Comparative mechanistic elucidation of adaptation of Sporisorium reilianum to its host plants maize and sorghum

SCHI 1114/3-1

Adaptation of plant-colonizing fungi to novel hosts is one of the major sources of newly emerging fungal plant pathogens. Although biotrophic fungi are known to tightly adapt to their hosts and often are specific to one particular host plant, host jumps were quite common during evolution of the smut fungi. The mechanisms allowing host-plant adapted strains to swap hosts are unclear. Mechanistic elucidation underlying adaptive host colonization is necessary for the development of protection strategies of our crop plants from tomorrows threats.

The genetically amenable smut fungus Sporisorium reilianum has recently swapped host from sorghum to maize. Today, two formae speciales have been recognized, S. reilianum f. sp. reilianum (SRS), a highly virulent pathogen of sorghum, and S. reilianum f. sp. zeae (SRZ), a moderately virulent pathogen of maize. In the laboratory, strains of SRS and SRZ can form hybrids that are weakly infectious on both host plants. We want to use Experimental Evolution by repeatedly subjecting natural and hybrid strains to selection pressure by the plant. Evolved strains will be compared to starting strains using genome, transcriptome and chromatin immunoprecipitation sequencing to explore whether adaptation to a new host plant involves slow but stable genetic changes, adaptive epigenetic changes, or is the result of hybridization.

Publications

• Frantzeskakis, L., Di Pietro, A., Rep, M., Schirawski, J., Wu, C.‐H. and Panstruga, R. (2019) Rapid evolution in plant–microbe interactions – a molecular genomics perspective. New Phytol. DOI: 10.1111/nph.15966

• Nilam Borah, Emad Albarouki, Jan Schirawski (2018) Comparative methods for molecular determination of host-specificity factors in plant-pathogenic fungi. International Journal of Molecular Sciences, 19: 863. DOI: 10.3390/ijms19030863