The genome and metabolome of the tobacco tree, Nicotiana glauca: a potential renewable feedstock for the bioeconomy

Background: Given its tolerance to stress and its richness in particular secondary metabolites, the tobacco tree, Nicotiana glauca, has been considered a promising biorefinery feedstock that would not be competitive with food and fodder crops. Results: Here we present a 3.5 Gbp draft sequence and annotation of the genome of N. glauca spanning 731,465 scaffold sequences, with an N50 size of approximately 92 kbases. Furthermore, we supply a comprehensive transcriptome and metabolome analysis of leaf development comprising multiple techniques and platforms. The genome sequence is predicted to cover nearly 80% of the estimated total genome size of N. glauca. With 73,799 genes predicted and a BUSCO score of 94.9%, we have assembled the majority of gene-rich regions successfully. RNA-Seq data revealed stage- and/or tissue-specific expression of genes, and we determined a general trend of a decrease of tricarboxylic acid cycle metabolites and an increase of terpenoids as well as some of their corresponding transcripts during leaf development. Conclusion: The N. glauca draft genome and its detailed transcriptome, together with paired metabolite data, constitute a resource for future studies of valuable compound analysis in tobacco species and present the first steps towards a further resolution of phylogenetic, whole genome studies in tobacco.