Chromosome-level genome assembly of the endangered plant Tetraena mongolica.

ABSTRACT

Tetraena mongolica is an endangered xerophytic shrub with high ecological value for the restoration of desert vegetation because of its high tolerance to drought and heat stress. Here, we generated a high-quality chromosome-level reference genome of T. mongolica by combining PacBio HiFi data and Hi-C sequencing technologies, which was approximately 1.12 Gb (contig N50 of 25.5 Mb) in size and contained 61,888 protein-coding genes; repetitive sequences comprised 44.8% of the genome. This genome of T. mongolica is the first published genome sequence of a member of the order Zygophyllales. Genome analysis showed that T. mongolica has undergone a recent whole genome duplication event, and a recent burst of long terminal repeat insertions afterward, which may be responsible for its genome size expansion and drought adaptation. We also conducted searches for gene homologues and identified terpene synthase (TPS) gene families and candidate genes involved in triacylglycerol biosynthesis. The T. mongolica genome sequence could aid future studies aimed at functional gene identification, germplasm resource management, molecular breeding efforts, as well as evolutionary studies of Fabids and angiosperm taxa.