The Mitochondrial Genome of the Holoparasitic Plant Thonningia sanguinea Provides Insights into the Evolution of the Multichromosomal Structure

作者：Shuaixi Zhou, Neng Wei, Matthias Jost, Stefan Wanke, Mathew Rees, Ying Liu, Renchao Zhou · 发表于：Genome Biology and Evolution · 年份：2023 · DOI：10.1093/gbe/evad155 · 被引用次数：24 · 研究领域：Plant Diversity and Evolution、Plant and Fungal Species Descriptions、Genomics and Phylogenetic Studies

Multichromosomal mitochondrial genome (mitogenome) structures have repeatedly evolved in many lineages of angiosperms. However, the underlying mechanism remains unclear. The mitogenomes of three genera of Balanophoraceae, namely Lophophytum, Ombrophytum, and Rhopalocnemis, have already been sequenced and assembled, all showing a highly multichromosomal structure, albeit with different genome and chromosome sizes. It is expected that characterization of additional lineages of this family may expand the knowledge of mitogenome diversity and provide insights into the evolution of the plant mitogenome structure and size. Here, we assembled and characterized the mitogenome of Thonningia sanguinea, which, together with Balanophora, forms a clade sister to the clade comprising Lophophytum, Ombrophytum, and Rhopalocnemis. The mitogenome of T. sanguinea possesses a multichromosomal structure of 18 circular chromosomes of 8.7-19.2 kb, with a total size of 246,247 bp. There are very limited shared regions and poor chromosomal correspondence between T. sanguinea and other Balanophoraceae species, suggesting frequent rearrangements and rapid sequence turnover. Numerous medium- and small-sized repeats were identified in the T. sanguinea mitogenome; however, no repeat-mediated recombination was detected, which was verified by Illumina reads mapping and PCR experiments. Intraspecific mitogenome variations in T. sanguinea are mostly insertions and deletions, some of which can lead to degradat...