Transcription Repressor SsGATA2 Regulates Broad-Spectrum Resistance to Fungicides and Pathogenicity in Sclerotinia sclerotiorum

The understanding of drug resistance mechanisms beyond increasing drug efflux and modifying drug targets remains limited. Here, we revealed that the GATA-type transcription repressor SsGATA2 negatively regulated the drug resistance of Sclerotinia sclerotiorum, a devastating phytopathogenic fungus, to various fungicides. In mechanism, the deletion of SsGATA2 led to the derepression of the expression of several enzymes responsible for synthesizing cell wall and membrane components, inducing the constitutive thickening of the cell wall and improved cell membrane stability, which eventually prevented fungicides from entering and conferred notable fungicide resistance. Furthermore, SsGATA2 plays a positive role in regulating mycelial growth, sclerotium development, infection cushion formation, nutrient assimilation, and pathogenicity in S. sclerotiorum. Our work demonstrates that transcription repressor SsGATA2 negatively regulates broad-spectrum resistance to fungicides and positively contributes to morphogenesis and pathogenicity. These findings reveal a strategy through which phytopathogenic fungi resist fungicides by fortifying the cell wall and membrane.