RESUMO
Tropane alkaloids and terpenoids are widely used in the medicine and pharmaceutic industry and evolved as chemical defenses against herbivores and pathogens in the annual herb Datura stramonium (Solanaceae). Here, we present the first draft genomes of two plants from contrasting environments of D. stramonium. Using these de novo assemblies, along with other previously published genomes from 11 Solanaceae species, we carried out comparative genomic analyses to provide insights on the genome evolution of D. stramonium within the Solanaceae family, and to elucidate adaptive genomic signatures to biotic and abiotic stresses in this plant. We also studied, in detail, the evolution of four genes of D. stramonium-Putrescine N-methyltransferase, Tropinone reductase I, Tropinone reductase II and Hyoscyamine-6S-dioxygenase-involved in the tropane alkaloid biosynthesis. Our analyses revealed that the genomes of D. stramonium show signatures of expansion, physicochemical divergence and/or positive selection on proteins related to the production of tropane alkaloids, terpenoids, and glycoalkaloids as well as on R defensive genes and other important proteins related with biotic and abiotic pressures such as defense against natural enemies and drought.
Assuntos
Datura stramonium/genética , Datura stramonium/metabolismo , Defesa das Plantas contra Herbivoria/genética , Oxirredutases do Álcool/metabolismo , Alcaloides/metabolismo , Evolução Biológica , Meio Ambiente , Evolução Molecular , Interação Gene-Ambiente , Genômica/métodos , Solanaceae/genética , Solanaceae/metabolismo , Tropanos/metabolismo , Sequenciamento Completo do GenomaRESUMO
The annual herb, Datura stramonium, is a member of the Solanaceae family. In this study, we report the chloroplast genomes of two Mexican plants of D. stramonium. Both chloroplast genomes of D. stramonium (GenBank accessions: MT610896 and MT610897) were assembled as a circular molecule. The genome size of both plants was similar (155,884 bp). The overall GC content was 38.59% for both genomes. Both chloroplast genomes contained 85 protein-coding sequences (CDS), 131 genes, 8 rRNA genes, and 38 tRNA genes. Thirty-nine microsatellites (SSRs) and 42 long tandem repeats were also identified for both genomes. The phylogenetic relationship between D. stramonium and related Solanaceae species revealed four main groups; Nicotiana, Datura, Capsicum, and Solanum clades. This species tree is consistent with other Solanaceae species trees already published.
