翅果油树种仁脂肪酸合成关键基因筛选

Screening of key genes in fatty acid synthesis in seed kernel of Elaeagnus mollis Diels.

[目的]通过翅果油树不同时期种仁的转录组学分析挖掘与脂肪酸合成相关的关键基因。[方法]观察记录翅果油树果实发育情况并以成年翅果油树果实开始膨大期(C6)、迅速膨大期(C7)和成熟期(C8)的新鲜种仁为材料,以水解-提取法测定3个时期种仁的脂肪酸组分与含量,用转录组测序技术分析C6、C7时期样品的表达差异,并寻找关键差异表达基因。[结果]3个时期的脂肪酸平均含量随时间推移呈逐渐上升趋势;C6、C7时期的种仁数据中共获得6375个上调表达基因、8124个下调表达基因;8137个差异表达基因在GO数据库中获得注释;4275个差异表达基因在KEGG数据库中获得注释,主要涉及代谢途径、次生代谢物的生物合成、激素传导和氨基酸合成途径等通路,其中,脂肪酸生物合成、不饱和脂肪酸生物合成等与脂肪酸相关的通路均被富集,并重点挖掘出8个与脂肪酸合成相关的候选基因,发现与果实膨大时期(C6)相比,EmBCCP1、EmSAD1、EmFAD2-1、Em-FAD3-1、EmPDCT1基因上调表达,同时EmFAbG1、EmPDAT1、EmKASI1基因下调表达。[结论]EmBCCP1、EmSAD1、EmFAD2-1、EmFAD3-1、EmPDCT1、EmKASI1、EmFAbG1、EmPDAT1基因促进了翅果油树种仁油酸、亚油酸的合成积累,可作为翅果油树种仁脂肪酸合成的关键候选基因。

[Objective]The study aims to mine the key genes involved in fatty acid synthesis using transcriptomic analysis of kernels from different periods of Elaeagnus mollis Diels.[Methods]We observed and recorded fruit development of E.mollis Diels.and used the fresh seed kernels of adult trees during the period of fruit initiation(C6),rapid fruit expansion(C7),and fruit maturity(C8)as materials.The fatty acid fractions and contents of the kernels of three periods were determined by hydrolysis extraction.The expression of samples from C6 and C7 was analyzed using transcriptome sequencing,in order tosearch the differentially expressed genes.[Results]The fatty acid content of the three periods showed a gradual increase over time.6375 up-regulated genes and 8124 down-regulated genes were obtained from the seed kernel data of C6 and C7 periods,totaling 14499 differentially expressed genes(DEGs).Among the selected DEGs,8137 genes were annotated in the GO database,and 4275 genes were annotated in the KEGG database,mainly involving in metabolic pathways,biosynthesis of secondary metabolites,hormone transduction,amino acid synthesis pathways,and other pathways.Among them,pathways related to fatty acid biosynthesis and unsaturated fatty acid biosynthesis were enriched,with a focus on identifying 8 candidate genes related to fatty acid synthesis.Compared with C6 stage,EmBCCP1,EmSAD1,Em-FAD2-1,EmFAD3-1,and EmPDCT1 genes were up regulated,while EmFAbG1,EmPDAT1,and EmKASI1 genes were down regulated.[Conclusion]EmBCCP1,EmSAD1,EmFAD2-1,EmFAD3-1,EmPDCT1,EmKASI1,EmFAbG1,and EmPDAT1 genes may promote the synthesis and accumulation of oleic acid and linoleic acid in the seeds,serving as key genes for fatty acid synthesis in E.mollis Diels.seed kernels.