Comparative chloroplast genomics and insights into the molecular evolution of Tanaecium (Bignonieae, Bignoniaceae)

• Published in: Scientific reports Vol. 13; no. 1; p. 12469
• Main Authors: Frazão, Annelise, Thode, Verônica A., Lohmann, Lúcia G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-08-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/181/735; 631/449; Bignoniaceae; Chloroplasts; Chloroplasts - genetics; DNA-directed RNA polymerase; Evolution, Molecular; Genome, Chloroplast; Genomes; Genomics; Humanities and Social Sciences; Lianas; Molecular evolution; multidisciplinary; Phylogeny; Plastomes; Pollination; Positive selection; rRNA; Science; Science (multidisciplinary); Topology; tRNA
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-39403-z

Species of
Tanaecium
(Bignonieae, Bignoniaceae) are lianas distributed in the Neotropics and centered in the Amazon. Members of the genus exhibit exceptionally diverse flower morphology and pollination systems. Here, we sequenced, assembled, and annotated 12 complete and four partial chloroplast genomes representing 15
Tanaecium
species and more than 70% of the known diversity in the genus. Gene content and order were similar in all species of
Tanaecium
studied, with genome sizes ranging between 158,470 and 160,935 bp.
Tanaecium
chloroplast genomes have 137 genes, including 80–81 protein-coding genes, 37 tRNA genes, and four rRNA genes. No rearrangements were found in
Tanaecium
plastomes, but two different patterns of boundaries between regions were recovered.
Tanaecium
plastomes show nucleotide variability, although only
rpo
A was hypervariable. Multiple SSRs and repeat regions were detected, and eight genes were found to have signatures of positive selection. Phylogeny reconstruction using 15
Tanaecium
plastomes resulted in a strongly supported topology, elucidating several relationships not recovered previously and bringing new insights into the evolution of the genus.