碱蓬转录组分析及油脂合成相关基因表达模式

摘要

Suaeda salsa L. seeds have high oil content and rich unsaturated fatty acid composition, so they have great potential for development and utilization as special oil crop. In this study, the Illumina Hi Seq 2000 high-throughput sequencing platform was used to detect and analyze the transcriptome of Suaeda salsa. 106 647 Unigenes were produced, and 76 755 of them were functionally annotated by blasting the online protein databases. In order to comprehensively study the classification and expression pattern of genes related to lipid synthesis in Suaeda salsa, the key genes involved in lipid synthesis in seed and leaf transcriptomes of Suaeda salsa were screened and their differential expression profiles were comparatively analyzed. A total of 45 Unigenes encoding key enzymes involved in fatty acid (FA) biosynthesis were obtained, of which 25 Unigenes were up-regulated in seeds of developing stage. In comparison to leaves, a number of Unigenes encoding ACCase, KAS III and EAR, and 5 out of 7 Unigenes encoding acyl carrier protein desaturase (SAD) were significantly up-regulated in developing seeds, which might be related to the formation of unsaturated FA in Suaeda salsa seeds oil. A total of 30 Unigenes encoding key enzymes involved in the synthesis of triacylglycerols (TAGs). Among them, 16 Unigenes were up-regulated in developing seeds, and multiple Unigenes encoding GPAT and DGAT were significantly upregulated. This study could make great countribution to the analysis of the regulation of lipid metabolism pathways and the exploration of the key genes involved in the lipid synthesis of Suaeda salsa.%碱蓬(Suaeda salsa)籽粒具有较高的含油量及丰富的不饱和脂肪酸,作为潜在的特种油料作物具有极高的开发和利用价值.为了研究碱蓬中油脂合成相关基因的构成及表达模式,本文利用Illumina Hi Seq 2000高通量测序平台对碱蓬根、叶和发育期种子进行转录组检测和分析,筛选碱蓬发育期种子和叶片转录组中参与油脂合成途径的关键脂类基因,并对其差异表达模式进行比较分析.本研究测序共计产出106 647条Unigenes,通过与各蛋白数据库比对,其中76 755条Unigenes成功获得了功能注释.共有45个Unigenes编码参与脂肪酸(FA)合成的关键酶,其中25个Unigenes在发育期种子中上调表达;多个编码ACCase、KASⅢ和EAR等的Unigenes上调表达;且7个编码酰基载体蛋白去饱和酶(SAD)的Unigenes中有5个在发育期种子中显著上调,可能与碱蓬油脂中不饱和脂肪酸的生成相关.共有30个Unigenes编码参与三酰甘油(TAG)合成的关键酶,其中16个Unigenes在发育期种子中上调表达,包括多个编码GPAT和DGAT的Unigenes.本研究对解析碱蓬脂类代谢途径的调控模式及发掘参与碱蓬油脂合成的关键基因具有重要的意义和参考价值.