Suppressing plant defense: Scavenge the ROS!

Reactive oxygen species (ROS)-mediated defense against fungal pathogens is an essential arm of plant immunity. As a counter defense, these pathogens synthesize antioxidant enzymes that scavenge the ROS produced by plants. The molecular mechanism behind the upregulation of these enzymes in fungal pathogens was unknown. A recent study by Zhang et al. (2023, https://doi.org/10.15252/embj.2022112634) has shed light on the mechanism, and it has been shown that deacetylation of FolSrpk1 protein on the K304 residue following oxidative stress is an important event in the signaling cascade leading to ROS detoxification in Fusarium oxysporum f. sp. lycopersici. Deacetylated FolSrpk1 moves to the nucleus where it hyperphosphorylates FolSr1, which further regulates the transcription of antioxidant enzymes. This mechanism of ROS detoxification is conserved in Botrytis cinerea as well. Several other phytopathogenic fungi have a corresponding K304 site and NLS present in their Srpk1, suggesting a similar mechanism of ROS detoxification and suppression of plant defense. In this article, we have presented our views on how future studies can be synthesized based on the pathway deciphered by Zhang et al. (2023, https://doi.org/10.15252/embj.2022112634).