New Insights into Plant Mitochondrial Genomes Reveal Rapid Structural Variations and Evolutionary Dynamics

A recent study published in BMC Plant Biology has shed light on the evolution of plant mitochondrial genomes, providing new insights into the structural complexity and evolutionary dynamics of these essential cellular components. Researchers from Shandong University in China conducted comprehensive pan-mitogenome analyses on 13 new mitogenomes from the Dipterocarpoideae family, a tropical tree family with approximately 470-650 species. The study found that the mitogenomes shared 64 conserved core fragments, but differed in their structural complexity due to the presence of mitochondrial plastid DNAs (MTPTs) and repeats.

Key Takeaways:

• The study focused on the Dipterocarpoideae family, a tropical tree family with approximately 470-650 species, which includes many ecologically and economically important taxa.
• The researchers assembled 13 new mitogenomes and conducted comprehensive pan-mitogenome analyses to investigate the evolution of these essential cellular components.
• The mitogenomes ranged from 378.3 to 442.8 kb in size and shared 64 conserved core fragments encoding 30 protein-coding genes, three unique rRNA genes, and nine unique tRNA genes.
• Phylogenetic analyses based on organellar and nuclear genomes consistently recovered three major clades: Vatica, Dipterocarpus, and a clade comprising Shorea, Hopea, and Parashorea.
• The study found that the Vatica mitogenomes contained fewer MTPTs and repeats, resulting in a simpler mitogenome structure, while the other clades contained more MTPTs and repeats, leading to a more complex mitogenome.
• The synonymous substitution rate in coding regions was comparable to that in non-coding regions, while the non-synonymous substitution rate was lower, indicating similar mutation inputs but different selective pressures.

Statistics:

• The researchers assembled 13 new mitogenomes from the Dipterocarpoideae family.
• The mitogenomes ranged from 378.3 to 442.8 kb in size.
• The shared 64 conserved core fragments encoded 30 protein-coding genes, three unique rRNA genes, and nine unique tRNA genes.
• The synonymous substitution rate in coding regions was comparable to that in non-coding regions.
• The non-synonymous substitution rate was lower, indicating different selective pressures.

Sources:

• Pan-mitogenome in Dipterocarpoideae: mitochondrial plastid DNAs and repeats shape the dynamic evolution of mitogenomes. BMC Plant Biology, 2025;25(1):1440.
• NewsRx. Recent Studies from Shandong University Add New Data to Botany (Pan-mitogenome in Dipterocarpoideae: mitochondrial plastid DNAs and repeats shape the dynamic evolution of mitogenomes). Life Science Weekly. November 4, 2025; p 4126.