce in the early seed germination of B.napus,which may help to improve the ability of seed germination to adapt to the environment.By using comparative proteomics and QTL mapping alignment analysis,Seventeen unique genes corresponding to the DEPs in the germination process were located within the confidence interval of germination-related QTLs,indicating that these genes may play an important regulatory role in the seed germination process.2.Oil content is an important factor that affecting the seed germination vigor and the effect of exogenous ABA on the germination vigor of different cultivars was not the same,but this effect does not have significant bias difference between high and low oil content groups.This indicated that the difference in germination vigor in B.napus seeds with high and low oil could be independent of exogenous ABA.The comparative proteomics analysis also showed that sulfur amino acid metabolic pathways have a higher activity in B napus seeds with highoil content,which may help improve seed-to-environment adaptability and then improve seed vigor.There were 21 protein metabolism-related proteins,10 amino acid metabolism-related proteins,11 sugars and carbohydrate metabolism-related proteins.15 energy-related proteins were highly expressed in high oil content seeds,indicating that high oil seeds had higher material and energy metabolic activity,which contribute to the more quickly start of germination and post-germination seedling growth in B.napus seeds with high oil content.3.31 unique genes were both found in two sets of proteomics analyzes,7 genes of which were located within the confidence interval of germination-related QTLs.These genes are involved in the processes of sulfur amino acid metabolism,energy metabolism,protein metabolism and so on,which may play an important role in regulating the seed germination vigor of B.napus.