Characterizing complete mitochondrial genome of Aquilegia amurensis and its evolutionary implications

Abstract

Abstract Background Aquilegia is a model system for studying the evolution of adaptive radiation. However, very few studies have been conducted on the Aquilegia mitochondrial genome. Since mitochondria play a key role in plant adaptation to abiotic stress, analyzing the mitochondrial genome may provide a new perspective for understanding adaptive evolution. Results The Aquilegia amurensis mitochondrial genome was characterized by a circular chromosome and two linear chromosomes, with a total length of 538,736 bp; the genes included 33 protein-coding genes, 24 transfer RNA (tRNA) genes and 3 ribosomal RNA (rRNA) genes. We subsequently conducted a phylogenetic analysis based on single nucleotide polymorphisms (SNPs) in the mitochondrial genomes of 18 Aquilegia species, which were roughly divided into two clades: the European-Asian clade and the North American clade. Moreover, the genes mttB and rpl5 were shown to be positively selected in European-Asian species, and they may help European and Asian species adapt to environmental changes. Conclusions In this study, we assembled and annotated the first mitochondrial genome of the adaptive evolution model plant Aquilegia. The subsequent analysis provided us with a basis for further molecular studies on Aquilegia mitochondrial genomes and valuable information on adaptive evolution in Aquilegia.

Keywords

• Aquilegia
• Mitochondrial genome
• Selection pressure analysis
• Phylogenetic analysis