1Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China 2Department of Plant Biotechnology and Bioinformatics, Ghent University, Gent, Belgium 3VIB Center for Plant Systems Biology, Gent, Belgium 4College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China 5Management Office of Yushan Scenic Area, Fuzhou, China 6College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China 7Key Laboratory of Plant Resource Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China 8PubBio-Tech, Wuhan, China 9Tsinghua-Berkeley Shenzhen Institute (TBSI), Center for Biotechnology and Biomedicine and Shenzhen Key Laboratory of Gene and Antibody Therapy, State Key Laboratory of Chemical Oncogenomics, State Key Laboratory of Health Sciences and Technology, Institute of Biopharmaceutical and Health Engineering (iBHE), Shenzhen International Graduate School, Tsinghua University, Shenzhen, China 10Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China 11Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa 12College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing, China 13Henry Fok College of Biology and Agriculture, Shaoguan University, Shaoguan, China 14Institute of Vegetable and Flowers, Shandong Academy of Agricultural Sciences, Jinan, China *Corresponding author. E-mail: yves.vandepeer@psb.vib-ugent.be,zjliu@fafu.edu.cn
Received: 25 Mar 2021 Revised: 25 Mar 2021 Accepted: 30 Jul 2021 Published online: 01 Dec 2021
Abstract
The marvelously diverse Orchidaceae constitutes the largest family of angiosperms. The genus Cymbidium in Orchidaceae is well known for its unique vegetation, floral morphology, and flower scent traits. Here, a chromosome-scale assembly of the genome of Cymbidium ensifolium (Jianlan) is presented. Comparative genomic analysis showed that C. ensifolium has experienced two whole-genome duplication (WGD) events, the most recent of which was shared by all orchids, while the older event was the τ event shared by most monocots. The results of MADS-box genes analysis provided support for establishing a unique gene model of orchid flower development regulation, and flower shape mutations in C. ensifolium were shown to be associated with the abnormal expression of MADS-box genes. The most abundant floral scent components identified included methyl jasmonate, acacia alcohol and linalool, and the genes involved in the floral scent component network of C. ensifolium were determined. Furthermore, the decreased expression of photosynthesis-antennae and photosynthesis metabolic pathway genes in leaves was shown to result in colorful striped leaves, while the increased expression of MADS-box genes in leaves led to perianth-like leaves. Our results provide fundamental insights into orchid evolution and diversification.
, Zhong-Jian Liu,1,13,14 ,
