Abstract Detail

Phylogenomics

Jo, Sangjin [1], Kim, Young-Kee [1], Jansen, Robert [2], Kim, Ki-Joong [1].

Inverted repeat region expansion and evolutionary dynamics of Annonaceae plastid genomes.

Annonaceae consist of 108 genera 2,400 species. To understand the evolutionary dynamics of plastomes of Annonaceae, 16 species are newly sequenced and compared with all available data. First, the plastome sizes of most Annonaceae species are substantially longer than the normal plant plastomes. It is due to the expansions of inverted repeat (IR) regions into single copy (SC) regions of the plastomes. The sizes of Annonaceae plastomes ranged from 158,837 bp (Stelechocarpus burahol) to 202,703 bp (Annona x atemoya) in length. Four subfamilies (Ambavioideae, Anaxagoreoideae, Annonoideae, and Malmeoideae) of Annonaceae show unique IR boundaries. Except of Malmeoideae, three of them show several IR expansion/contraction events. Genes shifted from the SC regions to the IR region generally show lower nonsynonymous and synonymous substitution rates than the genes remain in SC regions. Second, Ambavioideae, Annonoideae, and Malmeoideae share an 8 kb inversion mutation between atpE and ycf4 in LSC region. In addition to this shared inversion, three additional inversions were observed in independent lineages of Annonaceae. The inversion boundaries are associated with dispersed repeat sequences. Third, phylogenetic analysis of whole plastome data recognized four monophyletic subfamilies. The highest Pi values of genes and introns were recorded on rpoA (0.21708) and clpP intron 1 (0.061), respectively. The infA, rpoA, rpl36 and rps11 genes located in the IR region exhibit higher evolutionary rates than SC genes. This primarily due to the high numbers of indel mutations and high base substitution rates in the region. These four gene regions also show the strong positive or negative selection pressures compared to other genic regions.

1 - Korea University, Department of Life Sciences, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
2 - University Of Texas At Austin, Integrative Biology, 205 W. 24th St. Stop C0930, Austin, TX, 78712, United States

Keywords:
Annonaceae
inversion
inverted repeat (IR)
nucleotide substitution rates
Plastome.

Presentation Type: Poster
Session: P3, Phylogenomics Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3PL001
Abstract ID:265
Candidate for Awards:None