The Effect Of6b Genes Specially Expressed In Seed On Sugar And Fatty Acid Metabolism

6b genes, derived from the T-DNA fragment, belong to rolB genes family. In plants,6b genes can affect phytohormone levels and carbohydrate contents, and can also cause accumulation of secondary metabolites, as well as change the relative genes expression. Under normal circumstances, in order to prevent sucrose over-accumulation, plant can bring about a kind of down-regulation mechanism. But the study of Helfer has proved that6b genes can break the limit situation of sucrose accumulaion and improve the enzymatic activity that related to sucrose metabolism,which enable to enhance the content of sucrose. In the seed development process of Cruciferae,sucrose is an important carbon resource.It can produce-acetyl CoA through Glycolysis and Citric Acid Cycle.Acetyl CoA is the precursor of fatty acid-.So my research priority is to improve the content of fatty acid through sugar-fatty acid transformaion in the way of enhancing the content of sucrose. In the research, we have finished these jobs under the guidance of molecular biology and genetic engineering:1. With the determination of gas chromatography, we can find that the content of fatty acid enhanced in transgenic plant compared with wild type.2. The content of soluble-sugar increased obviously and the starch decreased in transgenic plant in comparison with wild type.3. The tissue-specificity expression vectors have been constructed and got transgenic Arabidopsis thaliana and Brassica napus, the transformation efficiency of arabidopsis was about0.5%.4. The expression map of two kinds of promoters has been got. Napin promoter had the highest expression in the1day after fertilization and gradually decreased until10days after flowering. But Gtl promoter had the highest expression in the flower and early stage of silique formation and disappeared after10days of fertilization.5. Compared with the1000-seeds weight and the size of the seeds of Arabidopsis, transgenic plants are heavier and larger than wild type.The results demonstrate that transgenic have produced more assimilate than wild type.