Department of Molecular Biology and Biotechnology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.
Tsukuba Division, Research Center for Medicinal Plant Resources, National Institutes of Biomedical Innovation, Health and Nutrition, Hachimandai 1-2, Tsukuba, Ibaraki, 305-0843, Japan.
J Nat Med. 2018 Sep;72(4):867-881. doi: 10.1007/s11418-018-1218-6. Epub 2018 May 7.
The three Forsythia species, F. suspensa, F. viridissima and F. koreana, have been used as herbal medicines in China, Japan and Korea for centuries and they are known to be rich sources of numerous pharmaceutical metabolites, forsythin, forsythoside A, arctigenin, rutin and other phenolic compounds. In this study, de novo transcriptome sequencing and assembly was performed on these species. Using leaf and flower tissues of F. suspensa, F. viridissima and F. koreana, 1.28-2.45-Gbp sequences of Illumina based pair-end reads were obtained and assembled into 81,913, 88,491 and 69,458 unigenes, respectively. Classification of the annotated unigenes in gene ontology terms and KEGG pathways was used to compare the transcriptome of three Forsythia species. The expression analysis of orthologous genes across all three species showed the expression in leaf tissues being highly correlated. The candidate genes presumably involved in the biosynthetic pathway of lignans and phenylethanoid glycosides were screened as co-expressed genes. They express highly in the leaves of F. viridissima and F. koreana. Furthermore, the three unigenes annotated as acyltransferase were predicted to be associated with the biosynthesis of acteoside and forsythoside A from the expression pattern and phylogenetic analysis. This study is the first report on comparative transcriptome analyses of medicinally important Forsythia genus and will serve as an important resource to facilitate further studies on biosynthesis and regulation of therapeutic compounds in Forsythia species.
三个连翘属植物，连翘、金钟花和金钟连翘，几个世纪以来一直被中国、日本和韩国用作草药，并且它们是许多药用代谢产物的丰富来源，如连翘苷、连翘酯苷 A、牛蒡子苷、芦丁和其他酚类化合物。在这项研究中，对这些物种进行了从头转录组测序和组装。使用连翘、金钟花和金钟连翘的叶和花组织，获得了基于 Illumina 的 1.28-2.45-Gbp 序列的双端 reads，并分别组装成 81913、88491 和 69458 个 unigenes。将注释的 unigenes 在基因本体论术语和 KEGG 途径中的分类用于比较三个连翘属植物的转录组。所有三个物种的同源基因表达分析表明，叶组织中的表达高度相关。筛选出假定参与木脂素和苯乙醇苷生物合成途径的候选基因作为共表达基因。它们在金钟花和金钟连翘的叶片中表达量较高。此外，根据表达模式和系统发育分析，注释为酰基转移酶的三个 unigenes被预测与毛蕊花糖苷和连翘酯苷 A 的生物合成有关。本研究是首次对药用连翘属植物进行比较转录组分析的报道，将为进一步研究连翘属植物中治疗化合物的生物合成和调控提供重要资源。
