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New Study Reshapes Understanding of Mitochondrial Inheritance
Potsdam, Germany – Mitochondria, the “powerhouses of the cell”, are passed down through the maternal line in animals and most plants. Researchers at the Max Planck Institute of Molecular Plant Physiology (MPI-MP) have now discovered how mitochondria can be inherited from the father in plants. Crucially, this paternal transmission can restore fertility when maternal mitochondria are defective.
In most plants and animals, including humans, mitochondria are inherited exclusively, or nearly exclusively, from the mother. By contrast, paternal transmission is observed only occasionally, and the mechanisms behind this phenomenon have remained largely unknown. In a study published today, researchers established a genetic screening system in tobacco plants that allowed them to detect paternal mitochondrial inheritance. They discovered that paternal transmission is more frequent than previously thought, and found conditions that boost it to even higher levels. Paternal inheritance can rescue plant growth and fertility when maternal mitochondria are dysfunctional.
Ruffled flowers reveal whose mitochondria are inherited
To be able to follow mitochondrial inheritance, the researchers developed a genetic screening system using tobacco plants engineered to carry functionally impaired mitochondria with easily recognizable visual growth defects. The engineered plants grew slowly, had curly leaves and developed wrinkled flowers with functional ovaries but sterile pollen. These flowers were then fertilized with pollen from plants carrying healthy mitochondria. While most of the offspring exclusively harbored maternal mitochondria and showed the expected defects, plants carrying paternal mitochondria can be readily identified by their normal growth properties. Molecular analyses and cutting-edge microscopy techniques confirmed the presence of paternal mitochondria and revealed the fate of mitochondria and their genomes during pollen development.
The team found that paternal transmission occurs at a basal frequency of 0.18%, but rises dramatically to over 7% when two conditions are combined: inactivation of an enzyme that degrades the mitochondrial DNA, and exposure of developing pollen to low temperature. Under these conditions, paternal mitochondria readily enter sperm cells and retain their genome, thus enabling their transmission to the offspring. Remarkably, paternal mitochondria restored normal development and fertility in plants that otherwise inherited defective mitochondria from their mother.
The findings challenge the idea that mitochondrial genomes function as strictly “asexual” genetic systems. If mitochondria from both parents occasionally mix, they can exchange genetic material (referred to as recombination), and create new mitochondrial genetic make-ups. This discovery also opens up new opportunities for plant breeding, particularly with respect to cytoplasmic male sterility, a trait encoded by the mitochondrial genome and widely used to produce hybrid seeds that give rise to high-yielding crop varieties.
“Understanding how mitochondrial inheritance can be controlled gives us powerful new tools for crop breeding,” says Professor Ralph Bock, director at MPI-MP and co-author of the study. “By enabling mitochondria to be transmitted by pollen, we will be able to generate new mitochondrial genomes that can improve stress tolerance, restore fertility, and help develop crops better suited for future environmental challenges.”
By altering mitochondrial inheritance, it also will be possible to directly compare the pros and cons of maternal versus paternal transmission. In this way, the work brings scientists closer to solving one of biology’s enduring mysteries: why maternal inheritance of mitochondria became dominant in both animals and plants. “This discovery provides us with a new tool to develop better and more resilient crops, and one day, it may explain why we get our mitochondria only from our mothers” says first author Enrique Gonzalez-Duran.
New questions ahead
Even under the most favorable conditions identified by the researchers, paternal mitochondria are still only found in a relatively small fraction of the offspring, suggesting that there are additional mechanisms that promote maternal inheritance, which remain to be discovered.
In summary, the study opens new avenues for research into mitochondrial inheritance, and may ultimately contribute to the development of more climate-resilient crops.
About the team
This research was a collaboration between MPI-MP researchers, Prof. Kin Pan Chung (University of Wageningen, Netherlands), and the team of Prof. Liwen Jiang (Chinese University of Hong Kong).
Dr. Enrique Gonzalez-Duran
Tel.: +49 331 567-8389
Mail: duran@mpimp-golm.mpg.de
Gonzalez-Duran, E., Liang, Z., Forner, J. et al. High-frequency biparental inheritance of plant mitochondria upon chilling stress and loss of a genome-degrading nuclease. Nat. Plants (2026). https://doi.org/10.1038/s41477-026-02242-7
A tobacco plant that harbors defective mitochondria has wrinkled and male-sterile flowers (left). Th ...
Source: MPI-MP/sevens+maltry
Copyright: MPI-MP/sevens+maltry
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A tobacco plant that harbors defective mitochondria has wrinkled and male-sterile flowers (left). Th ...
Source: MPI-MP/sevens+maltry
Copyright: MPI-MP/sevens+maltry
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