不饱和脂肪酸为人体提供基本代谢所必需的能量，须从膳食中补充。脂肪酸去饱和酶FAD(fatty acid desaturase)是植物不饱和脂肪酸合成途径中的关键酶，植物体内脂肪酸的各组分比例和不饱和度与FAD的去饱和作用息息相关。为探究亚麻FAD基因家族的表达与进化，为其在亚麻高品质育种中的应用提供理论依据。运用生物信息学方法对亚麻全基因组FAD基因家族的43个LuFADs基因进行分析。结果显示，该家族成员编码的蛋白质大小为152～453个氨基酸，大部分为碱性不稳定亲水蛋白。与拟南芥FADs蛋白序列构建系统发育树，可分为4个主要亚家族:Δ12/ω-3去饱和酶、“前端”去饱和酶、Δ7/Δ9去饱和酶和SAD去饱和酶。保守结构域和外显子-内含子结构分析得出，同一亚组中的家族成员具有较为相似的基因结构。染色体定位分析呈随机性分布。亚细胞定位预测得出，叶绿体上的家族成员最多。启动子顺式作用元件分析发现，该家族成员中抗氧化反应元件(ARE)数量最多。

Unsaturated fatty acids provide the human body with the energy necessary for basic metabolism and must be supplemented from the diet. FAD (fatty acid desaturase) is a key enzyme in the biosynthesis of unsaturated fatty acids in plants. The proportion and unsaturation of fatty acids in plants are closely related to the desaturation of FAD. In order to explore the expression and evolution of flax (Linum usitatissimum L.) FAD gene family and to provide theoretical basis for its application in high-quality flax breeding, in this study, bioinformatics method was used to analyze 43 LuFADs genes of flax. Results showed that the size of proteins encoded by the members of this family were between 152 to 453 amino acids, most of which were alkaline unstable hydrophilic proteins. The phylogenetic tree was constructed with the FADs protein sequence of Arabidopsis thaliana, which could be divided into four main subfamilies: Δ12/ω-3 desaturase, 'front-end' desaturase, Δ7/Δ9 desaturase and SAD desaturase. The analysis of conserved domain and exon-intron structure showed that the family members in the same subgroup had relatively similar gene structure. The chromosome localization analysis showed random distribution, and the subcellular localization predicted that the most family members were on the chloroplast. Analysis of promoter cis-acting elements showed that the number of antioxidant response elements (ARE) were the largest among this family.

S565.9

国家自然科学基金(32160497、32160499)；国家特色油料产业技术体系(CARS-14-1-03)。