Setosphaeria turcica ATR turns off appressorium‐mediated maize infection and triggers melanin‐involved self‐protection in response to genotoxic stress

摘要

Eukaryotic organisms activate conserved signalling networks to maintain genomic stability in response to DNA genotoxic stresses. However, the coordination of this response pathway in fungal pathogens remains largely unknown. In the present study, we investigated the mechanism by which the northern corn leaf blight pathogen controls maize infection and activates self‐protection pathways in response to DNA genotoxic insults. Appressorium‐mediated maize infection by was blocked by the S‐phase checkpoint. This repression was dependent on the checkpoint central kinase Ataxia Telangiectasia and Rad3 related (ATR), as inhibition of ATR activity or knockdown of the gene recovered appressorium formation in the presence of genotoxic reagents. ATR promoted melanin biosynthesis in as a defence response to stress. The melanin biosynthesis genes and were induced by the ATR‐mediated S‐phase checkpoint. The responses to DNA genotoxic stress were conserved in a wide range of phytopathogenic fungi, including , , , and , which are known causal agents for plant diseases. We propose that in response to genotoxic stress, phytopathogenic fungi including activate an ATR‐dependent pathway to suppress appressorium‐mediated infection and induce melanin‐related self‐protection in addition to conserved responses in eukaryotes.