{"title":"Integrative omics reveals mechanisms of biosynthesis and regulation of floral scent in Cymbidium tracyanum","authors":"Mengling Tu, Ningyawen Liu, Zheng-Shan He, Xiu-Mei Dong, Tian-Yang Gao, Andan Zhu, Jun-Bo Yang, Shi-Bao Zhang","doi":"10.1111/pbi.70025","DOIUrl":null,"url":null,"abstract":"Flower scent is a crucial determiner in pollinator attraction and a significant horticultural trait in ornamental plants. Orchids, which have long been of interest in evolutionary biology and horticulture, exhibit remarkable diversity in floral scent type and intensity. However, the mechanisms underlying floral scent biosynthesis and regulation in orchids remain largely unexplored. In this study, we focus on floral scent in <i>Cymbidium tracyanum</i>, a wild species known for its strong floral fragrance and as a primary breeding parent of commercial <i>Cymbidium</i> hybrids. We present a chromosome-level genome assembly of <i>C. tracyanum</i>, totaling 3.79 Gb in size. Comparative genomic analyses reveal significant expansion of gene families associated with terpenoid biosynthesis and related metabolic pathways in <i>C. tracyanum</i>. Integrative analysis of genomic, volatolomic and transcriptomic data identified terpenoids as the predominant volatile components in the flowers of <i>C. tracyanum</i>. We characterized the spatiotemporal patterns of these volatiles and identified <i>CtTPS</i> genes responsible for volatile terpenoid biosynthesis, validating their catalytic functions <i>in vitro</i>. Dual-luciferase reporter assays, yeast one-hybrid assays and EMSA experiments confirmed that <i>CtTPS2</i>, <i>CtTPS3,</i> and <i>CtTPS8</i> could be activated by various transcription factors (i.e., CtAP2/ERF1, CtbZIP1, CtMYB2, CtMYB3 and CtAP2/ERF4), thereby regulating the production of corresponding monoterpenes and sesquiterpenes. Our study elucidates the biosynthetic and regulatory mechanisms of floral scent in <i>C. tracyanum</i>, which is of great significance for the breeding of fragrant <i>Cymbidium</i> varieties and understanding the ecological adaptability of orchids. This study also highlights the importance of integrating multi-omics data in deciphering key horticultural traits in orchids.","PeriodicalId":221,"journal":{"name":"Plant Biotechnology Journal","volume":"24 1","pages":""},"PeriodicalIF":10.1000,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Biotechnology Journal","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1111/pbi.70025","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Flower scent is a crucial determiner in pollinator attraction and a significant horticultural trait in ornamental plants. Orchids, which have long been of interest in evolutionary biology and horticulture, exhibit remarkable diversity in floral scent type and intensity. However, the mechanisms underlying floral scent biosynthesis and regulation in orchids remain largely unexplored. In this study, we focus on floral scent in Cymbidium tracyanum, a wild species known for its strong floral fragrance and as a primary breeding parent of commercial Cymbidium hybrids. We present a chromosome-level genome assembly of C. tracyanum, totaling 3.79 Gb in size. Comparative genomic analyses reveal significant expansion of gene families associated with terpenoid biosynthesis and related metabolic pathways in C. tracyanum. Integrative analysis of genomic, volatolomic and transcriptomic data identified terpenoids as the predominant volatile components in the flowers of C. tracyanum. We characterized the spatiotemporal patterns of these volatiles and identified CtTPS genes responsible for volatile terpenoid biosynthesis, validating their catalytic functions in vitro. Dual-luciferase reporter assays, yeast one-hybrid assays and EMSA experiments confirmed that CtTPS2, CtTPS3, and CtTPS8 could be activated by various transcription factors (i.e., CtAP2/ERF1, CtbZIP1, CtMYB2, CtMYB3 and CtAP2/ERF4), thereby regulating the production of corresponding monoterpenes and sesquiterpenes. Our study elucidates the biosynthetic and regulatory mechanisms of floral scent in C. tracyanum, which is of great significance for the breeding of fragrant Cymbidium varieties and understanding the ecological adaptability of orchids. This study also highlights the importance of integrating multi-omics data in deciphering key horticultural traits in orchids.
期刊介绍:
Plant Biotechnology Journal aspires to publish original research and insightful reviews of high impact, authored by prominent researchers in applied plant science. The journal places a special emphasis on molecular plant sciences and their practical applications through plant biotechnology. Our goal is to establish a platform for showcasing significant advances in the field, encompassing curiosity-driven studies with potential applications, strategic research in plant biotechnology, scientific analysis of crucial issues for the beneficial utilization of plant sciences, and assessments of the performance of plant biotechnology products in practical applications.