Function Analysis Of Oleosin Genes In Arabidopsis Thaliana And Brassica Napus

Rapeseed is an important source of oil in our country, but the domestic production of rapeseed oil still cannot meet the requirements and need to be imported from abroad. So, improving rapeseed oil content by genetic engineering technology is one of the most important means to solve this problem. Oleosin is a kind of alkaline protein which surrounds the surface of oil droplets, and can affect the oil size and content of the seeds. Our research focused on cloning and overexpression of oleosin genes in Arabidopsis to verify the function of the genes, in order to find a way to improve the seed oil content. The main results were as follows:1) Genes cloned from Arabidopsis thaliana and Brassica napus pods included AtOLE1, AtOLE2, AtOLE3, AtOLE4 and BnOLE1, BnOLE2, BnOLE3, BnOLE4 genes. The gene sequences were used to analyze their structure, predict their subcellular localization and study their evolution through phylogenetic analysis.2) The genes of interest were successfully inserted to pBinGlyRed3, a recombinant plasmid for transgenic lines screening The genes were also inserted into another plasmid called pCambia1303-EGFP-DsRed3 for subcellular localization analysis. By using method of Agrobacterium mediated transformation in Arabidopsis thaliana, T0 generation of transgenic Arabidopsis seeds were obtained.3) After the analysis of the oil content and fatty acid composition of T2 generation seeds, the results showed that overexpression of oleosin genes in Arabidopsis thaliana had no influence on oil content in seeds but could increase the linoleic acid(C18:2) of 1.2%-6.2% and decrease the peanut acid(C20:1) of 1.0 %-2.9% compared to the control group(wild type).4) By verifying the seeds oil droplets size, the germination rate, the morphology and the subcellular localization, the results showed that the oil body diameter of transgenic seeds(BnOLE16 line) was smaller compared to wild type. Under light conditions, transgenic seeds germination rate was similar to the wild type, whereas under dark conditions, the rate was higher than the control. There was no difference in length, width and area type between the wild type and the transgenic lines. The subcellular localization analysis indicated that the oleosins were located on the cell membrane.