SsMFS - st1 Mediates Sugar Transport and Regulates the Virulence of Sclerotinia sclerotiorum via the JA Signaling Pathway

This study identifies a Major Facilitator Superfamily sugar transporter as a critical mediator of jasmonic acid (JA)-induced suppression of Sclerotinia sclerotiorum.We demonstrate that JA downregulates this MFS gene, and its genetic manipulation directly impairs fungal growth, sclerotia formation, and virulence-key determinants of pathogenicity.The discovery of this membrane-localized transporter and its downstream transcriptional targets provides mechanistic insight into JA-mediated fungal inhibition and reveals novel genetic targets for controlling devastating sclerotinia diseases in crops. Significance statementThe necrotrophic fungus Sclerotinia sclerotiorum (Lib.) de Bary, the causal agent of Sclerotinia stem rot, stands as one of the most destructive plant pathogens in modern agriculture.The Major Facilitator Superfamily (MFS), representing the largest clan of secondary transporters across all domains of life, has undergone dramatic expansion in phytopathogenic fungi.However, no studies have systematically linked MFS-mediated sugar transport to virulence or sclerotial development.