紫苏种子脂肪酸代谢及关键酶基因调控油脂合成规律的研究  

Regulation of Controlling Oil Synthesis by Fatty Acid Metabolism of Perilla Seed and Key Enzyme Gene

作　　者：王计平[1] 张玲慧[1] 赵静[1] 王彦尊 李润植[1] 

机构地区：[1]山西农业大学农学院,太谷030801

出　　处：《中国粮油学报》2016年第3期91-95,共5页Journal of the Chinese Cereals and Oils Association

基　　金：国家青年科学基金(31201266)

摘　　要：为了研究种子油脂及脂肪酸生物合成机制,特别是α-亚麻酸的高水平积累,采用气相色谱法分析7个紫苏品种的成熟种子及晋苏1号种子不同发育时期脂肪酸组成、含量及其动态变化;实时荧光定量PCR检测TAG生物合成关键酶基因在紫苏不同组织及种子发育不同时期的表达特性,分析基因表达与脂肪酸及α-亚麻酸合成积累之间的关系。结果表明,紫苏种子中不饱和脂肪酸(18∶1,18∶2,18∶3)含量占总脂肪酸90%以上,种子发育过程中,总脂肪酸含量随着鲜重增加而不断增加,种子形态也经历由多水透明状转变为乳白色或深紫色最后成为褐色;随着种子不断发育,亚油酸含量逐渐降低,而α-亚麻酸含量不断增加,到种子成熟时达总脂肪酸质量的60%以上。晋苏1号作为高含α-亚麻酸的优质品种,α-亚麻酸含量达456.6mg/g,亚麻酸与亚油酸之比为9∶1。Real-time PCR分析结果显示Pf DGAT1和Pf PDAT在紫苏茎和根系中的表达量均很低,而在叶片和种子中高量表达,在种子发育不同时期,Pf DGAT1表达量呈先升高后降低的趋势,开花后30 d,表达量最高。Pf DGAT1基因超量表达之后紧接着α-亚麻酸和总油脂快速积累,表明Pf DGAT1在紫苏α-亚麻酸和总油脂积累过程中起关键作用。In order to study the biosynthesis mechanism of grease and fatty acids in seeds,especially the high-level accumulation of α- linolenic acid,this paper adopted gas chromatography method to analyze composition,content and dynamic change of fatty acid in the mature seeds of seven perrila varieties and Jinsu No. 1 seed at different development stages; the developing seeds so as to investigate physiological- biochemical features of perilla seed oil and fatty acid biosynthesis. Expression pattern of key genes in fatty acid metabolism was analyzed. The results showed that unsaturated fatty acids（ 18∶ 1,18∶ 2,18∶ 3） made up 90% of total seed oil in perilla. Following seed developing,seed fresh weight and total fatty acid content were increased,and seed morphology was also changed from aqueous and transparent forms to milky white or dark purple and finally brown matured seeds. During seed development and maturation,linoleic（ 18∶ 2） content was gradually reduced while the level of α- linolenic acid（ 18∶ 3） was correspondingly increased up to more than 60% of the total fatty acids in the mature seeds. Of seven perilla varieties tested,variety Jinsu1 contained the highest level of α- linolenic acid（ 456. 6 mg / g）. The ratio of α- linolenic acid to linoleic acid is 9∶ 1. Real- time PCR analysis showed that small expression of Pf DGAT1 and Pf PDAT was in root and stems while large expression of the genes was in leaves and seeds. Following seed development,Pf DGAT1 expression increased slowly at the earlier stages,and then increased vastly at mid stages and reduced slowly at late stages,with the peak expression level in the seed at 30 days after flowering. The Pf DGAT1 highly expression stage was just ahead of the high accumulation stage of α- linolenic acid and total oil in seed development,indicating that Pf DGAT1 function importantly in perilla seed oil and α- linolenic acid accumulation.

关 键 词：紫苏 种子油脂 脂肪酸 二酰甘油酰基转移酶基因(DGAT1) 磷脂二酰甘油酰基转移酶(PDAT) 

分 类 号：S565.8[农业科学—作物学]