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Article|25 Jan 2022|OPEN
The reference genome of Camellia chekiangoleosa provides insights into Camellia evolution and tea oil biosynthesis
Teng-fei Shen1 ,† , Bin Huang2 ,† , Meng Xu1 ,† , Peng-yan Zhou1 , Zhou-xian Ni1 , Chun Gong2 , Qiang Wen2 , , Fu-liang Cao1 , and Li-An Xu,1 ,
1Co-Innovation Center for Sustainable Forestry in Southern China, Key Laboratory of Forest Genetics and Biotechnology Ministry of Education, Nanjing Forestry University, Nanjing 210037, China
2Jiangxi Provincial Key Laboratory of Camellia Germplasm Conservation and Utilization, Jiangxi Academy of Forestry, Nanchang, Jiangxi 330047, China
*Corresponding author. E-mail: jxwenqiang@aliyun.com,fuliangcaonjfu@163.com,laxu@njfu.edu.cn
Teng-fei Shen,Bin Huang and Meng Xu contributed equally to the study.

Horticulture Research 9,
Article number: uhab083 (2022)
doi: https://doi.org/10.1093/hr/uhab083
Views: 484

Received: 12 Nov 2021
Revised: 18 Dec 2021
Accepted: 18 Jan 2022
Published online: 25 Jan 2022

Abstract

Camellia oil extracted from Camellia seeds is rich in unsaturated fatty acids and secondary metabolites beneficial to human health. However, no oil-tea tree genome has yet been published, which is a major obstacle to investigating the heredity improvement of oil-tea trees. Here, using both Illumina and PicBio sequencing technologies, we present the first chromosome-level genome sequence of the oil-tea tree species Camellia chekiangoleosa Hu. (CCH). The assembled genome consists of 15 pseudochromosomes with a genome size of 2.73 Gb and a scaffold N50 of 185.30 Mb. At least 2.16 Gb of the genome assembly consists of repetitive sequences, and the rest involves a high-confidence set of 64 608 protein-coding gene models. Comparative genomic analysis revealed that the CCH genome underwent a whole-genome duplication event shared across the Camellia genus at ~57.48 MYA and a γ-WGT event shared across all core eudicot plants at ~120 MYA. Gene family clustering revealed that the genes involved in terpenoid biosynthesis have undergone rapid expansion. Furthermore, we determined the expression patterns of oleic acid accumulation- and terpenoid biosynthesis-associated genes in six tissues. We found that these genes tend to be highly expressed in leaves, pericarp tissues, roots, and seeds. The first chromosome-level genome of oil-tea trees will provide valuable resources for determining Camellia evolution and utilizing the germplasm of this taxon.