南湖新闻网讯（通讯员 郑伟康）近日，我室邓秀新院士团队与中国中医科学院黄璐琦院士团队合作研究成果以“Evolution-guided multiomics provide insights into the strengthening of bioactive flavone biosynthesis in medicinal pummelo”为题在Plant Biotechnology Journal发表。研究深刻解析了化橘红黄酮类药用成分高积累的代谢调控机制。
我国柑橘种质资源类型丰富，包括橘、柑、橙、柚、香橼以及枳等近缘种，不仅包含多种美味水果，还是多种重要的中药材基原植物。化橘红、陈皮、枳壳、香橼等柑橘类药材在许多经典名方中都起着重要作用，尤其是化橘红，在止咳、化痰、润肺方面都是君药。迄今研究认为化橘红主要有效成分为黄酮类化合物，但其代谢调控机制还远未明了。
为探究柑橘类药材品质形成机制，作者前期收集了154份柚种质资源，6种柑橘近缘种、7种野生柑橘，利用三代测序技术对化橘红百年树王进行了de novo基因组组装，含9条染色体，大小为345.2 Mb，N50是1.74 Mb，发现类黄酮、苯丙素和萜类途径基因在柚中显著扩张；相对于柑橘近缘种和野生柑橘，59种代谢物在柚中显著高积累，其中43种为具有药用价值的黄酮、黄烷酮、柠檬苦素代谢物及其衍生物；利用2种类型化州柚的6个果皮发育时期转录组和代谢组，构建了化橘红代谢物调控网络；鉴定到一个新的转录因子CmtMYB108，柑橘近缘种和野生柑橘相比，CmtMYB108在柚中显著低表达，PAL和FNS在柚中显著高表达，通过与PAL（phenylalanine ammonia-lyase）和FNS（flavone synthase）的启动子互作负调控黄酮合成途径。该研究丰富了中药材品质形成基础理论，也为开发我国丰富的柑橘类种质资源、提高柑橘类药材质量提供了重要科学依据。
我室博士研究生郑伟康和张旺为论文共同第一作者。我室马兆成副教授、徐强教授和中国中医科学院黄璐琦院士为论文共同通讯作者。海南大学罗杰教授、中国中医科学院郭兰萍研究员、华中农业大学梅之南教授、湖北中医药大学刘大会教授也参与了该项工作。本研究得到中医药资源可持续利用能力建设、国家中医药管理局创新团队及人才培养计划和国家自然科学基金的资金资助。
审核人：马兆成
【英文摘要】
Pummelo (Citrus maxima or Citrus grandis) is a basic species and an important type for breedingin Citrus. Pummelo is used not only for fresh consumption but also for medicinal purposes. However, the molecular basis of medicinal traits is unclear. Here, compared with wild citrus species/Citrus-related genera, the content of 43 bioactive metabolites and their derivatives increased in the pummelo. Furthermore, we assembled the genome sequence of a variety for medicinal purposes with a long history, Citrus maxima ‘Huazhouyou-tomentosa’ (HZY-T), at the chromosome level with a genome size of 349.07 Mb. Comparative genomics showed that the expanded gene family in the pummelo genome was enriched in flavonoids-, terpenoid-, and phenylpropanoid biosynthesis. Using the metabolome and transcriptome of six developmental stages of HZY-T and Citrus maxima ‘Huazhouyou-smooth’ (HZY-S) fruit peel, we generated the regulatory networks of bioactive metabolites and their derivatives. We identified a novel MYB transcription factor, CmtMYB108, as an important regulator of flavone pathways. Both mutations and expression of CmtMYB108, which targets the genes PAL (phenylalanine ammonia-lyase) and FNS (flavone synthase), displayed differential expression between Citrusrelated genera, wild citrus species and pummelo species. This study provides insights into the evolution-associated changes in bioactive metabolism during the origin process of pummelo.
论文链接：https://onlinelibrary.wiley.com/doi/epdf/10.1111/pbi.14058
