Alpha-linolenic acid (ALA, 18:3Δ9,12,15) and γ-linolenic acid (GLA, 18:3Δ6,9,12) are important trienoic fatty acids which are beneficial for human health in their own right, or as precursors for the biosynthesis of long chain polyunsaturated fatty acids. ALA and GLA in seed oil are synthesized from linoleic acid (LA, 18:2Δ9,12) by the microsomal ω-3 fatty acid desaturase (FAD3) and Δ6 desaturase (D6D), respectively. Cotton (Gossypium hirsutum L.) seed oil composition was modified by transforming with a FAD3 gene from Brassica napus and a D6D gene from Echium plantagineum, resulting in approximately 30% ALA and 20% GLA, respectively. The total oil content in transgenic seeds remained unaltered relative to parental seeds. Despite the use of a seed-specific promoter for transgene expression, low levels of GLA and increased levels of ALA were found in non-seed cotton tissues. At low temperature the germinating cottonseeds containing the linolenic acid isomers elongated faster than the untransformed controls. ALA-producing lines also showed higher photosynthetic rates at cooler temperature and better fibre quality compared to both untransformed controls and GLA-producing lines. The oxidative stability of the novel cottonseed oils was assessed, providing guidance for potential food, pharmaceutical and industrial applications of these oils.

中文翻译：

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将三烯脂肪酸工程化到棉籽油中可改善低温种子的萌发，植物光合作用和棉纤维质量。

α-亚麻酸（ALA，18：3Δ9,12,15）和γ-亚麻酸（GLA，18：3Δ6,9,12）是重要的三烯脂肪酸，它们本身或作为前体有益于人类健康用于长链多不饱和脂肪酸的生物合成。种子油中的ALA和GLA分别由亚油酸ω-3脂肪酸去饱和酶（FAD3）和Δ6去饱和酶（D6D）由亚油酸（LA，18：2Δ9,12）合成。棉花（Gossypium hirsutum L.）种子油成分通过用甘蓝型油菜的FAD3基因和车前草的D6D基因转化而得到修饰，分别得到约30％的ALA和20％的GLA。相对于亲本种子，转基因种子中的总油含量保持不变。尽管使用了种子特异性启动子进行转基因表达，在非种子棉组织中发现低水平的GLA和升高的ALA水平。在低温下，含有亚麻酸异构体的发芽棉籽的伸长速度要快于未转化的对照。与未转化的对照和GLA生产线相比，ALA生产线在较低的温度下也显示出更高的光合作用速率和更好的纤维质量。评估了新型棉籽油的氧化稳定性，为这些油的潜在食品，制药和工业应用提供了指导。与未转化的对照和GLA生产线相比，ALA生产线在较低的温度下也显示出更高的光合作用速率和更好的纤维质量。评估了新型棉籽油的氧化稳定性，为这些油的潜在食品，制药和工业应用提供了指导。与未转化的对照和GLA生产线相比，ALA生产线在较低的温度下也显示出更高的光合作用速率和更好的纤维质量。评估了新型棉籽油的氧化稳定性，为这些油的潜在食品，制药和工业应用提供了指导。