Evolutionary dynamics of chloroplast genomes in subfamily Aroideae (Araceae)

Aroideae is the largest and most diverse subfamily of the plant family Araceae. Despite its agricultural and horticultural importance, the genomic resources are sparse for this subfamily. Here, we report de novo assembled and fully annotated chloroplast genomes of 13 Aroideae species. The quadripartite chloroplast genomes (size range of 158,177-170,037 bp) are comprised of a large single copy (LSC; 75,594-94,702 bp), a small single copy (SSC; 12,903-23,981 bp) and a pair of inverted repeats (IRs; 25,266-34,840 bp). Notable gene rearrangements and IRs contraction / expansions were found for Anchomanes hookeri and Zantedeschia aethiopica. Codon usage, amino acid frequencies, oligonucleotide repeats, GC contents, and gene features revealed similarities among the 13 species. The number of oligonucleotide repeats was uncorrelated with genome size or phylogenetic position of the species. Phylogenetic analyses corroborated the monophyly of Aroideae but were unable to resolve the positions of Calla and Schismatoglottis.