Abstract Detail

Recent Topics Posters

Frazão, Annelise [1], Lohmann, Lucia [2].

Plastome structure of Tanaecium (Bignonieae, Bignoniaceae), a member of the trumpet-creeper family.

The chloroplast is a circular organelle found in plant cells with prokaryotic origin that is responsible for photosynthesis and critical for the biosynthesis of starch, fatty acids, pigments, and amino acids. Chloroplast genomes, also known as plastomes, range from 120 to 180 kb in size, and have a conserved quadripartite structure that consists of a Large Single-Copy (LSC), two Inverted Repeats (IRs), and a Small Single-Copy (SCC) region. Despite that, different rearrangements, structure organization, size, gene content, and order have been documented in the last few years. Furthermore, events of IR boundary shifts including contraction, expansion, or even loss of these regions seem to have occurred independently in different lineages, resulting in considerable plastome size variation. Here, we used Tanaecium (Bignonieae, Bignoniaceae), a member of the trumpet-creeper family, in a comparative plastome study. Tanaecium is a morphologically diverse Neotropical genus composed by lianas and shrubs. We assembled the plastome of 15 of the 21 species of Tanaecium recognized. The assembled plastomes ranged between 157,807 bp (in T. crucigerum) to 160,935 bp (in T. xanthophyllum). The plastomes show the typical quadripartite structure of Angiosperms but include five different LSC/IRb/SSC/IRa boundary patterns. Four patterns of IR region boundary shifts were also detected, leading to different levels of IR contraction and an expansion of the SSC or LSC. While the IRs of most species of Tanaecium have an average length of 30,648 bp and an a SSC with average length of 12,748 bp, variation was found in three species of Tanaecium as follows: (i) IRs with average size of 24,182 bp and SSC 26,057 bp long (found in T. bilabiatum); (ii) IRs with average size of 11,409 bp and SSC 49,868 bp long (found in T. tetragonolobum); and (iii) IRs with average size of 28,791 bp and LSC 89,092 bp long (found in T. tetramerum). This study brings novel insights into plastome structure in the Bignoniaceae.

1 - Universidade de São Paulo, Departamento de Botânica, Rua do Matão, 277, Cidade Universitária, São Paulo, SP, 05580-090, Brazil
2 - Universidade de São Paulo, Departamento de Botânica, Rua do Matão, 277, Cidade Universitária, São Paulo, SP, 05508-090, Brazil

Keywords:
lianas
Lamiales
Neotropical flora
Bignoniaceae
Plastomes.

Presentation Type:
Session: P, Recent Topics Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM
Number: PRT006
Abstract ID:1352
Candidate for Awards:None