Asymmetric mitonuclear interactions trigger transgressive inheritance and mitochondria-dependent heterosis in hybrids of the model system Pleurotus ostreatus

Author: mycolabadmin
10/31/2025
View Source

Summary

This research examines how mushroom hybrids inherit different combinations of genes from their parents, specifically looking at genes in the nucleus versus the mitochondria (cellular energy factories). When mushrooms with mismatched nuclear and mitochondrial genes are crossed, some grow slowly and show stress, while others surprisingly grow very well. The study identifies which genes are activated under these conditions and how they affect mushroom production quality and yield.

Background

Mitonuclear interactions are crucial for mitochondrial function and stress responses in eukaryotes. When genetically distinct populations interbreed, their offspring inherit nuclear and mitochondrial genomes that have not co-evolved, potentially disrupting fine-tuned genetic interactions. This study explores how varying mitochondrial haplotypes affect phenotype and oxidative stress response in basidiomycete hybrids.

Objective

To investigate how mitonuclear interactions affect growth rates, reactive oxygen species accumulation, and gene expression patterns in reciprocal crosses of Pleurotus ostreatus monokaryotic strains with distinct nuclear and mitochondrial genomes. The study aims to clarify the role of mitonuclear interactions in determining hybrid fitness and informing mushroom breeding programs.

Results

Hybrids with incompatible mitonuclear combinations displayed slower growth and elevated expression of genes associated with the Electron Transport Chain and antioxidant defences, some showing transgressive inheritance. Mitochondria-dependent heterosis was observed in hybrids sharing the same nuclear background but differing in mitochondrial genome. Temperature and carbon source influenced mitonuclear genome interactions affecting growth performance and oxidative stress response.

Conclusion

Mitonuclear incompatibilities can result in oxidative imbalance and compromised fungal performance, while compatible combinations exhibit heterosis. The findings highlight the significance of mitonuclear co-adaptation and offer valuable insights for enhancing hybrid breeding programs by accounting for mitonuclear interactions in shaping quantitative traits related to mushroom yield.

Published in:IMA Fungus,
Study Type:Experimental Study,
Source: PMID: 41209031, DOI: 10.3897/imafungus.16.165520