胡麻脂肪酸去饱和酶基因(fads)差异表达分析

Analysis of Differentia Expression of Fatty Acid Desaturase Gene(fads)in Oil Flax

为了了解fad基因在胡麻蒴果发育过程中对不饱和脂肪酸的调控,对高、中、低三个不同亚麻酸(C18:3)含量的胡麻品种(’CDC Gold’,‘内亚7号’,’Linola’)进行了不同时期的品质测定,以及脂肪酸去饱和酶2a基因(fad2a)、脂肪酸去饱和酶2b基因(fad2b)、脂肪酸去饱和酶2c基因(fad2c)、脂肪酸去饱和酶3a基因(fad3a)、脂肪酸去饱和酶3b基因(fad3b)的qRT-PCR定量分析。结果表明,随着蒴果成熟,可溶性糖含量呈降低趋势,粗脂肪与粗蛋白不断积累,且差异显著(p<0.05)。fad2a基因、fad3a基因以及fad3b基因在各个时期中的表达符合正态分布。以0 d的蒴果为对照,在胡麻种子形成过程中,‘内亚7号’的三个基因在5 d和15 d的表达量迅速增加,到30 d时急剧减少,15 d的fad2a基因表达量为5.23倍,fad3a基因表达量是fad2a基因表达量的14.52倍,fad3b基因的表达量是fad2a基因表达量的16.14倍,表明这三个基因参与不饱和脂肪酸积累过程。在低亚麻酸含量品种‘Linola’30 d中,fad3a基因是fad2a基因表达量的52.71倍,fad3b呈下调趋势;在高亚麻酸含量品种‘CDCGold’30d中,fad3a基因与fad2a基因的表达量均呈下调趋势,fad3b的表达量为3.92倍;在中等亚麻酸含量品种‘内亚7号’中,fad2a基因表达量降低了0.31倍,fad3a基因是fad3b基因表达量的1.87倍。fad2b基因、fad2c基因熔解曲线不稳定,峰值低,可以在后续试验中继续探索。

To better understand the control of fatty acid desaturase gene(fad)in development of oil flax balls,3 varieties of oil flax with high,medium and low linolenic acid(C18:3)content was investigated as materials.Real-time fluorescent quantitative PCR was applied to investigate the expression of 5 genes,that is fatty acid desaturase 2a gene(fad2a),fatty acid desaturase 2b gene(fad2b),fatty acid desaturase 2c gene(fad2c),fatty acid desaturase 3a gene(fad3a),fatty acid desaturase 3b gene(fad3b).And the content of soluble sugar,lipid and protein was analyzed in development periods of flax capsules.It was found that the soluble sugar was downtrend,while protein and fat content increased.And the difference was significant(p<0.05).In different period of flax capsules,every expression patterns followed the normal distribution.The expression of fad2a,fad3a,fad3b at 5 d and 15 d were increased and reduced at 30 d in’Neiya No.7’flax capsules(p<0.05).The expression of fad2a gene at 15 d was 5.23 times that compared with the period of 0 d.And the expression of fad3a gene was 14.52 times of the expression of fad2a gene at 15 d.The expression of fad3b gene was 16.14 times of the expression of fad3a gene at 15 d.It showed that these genes participated in accumulation of unsaturated fatty acid in flax.The expression fad3a gene was 52.71 times of fad2a in low linolenic acid variety’Linola’at 30 d,and fad3b gene was downtrend.The expression of fad3a gene and fad2a gene was downtrend,and the expression of fad3b gene was 3.92 times of high linolenic acid variety’CDC Gold’at 30 d which compared with 0 d.The expression of fad2a gene was 0.31 times lower than the expression at 0 d which was in’Neiya No.7’at 30 d.The expression of fad3b gene was 1.87 times of the expression of fad3b gene in middle linolenic acid variety’Neiya No.7’at 30 d.Dissociation curve of fad2b and fad2 c was not stable,and with low peak value.It can be further explored in subsequent experiments.