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.

青霉病是由扩展青霉（Penicillium expansum）引起的苹果采后最常见病害之一。目前已有研究通过实验室试验将拮抗性酵母菌应用于苹果采后病害的防治，但此类酵母菌的防治效果仍有待进一步提升。通过激发子诱导拮抗性酵母菌，是提升其生防效果的有效手段。本团队前期研究证实，褐藻寡糖（alginate oligosaccharide, AOS）可显著增强汉逊德巴利酵母（Debaryomyces hansenii）对苹果采后病害的生防效果，且该酵母菌的生理生防机制已有相关报道。然而其中涉及的分子机制仍不明确。本研究基于转录组与蛋白质组分析，探究了经AOS培养的汉逊德巴利酵母Y3生防效果提升的潜在分子机制。研究发现，AOS诱导产生了408个差异基因与114个差异蛋白，这些差异分子主要参与调控酵母菌的生长繁殖、代谢、抗逆性与能量合成等生理过程。上述调控作用共同提升了汉逊德巴利酵母Y3的拮抗活性。本研究结果为后续利用拮抗性酵母菌防治果蔬采后病害的相关研究提供了重要参考。