为研究胡麻叶片、果球不同发育阶段脂肪酸去饱和酶基因表达水平与脂肪酸组成之间的关系,以3个胡麻品种为材料,应用实时荧光定量PCR技术对4个基因,即磷脂酰胆碱甘油二脂转磷酸胆碱酶1基因(PDCT1)、磷脂酰胆碱甘油二脂转磷酸胆碱酶2基因(PDCT2)、脂肪酸去饱和酶2 a基因(FAD2 a )、脂肪酸去饱和酶3 a基因(FAD3 a )的相对表达量进行分析。同时研究了它们与脂肪酸组成之间的关系。结果表明,在胡麻叶片和果球中4个基因在各个时期中的表达模式符合正态分布模式。在胡麻种子形成过程中,这4个基因是高水平表达的主基因,不同基因之间表达量相关性极显著(相关系数范围0.989≥r≥0.643,P<0.01)。在胡麻种子成熟期基因表达量与胡麻品种的脂肪酸组成之间相关性显著。它们的表达与硬脂酸(STE)(0.548≥r≥0.405,P<0.01)、亚麻酸(LIN)(0.494≥r≥0.304,P<0.01)的含量呈显著正相关,与亚油酸(LIO)(-0.299≥r≥-0.497,P<0.01)呈显著负相关。胡麻中PDCT、FAD2 a、FAD3 a基因表达导致脂肪酸组成差异,从而影响胡麻油的品质。
Expression of functional genes related to fatty acid synthesis of oil flax
To better understand the relationship between fatty acid desaturation enzyme gene expression and fatty acid composition of leaves and capsule balls,3 varieties of oil flax were investigated as materials.Real-time fluorescence quantitative PCR was applied to investigate relative expression of these 4 genes (phosphatidylcholine diacylglycerol cholinephosphotransferase 1 gene PDCT1 ,phosphatidylcholine diacylglycerol cholinephosphotrans-ferase 2 gene PDCT2,fatty acid desaturases 2a gene FAD2a,and fatty acid desaturases 3a gene FAD3a).The re-lationship between relative expression and fatty acid composition was discussed.Results showed these 4 genes ex-pression patterns followed the normal distribution in leaves and capsule balls during development.At linseed form-ing period,these 4 genes were the major genes at high expression levels.Expression quantity was significantly cor-related among genes (correlation coefficiency r ranged from 0.989 to 0.643,P<0.01).At linseed mature stage, gene expressions were significantly correlated with fatty acid composition.The significant positive correlation coeffi-ciency were 0.548 to 0.405 with stearic acid,and 0.494 to 0.304 with linolenic acid.The significant negative correlation coefficiency was -0.299 to -0.497 with linoleic acid.The expression of PDCTs,FAD2a and FAD3a genes changed fatty acid compositions and led to oil quality change in oil flax.