The Genetic Regulatory Of BnFUS3 On Oil Synthesis In Brassica Napus Seed

The synthesis of vegetable oil is an important process for the formation of plant seed storage materials.Brassica napus is a heterotetraploid plant formed by natural hybridization between Brassica rapa and Brassica oleracea.At present,there are many studies on the genes related to oil and fat synthesis in Brassica napus,but the role of the regulatory factors of these genes has not been studied deeply.These include the key transcription factor FUS3 which regulates seed oil synthesis.In this study,the functions of four homologous genes of BnFUS3 in Brassica napus L.were studied in depth.The BnFUS3 homologous gene is highly expressed in the middle and late stages of rapeseed development,but the expression patterns of different members are different.In order to better understand the function of BnFUS3 homologous genes in oil accumulation during rapeseed development,four BnFUS3 homologous genes and promoters in Brassica napus L.were cloned.And the fusion expression vector of gene and GFP,the promoter and the GUS fusion expression vector were constructed.The latter two vector plasmids were transformed into Brassica napus L."Zhongshuang 11" by Agrobacterium-mediated transformation.We obtained transgenic plants,and the mechanism and agronomic traits of lipid regulation were studied.The following results have been achieved:1.Four BnFUS3 genes were highly expressed in the embryos of Brassica napus,but the expression patterns were different.Among them,BnFUS3-1 and BnFUS3-3 had the highest expression in 42 d embryos,BnFUS3-2 and BnFUS3-4 had the highest expression in 28 d embryos.2.The fusion expression vector of gene and GFP was successfully constructed and transformed into leaf tobacco for subcellular localization.BnFUS3-1,BnFUS3-3 and BnFUS3-4 were mainly located in the nucleus,and a small amount was localized in the cell membrane.It's indicated that BnFUS3 as a transcription factor in the nucleus.3.In order to understand the tissue expression site of BnFUS3 gene,the promoter and GUS fusion expression vector were successfully constructed.Then transformed them into rapeseed and successfully obtained transgenic lines.GUS staining of different tissue parts of transgenic plants indicated that BnFUS3 was mainly expressed in seed embryos.4.In view of the important role of BnFUS3 in embryonic development,conventional overexpression and mutations lead to seed development malformation.And it is difficult to obtain normal germinating seeds.This study improved the construction of BnFUS3 expression vector using a moderate expression promoter and transformed into rapeseed.We obtained multiple transgenic families successfully.Then analyze the phenotype and agronomic traits of transgenic plants,we found that the germination rate of BnFUS3-1 and BnFUS3-4 transgenic rapeseed decreased,the protein content of BnFUS3-4 transgenic rapeseed decreased and the oil content increased.