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

Abstract

BackgroundGiven 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.\n\nResultsHere 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.\n\nThe 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.\n\nConclusionThe 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.