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

植物定植真菌对新寄主的适应是新出现的植物病原菌的主要来源之一。虽然已知生物营养真菌与寄主紧密适应，并且通常是特定寄主植物所特有的，但在黑粉菌的进化过程中，寄主跳跃是相当常见的。允许寄主植物适应的菌株交换寄主的机制尚不清楚。从机理上阐明适应性寄主定殖对于制定保护作物免受未来威胁的策略是必要的。遗传上可遗传的黑穗病孢子菌最近将寄主从高粱换成了玉米。目前，已发现两种新种：雷氏链霉菌S.reilianum f.sp.Reilianum(SRS)和S.reilianum f.sp.玉米赤霉病(Zeae(SRZ))是一种中等毒力的玉米病原菌。在实验室中，SRS和SRZ菌株可以形成对两种寄主植物都具有弱感染性的杂交品种。我们希望通过反复让自然菌株和杂交菌株受到植物的选择压力来使用实验进化。进化菌株将与起始菌株进行比较，使用基因组、转录组和染色质免疫沉淀测序，以探索适应新寄主植物是涉及缓慢但稳定的遗传变化，适应性表观遗传变化，还是杂交的结果。

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.