Disentangling Complex Inheritance Patterns of Plant Organellar Genomes: An Example From Carrot

Area of Science:

• Plant biology
• Genetics
• Evolutionary biology

Background:

• Plant organelle genomes (mitochondria and plastids) exhibit diverse inheritance patterns and heteroplasmy.
• Understanding within-individual variation and inheritance is crucial but understudied in plants.

Purpose of the Study:

• To investigate organelle inheritance patterns and the fate of heteroplasmy in carrot (Daucus carota L.) using experimental crosses.
• To analyze maternal inheritance, paternal leakage, and variation across plant development.

Main Methods:

• Conducted controlled crosses in carrot (Daucus carota L.).
• Utilized mitochondrial and plastid markers to track organelle genomes.
• Assayed leaf samples at different developmental stages and ages.

Main Results:

• Maternal inheritance of heteroplasmy was predominant, with offspring inheriting similar mixtures to their mothers.
• Paternal leakage of mitochondrial and plastid DNA was rare.
• Offspring often showed a loss of genetic variation compared to heteroplasmic mothers.
• Mitochondrial variation remained stable throughout plant development, indicating minimal vegetative sorting.

Conclusions:

• Plant organelle heteroplasmy is primarily maintained through maternal inheritance.
• Controlled crosses provide quantitative insights into complex organelle inheritance dynamics.
• Future research using whole-genome data will further elucidate plant organelle genome evolution.