Our previous study demonstrated that the combined application with oligochitosan (OCH) improved the biocontrol efficacy of against postharvest black spot of tomato fruits. The involved mechanisms were elucidated based on the induction of fruit resistance. However, the mechanisms needed to be further explored from the antagonistic yeast perspective. The current study determined the effects of OCH on growth and the effects of combined application with OCH on the colonization ability, the reactive oxygen species (ROS) accumulation, especially the gene expression levels of in fruit wounds. The findings revealed that OCH increased the viable cell number of in NYDB and in tomato fruit wounds. Additionally, combined application with OCH could alleviate ROS accumulation in inoculated in fruit wounds. Transcriptome analysis revealed that the genes related to MAPK signal transduction, meiosis – yeast, DNA replication, tryptophan metabolism and glutathione metabolism of were induced by the combined application with OCH in fruit wounds, which triggered its MAPK signal transduction, promoted its growth and reproduction, and improved its antioxidant capability. Therefore, the capability of to survive and colonize fruit wounds were raised and its antagonistic efficacy against postharvest black spot pathogen was heightened by combined application with OCH. This study will open up new possibilities for improving the biocontrol efficacy of antagonists against postharvest pathogens of fruits and vegetables.

中文翻译：

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加勒比毕赤酵母与壳寡糖联用提高拮抗番茄采后黑斑病功效的机制探讨

我们前期的研究表明，与壳寡糖（OCH）联合施用可提高番茄采后黑斑病的生防效果。基于果实抗性的诱导阐明了相关机制。然而，其机制还需要从拮抗酵母的角度进一步探讨。本研究确定了OCH对生长的影响以及与OCH联合施用对定植能力、活性氧（ROS）积累，特别是果实伤口中基因表达水平的影响。研究结果表明，OCH 增加了 NYDB 和番茄果实伤口中的活细胞数量。此外，与OCH联合施用可以减轻接种果实伤口处ROS的积累。转录组分析显示，与OCH联合施用在果实伤口中，诱导了MAPK信号转导、酵母减数分裂、DNA复制、色氨酸代谢和谷胱甘肽代谢等相关基因，触发其MAPK信号转导，促进其生长繁殖，并提高其抗氧化能力。因此，与OCH联合施用可提高果实伤口的存活和定植能力，增强对采后黑斑病菌的拮抗效果。这项研究将为提高拮抗剂对水果和蔬菜采后病原体的生物防治功效开辟新的可能性。