Evolutionary constraints and regulatory plasticity shape host specialization in the Magnaporthe oryzae species complex.

Genomic, regulatory, and metabolic factors collectively constrain host specialization in Magnaporthe oryzae lineages, explaining their stability and rare host shifts.

• Why it matters: Understanding the evolutionary drivers of stable host adaptation in this pathogen is crucial for predicting and managing outbreaks like wheat blast, which threaten global food security.
• What they did: The study combines evolutionary genomics, transcriptomics, and metabolomics to develop the "Constrained Plasticity" framework, highlighting three interacting layers—genomic scaffolding, regulatory networks, and metabolic compatibility—that influence host adaptation.
• The result: This systems-level model explains the long-term stability of host-specific lineages and suggests testable predictions for pathogen emergence, guiding the development of lineage-aware resistance strategies.