Abstract
Maintaining genome integrity is essential, yet how DNA repair is balanced across life stages remains poorly understood. Here we uncover an epitranscriptomic mechanism in the fungal pathogen Fusarium graminearum that alleviates a trade-off between heat-stress adaptation and sexual reproduction. We show that FgMus81 acts independently of its nuclease activity and canonical partner FgMms4, and has dosage-dependent, stage-specific functions: restrained levels support meiosis, whereas elevated levels promote heat-stress survival. We identify a sexual stage-specific A-to-I RNA editing event that recodes FgMus81 (N420D) and tunes its abundance to meet meiotic demands without compromising stress resilience. Notably, both pre-editing and post-editing isoforms support meiotic interhomolog crossovers, but the post-editing isoform impairs mitotic recombination. Conservation of this editing across Sordariomycetes suggests evolutionary selection for stage-specific control. Together, these findings reveal an epitranscriptomic switch that partitions Mus81 functions across life stages and identify adaptive RNA editing as a regulator of homologous recombination in fungal pathogens.
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Data availability
Data supporting the findings of this work are available within the paper and its Supplementary Information file. DNA-sequencing data generated for this study and public RNA-sequencing data used in this study can be accessed from the Genome Sequence Archive using the accession numbers listed in Supplementary Table 3. Source data are provided in this paper.
Code availability
The custom codes used in this study for crossover event identification have been deposited in GitHub (https://github.com/qinhuwang/FG.crossover).
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Acknowledgements
We thank Dr. Guanghui Wang, Ming Xu, Ping Xiang, and Zhe Tang for their invaluable laboratory assistance. We also thank lab technicians Hua Zhao and Xueling Huang from the State Key Laboratory for Crop Stress Resistance and High-Efficiency Production for their assistance with the instrumental analysis. This work was supported by grants from the National Key Research and Development Program of China (2022YFD1400100) and the National Natural Science Foundation of China (No. 32170200) to H.L.
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H.L. and M.W. conceived and designed the experiments; M.W., J.L., P.C., and M.L. performed the experiments; H.L., C.F., Q.W., C.J., and J.R.X. contributed advice and reagents; M.W., J.L., Q.W., and H.L. analyzed data; H.L. and M.W. wrote the paper; and H.L. provided supervision. M.W. and J.L. contributed equally to this paper.
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Wu, M., Liu, J., Cao, P. et al. Epitranscriptomic RNA editing resolves Mus81 DNA repair tradeoffs in heat tolerance and meiosis. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71219-z
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DOI: https://doi.org/10.1038/s41467-026-71219-z
