R-evolution · Why two and not one? Evolutionary consequences of maintaining individual genome copies in two separate nuclei
Horizon Europe — Marie Skłodowska-Curie Actions
- Duration
- 2024-07-01 → 2027-06-30
- EU contribution
- €284,484
- Participants
- 2
- Scheme
- HORIZON-TMA-MSCA-PF-GF
Lines connect the coordinator with its partners.
Results in brief
Why two and not one? Evolutionary consequences of maintaining individual genome copies in two separate nuclei
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating fungal diseases of wheat worldwide, posing a major threat to global food security. This pathogen is notorious for its rapid adaptation to resistant wheat varieties, chemical controls, and changing environmental conditions. A striking feature of Pst is its unusual genome organization: unlike most organisms, it maintains two distinct haploid genomes in separate nuclei within each cell. This multinuclear architecture represents a largely unexplored dimension of fungal biology, with far-reaching implications for how genetic and epigenetic changes drive pathogen evolution. This project set out to uncover how the physical separation of genomes within Pst cells contributes to its evolutionary success. Specifically, it aims to understand the role of haplotype-specific regulation at the level of DNA, RNA, and translation in controlling virulence and adaptation in agricultural environments. By integrating cutting-edge molecular techniques and comparative genomics across historical isolates, the project investigates how epigenetic mechanisms shape gene expression and mutation patterns over time. The outcomes of this work are expected to fundamentally improve our understanding of genome evolution in complex pathogens and offer a new lens through which to interpret the emergence and persistence of virulent fungal lineages in the field. In the broader strategic context of global plant health and biosecurity, these insights have the potential to inform predictive models of pathogen evolution and support more durable disease management strategies.
Data: CORDIS, © European Union
Project objective
The effect of ploidy and genome organization on evolution and adaptation is a central question in biology. Most organisms contain a single nucleus per cell, irrespective of their genome size and ploidy level. The kingdom Fungi represents a notable, yet significantly understudied, exception. Most fungal species partition individual haplotype genome copies into discrete nuclei. What evolutionary advantages arise from partitioning different haplotypes into multiple nuclei is a fundamental and unsolved puzzle in eukaryote genomics. This project addresses several questions that will improve our fundamental understanding of multinuclear genome biology by identifying genetic and epigenetic inter-nuclear differences in the stripe rust fungus (Puccinia striiformis f. sp. tritici, Pst). In contrast to diploids, it partitions its two haplotypes into two distinct nuclei (dikaryon). It is one of the most harmful wheat pathogens with significant impacts on global wheat production and food security. Pst epidemics in wheat growing regions including Europe and Australia have been dominated by lineages that reproduced exclusively asexually for decades. The haplotypes of the asexually evolving lineages diverge over time through independent accumulation of genetic variation. In this proposal I will dissect how the presence of multiple nuclei in the same cytoplasm in rust fungi contributes to rapid adaptation to variable and changing agricultural environments. Understanding the underlying mechanisms that drive rapid evolution of new genotypes in absence of sexual recombination is important to make predictions about durability of host resistance and management strategies.
Original text from CORDIS.
Participants
Links
- View on CORDIS
- DOI: 10.3030/101109959
- https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e516ac98d1&appId=PPGMS
Data: CORDIS, © European Union