Whole-genome sequencing of Nicotiana glauca

Abstract

BackgroundNicotiana glauca (tree tobacco) is a member of the Solanaceae family, which includes important crops (potato, tomato, eggplant, pepper) and many medicinal plants. This diploid plant is native to South America and is one of the first Nicotiana species with Agrobacterium cellular T-DNA (cT-DNA). Its cT-DNA is a partial, inverted repeat, called gT. Tree tobacco belongs to the section Noctiflorae. Sequencing of the genomes of N. tomentosiformis and N. otophora (section Tomentosae) and N. tabacum (section Nicotiana) allowed the detection of previously unknown multiple cT-DNAs, raising the question whether there are other T-DNA insertions in the N. glauca. NGS data can help answer this question. Besides, N. glauca contains a profile of alkaloids different from N. tabacum. The plant is used for medicinal purposes. Comparative analysis of genomic data of phylogenetically distant tobacco species will provide valuable information on the genetic basis for various traits, especially secondary metabolism.\n\nFindingsWe report a high-depth sequencing and de novo assembly of N. glauca full genome, which was obtained from 210 Gb Illumina HiSeq data. The final draft genome is 3.2 Gb, with N50 size of 31.1 kbp. T-DNA analysis confirmed the presence of the previously described gT insertion and the absence of other ones.\n\nConclusionWe provide the first comprehensive de novo full genome assembly of three tobacco, and a cT-DNA insertion analysis. These genome data could be used in pharmacological and in phylogenetic studies.