| 摘要: |
| 藜麦营养丰富,油脂含量高,脂肪酸组成理想,是油脂提取物的潜在资源。植物油脂主要以三酰甘油的形式储存在作物种子和果实等器官中,其合成受到环境和基因水平的调控,涉及质体、内质网和油体等多个细胞器。该文基于藜麦转录组数据,对藜麦油脂合成相关的脂肪酸生物合成途径基因进行挖掘,并对基因表达模式进行分析。结果表明:在藜麦中,与脂肪酸生物合成相关的基因序列共87条,涉及乙酰CoA羧化酶和β-酮脂酰ACP合成酶等关键酶,其中编码长链酰基辅酶A合成酶基因和β-酮脂酰ACP还原酶数目最多。通过基因表达模式分析发现,与脂肪酸生物合成相关的基因在种子表达中呈现整体上调模式,可能与种子中油脂形成和积累密切相关。对藜麦乙酰CoA羧化酶亚基编码基因进行分析发现,accD基因在不同组织间无差异表达,表明在藜麦中accD编码的β-CT亚基可能不是影响乙酰CoA羧化酶发挥作用的限制因子。藜麦KASⅡ含有保守结构域,与其他组织相比,编码基因QcFb15、QcFb45和QcFb75在种子中均存在上调表达,参与藜麦脂肪酸碳链延伸及油脂形成。对藜麦脂肪酸生物合成途径相关基因的挖掘,为藜麦油脂合成和积累的研究提供了理论基础,对高油脂藜麦品种选育等后续研究也具有重要启示作用。 |
| 关键词: 藜麦, 转录组, 脂肪酸生物合成, 差异表达基因 |
| DOI：10.11931/guihaia.gxzw201905021 |
| 分类号: |
| 文章编号:1000-3142(2020)12-1721-11 |
| Fund project:国家自然科学基金(31701493); 农业农村部杂粮加工重点实验室开放课题(2018CC12)[Supported by the National Natural Science Foundation of China(31701493); Fund of Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs(2018CC12)]。 |
|
| Description of fatty acid biosynthesis pathway based on quinoa transcriptome |
|
SHI Xiaodong1,2, SUN Menghan1,2, WU Qi1,2, WU Xiaoyong1,2, ZHAO Gang1*
|
|
1. Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106,
China;2. College of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China
|
| Abstract: |
| Quinoa is rich in nutrients, high in oil content and ideal in fatty acid composition. It is a potential resource for oil extract. Plant oil is mainly stored in crop seeds and fruits in the form of triacylglycerol, and the biosynthesis of oil is catalyzed by a large set of enzymes and regulated by both environmental factors and related genes. In addition, the synthesis and storage of oil involve plastid, endoplasmic reticulum and oil body. The molecular mechanism related to the synthesis of quinoa oil will provide a basis for breeding of oil-quinoa. In this study, the transcriptome of quinoa was analyzed. Based on quinoa transcriptome data, genes involved in fatty acids biosynthesis were explored, and the expression pattern of quinoa genes related to acetyl CoA carboxylase and β-ketoacyl ACP synthase were analyzed. The results were as follows: There were 87 genes related to fatty acid biosynthesis in quinoa, involving key enzymes such as acetyl CoA carboxylase and β-ketoacyl ACP synthase. The number of long-chain acyl-CoA synthetase gene was the most, followed by the β-oxoacyl-ACP reductase gene. Through pathway enrichment analysis, all of these differentially expressed genes were classified into pathways including fatty acid biosynthesis and fatty acid metabolism which were involved in oil synthesis. Based on gene expression pattern analysis, it was found that the genes related to fatty acid biosynthesis showed up-regulation in quinoa seed, which was closely related to the production and accumulation of oil in seed. The accD gene was not differentially expressed between different tissues, indicating that the β-CT subunit may not be a limitation affecting factor for the function of acetyl-CoA carboxylase. The α-CT protein encoded by accD gene, with no signal peptide and was a hydrophobic protein. However, β-CT was a hydrophilic protein. KAS Ⅱ contained a conserved domain, and QcFb15, QcFb45 and QcFb75 were up-regulated in seeds, which were related to the chain extension of quinoa fatty acids and oil formation. The excavation of genes related to fatty acid biosynthesis pathway of quinoa will provide a theoretical basis for the study of the synthesis and accumulation of oil, and it has important enlightenment for the follow-up research of high oil quinoa varieties. |
| Key words: quinoa, transcriptome, fatty acid biosynthesis, different expression genes |
