Cloning And Expressing Of Lysophosphatidic Acid Acyltransferase Gene From Brassica Napus L

Rapeseed is one of the most widely cultivated oil crops in China. Inceasing the oil content and quality of seeds in Brassica napus is essential to improve our vegetable oil market competitiveness. Isolating the key genes which could improve the quality of rapeseed oil and oil content are important to enhance crop quality.Lysophosphatidic Acid Acyltransferase (LPAAT) is proven to be the key enzyme of oil accumulation in unmatured seeds and is divided as plastidial type and the microsomal type.It is reported that LPAATs have different substrates preference either in different species or the same species in different strains. In this study, we isolated the LPAAT in immature Brassica napus L. B351. The main research results are as follows,(1) Three sequences had been isolated from Brassica napus L. B351, the sequences are as follow,pBnLPAAT,sBnLPAAT1 sBnLPAAT4. The sequence length is 1035 bp, 1173 bp, 1302 bp respectively. Bioinformatics analysis showed that pBnLPAAT shares 99.9% identity with the gene deposits in GenBank(access number AF111161). sBnLPAAT1 and sBnLPAAT4 shares 93.8% and 85.3% identity with the gene deposits in GenBank(access number Z95637). sBnLPAAT4 have 123 bp repeats segment compared with the genes(GenBank access number Z95637).(2) Pichia pastoris expression vectors pPIC9K-pBnLPAAT, pPIC3.5K-sBnLPAAT1 and pPIC3.5K-sBnLPAAT4 had been constructed and transferred Pichia pastoris.The protein was expressed successfully. Fatty acid components of Pichia pastoris analysis shows that, sBnLPAAT1 and sBnLPAAT4 can both improve the accumulation of Stearic acid and Oleic acid.(3) A plant expression vector PBI121-pBnLPAAT had been constructed, and transferred Arabidopsis thaliana successful. Fatty acid components analysis will be carried out in the future.