大豆脂肪酸含量积累动态及亚麻酸代谢候选基因筛选

大豆脂肪酸5种组分中亚麻酸含量是影响大豆品质主要因素之一,与其他4种脂肪酸比例直接影响大豆油脂品质特性及贮运加工,大豆油具有适宜亚油酸与亚麻酸比例。文章通过高效气相色谱法对品种‘合丰25’(高亚麻酸含量品种,5.94%)与加拿大稳定品系‘L-5’(低亚麻酸含量品种,2.75%)及其组配重组自交系群体中选取高/低亚麻酸品系各2份,盆栽试验分析脂肪酸组分及含量。结合KEGG中大豆脂肪酸代谢途径筛选与不饱和脂肪酸代谢相关候选基因,对筛选RIL群体后代品系发育各时期作实时定量PCR,分析其在‘合丰25’和‘L-5’及后代品系中表达模式。结果表明,相同基因在不同品种之间对亚麻酸含量调控机制不同,不同时期基因表达量对亚麻酸积累量具有不同程度影响。研究结果为探索大豆亚麻酸积累规律及其候选基因影响,选育理想脂肪酸组分比例大豆新品种提供参考。

Accumulation dynamics of fatty acid in soybean seed and screening of candidate gene related to linolenic acid metabolism

Linolenic acid content,as one of thefive fatty acid components in soybean,is one of the important factors affecting the quality of soybean,its composition and ratio is also directly related to the quality of soybean oil,storage and processing etc.In comparison with other plant oil,soybean oil has better linoleic acid content and linolenic acid ratio.This study analyzed fatty acid content and proportion of'Hefeng 25'(high linolenic acid content of 5.94％ varieties,Canada) and stable strains'L-5'(low linolenic acid content of 2.75％ varieties),two lines from recombinant inbred lines derived from'Hefeng 25'and'L-5'through gas chromatography method.Additionally,combined with the metabolic pathways of KEGG in soybean fatty acids were screened and unsaturated fatty acid metabolism related candidate genes and screening lines produced during different developmental stages were analyzed by real-time quantitative PCR in'Hefeng 25'and'L-5'expression patterns.The results showed that the same gene in different varieties of linolenic acid content of different regulatory mechanisms,both positive and negative regulations of gene expression regulation in different periods had different degrees of influence on the accumulation of linolenic acid.The results,for exploring the regularity of soybean linolenic acid accumulation and the influence of its candidate genes,for breeding the ideal fatty acid composition and proportion of new soybean varieties,provided theoretical reference.