Comparison of Mitogenome Organellar Genome Architecture in Wild Lines and Cultivars Follows Domestication History

  • SorghumBase Team
  • 31 July 2023

The comparison of structural and sequence differences of organellar genomes among different sorghum lines is of great importance in further understanding the evolution of sorghum. There are few studies investigating the relationship between agronomic trait improvement and organelle evolution, structure, and function. In an effort to advance genomic understanding in sorghum, researchers from Huazhong Agricultural University, Chinese Academy of Agricultural Sciences, The University of Queensland, Hermitage Research Facility, USDA-ARS and Colorado State University sequenced and assembled organelle genomes (mitogenomes and plastid genomes) of six Sorghum bicolor accessions (IS929, IS8525, R931945-2-2, IS19953, PI525695, and PI536008), and one closely related wild species, S. propinquum (S369). These organelle genomes will complement the corresponding assembled and annotated nuclear genomes in SorghumBase. For more details see this post. Long-read sequencing and state-of-the-art assembly algorithms enabled a comparison of the architecture of the seven sorghum domesticated and wild sorghum mitochondrial and plastid genomes, grouping them into three structural conformations that differ in the content of repeats and genes by contig, and ultimately leading to a better understanding of the domestication events in East and West Africa on mitochondrial genome structure.

“Assembling the sorghum mitogenome is key to understanding fundamental aspects of sorghum biology associated with the mitochondria such as cellular energetics, cytoplasmic male sterility, and disease resistance. The publication of seven sorghum mitogenomes from diverse origins will therefore assist researchers working to improve agronomic traits in this important staple cereal.” – Luke R Tembrock

SorghumBase example:

Figure 1: Organellar genomes have not been determined for the majority of the sorghum assemblies in SorghumBase. Nonetheless, the corresponding nuclear genomes for the seven accessions in this study (Zhang et al, 2023) are available in SorghumBase and include unplaced scaffolds. ATMG00270 encodes Arabidopsis thaliana NAD6, one of the four genes (atp9, cox2, nad4, and nad6) with SNPs in the seven mitogenomes. The above image features Sobic.K010944.v5.1 mapping to a scaffold, and SbiRTX2783.MG002400 mapping to chrM, as the closest nad6 orthologs in BTx623 v5 and Tx2783, respectively.

Reference:

Zhang S, Wang J, e He W, Kan S, Liao X, Jordan DR, Mace ES, Tao Y, Cruickshank AW, Klein R, Yuan D, Tembrock LR, Wu Z. Variation in mitogenome structural conformation in wild and cultivated lineages of sorghum corresponds with domestication history and plastome evolution. BMC Plant Biol. 2023 Feb 13;23(1):91. PMID: 36782130. DOI: 10.1186/s12870-023-04104-2. Read more