Identification Of Rapeseed Oil Content Regulated Gene

In China,about 60% edible plant oils depend on the imports.Rapeseed,as the largest source of Chinese edible vegetable oil,accounts for 45% of the domestic oil crops production.Therefore,the improvement of the yield on rapeseed oil has a very important significance on the security of national edible oil supply.As an important composition of rapeseed oil yield,the improvement of the oil content will increase the yield of rapeseed oil effectively.Seed oil synthesis is a complex physiological and biochemical process and it involves the expression and regulation of many key enzymes.But now lots of regulatory mechanism in oil synthesis process is still not clear,so it is difficult to study the functional genes of oil content in rapeseed directly.Both of the model plant Arabidopsis and rapeseed belong to Cruciferae and they have high homology in genome.At the same time,Arabidopsis thaliana has many good charactors sunch as the short growth cycle,abundant biological information data,and varieties of mutants corresponding to many genes.Research on genes related to oil content in Arabidopsis are mostly through the mutants.Therefore,using Arabidopsis thaliana to screen the genes about lipid synthesis and applying the genes in rapeseed breeding is an effective method for improving oil content in rapeseed.In this paper,the following experiments were done to study the functional genes regulating oil content in rapeseed:1.We screened Arabidopsis thaliana mutant library through the method of organic reagent density gradient,and oil content of 96 seeds were found to be changed.After harvesting their seeds,the oil content of 9 mutant lines were identified to have change again.2.After identificated the insertion sites of the 9 mutant lines through tail-pcr technology,six functional genes are found: AT2G19450,AT3G26790,AT3G54320,AT5G06270,AT2G21840 and AT3G47450.The last three genes belong to undiscovered functional genes.3.The expression vector of AT2G21840 and AT3G47450 drove by their own promoter respectively were constructed into PBI-121 and then transformed successfully into their corresbonding Arabidopsis mutants through the technology of flower immersion.Finally,27 positive plants of AT2G21840 and 25 positive plants of AT3G47450 were obtained.The results showed that the oil contents of AT3G47450 transgenetic lines had no significant difference compared to that of WT,but the oil contents of AT2G21840 transgenetic lines did not reach the level of WT,which indicating that the AT3G47450 gene blongs to the oil related functional genes in Arabidopsis.4.Using the bioinformatics tools,the AT3G47450 was compared to the rape genome and the homologous gene Fna12334 was obtained.Through the sequence analysis and function prediction,the protein of Fna12334 is predicted to be an outer membrane protein with unknown function.The Fna12334 seed specific expression vector was constructed and then transformed into rapeseed using method of Agrobacterium transformation.Finally,6 positive transgenic plants were obtained.After detecting the seed oil content,oil content of transgenic rape increased by 1% than the control group.Through this research,we obtained a rapeseed oil content related functional genes,and made a preliminary validation and analysis,which laid a foundation for studying the gene regulation pathway.