Arabidopsis FAD8 Gene Transformed Brassica Napus Influence Fatty Acid Metabolish And Plants Resisted Cold

Rapeseed is an important oil economic crop.The mainly developed focus of oil crop is regulate the pathway of fatty acid metabolism, improve the oil nutrition and prompte the plant to endure stress by Genetic engineering . Arabidopsisω-3 fatty acid desaturase FAD8 is an enzyme which catalyze that the dienoic acid rapidly unsaturase to produce trienoic acid in cold condition., which can increase the content of unsaturased fatty acid in the seeds and plants, and improve the plant oil nutrition and provide plants obviously resistance in cold condition. In our research, set up better regenerated and transformed system , used agrobacteria -medidated method transformed Arabidopsis FAD8 gene into the rapeseed, research fatty acid metabolism and cold-resistance in the transgenic rapeseeds, and got better results.1,the Texuan 4 hypocotyls and cotyledon be used as the recipient, studied the various influence factors of transformed frequency, contending genotype,seedling age, hormone compose , cultural time et al. And found that the 6-day hypocotyls segments had better differentiated ability. Using MS+6-BA(3mg/L)+NAA(0.1mg/L) as differetiated medium could got higher induced frequence. The hypocotyl segments were precultured on preculture medium for 3 days, then submerged into 5-fold diluted Agrobacterium suspension (hypocotyls for 30 s and cotyledon for 5min), and placed on co-cultivation medium for 2 days could result in the highest transformation efficiency.2,Used agrobacteria-medidated method transformed the FAD8genes (the plasmid is pSH-FAD8 and pSH-anti-FAD8) into the rapeseed hypocotyls,cotyledon and petiole of cotyledon. Identified transgenic rapeseed plants by GUS staining,genomic PCR and RT-PCR, finally acquired 7 rapeseed plants of transformed the pSH- FAD8 gene and 9 plants of transformed the pSH-anti-FAD8 gene.3,Analysed the fatty acid content in the transgenic rapeseed by the reverse phase chromatography and gas chromatography method and showed descreased linolenic acid contents, increased oleic acid and linoleic acid contents in transformed the pSH-anti-FAD8 gene plant leaves. Only 1 plants in transformed pSH-FAD8 rapeseed had increased linoleic acid content. Analysed F1 seeds fatty acid contents by HPLC and found the oleic acid could reach to up 60%, which plants can made a new material in rapeseed breeding.4,Rapeseed leaves anti-cold experiment showed that obviously implove cold-resisted ability of transgenic rapeseed. Choosed two plants of transgenic pSH-FAD8 and pSH-anti-FAD8 plants, and study the cold-resisted ability of the F1 plants:the Chlorophyll,SOD,POD,CTA,proline content and malondialdehyde all showed that cold tolerance enhanced obviously in transgenic gene rapeseeds plants.5,The transgenic rapeseed plants in cropland can grow well and can bloom and harvest seeds, but the bud—differentiated and stem-growing period of transgenic pSH-FAD8 plants are latter 70days than control, transgenic pSH-anti-FAD8 plants are latter 40days . the Leaves type , leave organization , plant height, plant type in transgenic plants all have changed, the part of stem have naturally warping。Some of transgenic plants showed the phenomenon of male sterile.