基于转录组测序的香水月季花香代谢基因研究

Study on the Fragrance Metabolic Genes of Rosa odorata Based on Transcriptome Sequencing

通过转录组测序技术,探究大花香水月季及单瓣香水月季两个变种的花香代谢通路及花香差异形成的相关基因。在两个材料花蕾期、初开期及盛开期对比组中分别检测出8339、8849、7572个差异表达基因,其中3个阶段共有的差异基因3762个。GO和KEGG聚类分析显示,差异基因主要参与代谢过程、细胞过程、单一有机体过程、催化活性等生物学过程;主要富集于代谢途径、次生代谢物的生物合成、碳代谢等途径。在3组共有差异基因中共发现富集于6条重要花香物质合成通路(萜类骨架生物合成、苯丙素生物合成、脂肪酸生物合成、单萜类生物合成、双萜类生物合成及倍半萜和三萜类生物合成)中的差异基因27个。认为这27个基因对两个变种花香释放过程中的差异形成有较大影响。分析特征花香物质合成酶基因Rc_0128091及Rc_0119291在转录组数据中的表达,发现其表达量与相应的花香物质3,5–二甲氧基苯及1,3,5–三甲氧基苯释放量趋势基本一致,推测对特征花香物质的合成有决定性作用。随机选取10个差异表达基因进行qRT-PCR和RNA-seq的相关性验证,结果显示二者相关性较高,认为RNA-seq测序结果具有较高的准确性。

By using the technique of transcriptome sequencing,floral fragrance metabolic pathways and genes related to the unique floral fragrance of Rosa odorata var.gigantea and R.odorata var.odorata were investigated.The results showed that 8339,8849,and 7572 differentially expressed genes were detected in these two plant species at the flower budding stage,early flowering stage,and blooming stage,including 3762 differentially expressed genes that were detected in all three stages.Cluster analysis of GO and KEGG showed that the differentially expressed genes were mainly involved in the terms of metabolic process,cell process,single organism process,catalytic activity,and other biological processes.They were also largely enriched in the metabolic pathway,secondary metabolites biosynthesis,carbon metabolism,and other pathways.A total of 27 differentially expressed genes were predicted to be associated with six important floral fragrance biosynthesis pathways(terpenoid backbone biosynthesis,phenylpropanoid biosynthesis,fatty acid biosynthesis,monoterpenoid biosynthesis,diterpenoid biosynthesis,sesquiterpene,and triterpene biosynthesis).The results showed that these 27 genes had a significant effect on the difference of floral fragrance emission between the two species,and the difference was consistent in the three stages.Furthermore,the expression of Rc_0128091 and Rc_0119291,which are the characteristic floral substance synthetase genes,were investigated.It was found that the expression of Rc_0128091 and Rc_0119291 in the transcriptional data was consistent with the emission of 3,5-dimethoxybenzene and 1,3,5-trimethoxybenzene,suggesting that they are decisive for the synthesis of the characteristic aroma compounds.By randomly selecting 10 differentially expressed genes,the correlation between qRT-PCR and RNA-seq results was verified.The highly correlated results indicate that the RNA-seq results are of high accuracy.