SUMOylation regulates low-temperature survival and oxidative DNA damage tolerance in Botrytis cinerea

center dot SUMOylation as one of the protein post-translational modifications plays crucial roles in multiple biological processes of eukaryotic organisms. Botrytis cinerea is a devastating fungal pathogen and capable of infecting plant hosts at low temperature. However, the molecular mechanisms of low-temperature adaptation are largely unknown in fungi.center dot Combining with biochemical methods and biological analyses, we report that SUMOylation regulates pathogen survival at low temperature and oxidative DNA damage response during infection in B. cinerea. The heat shock protein (Hsp70) BcSsb and E3 ubiquitin ligase BcRad18 were identified as substrates of SUMOylation; moreover, their SUMOylation both requires a single unique SUMO-interacting motif (SIM).center dot SUMOylated BcSsb regulates beta-tubulin accumulation, thereby affecting the stability of microtubules and consequently mycelial growth at low temperature. On the contrary, SUMOylated BcRad18 modulates mono-ubiquitination of the sliding clamp protein proliferating cell nuclear antigen (PCNA), which is involved in response to oxidative DNA damage during infection.center dot Our study uncovers the molecular mechanisms of SUMOylation-mediated low-temperature survival and oxidative DNA damage tolerance during infection in a devastating fungal pathogen, which provides novel insights into low-temperature adaptation and pathogenesis for postharvest pathogens as well as new targets for inhibitor invention in disease control.

Automated summary

SUMOylation plays crucial roles in multiple biological processes in eukaryotic organisms. This study reveals the regulatory functions of SUMOylation in low-temperature survival and oxidative DNA damage tolerance during infection in B. cinerea. SUMOylated BcSsb affects the stability of microtubules and consequently mycelial growth at low temperature, while SUMOylated BcRad18 modulates the mono-ubiquitination of pcna involved in oxidative DNA damage response during infection.