Zymoseptoria tritici is a filamentous fungus causing Septoria tritici blotch in wheat. The pathogen has a narrow host range and infections of grasses other than susceptible wheat are blocked early after stomatal penetration. During these abortive infections, the fungus shows a markedly different gene expression pattern. However, the underlying mechanisms causing differential gene expression during host and non‐host interactions are largely unknown, but likely include transcriptional regulators responsible for the onset of an infection programme in compatible hosts. MoCOD1, a member of the fungal Zn(II)₂Cys₆ transcription factor family, has been shown to directly affect pathogenicity in the rice blast pathogen Magnaporthe oryzae. Here, we analyse the role of the putative transcription factor Zt107320, a homologue of MoCOD1, during infection of compatible and incompatible hosts by Z. tritici. We show for the first time that Zt107320 is differentially expressed in host versus non‐host infections and that lower expression corresponds to an incompatible infection of non‐hosts. Applying reverse genetics approaches, we further show that Zt107320 regulates the dimorphic switch as well as the growth rate of Z. tritici and affects fungal cell wall composition in vitro. Moreover, ∆Zt107320 mutants showed reduced virulence during compatible infections of wheat. We conclude that Zt107320 directly influences pathogen fitness and propose that Zt107320 is involved in the regulation of growth processes and pathogenicity during infection.

中文翻译：

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转录因子Zt107320影响小麦真菌病原体小麦三角酵母（Zymoseptoria tritici）的双态转换，生长和毒力。

Zymoseptoria tritici是一种丝状真菌，在小麦中引起小麦的Septictritici斑点。该病原体的寄主范围狭窄，气孔穿透后较早就阻止了除易感小麦以外的其他草类的感染。在这些流产感染期间，真菌显示出明显不同的基因表达模式。但是，在宿主和非宿主相互作用期间引起差异基因表达的潜在机制在很大程度上尚不清楚，但可能包括负责在兼容宿主中启动感染程序的转录调节因子。MoCOD1是真菌Zn（II）₂ Cys ₆转录因子家族的成员，已被证明可直接影响稻瘟病病原体稻瘟病菌中的致病性。。在这里，我们分析预测性转录因子Zt107320的感染兼容，不兼容主机的过程中的作用，MoCOD1的同系物，Z.小麦。我们首次显示Zt107320在宿主和非宿主感染中差异表达，而较低的表达对应于非宿主感染的不相容感染。施加反向遗传学方法，进一步的研究表明Zt107320调节二态开关以及增速Z.小麦和影响真菌细胞壁的组合物在体外。此外∆ Zt107320突变体在小麦兼容感染期间显示出降低的毒力。我们得出的结论是Zt107320直接影响病原体适应性，并建议Zt107320参与感染过程中生长过程和致病性的调节。