Human activity profoundly impacts the evolutionary trajectories of many species worldwide, including agricultural pathogens. Global trade of agricultural goods plays a crucial role in the dispersal of crop pathogens, reshaping their genetic makeup and providing opportunities for virulence gains. Understanding how pathogens surmount control strategies and cope with new climates is essential to predicting their future impact on crop production. In this context, a global thousand-genome panel of Zymoseptoria tritici, a major fungal pathogen of wheat reported in all production areas worldwide, has been assembled to study its evolutionary trajectory.
Through this study, the global invasion routes of Zymoseptoria tritici have been identified, and ongoing genetic exchange of the pathogen among wheat-growing regions has been uncovered.
The researchers found that the worldwide expansion of the pathogen was accompanied by increased activity of transposable elements and weakened genomic defenses. In addition, the pathogen’s ability to overcome control strategies and adapt to new climates was identified as a significant threat to global wheat production.
Interestingly, the study also found significant standing variation for adaptation to new climates encountered during the global spread of the pathogen. This discovery provides new insights into the evolutionary potential of the pathogen and its ability to adapt to new environments. Furthermore, the researchers suggest that these findings could help guide the development of new control strategies and inform breeding programs to improve wheat resistance to this pathogen.