Pichia kudriavzevii volatile organic compounds inhibit Botrytis cinerea by suppressing ribosomal function

Gray mold disease caused by Botrytis cinerea poses a serious threat to the postharvest quality and yield of strawberries. This study aimed to evaluate the efficacy and action mechanism of volatile organic compounds (VOCs) produced by the Pichia kudriavzevii strain Bg7 against B. cinerea in strawberries. In vitro, strain Bg7 VOCs completely inhibited B. cinerea mycelial growth and spore germination and induced hyphal degradation. Moreover, Bg7 VOCs induced endoplasmic reticulum stress and even cell death in B. cinerea. In vivo experiments demonstrated that treatment with Bg7 VOCs significantly inhibited B. cinerea-induced disease lesion expansion and preserved fruit quality metrics in strawberries. Transcriptomic analysis linked Bg7 VOCs-mediated suppression of B. cinerea to inhibition of the ribosomal pathway, with marked downregulation of ribosomal protein gene expression and impaired protein synthesis. Pharmacological or genetic disruption of ribosome biogenesis (via mycophenolic acid treatment and BcRPLP0 silencing, respectively) impaired B. cinerea vegetative growth and pathogenicity. Headspace gas chromatography-ion mobility spectrometry analysis identified 21 specific VOCs from strain Bg7 headspace, 10 of which showed significant antifungal activity against B. cinerea in vitro and in vivo. Together, these results position Bg7 VOCs as an effective biocontrol agent against strawberry gray mold, with their efficacy linked to ribosome-targeted inhibition of B. cinerea.