| As one of the most important oil plants in China,the quality of Brassica napus depends on the composition of fatty acid and oiliness.Recent studies on the composition of fatty acid and oiliness in oil plants showed that the level of fatty acid in seeds are regulated by a minority of key genes,one of which called fatty acid extending enzyme gene fael plays an important role in the level of erucic acid in seeds.Here,we intended to study the relationship between the sequence characteristic and function of promoter by cloning the protomer of key genes which regulate the level of fatty acid in low erucic acid brassica napus and high erucic acid brassica napus.In order to help to improve the quality of Brassica napus,our research also studied the synthesis model of fatty acid,protein subunit and fattiness,and compared the quality difference between low erucic acid brassica napus and low erucic acid brassica napus.1.The promoter sequences from the genome template of Qinyou No.7 and Zhongyou 821 were cloned and the relativity analysis was conducted.The results showed that the comparability between Qinyou No.7 and Zhongyou 821 is above 99%.The only difference was located on the site of-658bp upstream from start code,and the nucleotide on this site was T for Qinyou No.7 but A for Zhongyou 821.It's presumed that the replacement of A/T resulted in the functional change of enhancer and accordingly had an effect on transcriptional regulation of genes.The analysis on the primary functional element and nuclear region of promoter showed that there were three TATABOX,five CAATBOX upstream from start code.Besides,there were three GATABOX,two GT1CONSENSUS basic sequences,three ASF1MOTIFCAMV basic sequences and two abundant A/T sequences.2.In our research,the accumulation of key fatty acid during seed development of Brassica Napus was studied,compared anabolism models of 7 key fatty acid between high erucic acid Zhongyou 821 and low erucic acid Qinyou No.7,and the relativity analysis with data was performed.The results showed that,compared with oleic acid,score carbon olefine acid and erucic acid,the palmitic acid,stearic acid,linoleic acid and linolenic acid consistently accumulated early.The model of accumulation of palmitic acid,stearic acid, oleic acid,linoleic acid and linolenic acid were similar between the low erucic acid brassica napus and high erucic acid brassica napus.But the level of accumulation of oleic acid,score carbon olefine acid and erucic acid were largely different between the low erucic acid brassicd napus and high erucic acid brassica napus.3.With the material of Qinyou No.7 and Zhongyou 821,the model of accumulation of protein subunits was studied in different culit-vars of Brassica napus.The results showed that,at the initial stages,the synthesis protein subunits were unclear and the level of protein was low.Compared with Zhongyou 821,12S subunit was the `mainly synthesis product in Qinyou No.7 at the initial stage and was replaced by 2S subunit later.Moreover,the direction of protein subunits synthesis was totally different between the two culitvars.With the materials of Qinyou No.7 and Zhongyou 821,the accumulation model of fattiness was also studied.The results showed that the process of fattiness synthesis mostly conducted at the legumen-extended and seed-developing stages,with low level of fatty at the seed-maturing stage.Based on the similarity of both accumulation processes,we concluded that the fatty synthesis was little affected with different culitvars.The fatty level of matured seeds in both Qinyou No.7 and Zhongyou 821 was determined and the results were 42.92%and 39.58%,repectively.
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