Kim Jungeun, Kang Sang-Ho, Park Sin-Gi, Yang Tae-Jin, Lee Yi, Kim Ok Tae, Chung Oksung, Lee Jungho, Choi Jae-Pil, Kwon Soo-Jin, Lee Keunpyo, Ahn Byoung-Ohg, Lee Dong Jin, Yoo Seung-Il, Shin In-Gang, Um Yurry, Lee Dae Young, Kim Geum-Soog, Hong Chang Pyo, Bhak Jong, Kim Chang-Kug
Personal Genomics Institute, Genome Research Foundation, Osong, 28160 Korea.
Genomics Division, National Institute of Agricultural Sciences (NAS), Jeonju, 54874 Korea.
Hortic Res. 2020 Jul 1;7:112. doi: 10.1038/s41438-020-0329-x. eCollection 2020.
Triterpenoid saponins (TSs) are common plant defense phytochemicals with potential pharmaceutical properties. (Campanulaceae) has been traditionally used to treat bronchitis and asthma in East Asia. The oleanane-type TSs, platycosides, are a major component of the root extract. Recent studies show that platycosides exhibit anti-inflammatory, antiobesity, anticancer, antiviral, and antiallergy properties. However, the evolutionary history of platycoside biosynthesis genes remains unknown. In this study, we sequenced the genome of and investigated the genes involved in platycoside biosynthesis. The draft genome of is 680.1 Mb long and contains 40,017 protein-coding genes. Genomic analysis revealed that the family genes play a major role in platycoside oxidation. The gene family of was much larger than that of other Asterid species. Orthologous gene annotation also revealed the expansion of () in , which was confirmed by tissue-specific gene expression. In these expanded gene families, we identified key genes showing preferential expression in roots and association with platycoside biosynthesis. In addition, whole-genome bisulfite sequencing showed that and genes are hypomethylated in , suggesting that epigenetic modification of these two gene families affects platycoside biosynthesis. Thus whole-genome, transcriptome, and methylome data of provide novel insights into the regulation of platycoside biosynthesis by and gene families.
三萜皂苷（TSs）是常见的具有潜在药用特性的植物防御性植物化学物质。桔梗科植物在东亚传统上被用于治疗支气管炎和哮喘。齐墩果烷型三萜皂苷，即桔梗皂苷，是根部提取物的主要成分。最近的研究表明，桔梗皂苷具有抗炎、抗肥胖、抗癌、抗病毒和抗过敏特性。然而，桔梗皂苷生物合成基因的进化历史仍然未知。在本研究中，我们对桔梗的基因组进行了测序，并研究了参与桔梗皂苷生物合成的基因。桔梗的基因组草图长680.1 Mb，包含40,017个蛋白质编码基因。基因组分析表明，桔梗科基因家族在桔梗皂苷氧化中起主要作用。桔梗的基因家族比其他菊类物种的基因家族大得多。直系同源基因注释还揭示了桔梗中该基因家族的扩增，这一点通过组织特异性基因表达得到了证实。在这些扩增的基因家族中，我们鉴定出了在根中优先表达且与桔梗皂苷生物合成相关的关键基因。此外，全基因组亚硫酸氢盐测序表明，桔梗中的和基因是低甲基化的，这表明这两个基因家族的表观遗传修饰影响桔梗皂苷的生物合成。因此，桔梗的全基因组、转录组和甲基化组数据为桔梗科和基因家族对桔梗皂苷生物合成的调控提供了新的见解。
