Fungal Pathogen Emergence: Investigations with an Ustilago maydis × Sporisorium reilianum Hybrid

Journal of Fungi

Emilee R. M. Storfie¹  Barry J. Saville² 

[1] Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada;Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON K9J 7B8, Canada;

关键词: Ustilago maydis;    Sporisorium reilianum;    fungal hybridization;    pathogenesis assays;    virulence factors;    transcription factors;   

DOI  :  10.3390/jof7080672

来源: DOAJ

【 摘 要 】

The emergence of new fungal pathogens threatens sustainable crop production worldwide. One mechanism by which new pathogens may arise is hybridization. To investigate hybridization, the related smut fungi, Ustilago maydis and Sporisorium reilianum, were selected because they both infect Zea mays, can hybridize, and tools are available for their analysis. The hybrid dikaryons of these fungi grew as filaments on plates but their colonization and virulence in Z. mays were reduced compared to the parental dikaryons. The anthocyanin induction caused by the hybrid dikaryon infections was distinct, suggesting its interaction with the host was different from that of the parental dikaryons. Selected virulence genes previously characterized in U. maydis and their predicted S. reilianum orthologs had altered transcript levels during hybrid infection of Z. mays. The downregulated U. maydis effectors, tin2, pit2, and cce1, and transcription factors, rbf1, hdp2, and nlt1, were constitutively expressed in the hybrid. Little impact was observed with increased effector expression; however, increased expression of rbf1 and hdp2, which regulate early pathogenic development by U. maydis, increased the hybrid’s capacity to induce symptoms including the rare induction of small leaf tumors. These results establish a base for investigating molecular aspects of smut fungal hybrid pathogen emergence.

【 授权许可】

Unknown