转基因高油酸油菜株系W-4种子脂肪酸组成

Fatty acid composition of transgenic high oleic acid rapeseed W- 4( Brassica napus L. )

为研究fad2基因下调表达对油菜种子脂肪酸组成的影响,分析比较了转基因高油酸油菜品系W-4的T5、T6和T7种子以及非转基因对照Westar种子中的脂肪酸组成。数据显示W-4种子中油酸平均含量为84.61%±1.41%,较对照增加了25.91%,达到极显著水平;亚油酸和亚麻酸含量分别为3.22%±0.56%和3.45%±0.51%,较对照分别下降了80.89%和47.00%,降幅均达极显著水平。此外,W-4种子中棕榈酸平均含量为3.42%±0.18%,较对照Westar下降18.10%,达到极显著水平;而硬脂酸平均含量为1.87%±0.19%,较对照下降了8.33%,亦达到显著水平;W-4种子中廿碳烯酸的平均含量为1.54%±0.06%,较对照平均增幅为18.46%,达到极显著水平;W-4平均芥酸含量较对照略有增加,但不显著。结果表明油菜种子中fad2基因下调表达对种子的脂肪酸合成与积累影响较大,其不仅显著降低种子中多不饱和脂肪酸含量,增加油酸的含量;而且也显著降低饱和脂肪酸含量,并促进长链单烯酸的合成。

To investigate fatty acid changes of a down- regulated fad2 gene transgenic rapeseed line W- 4,its T5 to T7generations and wild type Westar（ WT） were used to study seeds fatty acid composition. Results showed that the increase of oleic acid and eicosenoic acid contents were highly significant. Oleic acid was 84. 62 ± 1. 41%in W- 4 seed,25. 91% higher than that of wild type and eicosenoic acid was 18. 46% higher too. While linoleic acid and linolenic acid were 3. 22 ± 0. 56% and 3. 45 ± 0. 51% respectively,which were 80. 89% and 47% lower than that of WT respectively,and the decrease were highly significant. Moreover,palmitic acid and stearic acid were 3. 42 ± 0. 18% and 1. 87 ± 0. 19%,which were 18. 10% and 8. 33% lower than that of WT respectively. Both were highly significant. The results indicated that down- regulation of fad2 gene significantly changed the fatty acid composition. Thus the polyunsaturated fatty acid contents were significantly reduced,and monounsaturated fatty acid contents were increased.