|SOLTANI, ALI - North Dakota State University|
|GHAVAMI, FARHAD - University Of Minnesota|
|MERGOUM, MOHAMED - North Dakota State University|
|HEGSTAD, JUSTIN - North Dakota State University|
|NOYSZEWSKI, ANDRZEJ - University Of Minnesota|
|MEINHARDT, STEVEN - North Dakota State University|
Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2014
Publication Date: 7/30/2014
Citation: Soltani, A., Ghavami, F., Mergoum, M., Hegstad, J., Noyszewski, A., Meinhardt, S., Kianian, S. 2014. Analysis of ATP6 sequence diversity in the Triticum-Aegilops group of species reveals the crucial role of rearrangement in mitochondrial genome evolution. Genome. 57(5):279-288.
Interpretive Summary: Coordination of gene expression between the genomes present in mitochondria and nucleus is of crucial importance for cells of all Eukaryotes. Distruption in this mechanism leads to many diseases in humans (e.g., type II diabetes, Alzheimer, and Parkinson) and many changes in plant phenotypes. To better understand the changes in the mitochondrial genome of Triticeae species we analyzed the diversity in the ATP6 gene among wheat and related specie. ATP6 provides a vital inner membrane channel that couples the proton gradient to ATP production in the mitochondria of all eukaryotes. This analysis provided critical evidence as to changes in these genes that may have lead to evolution of polyploid wheat and domestication of modern cultivars. These results are critical to better utilization of wild species in improving modern cultivars.
Technical Abstract: Mutation and chromosomal rearrangements are the two main forces of increasing genetic diversity for natural selection to act upon, and ultimately drive the evolutionary process. Although genome evolution is a function of both forces, simultaneously, the ratio of each can be varied among different genomes and genomic regions. It is believed that in plant mitochondrial genome, rearrangements plays a more important role than point mutations, but relatively few studies have directly addressed this phenomenon. To address this issue, we isolated and sequenced the ATP6-1 and ATP6-2 genes from forty-six different euplasmic and alloplasmic wheat lines. Four different ATP6-1 orthologs were detected, two of them reported for the first time. Expression analysis revealed that all four orthologs are transcriptionally active. Results also indicated that both point mutations and genomic rearrangement are involved in the ATP6 evolution. However, rearrangement is the predominant force that triggers drastic variation. Data also indicated that speciation of domesticated wheat cultivars were simultaneous with the duplication of this gene. These results directly support the notion that rearrangement plays a significant role in driving plant mitochondrial genome evolution.