Genome assembly of the Brassicaceae diploid Orychophragmus violaceus reveals complex whole-genome duplication and evolution of dihydroxy fatty acid metabolism

Fan Huang; Peng Chen; Xinyu Tang; Ting Zhong; Taihua Yang; Chinedu Charles Nwafor; Chao Yang; Xianhong Ge; Hong An; Zaiyun Li; Edgar B Cahoon; Chunyu Zhang

doi:10.1016/j.xplc.2022.100432

Genome assembly of the Brassicaceae diploid Orychophragmus violaceus reveals complex whole-genome duplication and evolution of dihydroxy fatty acid metabolism

Plant Commun. 2023 Mar 13;4(2):100432. doi: 10.1016/j.xplc.2022.100432. Epub 2022 Sep 7.

Authors

Affiliations

¹ National Key Lab of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
² Bioinformatics and Analytics Core, University of Missouri-Columbia, Columbia, MO, USA.
³ Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, USA; Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, USA. Electronic address: ecahoon2@unl.edu.
⁴ National Key Lab of Crop Genetic Improvement and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China. Electronic address: zhchy@mail.hzau.edu.cn.

Abstract

Orychophragmus violaceus is a Brassicaceae species widely cultivated in China, particularly as a winter cover crop in northern China because of its low-temperature tolerance and low water demand. Recently, O. violaceus has also been cultivated as a potential industrial oilseed crop because of its abundant 24-carbon dihydroxy fatty acids (diOH-FAs), which contribute to superior high-temperature lubricant properties. In this study, we performed de novo assembly of the O. violaceus genome. Whole-genome synteny analysis of the genomes of its relatives demonstrated that O. violaceus is a diploid that has undergone an extra whole-genome duplication (WGD) after the Brassicaceae-specific α-WGD event, with a basic chromosome number of x = 12. Formation of diOH-FAs is hypothesized to have occurred after the WGD event. Based on the genome and the transcriptome data from multiple stages of seed development, we predicted that OvDGAT1-1 and OvDGAT1-2 are candidate genes for the regulation of diOH-FA storage in O. violaceus seeds. These results may greatly facilitate the development of heat-tolerant and eco-friendly plant-based lubricants using O. violaceus seed oil and improve our understanding of the genomic evolution of Brassicaceae.

Keywords: Brassicaceae; Orychophragmus violaceus; dihydroxy fatty acids; genome evolution; lubricant oil; oilseed; polyestolides.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brassicaceae* / genetics
Diploidy
Fatty Acids
Gene Duplication
Seeds

Substances

Fatty Acids