A chromosome-level genome assembly reveals that a bipartite gene cluster formed via an inverted duplication controls monoterpenoid biosynthesis in Schizonepeta tenuifolia  

作　　者：Chanchan Liu Samuel J.Smit Jingjie Dang Peina Zhou Grant T.Godden Zheng Jiang Wukun Liu Licheng Liui Wei Lin Jinao Duan Qinan Wu Benjamin R.Lichman 

机构地区：[1]School of Pharmacy,Nanjing University of Chinese Medicine,Nanjing,China [2]Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization,Nanjing University of Chinese Medicine,Nanjing,China [3]Centre for Novel Agricultural Products,Department of Biology,University of York,York YO105DD,UK [4]Florida Museum of Natural History,University of Florida,Gainesile,FL,USA [5]Department of Pathogen Biology,School of Medicine and Holistic Integrative Medicine,Nanjing University of Chinese Medicine,Nanjng,China

出　　处：《Molecular Plant》2023年第3期533-548,共16页分子植物（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant nos.81973435 and 81473313);the National Natural Science Foundation for Young Scientists of China(grant no.81903756);the Open Project of the Natural Science Foundation of Nanjing University of Chinese Medicine(no.NZY81903756);research on ecological planting and quality assurance of Jiangsu Dao-di herbs(2021);and a Jiangsu Government Scholarship for Overseas Studies(JS-2020-044).We also acknowledge support from the BBSRC(BBN006452/1)and UKRI(MR/S01862X/1).

摘　　要：Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain largely unclear.In this study,we have assembled a chromosome-scale genome of Japanese catnip(Schizonepeta tenuifolia)and discovered a BGC that contains multiple copies of genes involved in four adjacent steps in the biosynthesis of p-menthane monoterpenoids.This BGC has an unprecedented bipartite structure,with mirrored biosynthetic regions separated by 260 kilobases.This bipartite BGC includes identical copies of a gene encoding an old yellow enzyme,a type of flavin-dependent reductase.In vitro assays and virus-induced gene silencing revealed that this gene encodes the missing isopiperitenone reductase.This enzyme evolved from a completely different enzyme family to isopiperitenone reductase from closely related Mentha spp.,indicating convergent evolution of this pathway step.Phylogenomic analysis revealed that this bipartite BGC has emerged uniquely in the S.tenuifolia lineage and through insertion of pathway genes into a region rich in monoterpene synthases.The cluster gained its bipartite structure via an inverted duplication.The discovered bipartite BGC for p-menthane biosynthesis in S.tenuifolia has similarities to the recently described duplicated p-menthane biosynthesis gene pairs in the Mentha longifolia genome,providing an example of the convergent evolution of gene order.This work expands our understanding of plant BGCs with respect to both form and evolution,and highlights the power of BGCs for gene discovery in plant biosynthetic pathways.

关 键 词：specialized metabolism MONOTERPENOIDS biosynthetic gene cluster Lamiaceae BIOSYNTHESIS chromosomal inversion 

分 类 号：O41[理学—理论物理]