Whole-genome sequencing and analysis of the Chinese herbal plant Gelsemium elegans

摘要

Gelsemium elegans(G.elegans)(2 n=2 x=16)is genus of flowering plants belonging to the Gelsemicaeae family.Here,a high-quality genome assembly using the Oxford Nanopore Technologies(ONT)platform and high-throughput chromosome conformation capture techniques(Hi-C)were used.A total of 56.11 Gb of raw GridION X5 platform ONT reads(6.23 Gb per cell)were generated.After filtering,53.45 Gb of clean reads were obtained,giving 160 x coverage depth.The de novo genome assemblies 335.13 Mb,close to the 338 Mb estimated by k-mer analysis,was generated with contig N50 of 10.23 Mb.The vast majority(99.2%)of the G.elegans assembled sequence was anchored onto 8 pseudo-chromosomes.The genome completeness was then evaluated and 1338 of the 1440 conserved genes(92.9%)could be found in the assembly.Genome annotation revealed that 43.16%of the G.elegans genome is composed of repetitive elements and 23.9%is composed of long terminal repeat elements.We predicted 26,768 protein-coding genes,of which 84.56%were functionally annotated.The genomic sequences of G.elegans could be a valuable source for comparative genomic analysis in the Gelsemicaeae family and will be useful for understanding the phylogenetic relationships of the indole alkaloid metabolism.