Abstract: Meyerozyma caribbica is an antagonistic yeast used for biocontrol, which has demonstrated significant control efficacy against postharvest blue mold of pears caused by Penicillium expansum. Storage experiments confirmed that M. caribbica effectively reduced the incidence of postharvest natural decay of pears with no significantly negative impact on postharvest fruit quality throughout the storage period. In order to further analyze the molecular mechanism of M. caribbica-induced enhancement of disease resistance in pears, this study conducted a systematic transcriptomic analysis of gene expression in M. caribbica-treated pears using high-throughput transcriptome sequencing technology. The results showed that M. caribbica treatment induced upregulation ​of genes related to the plant-pathogen interaction pathway, phytohormone signaling pathway, and reactive oxygen species (ROS) metabolism pathway in pears, as well as those related to the synthesis of resistance substances. These synergistic regulatory effects on gene expression enhanced the response of pears to environmental stress, improved defense mechanisms and disease resistance, and significantly improved the antioxidant capacity and biosynthesis of resistance substances, thereby strengthening postharvest resistance to pathogen infection. This study comprehensively elucidated the effects of M. caribbica on the postharvest quality of pears during storage, and revealed the molecular mechanisms underlying M. caribbica-induced improvement of disease resistance in pears at the transcriptome level.

Key words: Meyerozyma caribbica; Penicillium expansum; pear; storage quality; transcriptomic analysis