|ZHANG, NING - Rutgers University|
|PRICE, DANA - Rutgers University|
|GLADIEUX, PIERRE - Cirad, France|
|HILLMAN, BRADLEY - Rutgers University|
|KHANG, CHANG - University Of Georgia|
|LEBRUN, MARC-HENRI - French National Institute For Agricultural Research|
|LEE, YONG-HWAN - Seoul National University|
|LUO, JING - Rutgers University|
|QIU, HUAN - Rutgers University|
|VELTRI, DANIEL - National Institutes Of Health (NIH)|
|WISECARVER, JENNIFER - Purdue University|
|ZHU, JIE - University Of Georgia|
|BHATTACHARYA, DEBASHISH - Rutgers University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2018
Publication Date: 4/12/2018
Citation: Zhang, N., Cai, G., Price, D.C., Crouch, J., Gladieux, P., Hillman, B., Khang, C.H., Lebrun, M., Lee, Y., Luo, J., Qiu, H., Veltri, D., Wisecarver, J.H., Zhu, J., Bhattacharya, D. 2018. Genome wide analysis of the transition to pathogenic lifestyles in Magnaporthales fungi. Scientific Reports. 8:5862. https://doi.org/10.1038/s41598-018-24301-6.
Interpretive Summary: Members of the fungal group Magnaporthales cause many serious infectious diseases of economically important cereal and grass crops. The best known fungus in this group causes rice blast, the most common and severe disease of rice. This group also includes non-pathogens that are unable to cause plant diseases. In this study, we looked at how some of these fungi gained the ability to infect plants and became pathogens that can cause disease. The genomes of 13 fungi were compared, including pathogens and non-pathogens in Magnaporthales. Through this comparison, we identified genes important for pathogenicity. We also estimated that the Magnaporthales fungi first gained the ability to infect plant leaves approximately 21 million years ago and gained the ability to infect plant roots approximately 14 million years ago. These findings are important because understanding how fungi gain the ability to infect plants lays the foundation for effective disease management.
Technical Abstract: The rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae, Magnaporthe grisea), a member of the order Magnaporthales in the class Sordariomycetes, is an important plant pathogen and a model species for studying pathogen infection and plant-fungal interaction. In this study, we generated genome sequence data from five additional Magnaporthales fungi, including nonpathogenic species, and performed comparative genome analysis of a total of 13 fungal species in the class Sordariomycetes to understand the evolutionary history of the Magnaporthales and of fungal pathogenesis. Our results suggest that the Magnaporthales diverged ca. 31 millon years ago from other Sordariomycetes, with the phytopathogenic blast clade diverging ca. 21 million years ago. Little evidence of interphylum horizontal gene transfer (HGT) was detected in Magnaporthales. In contrast, many genes underwent positive selection in this order and the majority of these sequences are clade specific. The blast clade genomes contain more secretome and avirulence effector genes which likely play key roles in the interaction between Pyricularia species and their plant hosts. Finally, analysis of transposable elements (TE) showed differing proportions of TE classes among Magnaporthales genomes, suggesting that species-specific patterns may hold clues to the history of host/environmental adaptation in these fungi.