Alginate oligosaccharide-driven resistance in <i>Debaryomyces hansenii</i> Y3: a dual omics perspective

Blue mould disease is one of the most common postharvest apple diseases caused by <i>Penicillium expansum</i>. Some antagonistic yeasts have been used through laboratory experimentation to control the postharvest diseases of apples, but their control effectiveness needs further improvement. Induction of antagonistic yeasts by elicitors is an effective method that improves the biocontrol effectiveness of the yeast. Our previous study demonstrated that alginate oligosaccharide (AOS) significantly enhanced the biocontrol effectiveness of <i>Debaryomyces hansenii</i> in combating postharvest diseases in apples. Furthermore, the yeast's potential physiological biocontrol mechanisms have been previously documented. However, the molecular mechanisms associated with this were unclear. This study investigated the possible molecular mechanisms behind the enhanced efficacy of biological control by <i>D. hansenii</i> Y3 when cultured with AOS, based on transcriptome and proteome analysis. There were 408 differential genes and 114 differential proteins induced by AOS, which were mainly involved in enhancing the growth, reproduction, metabolism, stress resistance and energy synthesis, and more. These improvements collectively contribute to the heightened antagonistic efficacy of <i>D. hansenii</i> Y3. Our findings offer a valuable reference for future investigations into the utilisation of antagonistic yeasts for preventing and managing postharvest diseases in fruits and vegetables.